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Wang X, Wang J, Fei N, Duanmu D, Feng B, Li X, IP WY, Hu Y. Alternative muscle synergy patterns of upper limb amputees. Cogn Neurodyn 2024; 18:1119-1133. [PMID: 38826662 PMCID: PMC11143172 DOI: 10.1007/s11571-023-09969-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 03/29/2023] [Accepted: 04/11/2023] [Indexed: 06/04/2024] Open
Abstract
Myoelectric hand prostheses are effective tools for upper limb amputees to regain hand functions. Much progress has been made with pattern recognition algorithms to recognize surface electromyography (sEMG) patterns, but few attentions was placed on the amputees' motor learning process. Many potential myoelectric prostheses users could not fully master the control or had declined performance over time. It is possible that learning to produce distinct and consistent muscle activation patterns with the residual limb could help amputees better control the myoelectric prosthesis. In this study, we observed longitudinal effect of motor skill learning with 2 amputees who have developed alternative muscle activation patterns in response to the same set of target prosthetic actions. During a 10-week program, amputee participants were trained to produce distinct and constant muscle activations with visual feedback of live sEMG and without interaction with prosthesis. At the end, their sEMG patterns were different from each other and from non-amputee control groups. For certain intended hand motion, gradually reducing root mean square (RMS) variance was observed. The learning effect was also assessed with a CNN-LSTM mixture classifier designed for mobile sEMG pattern recognition. The classification accuracy had a rising trend over time, implicating potential performance improvement of myoelectric prosthesis control. A follow-up session took place 6 months after the program and showed lasting effect of the motor skill learning in terms of sEMG pattern classification accuracy. The results indicated that with proper feedback training, amputees could learn unique muscle activation patterns that allow them to trigger intended prosthesis functions, and the original motor control scheme is updated. The effect of such motor skill learning could help to improve myoelectric prosthetic control performance.
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Affiliation(s)
- Xiaojun Wang
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
| | - Junlin Wang
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
- Orthopedics Center, The University of Hong Kong-Shenzhen Hospital, Shenzhen, 518000 China
| | - Ningbo Fei
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
| | - Dehao Duanmu
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
| | - Beibei Feng
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
| | - Xiaodong Li
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
- Orthopedics Center, The University of Hong Kong-Shenzhen Hospital, Shenzhen, 518000 China
| | - Wing-Yuk IP
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
| | - Yong Hu
- Department of Orthopedics and Traumatology, LKS Faculty of Medicine, The University of Hong Kong, 999077 Hong Kong, China
- Orthopedics Center, The University of Hong Kong-Shenzhen Hospital, Shenzhen, 518000 China
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Amoruso E, Terhune DB, Kromm M, Kirker S, Muret D, Makin TR. Reassessing referral of touch following peripheral deafferentation: The role of contextual bias. Cortex 2023; 167:167-177. [PMID: 37567052 PMCID: PMC11139647 DOI: 10.1016/j.cortex.2023.04.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 01/28/2023] [Accepted: 04/21/2023] [Indexed: 08/13/2023]
Abstract
Some amputees have been famously reported to perceive facial touch as arising from their phantom hand. These referred sensations have since been replicated across multiple neurological disorders and were classically interpreted as a perceptual correlate of cortical plasticity. Common to all these and related studies is that participants might have been influenced in their self-reports by the experimental design or related contextual biases. Here, we investigated whether referred sensations reports might be confounded by demand characteristics (e.g., compliance, expectation, suggestion). Unilateral upper-limb amputees (N = 18), congenital one-handers (N = 19), and two-handers (N = 22) were repeatedly stimulated with computer-controlled vibrations on 10 body-parts and asked to report the occurrence of any concurrent sensations on their hand(s). To further manipulate expectations, we gave participants the suggestion that some of these vibrations had a higher probability to evoke referred sensations. We also assessed similarity between (phantom) hand and face representation in primary somatosensory cortex (S1), using functional Magnetic Resonance Imaging (fMRI) multivariate representational similarity analysis. We replicated robust reports of referred sensations in amputees towards their phantom hand; however, the frequency and distribution of reported referred sensations were similar across groups. Moreover, referred sensations were evoked by stimulation of multiple body-parts and similarly reported on both the intact and phantom hand in amputees. Face-to-phantom-hand representational similarity was not different in amputees' missing hand region, compared with controls. These findings weaken the interpretation of referred sensations as a perceptual correlate of S1 plasticity and reveal the need to account for contextual biases when evaluating anomalous perceptual phenomena.
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Affiliation(s)
- Elena Amoruso
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK
| | - Devin B Terhune
- Department of Psychology, Goldsmiths, University of London, London SE14 6NW, UK
| | - Maria Kromm
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK
| | - Stephen Kirker
- Cambridge University Hospitals NHS Foundation Trust, Cambridge CB2 0QQ, UK
| | - Dollyane Muret
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK.
| | - Tamar R Makin
- Institute of Cognitive Neuroscience, University College London, London WC1N 3AZ, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3AR, UK
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Muret D, Root V, Kieliba P, Clode D, Makin TR. Beyond body maps: Information content of specific body parts is distributed across the somatosensory homunculus. Cell Rep 2022; 38:110523. [PMID: 35294887 PMCID: PMC8938902 DOI: 10.1016/j.celrep.2022.110523] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/10/2021] [Accepted: 02/21/2022] [Indexed: 11/23/2022] Open
Abstract
The homunculus in primary somatosensory cortex (S1) is famous for its body part selectivity, but this dominant feature may eclipse other representational features, e.g., information content, also relevant for S1 organization. Using multivariate fMRI analysis, we ask whether body part information content can be identified in S1 beyond its primary region. Throughout S1, we identify significant representational dissimilarities between body parts but also subparts in distant non-primary regions (e.g., between the hand and the lips in the foot region and between different face parts in the foot region). Two movements performed by one body part (e.g., the hand) could also be dissociated well beyond its primary region (e.g., in the foot and face regions), even within Brodmann area 3b. Our results demonstrate that information content is more distributed across S1 than selectivity maps suggest. This finding reveals underlying information contents in S1 that could be harnessed for rehabilitation and brain-machine interfaces. We replicate the high univariate selectivity profile of the somatosensory homunculus We use multivariate fMRI analysis to identify information content beyond selectivity Significant body part and action-related content are found throughout the homunculus Functional information is available, even in regions selective to other body parts
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Affiliation(s)
- Dollyane Muret
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AZ, UK.
| | - Victoria Root
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AZ, UK; Wellcome Centre of Integrative Neuroimaging, University of Oxford, Oxford OX3 9DU, UK
| | - Paulina Kieliba
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AZ, UK
| | - Danielle Clode
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AZ, UK; Dani Clode Design, 40 Hillside Road, London SW2 3HW, UK
| | - Tamar R Makin
- Institute of Cognitive Neuroscience, University College London, 17 Queen Square, London WC1N 3AZ, UK; Wellcome Trust Centre for Neuroimaging, University College London, London WC1N 3AR, UK
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Pondelis NJ, Moulton EA. Supraspinal Mechanisms Underlying Ocular Pain. Front Med (Lausanne) 2022; 8:768649. [PMID: 35211480 PMCID: PMC8862711 DOI: 10.3389/fmed.2021.768649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 12/27/2021] [Indexed: 12/04/2022] Open
Abstract
Supraspinal mechanisms of pain are increasingly understood to underlie neuropathic ocular conditions previously thought to be exclusively peripheral in nature. Isolating individual causes of centralized chronic conditions and differentiating them is critical to understanding the mechanisms underlying neuropathic eye pain and ultimately its treatment. Though few functional imaging studies have focused on the eye as an end-organ for the transduction of noxious stimuli, the brain networks related to pain processing have been extensively studied with functional neuroimaging over the past 20 years. This article will review the supraspinal mechanisms that underlie pain as they relate to the eye.
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Affiliation(s)
- Nicholas J Pondelis
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
| | - Eric A Moulton
- Brain and Eye Pain Imaging Lab, Pain and Affective Neuroscience Center, Department of Anesthesiology, Critical Care and Pain Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States.,Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA, United States
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5
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Su S, Chai G, Meng J, Sheng X, Mouraux A, Zhu X. Towards optimizing the non-invasive sensory feedback interfaces in a neural prosthetic control. J Neural Eng 2022; 19. [DOI: 10.1088/1741-2552/ac4e1b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 01/24/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. The somatotopic interface (SI) and non-somatotopic interface (NI) are commonly used to provide non-invasive sensory feedback. Nevertheless, differences between SI and NI are rarely reported, and objective evaluations of the corresponding brain response are missing as well. Few studies have reported how to design the stimulation encoding based on the two interfaces. The objective of this study was to investigate the difference in sensory characteristics between SI and NI, and propose an optimal encoding method for non-invasive feedback interfaces. Approach. We recruited seven amputees and compared the tactile sensitivity to stimulated positions and intensities between SI (phantom finger area) and NI (upper arm) in a tactile discrimination task. Electroencephalography (EEG) evaluation task was subsequently conducted to objectively evaluate the stimulus-evoked brain response. Finally, the two kinds of tactile information (stimulated position and intensity) was applied to an object recognition task. Specifically, the object size was reflected by the prosthetic finger position through stimulated position encoding, and the object stiffness was reflected by the contact force of prosthetic fingers through stimulated intensity encoding. We compared the performance under four feedback conditions (combinations between two kinds of tactile information and two interfaces). Results. Behavioral results showed that NI was more sensitive to position information while SI was more sensitive to intensity information. EEG results were consistent with behavioral results, showing a higher sensitivity of sensory alpha ERD for NI in the position discrimination, while the trend was opposite in the intensity discrimination. The feedback encoding allowed amputees to discriminate the size and stiffness of nine objects with the best performance of 62% overall accuracy (84% for size discrimination, 71% for stiffness discrimination) when position and intensity information was delivered on the NI and SI, respectively. Signicance. Our results provided an instructive strategy for sensory feedback via non-invasive solutions.
