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Tisoncik-Go J, Stokes C, Whitmore LS, Newhouse DJ, Voss K, Gustin A, Sung CJ, Smith E, Stencel-Baerenwald J, Parker E, Snyder JM, Shaw DW, Rajagopal L, Kapur RP, Waldorf KA, Gale M. Disruption of myelin structure and oligodendrocyte maturation in a pigtail macaque model of congenital Zika infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.11.561759. [PMID: 37873381 PMCID: PMC10592731 DOI: 10.1101/2023.10.11.561759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Zika virus (ZikV) infection during pregnancy can cause congenital Zika syndrome (CZS) and neurodevelopmental delay in non-microcephalic infants, of which the pathogenesis remains poorly understood. We utilized an established pigtail macaque maternal-to-fetal ZikV infection/exposure model to study fetal brain pathophysiology of CZS manifesting from ZikV exposure in utero. We found prenatal ZikV exposure led to profound disruption of fetal myelin, with extensive downregulation in gene expression for key components of oligodendrocyte maturation and myelin production. Immunohistochemical analyses revealed marked decreases in myelin basic protein intensity and myelinated fiber density in ZikV-exposed animals. At the ultrastructural level, the myelin sheath in ZikV-exposed animals showed multi-focal decompaction consistent with perturbation or remodeling of previously formed myelin, occurring concomitant with dysregulation of oligodendrocyte gene expression and maturation. These findings define fetal neuropathological profiles of ZikV-linked brain injury underlying CZS resulting from ZikV exposure in utero. Because myelin is critical for cortical development, ZikV-related perturbations in oligodendrocyte function may have long-term consequences on childhood neurodevelopment, even in the absence of overt microcephaly.
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Affiliation(s)
- Jennifer Tisoncik-Go
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Caleb Stokes
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Leanne S Whitmore
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Daniel J Newhouse
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Kathleen Voss
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Andrew Gustin
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Cheng-Jung Sung
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Elise Smith
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Jennifer Stencel-Baerenwald
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
| | - Edward Parker
- Department of Ophthalmology, NEI Core for Vision Research, University of Washington, Seattle, Washington, USA
| | - Jessica M Snyder
- Department of Comparative Medicine, University of Washington, Seattle, Washington, USA
| | - Dennis W Shaw
- Department of Radiology, University of Washington, Seattle Washington, USA
| | - Lakshmi Rajagopal
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Center for Global Infectious Disease Research, Seattle Children's Research Institute, Seattle, Washington, USA
- Department of Global Health, University of Washington, Seattle, Washington, USA
| | - Raj P Kapur
- Department of Pathology, University of Washington, Seattle, Washington, USA
- Department of Pathology, Seattle Children's Hospital, Seattle, Washington, USA
| | - Kristina Adams Waldorf
- Department of Global Health, University of Washington, Seattle, Washington, USA
- Department of Obstetrics & Gynecology, University of Washington, Seattle, Washington, USA
- Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | - Michael Gale
- Center for Innate Immunity and Immune Disease, Department of Immunology, University of Washington, Seattle, Washington, USA
- Department of Global Health, University of Washington, Seattle, Washington, USA
- Department of Obstetrics & Gynecology, University of Washington, Seattle, Washington, USA
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Marsico P, Meier L, van der Linden ML, Mercer TH, van Hedel HJA. Feasibility, Validity, and Reliability of Lower Limb Tactile and Body Awareness Assessments in Children With Upper Motor Neuron Lesions. Arch Phys Med Rehabil 2023; 104:1447-1455. [PMID: 36935032 DOI: 10.1016/j.apmr.2023.02.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 01/24/2023] [Accepted: 02/26/2023] [Indexed: 03/19/2023]
Abstract
OBJECTIVE To investigate the feasibility, discriminative and convergent validity, and inter-rater reliability of a lower limb tactile function and 2 body awareness assessments in children with upper motor neuron (UMN) lesions. DESIGN Cross-sectional psychometric study. SETTING Pediatric rehabilitation center. PARTICIPANTS Forty individuals with UMN lesions (mean age 11.7 years, SD 3.4 years; 27 girls) and 40 neurotypically developing children of the same age participated (N=80). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES We assessed the tactile threshold (TT) with monofilaments and body awareness with tactile localization tasks (TLTs) for structural (TLTaction) and spatial (TLTperception) body representation at the foot sole. We compared the test outcomes between children with UMN lesions and neurotypically developing children with the Wilcoxon signed-rank test. Furthermore, we quantified the relations between the 3 tests with Spearman correlations (rs) and the interrater reliability with quadratic weighted kappa (κQW). RESULTS About 80% of the children with UMN lesions perceived the tests easy to perform. The children with UMN lesions had significantly reduced somatosensory function compared with the neurotypically developing children. For the more affected leg, we found good relations between the TT and the TLTaction (rs=0.71; P<.001) and between the 2 TLTs (rs=0.66; P<.001), and a fair relation between the TT and the TLTperception (rs=0.31; P=.06). The inter-rater reliability analyses for the sum scores showed almost perfect agreement for the TT (κQW more affected leg 0.86; less affected leg 0.81), substantial agreement for TLTaction (κQW more affected leg 0.76; less affected leg 0.63), and almost perfect agreement for TLTperception (κQW more affected leg 0.88; less affected leg 0.74). CONCLUSION The 3 tests are feasible to assess lower limb somatosensory function in children with UMN lesions. Discriminative and convergent validity and reliability of the 3 tests were confirmed. Further studies should investigate responsiveness and association with motor function of these outcome measures.