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Doshi TL, Dworkin RH, Polomano RC, Carr DB, Edwards RR, Finnerup NB, Freeman RL, Paice JA, Weisman SJ, Raja SN. AAAPT Diagnostic Criteria for Acute Neuropathic Pain. PAIN MEDICINE 2021; 22:616-636. [PMID: 33575803 DOI: 10.1093/pm/pnaa407] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE Acute neuropathic pain is a significant diagnostic challenge, and it is closely related to our understanding of both acute pain and neuropathic pain. Diagnostic criteria for acute neuropathic pain should reflect our mechanistic understanding and provide a framework for research on and treatment of these complex pain conditions. METHODS The Analgesic, Anesthetic, and Addiction Clinical Trial Translations, Innovations, Opportunities, and Networks (ACTTION) public-private partnership with the U.S. Food and Drug Administration (FDA), the American Pain Society (APS), and the American Academy of Pain Medicine (AAPM) collaborated to develop the ACTTION-APS-AAPM Pain Taxonomy (AAAPT) for acute pain. A working group of experts in research and clinical management of neuropathic pain was convened. Group members used literature review and expert opinion to develop diagnostic criteria for acute neuropathic pain, as well as three specific examples of acute neuropathic pain conditions, using the five dimensions of the AAAPT classification of acute pain. RESULTS AAAPT diagnostic criteria for acute neuropathic pain are presented. Application of these criteria to three specific conditions (pain related to herpes zoster, chemotherapy, and limb amputation) illustrates the spectrum of acute neuropathic pain and highlights unique features of each condition. CONCLUSIONS The proposed AAAPT diagnostic criteria for acute neuropathic pain can be applied to various acute neuropathic pain conditions. Both the general and condition-specific criteria may guide future research, assessment, and management of acute neuropathic pain.
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Affiliation(s)
- Tina L Doshi
- Department of Anesthesiology and Critical Care Medicine, Division of Pain Medicine, Johns Hopkins University, Baltimore, Maryland, USA
| | - Robert H Dworkin
- Department of Anesthesiology, University of Rochester School of Medicine and Dentistry, Rochester, New York, and Department of Neurology, Center for Human Experimental Therapeutics, University of Rochester School of Medicine and Dentistry, Rochester, New York, USA
| | - Rosemary C Polomano
- Division of Biobehavioral Health Sciences, University of Pennsylvania-School of Nursing, Philadelphia, Pennsylvania, USA
| | - Daniel B Carr
- Public Health and Community Medicine Program, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Robert R Edwards
- Department of Anesthesiology, Perioperative, and Pain Medicine, Brigham and Women's Hospital, Boston, Massachusetts, USA
| | - Nanna B Finnerup
- Danish Pain Research Center, Department of Clinical Medicine, Aarhus University, and Department of Neurology, Aarhus University Hospital, Aarhus, Denmark
| | - Roy L Freeman
- Center for Autonomic and Peripheral Nerve Disorders, Beth Israel Deaconess Medical Center, Boston, Massachusetts, USA
| | - Judith A Paice
- Cancer Pain Program, Northwestern University, Feinberg School of Medicine, Chicago, Illinois, USA
| | - Steven J Weisman
- Jane B. Pettit Pain and Headache Center, Children's Wisconsin, Departments of Anesthesiology and Pediatrics, Medical College of Wisconsin, Milwaukee, Wisconsin, USA
| | - Srinivasa N Raja
- Department of Anesthesiology and Critical Care Medicine, Division of Pain Medicine, Johns Hopkins University, Baltimore, Maryland, USA
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Duarte D, Bauer CCC, Pinto CB, Saleh Velez FG, Estudillo-Guerra MA, Pacheco-Barrios K, Gunduz ME, Crandell D, Merabet L, Fregni F. Cortical plasticity in phantom limb pain: A fMRI study on the neural correlates of behavioral clinical manifestations. Psychiatry Res Neuroimaging 2020; 304:111151. [PMID: 32738724 PMCID: PMC9394643 DOI: 10.1016/j.pscychresns.2020.111151] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2019] [Revised: 07/21/2020] [Accepted: 07/21/2020] [Indexed: 12/29/2022]
Abstract
The neural mechanism of phantom limb pain (PLP) is related to the intense brain reorganization process implicating plasticity after deafferentation mostly in sensorimotor system. There is a limited understanding of the association between the sensorimotor system and PLP. We used a novel task-based functional magnetic resonance imaging (fMRI) approach to (1) assess neural activation within a-priori selected regions-of-interested (motor cortex [M1], somatosensory cortex [S1], and visual cortex [V1]), (2) quantify the cortical representation shift in the affected M1, and (3) correlate these changes with baseline clinical characteristics. In a sample of 18 participants, we found a significantly increased activity in M1 and S1 as well as a shift in motor cortex representation that was not related to PLP intensity. In an exploratory analyses (not corrected for multiple comparisons), they were directly correlated with time since amputation; and there was an association between increased activity in M1 with a lack of itching sensation and V1 activation was negatively correlated with PLP. Longer periods of amputation lead to compensatory changes in sensory-motor areas; and itching seems to be a protective marker for less signal changes. We confirmed that PLP intensity is not associated with signal changes in M1 and S1 but in V1.
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Affiliation(s)
- D Duarte
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA; Department of Psychiatry and Behavioural Neurosciences, McMaster University. 100 West 5th Street, Hamilton, ON L8N 3K7, Canada
| | - C C C Bauer
- McGovern Institute for Brain Research, MIT. 43 Vassar St, Cambridge, MA 02139, USA; Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM 3001, 76230 Juriquilla, Querétaro, 76230, México; Department of Psychology, Northeastern University, 805 Columbus Avenue, Boston, MA 02139, USA.
| | - C B Pinto
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA
| | - F G Saleh Velez
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA; University of Chicago Medical Center, Department of Neurology, University of Chicago. 5841 S Maryland Ave # C411, Chicago, IL 60637, USA
| | - M A Estudillo-Guerra
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA
| | - K Pacheco-Barrios
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA; Universidad San Ignacio de Loyola, Vicerrectorado de Investigación, Unidad de Investigación para la Generación y Síntesis de Evidencias en Salud. Lima, Peru. Av. La Fontana 750 Edificio El Cubo, La Molina - Perú
| | - M E Gunduz
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA
| | - D Crandell
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA
| | - L Merabet
- Massachusetts Eye and Ear, Department of Ophthalmology, Harvard Medical School. 243 Charles St, Boston, MA 02114, USA
| | - F Fregni
- Spaulding Neuromodulation Center, Spaulding Rehabilitation Hospital, Harvard Medical School. 96 13th Street, Charlestown, Boston, MA 02129, USA; Massachusetts General Hospital, Harvard Medical School. 55 Fruit St, Boston, MA 02114, USA.
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8
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Kanjlia S, Pant R, Bedny M. Sensitive Period for Cognitive Repurposing of Human Visual Cortex. Cereb Cortex 2020; 29:3993-4005. [PMID: 30418533 DOI: 10.1093/cercor/bhy280] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 09/03/2018] [Indexed: 12/12/2022] Open
Abstract
Studies of sensory loss are a model for understanding the functional flexibility of human cortex. In congenital blindness, subsets of visual cortex are recruited during higher-cognitive tasks, such as language and math tasks. Is such dramatic functional repurposing possible throughout the lifespan or restricted to sensitive periods in development? We compared visual cortex function in individuals who lost their vision as adults (after age 17) to congenitally blind and sighted blindfolded adults. Participants took part in resting-state and task-based fMRI scans during which they solved math equations of varying difficulty and judged the meanings of sentences. Blindness at any age caused "visual" cortices to synchronize with specific frontoparietal networks at rest. However, in task-based data, visual cortices showed regional specialization for math and language and load-dependent activity only in congenital blindness. Thus, despite the presence of long-range functional connectivity, cognitive repurposing of human cortex is limited by sensitive periods.
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Affiliation(s)
- Shipra Kanjlia
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Rashi Pant
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Marina Bedny
- Department of Psychological and Brain Sciences, Johns Hopkins University, Baltimore, MD 21218, USA
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Kiyuna A, Kise N, Hiratsuka M, Maeda H, Hirakawa H, Ganaha A, Suzuki M. Brain Activity in Patients With Unilateral Vocal Fold Paralysis Detected by Functional Magnetic Resonance Imaging. J Voice 2020; 36:738.e1-738.e9. [PMID: 32873428 DOI: 10.1016/j.jvoice.2020.08.008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 08/07/2020] [Indexed: 11/20/2022]
Abstract
OBJECTIVES Understanding brain activity in response to unilateral vocal fold paralysis is essential to determine the neural compensatory mechanism underlying adaptation to voice disorders and to develop novel and improved rehabilitation programs for these disorders. We aimed to clarify brain activity during phonation (prolonged vowel, |i:|) in patients with chronic left vocal fold paralysis (LVFP) and compare with that in normal controls. STUDY DESIGN Case-control study. METHODS This functional magnetic resonance imaging (fMRI) study of an event-related task comprised 12 individuals with LVFP of more than 6 months duration and 12 healthy controls. The experimental task alternated phonation (prolonged vowel, |i:|) and no phonation (rest) conditions. The functional images obtained were single-shot gradient-echo echo-planar imaging. The volumes were acquired parallel to the anterior-posterior commissure plane and were sensitive to BOLD contrast. Data sets were processed and statistically analyzed using Statistical Parametric Mapping 8 software. Within-group analyses were conducted by applying the one-sample t test (P < 0.001, uncorrected). A random-effects analysis was used for group comparison. RESULTS The LVFP group showed significantly higher brain activity in the right premotor areas, left parietal lobule, right primary somatosensory areas, and bilateral supplementary motor area and lower brain activity in the auditory-related areas of the superior temporal gyrus. There were no significant correlations of the percent signal change on fMRI with disease duration, maximum phonation time, or age. CONCLUSION Patients with chronic unilateral vocal fold paralysis have stronger activity during voluntary phonation in various central networks. More detailed information on the central nervous system regions related to voluntary phonation from early to chronic phase is needed to understand the compensatory mechanisms in vocal fold paralysis and to establish an effective rehabilitation program. This is the first report to investigate brain activity in chronic unilateral vocal fold paralysis.
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Affiliation(s)
- Asanori Kiyuna
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Norimoto Kise
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Munehisa Hiratsuka
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Hiroyuki Maeda
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Hitoshi Hirakawa
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan
| | - Akira Ganaha
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Miyazaki, Miyazaki, Japan
| | - Mikio Suzuki
- Department of Otorhinolaryngology, Head and Neck Surgery, Graduate School of Medicine, University of the Ryukyus, Nishihara, Okinawa, Japan.
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Adaptive analysis of cortical plasticity with fMRI in full face and arm transplants. Brain Imaging Behav 2020; 15:1788-1801. [DOI: 10.1007/s11682-020-00374-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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11
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Su S, Chai G, Shu X, Sheng X, Zhu X. Electrical stimulation-induced SSSEP as an objective index to evaluate the difference of tactile acuity between the left and right hand. J Neural Eng 2020; 17:016053. [PMID: 31801122 DOI: 10.1088/1741-2552/ab5ee9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVE The objective of this study is to propose an objective index to evaluate the difference of tactile acuity between the left and right hand based on steady-state somatosensory evoked potential (SSSEP). APPROACH Two kinds of tactile sensations (vibration and pressure) with three levels of intensities (low/medium/high) were evoked on two finger areas of the left or right hand (thumb and index for healthy hands, thumb and index-projected areas for disabled hands) via transcutaneous electrical nerve stimulation (TENS). Three forearm amputees and 13 able-bodied subjects were recruited to discriminate the specific level and area of the applied stimulation. Electroencephalography was adopted to simultaneously record the somatosensory cortex response to TENS. We assessed the discrimination performance (discrimination accuracy rate (AR) and response time (RT)) to quantify the tactile acuity, while the evoked SSSEP was synchronously analyzed. Linear regression analyses were performed between the difference of SSSEP amplitudes and the difference of discrimination performance for the left and right hand stimulation. MAIN RESULTS Frequency domain analysis revealed that SSSEP amplitude increased with the increase of the stimulation intensity. There were positive correlations between the difference of SSSEP amplitudes and the difference of ARs for the left and right hand stimulation in the sensations of vibration (R 2 = 0.6389 for able-bodied subjects, R 2 = 0.5328 for amputees) and pressure (R 2 = 0.6102 for able-bodied subjects, R 2 = 0.5452 for amputees), respectively. Significance The SSSEP amplitude could be used as an objective index to evaluate the difference of the tactile acuity between the left and right hand and has the potential to be applied in sensory rehabilitation for amputees or stroke patients.
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Affiliation(s)
- Shiyong Su
- State Key Laboratory of Mechanical System and Vibration, Shanghai Jiao Tong University, Shanghai, People's Republic of China
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12
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Azañón E, Longo MR. Tactile Perception: Beyond the Somatotopy of the Somatosensory Cortex. Curr Biol 2020; 29:R322-R324. [PMID: 31063723 DOI: 10.1016/j.cub.2019.03.037] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
New research demonstrates systematic errors of tactile localisation, involving confusions of body parts and body sides. Such errors do not follow the organisation of topographic maps in somatosensory cortex, suggesting that tactile localisation involves coding of abstract features of limbs.
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Affiliation(s)
- Elena Azañón
- Institute of Psychology, Otto von Guericke University Magdeburg, 39106 Magdeburg, Germany; Center for Behavioral Brain Sciences, 39106 Magdeburg, Germany; Department of Behavioral Neurology, Leibniz Institute for Neurobiology, 39118 Magdeburg, Germany.
| | - Matthew R Longo
- Department of Psychological Sciences, Birkbeck, University of London, London WC1E 7HX, UK.
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13
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Madden DJ, Melton MS, Jain S, Cook AD, Browndyke JN, Harshbarger TB, Cendales LC. Neural activation for actual and imagined movement following unilateral hand transplantation: a case study. Neurocase 2019; 25:225-234. [PMID: 31549902 PMCID: PMC6814578 DOI: 10.1080/13554794.2019.1667398] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 09/07/2019] [Indexed: 10/26/2022]
Abstract
Transplantation of a donor hand has been successful as a surgical treatment following amputation, but little is known regarding the brain mechanisms contributing to the recovery of motor function. We report functional magnetic resonance imaging (fMRI) findings for neural activation related to actual and imagined movement, for a 54-year-old male patient, who had received a donor hand transplant 50 years following amputation. Two assessments, conducted 3 months and 6 months post-operatively, demonstrate engagement of motor-control related brain regions for the transplanted hand, during both actual and imagined movement of the fingers. The intact hand exhibited a more intense and focused pattern of activation for actual movement relative to imagined movement, whereas activation for the transplanted hand was more widely distributed and did not clearly differentiate actual and imagined movement. However, the spatial overlap of actual-movement and imagined-movement voxels, for the transplanted hand, did increase over time to a level comparable to that of the intact hand. At these relatively early post-operative assessments, brain regions outside of the canonical motor-control networks appear to be supporting movement of the transplanted hand.
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Affiliation(s)
- David J Madden
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center , Durham , NC , USA
- Brain Imaging and Analysis Center, Duke University Medical Center , Durham , NC , USA
| | - M Stephen Melton
- Department of Anesthesiology, Duke University Medical Center , Durham , NC , USA
| | - Shivangi Jain
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center , Durham , NC , USA
- Brain Imaging and Analysis Center, Duke University Medical Center , Durham , NC , USA
| | - Angela D Cook
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center , Durham , NC , USA
- Brain Imaging and Analysis Center, Duke University Medical Center , Durham , NC , USA
| | - Jeffrey N Browndyke
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center , Durham , NC , USA
- Brain Imaging and Analysis Center, Duke University Medical Center , Durham , NC , USA
| | - Todd B Harshbarger
- Brain Imaging and Analysis Center, Duke University Medical Center , Durham , NC , USA
- Department of Radiology, Duke University Medical Center , Durham , NC , USA
| | - Linda C Cendales
- Department of Surgery, Duke University Medical Center , Durham , NC , USA
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14
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Ando A, Mazzone SB, Farrell MJ. Altered neural activity in brain cough suppression networks in cigarette smokers. Eur Respir J 2019; 54:13993003.00362-2019. [PMID: 31248952 DOI: 10.1183/13993003.00362-2019] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/12/2019] [Indexed: 11/05/2022]
Abstract
Cough is important for airway defence, and studies in healthy animals and humans have revealed multiple brain networks intimately involved in the perception of airway irritation, cough induction and cough suppression. Changes in cough sensitivity and/or the ability to suppress cough accompany pulmonary pathologies, suggesting a level of plasticity is possible in these central neural circuits. However, little is known about how persistent inputs from the lung might modify the brain processes regulating cough.In the present study, we used human functional brain imaging to investigate the central neural responses that accompany an altered cough sensitivity in cigarette smokers.In nonsmokers, inhalation of the airway irritant capsaicin induced a transient urge-to-cough associated with the activation of a distributed brain network that included sensory, prefrontal and motor cortical regions. Cigarette smokers demonstrated significantly higher thresholds for capsaicin-induced urge-to-cough, consistent with a reduced sensitivity to airway irritation. Intriguingly, this was accompanied by increased activation in brain regions known to be involved in both cough sensory processing (primary sensorimotor cortex) and cough suppression (dorsolateral prefrontal cortex and the midbrain nucleus cuneiformis). Activations in the prefrontal cortex were highest among participants with the least severe smoking behaviour, whereas those in the midbrain correlated with more severe smoking behaviour.These outcomes suggest that smoking-induced sensitisation of central cough neural circuits is offset by concurrently enhanced central suppression. Furthermore, central suppression mechanisms may evolve with the severity of smoke exposure, changing from initial prefrontal inhibition to more primitive midbrain processes as exposure increases.
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Affiliation(s)
- Ayaka Ando
- School of Biomedical Sciences, The University of Queensland, Brisbane, Australia
| | - Stuart B Mazzone
- Dept of Anatomy and Neuroscience, The University of Melbourne, Melbourne, Australia
| | - Michael J Farrell
- Dept of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia.,Monash Biomedical Imaging Research Centre, Monash University, Melbourne, Australia
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15
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Cuberovic I, Gill A, Resnik LJ, Tyler DJ, Graczyk EL. Learning of Artificial Sensation Through Long-Term Home Use of a Sensory-Enabled Prosthesis. Front Neurosci 2019; 13:853. [PMID: 31496931 PMCID: PMC6712074 DOI: 10.3389/fnins.2019.00853] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 07/30/2019] [Indexed: 12/14/2022] Open
Abstract
Upper limb prostheses are specialized tools, and skilled operation is learned by amputees over time. Recently, neural prostheses using implanted peripheral nerve interfaces have enabled advances in artificial somatosensory feedback that can improve prosthesis outcomes. However, the effect of sensory learning on artificial somatosensation has not been studied, despite its known influence on intact somatosensation and analogous neuroprostheses. Sensory learning involves changes in the perception and interpretation of sensory feedback and may further influence functional and psychosocial outcomes. In this mixed methods case study, we examined how passive learning over 115 days of home use of a neural-connected, sensory-enabled prosthetic hand influenced perception of artificial sensory feedback in a participant with transradial amputation. We examined perceptual changes both within individual days of use and across the duration of the study. At both time scales, the reported percept locations became significantly more aligned with prosthesis sensor locations, and the phantom limb became significantly more extended toward the prosthesis position. Similarly, the participant’s ratings of intensity, naturalness, and contact touch significantly increased, while his ratings of vibration and movement significantly decreased across-days for tactile channels. These sensory changes likely resulted from engagement of cortical plasticity mechanisms as the participant learned to use the artificial sensory feedback. We also assessed psychosocial and functional outcomes through surveys and interviews, and found that self-efficacy, perceived function, prosthesis embodiment, social touch, body image, and prosthesis efficiency improved significantly. These outcomes typically improved within the first month of home use, demonstrating rapid benefits of artificial sensation. Participant interviews indicated that the naturalness of the experience and engagement with the prosthesis increased throughout the study, suggesting that artificial somatosensation may decrease prosthesis abandonment. Our data showed that prosthesis embodiment was intricately related to naturalness and phantom limb perception, and that learning the artificial sensation may have modified the body schema. As another indicator of successfully learning to use artificial sensation, the participant reported the emergence of stereognosis later in the study. This study provides the first evidence that artificial somatosensation can undergo similar learning processes as intact sensation and highlights the importance of sensory restoration in prostheses.
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Affiliation(s)
- Ivana Cuberovic
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
| | - Anisha Gill
- Providence VA Medical Center, Providence, RI, United States
| | - Linda J Resnik
- Providence VA Medical Center, Providence, RI, United States.,Department of Health Services, Policy, and Practice, Brown University, Providence, RI, United States
| | - Dustin J Tyler
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
| | - Emily L Graczyk
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, United States.,Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States
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16
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Chan AWY, Bilger E, Griffin S, Elkis V, Weeks S, Hussey-Anderson L, Pasquina PF, Tsao JW, Baker CI. Visual responsiveness in sensorimotor cortex is increased following amputation and reduced after mirror therapy. NEUROIMAGE-CLINICAL 2019; 23:101882. [PMID: 31226622 PMCID: PMC6587025 DOI: 10.1016/j.nicl.2019.101882] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 04/17/2019] [Accepted: 05/25/2019] [Indexed: 11/07/2022]
Abstract
Phantom limb pain (PLP) following amputation, which is experienced by the vast majority of amputees, has been reported to be relieved with daily sessions of mirror therapy. During each session, a mirror is used to view the reflected image of the intact limb moving, providing visual feedback consistent with the movement of the missing/phantom limb. To investigate potential neural correlates of the treatment effect, we measured brain responses in volunteers with unilateral leg amputation using functional magnetic resonance imaging (fMRI) during a four-week course of mirror therapy. Mirror therapy commenced immediately following baseline scans, which were repeated after approximately two and four week intervals. We focused on responses in the region of sensorimotor cortex corresponding to primary somatosensory and motor representations of the missing leg. At baseline, prior to starting therapy, we found a strong and unexpected response in sensorimotor cortex of amputees to visually presented images of limbs. This response was stronger for images of feet compared to hands and there was no such response in matched controls. Further, this response to visually presented limbs was no longer present at the end of the four week mirror therapy treatment, when perceived phantom limb pain was also reduced. A similar pattern of results was also observed in extrastriate and parietal regions typically responsive to viewing hand actions, but not in regions corresponding to secondary somatosensory cortex. Finally, there was a significant correlation between initial visual responsiveness in sensorimotor cortex and reduction in PLP suggesting a potential marker for predicting efficacy of mirror therapy. Thus, enhanced visual responsiveness in sensorimotor cortex is associated with PLP and modulated over the course of mirror therapy. Visual responsiveness to the sight of limbs in sensorimotor cortex of leg amputees but not matched controls Consistent with prior studies, mirror therapy over 4 weeks reduced phantom limb pain Visual responsiveness in sensorimotor cortex of amputees diminished following mirror therapy Visual responsiveness in sensorimotor cortex might be useful in predicting the potential efficacy of mirror therapy
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Affiliation(s)
- Annie W-Y Chan
- Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; Department of Life Sciences, Division of Psychology, Centre for Cognitive Neuroscience, Brunel University London, UK; University of Tennessee Health Science Center, Department of Radiology, Memphis, TN, USA.