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Affiliation(s)
- Petra Marsico
- Research Department, Swiss Children's Rehab, University Children's Hospital Zurich, Affoltern am Albis, Switzerland; Children's Research Center CRC, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland; Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, Scotland.
| | - Lea Meier
- Research Department, Swiss Children's Rehab, University Children's Hospital Zurich, Affoltern am Albis, Switzerland; Children's Research Center CRC, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland; ZHAW, Institute for Physiotherapy, Zürich University of Applied Studies, Winterthur, Switzerland
| | - Marietta L van der Linden
- Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, Scotland
| | - Tom H Mercer
- Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, Scotland
| | - Hubertus J A van Hedel
- Research Department, Swiss Children's Rehab, University Children's Hospital Zurich, Affoltern am Albis, Switzerland; Children's Research Center CRC, University Children's Hospital Zurich, University of Zurich, Zurich, Switzerland; Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, Scotland
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Zhang H, Wei P, Lu C, Wang Z, Fan X, Shan Y, Zhao G. Assessing structural integrity of the pyramidal tracts with diffusion spectrum imaging to predict postoperative motor function in pediatric epilepsy patients with hemispherectomy. ACTA EPILEPTOLOGICA 2023. [DOI: 10.1186/s42494-022-00115-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023] Open
Abstract
Abstract
Background
Hemispherectomy is an effective treatment option for patients with drug-resistant epilepsy caused by hemispheric lesions. However, patients often have deterioration of their motor functions postoperatively. Diffusion spectrum imaging (DSI) was reliable in presenting the natural shape of the white matter fibers. At the same time, the natural sprawl pyramid tract (PT) might be more intuitive for predicting postoperative motor functions. Therefore, we assessed the motor functions by the natural shape revealed by DSI tractography.
Methods
Ten children with drug-resistant epilepsy who were candidates for hemispherectomy performed DSI PTs tractography and transcranial magnetic stimulation (TMS) for motor mapping. The motor function was evaluated with muscle strength and hand grasping capability. Pyramidal tract (PT) structural integrity and TMS mapping results were compared between patients who remained stable and those with deteriorated motor functions. Receiver operating characteristic (ROC) curves with PTs asymmetric ratio were analyzed to evaluate DSI tractography diagnostic value.
Results
All patients underwent DSI acquisition, while four patients successfully performed TMS. One patient had no response to TMS until the maximal machine output was reached. Four patients failed to perform TMS due to lacking cooperation. One patient was contraindicated to TMS. DSI successfully reconstructed the sharp angle fan-shaped PTs within the hemisphere. The accurate fiber distribution with fiber termination and thickness within the lesioned hemisphere was replicated with DSI tractography. No significance was found in patients’ age, sex, seizure frequency, or medication between patients with stable or deteriorated postoperative motor functions. DSI effectively predicted postoperative motor function as stable with damaged PTs, mild deterioration with atrophied PTs, and intact PTs with contralateral innervation confirmed by intracranial stimulation. The area under the curve (AUC) of DSI tractography was 0.84. According to ROC, the cut-off value of PTs asymmetric ratio was 11.5% with 100% sensitivity and 75% specificity. The sensitivity and specificity of TMS were 2/3 and 1/2, respectively.
Conclusions
The anatomic integrity of PTs with DSI tractography could effectively predict postoperative motor function after hemispherectomy. This enables neurosurgeons to inform patients and relatives about postoperative motor functions with direct morphological evidence of PTs to help them with their surgical decisions.