| | - Emily Bilger
- Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA; George Washington University Hospital, USA
| | - Sarah Griffin
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Viktoria Elkis
- Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
| | - Sharon Weeks
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | | | - Paul F Pasquina
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Jack W Tsao
- Uniformed Services University of the Health Sciences, Bethesda, MD, USA; University of Tennessee Health Science Center, Department of Neurology, Memphis, TN, USA; Le Bonheur Children's Hospital, Memphis, TN, USA; Memphis Veterans Affairs Medical Center, Memphis, TN, USA
| | - Chris I Baker
- Laboratory of Brain and Cognition, National Institute of Mental Health, National Institutes of Health, Bethesda, MD, USA
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17
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Nardone R, Versace V, Sebastianelli L, Brigo F, Christova M, Scarano GI, Saltuari L, Trinka E, Hauer L, Sellner J. Transcranial magnetic stimulation in subjects with phantom pain and non-painful phantom sensations: A systematic review. Brain Res Bull 2019; 148:1-9. [DOI: 10.1016/j.brainresbull.2019.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2019] [Revised: 03/03/2019] [Accepted: 03/05/2019] [Indexed: 12/18/2022]
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18
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Badde S, Röder B, Heed T. Feeling a Touch to the Hand on the Foot. Curr Biol 2019; 29:1491-1497.e4. [PMID: 30955931 DOI: 10.1016/j.cub.2019.02.060] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/15/2019] [Accepted: 02/27/2019] [Indexed: 10/27/2022]
Abstract
Where we perceive a touch putatively depends on topographic maps that code the touch's location on the skin [1] as well as its position in external space [2-5]. However, neither somatotopic nor external-spatial representations can account for atypical tactile percepts in some neurological patients and amputees; referral of touch to an absent or anaesthetized hand after stimulation of a foot [6, 7] or the contralateral hand [8-10] challenges the role of topographic representations when attributing touch to the limbs. Here, we show that even healthy adults systematically misattribute touch to other limbs. Participants received two tactile stimuli, each to a different limb-hand or foot-and reported which of all four limbs had been stimulated first. Hands and feet were either uncrossed or crossed to dissociate body-based and external-spatial representations [11-14]. Remarkably, participants regularly attributed the first touch to a limb that had received neither of the two stimuli. The erroneously reported, non-stimulated limb typically matched the correct limb with respect to limb type or body side. Touch was misattributed to non-stimulated limbs of the other limb type and body side only if they were placed at the correct limb's canonical (default) side of space. The touch's actual location in external space was irrelevant. These errors replicated across several contexts, and modeling linked them to incoming sensory evidence rather than to decision strategies. The results highlight the importance of the touched body part's identity and canonical location but challenge the role of external-spatial tactile representations when attributing touch to a limb.
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Affiliation(s)
- Stephanie Badde
- Department of Psychology and Center of Neural Sciences, New York University, 6 Washington Place, New York, NY 10003, USA; Biological Psychology and Neuropsychology, University of Hamburg, Von-Melle-Park 11, 20146 Hamburg, Germany.
| | - Brigitte Röder
- Biological Psychology and Neuropsychology, University of Hamburg, Von-Melle-Park 11, 20146 Hamburg, Germany
| | - Tobias Heed
- Biopsychology & Cognitive Neuroscience, Bielefeld University, Universitätsstrasse 25, 33615 Bielefeld, Germany; Center of Excellence Cognitive Interaction Technology (CITEC), Bielefeld University, Inspiration 1, 33619 Bielefeld, Germany
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19
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Li Y, Li Y, Omire-Mayor D, Bo B, Li H, Tong S. Cortical functional reorganization in response to intact forelimb stimulation from acute to chronic stage in rodent amputation model. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2018; 2018:21-24. [PMID: 30440331 DOI: 10.1109/embc.2018.8512218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Brain plasticity after amputation is related to the short-term unmasking of latent synapses as well as the long-term reorganization due to the sprouting new synaptic connections. The cortical functional reorganization has been reported along the intact somatosensory pathway after unilateral deafferentation. Cerebral blood flow (CBF) change serves as an important biomarker of the functional reorganization of brain. Using laser speckle contrast imaging (LSCI) technology, we performed a longitudinal study to unveil the cortical functional reorganization after forelimb amputation in rodent model, particularly along the intact somatosensory pathway. Our results showed that the CBF response to electrical stimulation of the intact forepaw increased significantly at 9 hours after amputation in acute stage. While in chronic stage (>14 days), the CBF response showed a pattern similar to the control group. The results showed the dynamic brain functional response along the intact somatosensory pathway at different stages after amputation and indicated that cortical functional reorganization occurred within the acute stage. Our work provided additional insights in understanding the inter-hemispheric functional changes from acute to chronic stages of amputation.
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20
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Garside T, Wood FM, Vallence AM. Case series investigating the cortical silent period after burns using transcranial magnetic stimulation. Burns 2018; 44:1195-1202. [DOI: 10.1016/j.burns.2018.04.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/02/2018] [Accepted: 04/10/2018] [Indexed: 12/25/2022]
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21
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Collins KL, Russell HG, Schumacher PJ, Robinson-Freeman KE, O'Conor EC, Gibney KD, Yambem O, Dykes RW, Waters RS, Tsao JW. A review of current theories and treatments for phantom limb pain. J Clin Invest 2018; 128:2168-2176. [PMID: 29856366 DOI: 10.1172/jci94003] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Following amputation, most amputees still report feeling the missing limb and often describe these feelings as excruciatingly painful. Phantom limb sensations (PLS) are useful while controlling a prosthesis; however, phantom limb pain (PLP) is a debilitating condition that drastically hinders quality of life. Although such experiences have been reported since the early 16th century, the etiology remains unknown. Debate continues regarding the roles of the central and peripheral nervous systems. Currently, the most posited mechanistic theories rely on neuronal network reorganization; however, greater consideration should be given to the role of the dorsal root ganglion within the peripheral nervous system. This Review provides an overview of the proposed mechanistic theories as well as an overview of various treatments for PLP.
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Affiliation(s)
| | - Hannah G Russell
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Patrick J Schumacher
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | | | - Ellen C O'Conor
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Kyla D Gibney
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Olivia Yambem
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Robert W Dykes
- School of Physical and Occupational Therapy, McGill University, Montreal, Quebec, Canada
| | | | - Jack W Tsao
- Department of Neurology, University of Tennessee Health Science Center, Memphis, Tennessee, USA.,Department of Neurology, Memphis Veterans Affairs Medical Center, Memphis, Tennessee, USA.,Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
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22
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23
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Kuehn E, Dinse J, Jakobsen E, Long X, Schäfer A, Bazin PL, Villringer A, Sereno MI, Margulies DS. Body Topography Parcellates Human Sensory and Motor Cortex. Cereb Cortex 2018; 27:3790-3805. [PMID: 28184419 PMCID: PMC6248394 DOI: 10.1093/cercor/bhx026] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Indexed: 12/25/2022] Open
Abstract
The cytoarchitectonic map as proposed by Brodmann currently dominates models of human sensorimotor cortical structure, function, and plasticity. According to this model, primary motor cortex, area 4, and primary somatosensory cortex, area 3b, are homogenous areas, with the major division lying between the two. Accumulating empirical and theoretical evidence, however, has begun to question the validity of the Brodmann map for various cortical areas. Here, we combined in vivo cortical myelin mapping with functional connectivity analyses and topographic mapping techniques to reassess the validity of the Brodmann map in human primary sensorimotor cortex. We provide empirical evidence that area 4 and area 3b are not homogenous, but are subdivided into distinct cortical fields, each representing a major body part (the hand and the face). Myelin reductions at the hand-face borders are cortical layer-specific, and coincide with intrinsic functional connectivity borders as defined using large-scale resting state analyses. Our data extend the Brodmann model in human sensorimotor cortex and suggest that body parts are an important organizing principle, similar to the distinction between sensory and motor processing.
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Affiliation(s)
- Esther Kuehn
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany.,Department of Psychology and Language Sciences, University College London, London WC1H 0DG, UK.,Center for Behavioral Brain Sciences Magdeburg, Magdeburg 39106, Germany.,Aging and Cognition Research Group, DZNE, Magdeburg 39106, Germany
| | - Juliane Dinse
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany.,Faculty of Computer Science, Otto-von-Guericke University, Magdeburg 39106, Germany
| | - Estrid Jakobsen
- Max Planck Research Group for Neuroanatomy & Connectivity, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig04103, Germany
| | - Xiangyu Long
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig04103, Germany
| | - Andreas Schäfer
- Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig04103, Germany
| | - Pierre-Louis Bazin
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany.,Department of Neurophysics, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig 04103, Germany
| | - Arno Villringer
- Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig04103, Germany
| | - Martin I Sereno
- Department of Psychology and Language Sciences, University College London, LondonWC1H 0DG, UK
| | - Daniel S Margulies
- Max Planck Research Group for Neuroanatomy & Connectivity, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig04103, Germany
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24
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Abstract
Most behaviors in mammals are directly or indirectly guided by prior experience and therefore depend on the ability of our brains to form memories. The ability to form an association between an initially possibly neutral sensory stimulus and its behavioral relevance is essential for our ability to navigate in a changing environment. The formation of a memory is a complex process involving many areas of the brain. In this chapter we review classic and recent work that has shed light on the specific contribution of sensory cortical areas to the formation of associative memories. We discuss synaptic and circuit mechanisms that mediate plastic adaptations of functional properties in individual neurons as well as larger neuronal populations forming topographically organized representations. Furthermore, we describe commonly used behavioral paradigms that are used to study the mechanisms of memory formation. We focus on the auditory modality that is receiving increasing attention for the study of associative memory in rodent model systems. We argue that sensory cortical areas may play an important role for the memory-dependent categorical recognition of previously encountered sensory stimuli.
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Affiliation(s)
- Dominik Aschauer
- Institute of Physiology, Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg University, Mainz, Germany
| | - Simon Rumpel
- Institute of Physiology, Focus Program Translational Neurosciences (FTN), University Medical Center, Johannes Gutenberg University, Mainz, Germany.
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25
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Kim W, Kim SK, Nabekura J. Functional and structural plasticity in the primary somatosensory cortex associated with chronic pain. J Neurochem 2017; 141:499-506. [PMID: 28278355 DOI: 10.1111/jnc.14012] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 02/28/2017] [Accepted: 03/02/2017] [Indexed: 02/03/2023]
Abstract
Tissue or nerve injury induces widespread plastic changes from the periphery and spinal cord up to the cortex, resulting in chronic pain. Although many clinicians and researchers have extensively studied altered nociceptive signaling and neural circuit plasticity at the spinal cord level, effective treatments to ameliorate chronic pain are still insufficient. For about the last two decades, the rapid development in macroscopic brain imaging studies on humans and animal models have revealed maladaptive plastic changes in the 'pain matrix' brain regions, which may subsequently contribute to chronic pain. Among these brain regions, our group has concentrated for many years on the primary somatosensory (S1) cortex with a help of advanced imaging techniques and has found the functional and structural changes in neurons/glia as well as individual synapses in the S1 cortex during chronic pain. Taken together, it is now believed that such S1 plasticity is one of the causes for chronic pain, not a simple and passive epiphenomenon following tissue/nerve injury as previously thought. In this small review, we discuss the relation of plasticity in the S1 cortex with chronic pain, based on clinical trials and experimental studies conducted on this field. This article is part of the special article series "Pain".
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Affiliation(s)
- Woojin Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Sun Kwang Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi, Japan.,Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama, Kanagawa, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, Japan
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26
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Rosén B, Balkeniu C, Lundborg G. Sensory Re-education Today and Tomorrow: A Review of Evolving Concepts. ACTA ACUST UNITED AC 2016. [DOI: 10.1177/175899830300800201] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Following surgical repair of major nerve trunks there is a rapid functional reorganisation in the brain, characterised by a changed cortical mapping of the hand secondary to incorrect reinnervation of peripheral targets. Sensory re-educational programmes are used in the rehabilitation phase to facilitate and positively influence the re-learning process, which is required to make possible an adaptation to the new synaptic organisation and to improve the recovery of functional sensibility - tactile gnosis. However, the outcome is often disappointing, especially in adults. The design of sensory re-education programmes has not changed for several decades. The purpose of this paper is to review evolving concepts in neuroscience and cognitive science, present a rationale for a modified approach to classic sensory re-education, and suggest new strategies for enhanced sensory re-learning following nerve repair.
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Affiliation(s)
- Birgitta Rosén
- Department of Hand Surgery, University Hospital MAS, Malmö, Sweden
| | | | - Göran Lundborg
- Department of Hand Surgery, University Hospital MAS, Malmö, Sweden
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27
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Pazzaglia M, Zantedeschi M. Plasticity and Awareness of Bodily Distortion. Neural Plast 2016; 2016:9834340. [PMID: 27630779 PMCID: PMC5007354 DOI: 10.1155/2016/9834340] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Revised: 07/20/2016] [Accepted: 08/01/2016] [Indexed: 12/26/2022] Open
Abstract
Knowledge of the body is filtered by perceptual information, recalibrated through predominantly innate stored information, and neurally mediated by direct sensory motor information. Despite multiple sources, the immediate prediction, construction, and evaluation of one's body are distorted. The origins of such distortions are unclear. In this review, we consider three possible sources of awareness that inform body distortion. First, the precision in the body metric may be based on the sight and positioning sense of a particular body segment. This view provides information on the dual nature of body representation, the reliability of a conscious body image, and implicit alterations in the metrics and positional correspondence of body parts. Second, body awareness may reflect an innate organizational experience of unity and continuity in the brain, with no strong isomorphism to body morphology. Third, body awareness may be based on efferent/afferent neural signals, suggesting that major body distortions may result from changes in neural sensorimotor experiences. All these views can be supported empirically, suggesting that body awareness is synthesized from multimodal integration and the temporal constancy of multiple body representations. For each of these views, we briefly discuss abnormalities and therapeutic strategies for correcting the bodily distortions in various clinical disorders.
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Affiliation(s)
- Mariella Pazzaglia
- Department of Psychology, University of Rome “La Sapienza,” Via dei Marsi 78, 00185 Rome, Italy
- IRCCS Santa Lucia Foundation, Via Ardeatina 306, 00179 Rome, Italy
| | - Marta Zantedeschi
- Department of Psychology, University of Rome “La Sapienza,” Via dei Marsi 78, 00185 Rome, Italy
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28
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Williams L, Pirouz N, Mizelle JC, Cusack W, Kistenberg R, Wheaton LA. Remodeling of cortical activity for motor control following upper limb loss. Clin Neurophysiol 2016; 127:3128-3134. [PMID: 27472549 DOI: 10.1016/j.clinph.2016.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/05/2016] [Accepted: 07/10/2016] [Indexed: 12/17/2022]
Abstract
OBJECTIVE Upper extremity loss presents immediate and lasting challenges for motor control. While sensory and motor representations of the amputated limb undergo plasticity to adjacent areas of the sensorimotor homunculus, it remains unclear whether laterality of motor-related activity is affected by neural reorganization following amputation. METHODS Using electroencephalography, we evaluated neural activation patterns of formerly right hand dominant persons with upper limb loss (amputees) performing a motor task with their residual right limb, then their sound left limb. We compared activation patterns with left- and right-handed persons performing the same task. RESULTS Amputees have involvement of contralateral motor areas when using their sound limb and atypically increased activation of posterior parietal regions when using the affected limb. When using the non-amputated left arm, patterns of activation remains similar to right handed persons using their left arm. CONCLUSIONS A remodeling of activations from traditional contralateral motor areas into posterior parietal areas occurs for motor planning and execution when using the amputated limb. This may reflect an amputation-specific adaptation of heightened visuospatial feedback for motor control involving the amputated limb. SIGNIFICANCE These results identify a neuroplastic mechanism for motor control in amputees, which may have great relevance to development of motor rehabilitation paradigms and prosthesis adaptation.
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Affiliation(s)
| | | | - J C Mizelle
- School of Applied Physiology, Georgia Tech, USA; Department of Kinesiology, East Carolina University, USA
| | - William Cusack
- School of Applied Physiology, Georgia Tech, USA; St. Jude Medical, Sunnyvale, CA, USA
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Pinto CB, Saleh Velez FG, Bolognini N, Crandell D, Merabet LB, Fregni F. Optimizing Rehabilitation for Phantom Limb Pain Using Mirror Therapy and Transcranial Direct Current Stimulation: A Randomized, Double-Blind Clinical Trial Study Protocol. JMIR Res Protoc 2016; 5:e138. [PMID: 27383993 PMCID: PMC4954918 DOI: 10.2196/resprot.5645] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 03/30/2016] [Accepted: 04/18/2016] [Indexed: 12/20/2022] Open
Abstract
Background Despite the multiple available pharmacological and behavioral therapies for the management of chronic phantom limb pain (PLP) in lower limb amputees, treatment for this condition is still a major challenge and the results are mixed. Given that PLP is associated with maladaptive brain plasticity, interventions that promote cortical reorganization such as non-invasive brain stimulation and behavioral methods including transcranial direct current stimulation (tDCS) and mirror therapy (MT), respectively, may prove to be beneficial to control pain in PLP. Due to its complementary effects, a combination of tDCS and MT may result in synergistic effects in PLP. Objective The objective of this study is to evaluate the efficacy of tDCS and MT as a rehabilitative tool for the management of PLP in unilateral lower limb amputees. Methods A prospective, randomized, placebo-controlled, double-blind, factorial, superiority clinical trial will be carried out. Participants will be eligible if they meet the following inclusion criteria: lower limb unilateral traumatic amputees that present PLP for at least 3 months after the amputated limb has completely healed. Participants (N=132) will be randomly allocated to the following groups: (1) active tDCS and active MT, (2) sham tDCS and active MT, (3) active tDCS and sham MT, and (4) sham tDCS and sham MT. tDCS will be applied with the anodal electrode placed over the primary motor cortex (M1) contralateral to the amputation side and the cathode over the contralateral supraorbital area. Stimulation will be applied at the same time of the MT protocol with the parameters 2 mA for 20 minutes. Pain outcome assessments will be performed at baseline, before and after each intervention session, at the end of MT, and in 2 follow-up visits. In order to assess cortical reorganization and correlate with clinical outcomes, participants will undergo functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) before and after the intervention. Results This clinical trial received institutional review board (IRB) approval in July of 2015 and enrollment started in December of 2015. To date 2 participants have been enrolled. The estimate enrollment rate is about 30 to 35 patients per year; thus we expect to complete enrollment in 4 years. Conclusions This factorial design will provide relevant data to evaluate whether tDCS combined with MT is more effective than each therapy alone, as well as with no intervention (sham/sham) in patients with chronic PLP after unilateral lower limb amputation. In addition, this randomized clinical trial will help to investigate the neurophysiological mechanisms underlying the disease, which could potentially provide relevant findings for further management of this chronic condition and also help to optimize the use of this novel intervention. Trial Registration Clinicaltrials.gov NCT02487966; https://clinicaltrials.gov/ct2/show/NCT02487966 (Archived by WebCite at http://www.webcitation.org/6i3GrKMyf)
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Affiliation(s)
- Camila Bonin Pinto
- Laboratory of Neuromodulation & Center for Clinical Research Learning, Physics and Rehabilitation Department, Spaulding Rehabilitation Hospital, Harvard Medical School, Boston, MA, United States
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Ramshur JT, de Jongh Curry AL, Waters RS. Wireless simultaneous stimulation-and-recording device to train cortical circuits in somatosensory cortex. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2016; 2014:426-9. [PMID: 25569987 DOI: 10.1109/embc.2014.6943619] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
We describe for the first time the design, implementation, and testing of a telemetry controlled simultaneous stimulation and recording device (SRD) to deliver chronic intercortical microstimulation (ICMS) to physiologically identified sites in rat somatosensory cortex (SI) and test hypotheses that chronic ICMS strengthens interhemispheric pathways and leads to functional reorganization in the enhanced cortex. The SRD is a custom embedded device that uses the Cypress Semiconductor's programmable system on a chip (PSoC) that is remotely controlled via Bluetooth. The SRC can record single or multiunit responses from any two of 12 available inputs at 1-15 ksps per channel and simultaneously deliver stimulus pulses (0-255 μA; 10 V compliance) to two user selectable electrodes using monophasic, biphasic, or pseudophasic stimulation waveforms (duration: 0-5 ms, inter-phase interval: 0-5 ms, frequency: 0.1-5 s, delay: 0-10 ms). The SRD was bench tested and validated in vivo in a rat animal model.