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Cortical change after a 2-week novel robotic rehabilitation program in children with prior hemispherectomy: pilot imaging study. Childs Nerv Syst 2023; 39:443-449. [PMID: 36085526 DOI: 10.1007/s00381-022-05664-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 09/03/2022] [Indexed: 11/03/2022]
Abstract
INTRODUCTION Partial preservation of sensory and motor functions in the contralateral extremities after hemispherectomy is likely secondary to cortical reorganization of the remaining hemisphere and can be improved by rehabilitation. This study aims to investigate behavioral and structural cerebral cortical changes that may occur after a 2-week novel robotic rehabilitation program in children with prior anatomic hemispherectomy. METHODS Five patients with prior anatomic hemispherectomy (average age 10.8 years; all female) participated in a 2-week novel robotic rehabilitation program. Pre- and post-treatment (2 time points) high-resolution structural 3D FSPGR (fast spoiled gradient echo) magnetic resonance images were analyzed to measure cortical thickness and gray matter volume using a locally designed image processing pipeline. RESULTS Four of the five patients showed improvement in the Fugl-Meyer score (average increase 2.5 + 2.1 SD. Individual analyses identified small increases in gray matter volume near the hand knob area of the primary cortex in three of the five patients. Group analyses identified an increase in cortical thickness near the hand knob area of the primary motor cortex, in addition to other sensorimotor regions. CONCLUSION This small pilot study demonstrates that potentially rehabilitation-associated cortical changes can be identified with MRI in hemispherectomy patients.
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Marsico P, Mercer TH, van Hedel HJA, van der Linden ML. What are the relevant categories, modalities, and outcome measures for assessing lower limb somatosensory function in children with upper motor neuron lesions? A Delphi study. Disabil Rehabil 2022:1-10. [PMID: 35906774 DOI: 10.1080/09638288.2022.2102257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE Somatosensory function of the lower limbs is rarely assessed in children with upper motor neuron lesions despite its potential relevance for motor function. We explored consensus regarding somatosensory categories (exteroception, proprioception, interoception, and body awareness), modalities, and outcome measures relevant to lower limb motor function. METHODS Fifteen international experts with experience of somatosensory function assessment participated in this Delphi study. Surveys of four rounds, conducted online, included questions on the relevance of somatosensory categories and modalities for motor function and on the use of potential outcome measures in clinical practice. RESULTS The experts reached consensus on the relevance of six modalities of the categories exteroception, proprioception, and body awareness. Based on their feedback, we formulated three core criteria for somatosensory outcome measures, namely suitability for clinical practice, child-friendliness, and relevance for motor function. None of the nine available outcome measures fulfilled each criterion. The experts also highlighted the importance of using and interpreting the tests in relation to the child's activity and participation. CONCLUSION There was expert consensus on three categories and six modalities of somatosensory function relevant for lower limb motor function. However, existing outcome measures will need to be adapted for use in paediatric clinical practice. IMPLICATION FOR REHABILITATIONConsensus was established for the categories and modalities of somatosensory function relevant for lower limb motor function of children with UMN lesion.Outcome measures should cover tactile function, joint movement and joint position and dynamic position sense, and spatial and structural body representation.None of the nine existing outcome measures fulfilled the core criteria: feasibility for clinical practice, child-friendliness, and relevance to motor function.