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George E, Elman I, Becerra L, Berg S, Borsook D. Pain in an era of armed conflicts: Prevention and treatment for warfighters and civilian casualties. Prog Neurobiol 2016; 141:25-44. [PMID: 27084355 DOI: 10.1016/j.pneurobio.2016.04.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 03/23/2016] [Accepted: 04/08/2016] [Indexed: 12/13/2022]
Abstract
Chronic pain is a common squealae of military- and terror-related injuries. While its pathophysiology has not yet been fully elucidated, it may be potentially related to premorbid neuropsychobiological status, as well as to the type of injury and to the neural alterations that it may evoke. Accordingly, optimized approaches for wounded individuals should integrate primary, secondary and tertiary prevention in the form of thorough evaluation of risk factors along with specific interventions to contravene and mitigate the ensuing chronicity. Thus, Premorbid Events phase may encompass assessments of psychological and neurobiological vulnerability factors in conjunction with fostering preparedness and resilience in both military and civilian populations at risk. Injuries per se phase calls for immediate treatment of acute pain in the field by pharmacological agents that spare and even enhance coping and adaptive capabilities. The key objective of the Post Injury Events is to prevent and/or reverse maladaptive peripheral- and central neural system's processes that mediate transformation of acute to chronic pain and to incorporate timely interventions for concomitant mental health problems including post-traumatic stress disorder and addiction We suggest that the proposed continuum of care may avert more disability and suffering than the currently employed less integrated strategies. While the requirements of the armed forces present a pressing need for this integrated continuum and a framework in which it can be most readily implemented, this approach may be also instrumental for the care of civilian casualties.
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Affiliation(s)
- E George
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, MGH, HMS, Boston, MA, United States; Commander, MC, USN (Ret), United States
| | - I Elman
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Psychiatry, Boonshoft School of Medicine and Dayton VA Medical Center, United States; Veterans Administration Medical Center, Dayton, OH, United States
| | - L Becerra
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, BCH, HMS, Boston, MA, United States; Departments of Psychiatry and Radiology, MGH, Boston, MA, United States
| | - Sheri Berg
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, MGH, HMS, Boston, MA, United States
| | - D Borsook
- Center for Pain and the Brain, Harvard Medical School (HMS), United States; Department of Anesthesia, Critical Care and Pain Medicine, BCH, HMS, Boston, MA, United States; Departments of Psychiatry and Radiology, MGH, Boston, MA, United States.
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Abstract
UNLABELLED Plasticity in the visual cortex of blind individuals provides a rare window into the mechanisms of cortical specialization. In the absence of visual input, occipital ("visual") brain regions respond to sound and spoken language. Here, we examined the time course and developmental mechanism of this plasticity in blind children. Nineteen blind and 40 sighted children and adolescents (4-17 years old) listened to stories and two auditory control conditions (unfamiliar foreign speech, and music). We find that "visual" cortices of young blind (but not sighted) children respond to sound. Responses to nonlanguage sounds increased between the ages of 4 and 17. By contrast, occipital responses to spoken language were maximal by age 4 and were not related to Braille learning. These findings suggest that occipital plasticity for spoken language is independent of plasticity for Braille and for sound. We conclude that in the absence of visual input, spoken language colonizes the visual system during brain development. Our findings suggest that early in life, human cortex has a remarkably broad computational capacity. The same cortical tissue can take on visual perception and language functions. SIGNIFICANCE STATEMENT Studies of plasticity provide key insights into how experience shapes the human brain. The "visual" cortex of adults who are blind from birth responds to touch, sound, and spoken language. To date, all existing studies have been conducted with adults, so little is known about the developmental trajectory of plasticity. We used fMRI to study the emergence of "visual" cortex responses to sound and spoken language in blind children and adolescents. We find that "visual" cortex responses to sound increase between 4 and 17 years of age. By contrast, responses to spoken language are present by 4 years of age and are not related to Braille-learning. These findings suggest that, early in development, human cortex can take on a strikingly wide range of functions.
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Choi MH, Kim HS, Baek JH, Lee JC, Park SJ, Jeong UH, Gim SY, Kim SP, Lim DW, Chung SC. Differences in Activation Area Within Brodmann Area 2 Caused by Pressure Stimuli on Fingers and Joints: In Case of Male Subjects. Medicine (Baltimore) 2015; 94:e1657. [PMID: 26402840 PMCID: PMC4635780 DOI: 10.1097/md.0000000000001657] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
In this study, a constant pressure stimulus was applied on the 3 joints (first [p1], second [p2], and third [p3] joints) of 4 fingers (index, middle, ring, and little fingers), and the activation areas within Brodmann area 2 (BA 2) were compared for these different fingers and joints by using functional magnetic resonance imaging. Eight healthy male college students (25.4 ± 1.32 years) participated in the study. Each session was composed of 3 blocks, and each block was composed of a Control phase (30 seconds) and a Pressure phase (30 seconds). No pressure stimulus was applied in the Control phase, during which the subjects would simply lay comfortably with their eyes closed. In the Pressure phase, a pressure stimulus was applied onto one of the joints of the selected finger. For each finger and joint, BA 2 areas activated by the pressure stimulus were extracted by the region of interest method. There was a significant difference in the activation areas for the different fingers (P = .042) as well as for the different joints (P = .050). The activation area decreased in the order of the little, index, and middle fingers, as well as in the order of p1, p3, and p2.
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Affiliation(s)
- Mi-Hyun Choi
- From the Department of Biomedical Engineering (M-HC, H-SK, J-HB, J-CL, S-JP, U-HJ, S-YG, S-CC), Research Institute of Biomedical Engineering, College of Biomedical & Health Science, Konkuk University, Chungju; Department of Human and Systems Engineering (S-PK), Ulsan National Institute of Science and Technology, Ulsan; and Department of Information and Communication Engineering (D-WL), Dongguk University, Seoul, South Korea
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A Clinical Evaluation of Postamputation Phenomena Including Phantom Limb Pain after Lower Limb Amputation in Dysvascular Patients. Pain Manag Nurs 2015; 16:561-9. [DOI: 10.1016/j.pmn.2014.10.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2014] [Revised: 10/13/2014] [Accepted: 10/17/2014] [Indexed: 11/20/2022]
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Restoring tactile and proprioceptive sensation through a brain interface. Neurobiol Dis 2014; 83:191-8. [PMID: 25201560 DOI: 10.1016/j.nbd.2014.08.029] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 08/08/2014] [Accepted: 08/27/2014] [Indexed: 11/21/2022] Open
Abstract
Somatosensation plays a critical role in the dexterous manipulation of objects, in emotional communication, and in the embodiment of our limbs. For upper-limb neuroprostheses to be adopted by prospective users, prosthetic limbs will thus need to provide sensory information about the position of the limb in space and about objects grasped in the hand. One approach to restoring touch and proprioception consists of electrically stimulating neurons in somatosensory cortex in the hopes of eliciting meaningful sensations to support the dexterous use of the hands, promote their embodiment, and perhaps even restore the affective dimension of touch. In this review, we discuss the importance of touch and proprioception in everyday life, then describe approaches to providing artificial somatosensory feedback through intracortical microstimulation (ICMS). We explore the importance of biomimicry--the elicitation of naturalistic patterns of neuronal activation--and that of adaptation--the brain's ability to adapt to novel sensory input, and argue that both biomimicry and adaptation will play a critical role in the artificial restoration of somatosensation. We also propose that the documented re-organization that occurs after injury does not pose a significant obstacle to brain interfaces. While still at an early stage of development, sensory restoration is a critical step in transitioning upper-limb neuroprostheses from the laboratory to the clinic.
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Henkin RI, Potolicchio SJ, Levy LM. Olfactory Hallucinations without Clinical Motor Activity: A Comparison of Unirhinal with Birhinal Phantosmia. Brain Sci 2013; 3:1483-553. [PMID: 24961619 PMCID: PMC4061890 DOI: 10.3390/brainsci3041483] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Revised: 10/11/2013] [Accepted: 10/12/2013] [Indexed: 01/14/2023] Open
Abstract
Olfactory hallucinations without subsequent myoclonic activity have not been well characterized or understood. Herein we describe, in a retrospective study, two major forms of olfactory hallucinations labeled phantosmias: one, unirhinal, the other, birhinal. To describe these disorders we performed several procedures to elucidate similarities and differences between these processes. From 1272, patients evaluated for taste and smell dysfunction at The Taste and Smell Clinic, Washington, DC with clinical history, neurological and otolaryngological examinations, evaluations of taste and smell function, EEG and neuroradiological studies 40 exhibited cyclic unirhinal phantosmia (CUP) usually without hyposmia whereas 88 exhibited non-cyclic birhinal phantosmia with associated symptomology (BPAS) with hyposmia. Patients with CUP developed phantosmia spontaneously or after laughing, coughing or shouting initially with spontaneous inhibition and subsequently with Valsalva maneuvers, sleep or nasal water inhalation; they had frequent EEG changes usually ipsilateral sharp waves. Patients with BPAS developed phantosmia secondary to several clinical events usually after hyposmia onset with few EEG changes; their phantosmia could not be initiated or inhibited by any physiological maneuver. CUP is uncommonly encountered and represents a newly defined clinical syndrome. BPAS is commonly encountered, has been observed previously but has not been clearly defined. Mechanisms responsible for phantosmia in each group were related to decreased gamma-aminobutyric acid (GABA) activity in specific brain regions. Treatment which activated brain GABA inhibited phantosmia in both groups.
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Affiliation(s)
- Robert I Henkin
- Center for Molecular Nutrition and Sensory Disorders, The Taste and Smell Clinic, 5125 MacArthur Blvd, NW, Suite 20, Washington, DC 20016, USA.
| | - Samuel J Potolicchio
- Department of Neurology, The George Washington University Medical Center, 2150 Pennsylvania Avenue, NW, 7th Floor, Washington, DC 20037, USA.
| | - Lucien M Levy
- Department of Radiology, The George Washington University Medical Center, 900 23rd Street, NW, Washington, DC 20037, USA.
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McCormick Z, Chang-Chien G, Marshall B, Huang M, Harden RN. Phantom limb pain: a systematic neuroanatomical-based review of pharmacologic treatment. PAIN MEDICINE 2013; 15:292-305. [PMID: 24224475 DOI: 10.1111/pme.12283] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVE Review the current evidence-based pharmacotherapy for phantom limb pain (PLP) in the context of the current understanding of the pathophysiology of this condition. DESIGN We conducted a systematic review of original research papers specifically investigating the pharmacologic treatment of PLP. Literature was sourced from PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials (CENTRAL). Studies with animals, "neuropathic" but not "phantom limb" pain, or without pain scores and/or functional measures as primary outcomes were excluded. A level of evidence 1-4 was ascribed to individual treatments. These levels included meta-analysis or systematic reviews (level 1), one or more well-powered randomized, controlled trials (level 2), retrospective studies, open-label trials, pilot studies (level 3), and anecdotes, case reports, or clinical experience (level 4). RESULTS We found level 2 evidence for gabapentin, both oral (PO) and intravenous (IV) morphine, tramadol, intramuscular (IM) botulinum toxin, IV and epidural Ketamine, level 3 evidence for amitriptyline, dextromethorphan, topiramate, IV calcitonin, PO memantine, continuous perineural catheter analgesia with ropivacaine, and level 4 evidence for methadone, intrathecal (IT) buprenorphine, IT and epidural fentanyl, duloxetine, fluoxetine, mirtazapine, clonazepam, milnacipran, capsaicin, and pregabalin. CONCLUSIONS Currently, the best evidence (level 2) exists for the use of IV ketamine and IV morphine for the short-term perioperative treatment of PLP and PO morphine for an intermediate to long-term treatment effect (8 weeks to 1 year). Level 2 evidence is mixed for the efficacy of perioperative epidural anesthesia with morphine and bupivacaine for short to long-term pain relief (perioperatively up to 1 year) as well as for the use of gabapentin for pain relief of intermediate duration (6 weeks).
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Affiliation(s)
- Zachary McCormick
- Department of Physical Medicine and Rehabilitation, The Rehabilitation Institute of Chicago/Northwestern McGaw Medical Center, Chicago, Illinois, USA
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Chen A, Yao J, Kuiken T, Dewald JPA. Cortical motor activity and reorganization following upper-limb amputation and subsequent targeted reinnervation. NEUROIMAGE-CLINICAL 2013; 3:498-506. [PMID: 24273732 PMCID: PMC3830062 DOI: 10.1016/j.nicl.2013.10.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Revised: 09/23/2013] [Accepted: 10/01/2013] [Indexed: 11/25/2022]
Abstract
Previous studies have postulated that the amount of brain reorganization following peripheral injuries may be correlated with negative symptoms or consequences. However, it is unknown whether restoring effective limb function may then be associated with further changes in the expression of this reorganization. Recently, targeted reinnervation (TR), a surgical technique that restores a direct neural connection from amputated sensorimotor nerves to new peripheral targets such as muscle, has been successfully applied to upper-limb amputees. It has been shown to be effective in restoring both peripheral motor and sensory functions via the reinnervated nerves as soon as a few months after the surgery. However, it was unclear whether TR could also restore normal cortical motor representations for control of the missing limb. To answer this question, we used high-density electroencephalography (EEG) to localize cortical activity related to cued motor tasks generated by the intact and missing limb. Using a case study of 3 upper-limb amputees, 2 of whom went through pre and post-TR experiments, we present unique quantitative evidence for the re-mapping of motor representations for the missing limb closer to their original locations following TR. This provides evidence that an effective restoration of peripheral function from TR can be linked to the return of more normal cortical expression for the missing limb. Therefore, cortical mapping may be used as a potential guide for monitoring rehabilitation following peripheral injuries.
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Affiliation(s)
- Albert Chen
- Department of Biomedical Engineering, Northwestern University, IL, USA ; Department of Physical Therapy and Human Movement Sciences, Northwestern University, IL, USA
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Canzoneri E, Marzolla M, Amoresano A, Verni G, Serino A. Amputation and prosthesis implantation shape body and peripersonal space representations. Sci Rep 2013; 3:2844. [PMID: 24088746 PMCID: PMC3789144 DOI: 10.1038/srep02844] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2013] [Accepted: 09/11/2013] [Indexed: 11/21/2022] Open
Abstract
Little is known about whether and how multimodal representations of the body (BRs) and of the space around the body (Peripersonal Space, PPS) adapt to amputation and prosthesis implantation. In order to investigate this issue, we tested BR in a group of upper limb amputees by means of a tactile distance perception task and PPS by means of an audio-tactile interaction task. Subjects performed the tasks with stimulation either on the healthy limb or the stump of the amputated limb, while wearing or not wearing their prosthesis. When patients performed the tasks on the amputated limb, without the prosthesis, the perception of arm length shrank, with a concurrent shift of PPS boundaries towards the stump. Conversely, wearing the prosthesis increased the perceived length of the stump and extended the PPS boundaries so as to include the prosthetic hand, such that the prosthesis partially replaced the missing limb.
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Affiliation(s)
- Elisa Canzoneri
- CsrNC, Centro studi e ricerche in Neuroscienze Cognitive, Polo Scientifico-Didattico di Cesena, ALMA MATER STUDIORUM, Università di Bologna
- Dipartimento di Psicologia, ALMA MATER STUDIORUM, Università di Bologna
- Current address: Laboratory of Cognitive Neuroscience & Center for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Marilena Marzolla
- CsrNC, Centro studi e ricerche in Neuroscienze Cognitive, Polo Scientifico-Didattico di Cesena, ALMA MATER STUDIORUM, Università di Bologna
| | | | | | - Andrea Serino
- CsrNC, Centro studi e ricerche in Neuroscienze Cognitive, Polo Scientifico-Didattico di Cesena, ALMA MATER STUDIORUM, Università di Bologna
- Dipartimento di Psicologia, ALMA MATER STUDIORUM, Università di Bologna
- Current address: Laboratory of Cognitive Neuroscience & Center for Neuroprosthetics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
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Lasko L, Huang X, Voorbach MJ, Lewis LGR, Stavropoulos J, Carriker J, Seifert TR, Baker SJ, Upadhyay J. Multimodal assessment of nervous and immune system responses following sciatic nerve injury. Pain 2013; 154:2782-2793. [PMID: 23973359 DOI: 10.1016/j.pain.2013.08.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 08/13/2013] [Accepted: 08/15/2013] [Indexed: 12/14/2022]
Abstract
Subsequent to peripheral nerve compression and irritation, pathophysiological processes take place within nervous and immune systems. Here, we utilized a multimodal approach to comprehend peripheral and central soft tissue changes as well as alterations occurring in systemic analytes following unilateral chronic constriction injury (CCI) of the sciatic nerve in rodents. Using magnetic resonance imaging and [18F]-2-fluoro-2-deoxy-d-glucose (FDG) positron emission tomography, we demonstrated robust structural abnormalities and enhanced FDG uptake within the injured nerve and surrounding muscle, respectively. To assess whether central morphological changes were induced by nerve injury, diffusion tenor imaging was performed. A decrease in fractional anisotropy in primary motor cortex contralateral to the injury site was observed. Evaluation of a panel of circulating cytokines, chemokines, and growth factors showed decreased levels of interleukin-1β and Fractalkine in CCI animals. Area under the receiver operating curve (ROC) calculations of analyte levels, imaging, and behavioral end points ranged from 0.786 to 1, where behavioral and peripheral imaging end points (eg, FDG uptake in muscle) were observed to have the highest discriminatory capabilities (maximum area under ROC = 1) between nerve injury and sham conditions. Lastly, performance of correlation analysis involving all analyte, behavioral, and imaging data provided an understanding of the overall association amongst these end points, and importantly, a distinction in correlation patterns was observed between CCI and sham conditions. These findings demonstrate the multidimensional pathophysiology of sciatic nerve injury and how a combined analyte, behavioral, and imaging assessment can be implemented to probe this complexity.
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Affiliation(s)
- Loren Lasko
- Integrated Sciences and Technology, AbbVie Inc., North Chicago, IL, USA Exploratory Statistics, AbbVie Inc., North Chicago, IL, USA Neuroscience Discovery, AbbVie Inc., North Chicago, IL, USA Comparative Medicine, AbbVie Inc., North Chicago, IL, USA
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Williams DB. Denervation of the ear and the 'folding flower' illusion. BMJ Case Rep 2013; 2013:bcr-2012-008232. [PMID: 23354866 DOI: 10.1136/bcr-2012-008232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Following acute denervation of the ear, I experienced altered cutaneous sensory perception analogous to that reported by patients after limb amputation. This suggests that any sudden, complete loss of somaesthetic sensation can result in cortical reorganisation reflecting lost peripheral input. Although the short time course of the phenomenon suggests an initial functional reorganisation, it does not preclude longer time course structural alterations at multiple levels of the nervous system.
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Affiliation(s)
- David Bruce Williams
- Department of Neurology, John Hunter Hospital, Newcastle, New South Wales, Australia.
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Antfolk C, D'Alonzo M, Controzzi M, Lundborg G, Rosén B, Sebelius F, Cipriani C. Artificial redirection of sensation from prosthetic fingers to the phantom hand map on transradial amputees: vibrotactile versus mechanotactile sensory feedback. IEEE Trans Neural Syst Rehabil Eng 2012; 21:112-20. [PMID: 23033439 DOI: 10.1109/tnsre.2012.2217989] [Citation(s) in RCA: 132] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This work assesses the ability of transradial amputees to discriminate multi-site tactile stimuli in sensory discrimination tasks. It compares different sensory feedback modalities using an artificial hand prosthesis in: 1) a modality matched paradigm where pressure recorded on the five fingertips of the hand was fed back as pressure stimulation on five target points on the residual limb; and 2) a modality mismatched paradigm where the pressures were transformed into mechanical vibrations and fed back. Eight transradial amputees took part in the study and were divided in two groups based on the integrity of their phantom map; group A had a complete phantom map on the residual limb whereas group B had an incomplete or nonexisting map. The ability in localizing stimuli was compared with that of 10 healthy subjects using the vibration feedback and 11 healthy subjects using the pressure feedback (in a previous study), on their forearms, in similar experiments. Results demonstrate that pressure stimulation surpassed vibrotactile stimulation in multi-site sensory feedback discrimination. Furthermore, we demonstrate that subjects with a detailed phantom map had the best discrimination performance and even surpassed healthy participants for both feedback paradigms whereas group B had the worst performance overall. Finally, we show that placement of feedback devices on a complete phantom map improves multi-site sensory feedback discrimination, independently of the feedback modality.
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Affiliation(s)
- Christian Antfolk
- Department of Measurement Technology and Industrial Electrical Engineering, Lund University, 22100 Lund, Sweden.