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Affiliation(s)
- Petra Marsico
- Research Department, Swiss Children's Rehab, University Children's Hospital Zurich, Affoltern am Albis, Switzerland.,Children's Research Center CRC, University Children's Hospital Zurich, Zurich, Switzerland.,Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, UK
| | - Tom H Mercer
- Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, UK
| | - Hubertus J A van Hedel
- Research Department, Swiss Children's Rehab, University Children's Hospital Zurich, Affoltern am Albis, Switzerland.,Children's Research Center CRC, University Children's Hospital Zurich, Zurich, Switzerland.,Centre for Health, Activity and Rehabilitation Research, Queen Margaret University, Edinburgh, UK
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Batschelett M, Gibbs S, Holder CM, Holcombe B, Wheless JW, Narayana S. Plasticity in the developing brain: neurophysiological basis for lesion-induced motor reorganization. Brain Commun 2021; 4:fcab300. [PMID: 35174326 PMCID: PMC8842689 DOI: 10.1093/braincomms/fcab300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 11/10/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
The plasticity of the developing brain can be observed following injury to the
motor cortex and/or corticospinal tracts, the most commonly injured brain area
in the pre- or peri-natal period. Factors such as the timing of injury, lesion
size and lesion location may affect a single hemisphere’s ability to
acquire bilateral motor representation. Bilateral motor representation of single
hemisphere origin is most likely to occur if brain injury occurs before the age
of 2 years; however, the link between injury aetiology, reorganization type and
functional outcome is largely understudied. We performed a retrospective review
to examine reorganized cortical motor maps identified through transcranial
magnetic stimulation in a cohort of 52 patients. Subsequent clinical,
anthropometric and demographic information was recorded for each patient. Each
patient’s primary hand motor cortex centre of gravity, along with the
Euclidian distance between reorganized and normally located motor cortices, was
also calculated. The patients were classified into broad groups including
reorganization type (inter- and intrahemispheric motor reorganization), age at
the time of injury (before 2 years and after 2 years) and injury aetiology
(developmental disorders and acquired injuries). All measures were analysed to
find commonalities between motor reorganization type and injury aetiology,
function and centre of gravity distance. There was a significant effect of
injury aetiology on type of motor reorganization
(P < 0.01), with 60.7% of patients
with acquired injuries and 15.8% of patients with developmental disorders
demonstrating interhemispheric motor reorganization. Within the interhemispheric
motor reorganization group, ipsilaterally and contralaterally projecting hand
motor cortex centres of gravity overlapped, indicating shared cortical motor
representation. Furthermore, the data suggest significantly higher prevalence of
bilateral motor representation from a single hemisphere in cases of acquired
injuries compared to those of developmental origin. Functional outcome was found
to be negatively affected by acquired injuries and interhemispheric motor
reorganization relative to their respective counterparts with developmental
lesions and intrahemispheric motor reorganization. These results provide novel
information regarding motor reorganization in the developing brain via an
unprecedented cohort sample size and transcranial magnetic stimulation.
Transcranial magnetic stimulation is uniquely suited for use in understanding
the principles of motor reorganization, thereby aiding in the development of
more efficacious therapeutic techniques to improve functional recovery following
motor cortex injury.
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Affiliation(s)
- Mitchell Batschelett
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Rhodes College, Memphis, TN, USA
| | - Savannah Gibbs
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
| | - Christen M. Holder
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Billy Holcombe
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - James W. Wheless
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
| | - Shalini Narayana
- Neuroscience Institute, Le Bonheur Children’s Hospital, Memphis, TN, USA
- Department of Pediatrics, Division of Pediatric Neurology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
- Department of Anatomy and Neurobiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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Gaubatz J, Prillwitz CC, Ernst L, David B, Hoppe C, Hattingen E, Weber B, Vatter H, Surges R, Elger CE, Rüber T. Contralesional White Matter Alterations in Patients After Hemispherotomy. Front Hum Neurosci 2020; 14:262. [PMID: 32733222 PMCID: PMC7358777 DOI: 10.3389/fnhum.2020.00262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Accepted: 06/12/2020] [Indexed: 12/17/2022] Open
Abstract
Cerebral lesions may cause degeneration and neuroplastic reorganization in both the ipsi- and the contralesional hemisphere, presumably creating an imbalance of primarily inhibitory interhemispheric influences produced via transcallosal pathways. The two hemispheres are thought to mutually hamper neuroplastic reorganization of the other hemisphere. The results of preceding degeneration and neuroplastic reorganization of white matter may be reflected by Diffusion Tensor Imaging-derived diffusivity parameters such as fractional anisotropy (FA). In this study, we applied Diffusion Tensor Imaging (DTI) to contrast the white matter status of the contralesional hemisphere of young lesioned brains with and without contralateral influences by comparing patients after hemispherotomy to those who had not undergone neurosurgery. DTI was applied to 43 healthy controls (26 females, mean age ± SD: 25.07 ± 11.33 years) and two groups of in total 51 epilepsy patients with comparable juvenile brain lesions (32 females, mean age ± SD: 25.69 ± 12.77 years) either after hemispherotomy (30 of 51 patients) or without neurosurgery (21 of 51 patients), respectively. FA values were compared between these groups using the unbiased tract-based spatial statistics approach. A voxel-wise ANCOVA controlling for age at scan yielded significant group differences in FA. A post hoc t-test between hemispherotomy patients and healthy controls revealed widespread supra-threshold voxels in the contralesional hemisphere of hemispherotomy patients indicating comparatively higher FA values (p < 0.05, FWE-corrected). The non-surgery group, in contrast, showed extensive supra-threshold voxels indicating lower FA values in the contralesional hemisphere as compared to healthy controls (p < 0.05, FWE-corrected). Whereas lower FA values are suggestive of pronounced contralesional degeneration in the non-surgery group, higher FA values in the hemispherotomy group may be interpreted as a result of preceding plastic remodeling. We conclude that, whether juvenile brain lesions are associated with contralesional degeneration or reorganization partly depends on the ipsilesional hemisphere. Contralesional reorganization as observed in hemispherotomy patients was most likely enabled by the complete neurosurgical deafferentation of the ipsilesional hemisphere and, thereby, the disinhibition of the neuroplastic potential of the contralesional hemisphere. The main argument of this study is that hemispherotomy may be seen as a major plastic stimulus and as a prerequisite for contralesional neuroplastic remodeling in patients with juvenile brain lesions.