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Björkman A, Weibull A, Olsrud J, Ehrsson HH, Rosén B, Björkman-Burtscher IM. Phantom digit somatotopy: a functional magnetic resonance imaging study in forearm amputees. Eur J Neurosci 2012; 36:2098-106. [PMID: 22537316 DOI: 10.1111/j.1460-9568.2012.08099.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Forearm amputees often experience non-painful sensations in their phantom when the amputation stump is touched. Cutaneous stimulation of specific stump areas may be perceived as stimulation of specific phantom fingers (stump hand map). The neuronal basis of referred phantom limb sensations is unknown. We used functional magnetic resonance imaging to demonstrate a somatotopic map of the phantom fingers in the hand region of the primary somatosensory cortex after tactile stump stimulation. The location and extent of phantom finger activation in the primary somatosensory cortex corresponded well to the location of normal fingers in a reference population. Stimulation of the stump hand map resulted in an increased bilateral activation of the primary somatosensory cortex compared with stimulation of forearm regions outside the stump hand map. Increased activation was also seen in contralateral posterior parietal cortex and premotor cortex. Ipsilateral primary somatosensory cortex activation might represent a compensatory mechanism and activation of the non-primary fronto-parietal areas might correspond to awareness of the phantom limb, which is enhanced when experiencing the referred sensations. It is concluded that phantom sensation elicited by stimulation of stump hand map areas is associated with activation of finger-specific somatotopical representations in the primary somatosensory cortex. This suggests that the primary somatosensory cortex could be a neural substrate of non-painful phantom sensations. The stump hand map phenomenon might be useful in the development of prosthetic hand devices.
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Affiliation(s)
- Anders Björkman
- Department of Hand Surgery, Lund University, Skåne University Hospital, SE - 20502, Malmo, Sweden.
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Functional expansion of sensorimotor representation and structural reorganization of callosal connections in lower limb amputees. J Neurosci 2012; 32:3211-20. [PMID: 22378892 DOI: 10.1523/jneurosci.4592-11.2012] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Previous studies have indicated that amputation or deafferentation of a limb induces functional changes in sensory (S1) and motor (M1) cortices, related to phantom limb pain. However, the extent of cortical reorganization after lower limb amputation in patients with nonpainful phantom phenomena remains uncertain. In this study, we combined functional magnetic resonance (fMRI) and diffusion tensor imaging (DTI) to investigate the existence and extent of cortical and callosal plasticity in these subjects. Nine "painless" patients with lower limb amputation and nine control subjects (sex- and age-matched) underwent a 3-T MRI protocol, including fMRI with somatosensory stimulation. In amputees, we observed an expansion of activation maps of the stump in S1 and M1 of the deafferented hemisphere, spreading to neighboring regions that represent the trunk and upper limbs. We also observed that tactile stimulation of the intact foot in amputees induced a greater activation of ipsilateral S1, when compared with controls. These results demonstrate a functional remapping of S1 in lower limb amputees. However, in contrast to previous studies, these neuroplastic changes do not appear to be dependent on phantom pain but do also occur in those who reported only the presence of phantom sensation without pain. In addition, our findings indicate that amputation of a limb also induces changes in the cortical representation of the intact limb. Finally, DTI analysis showed structural changes in the corpus callosum of amputees, compatible with the hypothesis that phantom sensations may depend on inhibitory release in the sensorimotor cortex.
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Jamali S, Ross B. Precise mapping of the somatotopic hand area using neuromagnetic steady-state responses. Brain Res 2012; 1455:28-39. [PMID: 22507747 DOI: 10.1016/j.brainres.2012.02.038] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2011] [Revised: 02/14/2012] [Accepted: 02/14/2012] [Indexed: 12/01/2022]
Abstract
The body surface is represented in somatotopically organized maps in the primary somatosensory cortex. Estimating the size of the hand area with neuromagnetic source analysis has been used as a metric for monitoring neuroplastic changes related to training, learning, and brain injury. Commonly, results were significant as group statistics only because source localization accuracy was limited by factors such as residual noise and head motion. In this study we aimed to develop a robust method for obtaining the somatotopic map of the hand area in individuals using the bootstrap framework. Furthermore, a comprehensive analysis of the different factors affecting the accuracy of the obtained maps was provided. We applied vibrotactile touch stimuli to the tip of the index finger or the ring finger of the right hand and recorded the 22-Hz steady-state response using MEG. Single equivalent dipole sources were localized in contralateral left somatosensory cortex. Bootstrap resampling revealed the confidence intervals for the source coordinates using a single block of 5 min MEG recording. Residual noise in the averaged evoked response predominantly affected source localization, and the related confidence interval was reciprocally related to the signal-to-noise ratio. Apparently, head movements within a block of MEG recording contributed less to the variability of source localization in cooperative volunteers. The results of the current study indicate that significant separations of index finger and ring finger representations along the somatotopic map can be revealed in an individual using bootstrap framework.
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Affiliation(s)
- Shahab Jamali
- Rotman Research Institute, Baycrest Centre, Toronto, ON, Canada.
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Carlstedt T, Havton L. The longitudinal spinal cord injury: lessons from intraspinal plexus, cauda equina and medullary conus lesions. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:337-54. [PMID: 23098723 DOI: 10.1016/b978-0-444-52137-8.00021-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Spinal nerve root avulsion injury interrupts the transverse segmental spinal cord nerve fibers. There is degeneration of sensory, motor, and autonomic axons, loss of synapses, deterioration of local segmental connections, nerve cell death, and reactions among non neuronal cells with central nerve system (CNS) scar formation, i.e., a cascade of events similar to those known to occur in any injury to the spinal cord. This is the longitudinal spinal cord injury (SCI). For function to be restored, nerve cells must survive and there must be regrowth of new nerve fibers along a trajectory consisting of CNS growth-inhibitory tissue in the spinal cord as well as peripheral nervous system (PNS) growth-promoting tissue in nerves. Basic science results have been translated into a successful surgical strategy to treat root avulsion injuries in man. In humans, this technique is currently the most promising treatment of any spinal cord injury, with return of useful muscle function together with pain alleviation. Experimental studies have also identified potential candidates for adjunctive therapies that, together with surgical replantation of avulsed roots after brachial plexus and cauda equina injuries, can restore not only motor but also autonomic and sensory trajectories to augment the recovery of neurological function. This is the first example of a spinal cord lesion that can be treated surgically, leading to restoration of somatic and autonomic activity and alleviation of pain.
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Lillard AS, Erisir A. Old Dogs Learning New Tricks: Neuroplasticity Beyond the Juvenile Period. DEVELOPMENTAL REVIEW 2011; 31:207-239. [PMID: 24648605 PMCID: PMC3956134 DOI: 10.1016/j.dr.2011.07.008] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Twenty years ago, the prevalent view in psychology was that although learning and the formation of new memories are lifelong occurrences, the neural changes associated with these events were all in the existing receptors. No new neural hardware, from synapses to neurons, was thought to appear after a protracted period early in life. In the past 20 years, another view has supplanted this one, showing that although the juvenile period is especially suited to neuroplastic adaptation, there is hard neuroplastic change later in life as well. We review a selection of evidence for this view from both animal and human models, showing how it reflects three principles of neuroplasticity: 1) earlier and later experience-induced changes to neuroarchitecture differ in degree more so than in type; 2) the types of experiences that lead to neuroplastic change narrow with age; and 3) differences in the amenability of neural circuitry to change result from basic differences in neuroarchitecture and neuroenvironment in different phases of development.
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Rode G, Vallar G, Revol P, Tilikete C, Jacquin-Courtois S, Rossetti Y, Farnè A. Facial macrosomatognosia and pain in a case of Wallenberg's syndrome: selective effects of vestibular and transcutaneous stimulations. Neuropsychologia 2011; 50:245-53. [PMID: 22142667 DOI: 10.1016/j.neuropsychologia.2011.11.018] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2011] [Revised: 10/11/2011] [Accepted: 11/21/2011] [Indexed: 11/28/2022]
Abstract
Macro- and micro-somatognosia refer to rare disorders of the cerebral representation of the body whereby patients perceive body parts as disproportionately large or small. Here we report the experimental study of a patient who, following a left lateral medullary stroke (Wallenberg's syndrome, including vestibular deficits) complained of a persistent somatosensory illusory sensation of swelling, confined to the left side of his face (i.e., left macrosomatognosia). This hemifacial somatosensory distortion was associated with a left facial anesthesia, and a neuropathic pain affecting the three branches of the left trigeminal nerve. In this study, we first document quantitatively the patient's somatosensory illusion by using a somatosensory-to-visual matching task in which the patient modified the picture of his own face to fit his left-sided somatosensory misperception. The patient's performance revealed that macrosomatognosia was confined to the second branch of the left trigeminal nerve. Perception of the size of visual objects was comparatively preserved. Second, we investigated the effects of two peripheral stimulations, which may affect the spatial component of somatosensory deficits (caloric vestibular stimulation, CVS; transcutaneous electrical nervous stimulation, TENS) and pain (TENS). Left CVS abolished the facial somatosensory illusion, for about 30min, but had no effect on the left facial pain. Conversely, left TENS substantially reduced the neuropathic pain during stimulation, but had no effect on macrosomatognosia, indicating a double dissociation between the two disorders. These results reveal that facial macrosomatognosia may be regarded as a high-order deficit of somatosensory perception of the shape and volume of the face, which fits the definition of 'hyperschematia' (i.e., when the body takes up too much room) originally proposed by Bonnier (1905). Our data also indicate that CVS may favor the restoration of the conscious representation of the shape and size of the face. Overall, these findings lend support to the view that afferent inputs from the vestibular system can affect in a specific fashion the activity of cerebral structures involved in the building up and updating of the topological description of body parts.
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Affiliation(s)
- G Rode
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Centre, ImpAct Team, Lyon, France.
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Abstract
Chronic pain is a frequent component of many neurological disorders, affecting 20-40% of patients for many primary neurological diseases. These diseases result from a wide range of pathophysiologies including traumatic injury to the central nervous system, neurodegeneration and neuroinflammation, and exploring the aetiology of pain in these disorders is an opportunity to achieve new insight into pain processing. Whether pain originates in the central or peripheral nervous system, it frequently becomes centralized through maladaptive responses within the central nervous system that can profoundly alter brain systems and thereby behaviour (e.g. depression). Chronic pain should thus be considered a brain disease in which alterations in neural networks affect multiple aspects of brain function, structure and chemistry. The study and treatment of this disease is greatly complicated by the lack of objective measures for either the symptoms or the underlying mechanisms of chronic pain. In pain associated with neurological disease, it is sometimes difficult to obtain even a subjective evaluation of pain, as is the case for patients in a vegetative state or end-stage Alzheimer's disease. It is critical that neurologists become more involved in chronic pain treatment and research (already significant in the fields of migraine and peripheral neuropathies). To achieve this goal, greater efforts are needed to enhance training for neurologists in pain treatment and promote greater interest in the field. This review describes examples of pain in different neurological diseases including primary neurological pain conditions, discusses the therapeutic potential of brain-targeted therapies and highlights the need for objective measures of pain.
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Affiliation(s)
- David Borsook
- MD Center for Pain and the Brain C/O Brain Imaging Center, McLean Hospital Belmont, MA 02478, USA.
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