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Affiliation(s)
- Jennifer Gaubatz
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Conrad C Prillwitz
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Leon Ernst
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Bastian David
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Christian Hoppe
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Elke Hattingen
- Department of Neuroradiology, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - Bernd Weber
- Institute for Experimental Epileptology and Cognition Research, University of Bonn Medical Center, Bonn, Germany
| | - Hartmut Vatter
- Department of Neurosurgery, University of Bonn Medical Center, Bonn, Germany
| | - Rainer Surges
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Christian E Elger
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - Theodor Rüber
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany.,Epilepsy Center Frankfurt Rhine-Main, Department of Neurology, Goethe University Frankfurt, Frankfurt am Main, Germany.,Center for Personalized Translational Epilepsy Research (CePTER), Goethe University Frankfurt, Frankfurt am Main, Germany
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Quentin R, Awosika O, Cohen LG. Plasticity and recovery of function. HANDBOOK OF CLINICAL NEUROLOGY 2019; 163:473-483. [PMID: 31590747 DOI: 10.1016/b978-0-12-804281-6.00025-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
The frontal lobe plays a crucial role in human motor behavior. It is one of the last areas of the brain to mature, especially the prefrontal regions. After a brief historical perspective on the perceived dichotomy between the view of the brain as a static organ and that of a plastic, constantly changing structure, we discuss the stability/plasticity dilemma including examples of documented cortical reorganization taking place at multiple spatial and temporal scales. We pose that while plasticity is needed for motor learning, stability of the system is necessary for storage and maintenance of memorized skills. We discuss how this plasticity/stability dilemma is resolved along the life span and after a brain injury. We then examine the main challenges that clinicians have to overcome to promote recovery of function in patients with brain lesions, including attempts to use neurostimulation techniques as adjuvant to training-based customary neurorehabilitation.
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Affiliation(s)
- Romain Quentin
- Human Cortical Physiology and Neurorehabilitation Section, NINDS, Bethesda, MD, United States
| | - Oluwole Awosika
- Human Cortical Physiology and Neurorehabilitation Section, NINDS, Bethesda, MD, United States; University of Cincinnati, College of Medicine, Department of Neurology and Rehabilitation Medicine, Cincinnati, OH, United States
| | - Leonardo G Cohen
- Human Cortical Physiology and Neurorehabilitation Section, NINDS, Bethesda, MD, United States.
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Peng H, Cirstea CM, Kaufman CL, Frey SH. Microstructural integrity of corticospinal and medial lemniscus tracts: insights from diffusion tensor tractography of right-hand amputees. J Neurophysiol 2019; 122:316-324. [PMID: 31116678 DOI: 10.1152/jn.00316.2018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Reductions in sensory and motor activity following unilateral upper limb amputation during adulthood are associated with widespread, activity-dependent reorganization of the gray matter and white matter through the central nervous system. Likewise, in cases of congenital limb absence there is evidence that limited afferent or efferent activity affects the structural integrity of white matter pathways serving the affected side. Evidence that the structural integrity of mature sensory and motor tracts controlling the lost upper limb exhibits similar activity dependence is, however, sparse and inconsistent. Here we used diffusion tensor tractography to test whether amputation of the dominant right hand during adulthood (n = 16) alters the microstructural integrity of the major sensory (medial lemniscus, ML) and motor (corticospinal tract, CST) pathways controlling missing hand function. Consistent with prior findings, healthy control subjects (n = 27) exhibited higher fractional anisotropy (FA), an index of white matter microstructural integrity, within dominant left CST and nondominant right ML. Critically, in contrast to what might be expected if the microstructural organization of these tracts is activity dependent, these asymmetries persisted in amputees. Moreover, we failed to detect any differences in dominant left ML or CST between healthy control subjects and amputees. Our results are consistent with these white matter tracts being robust to changes in activity once mature or that continued use of the residual limb (in a compensatory fashion or with prosthesis) provides stimulation sufficient to maintain tract integrity. NEW & NOTEWORTHY We report that unilateral hand amputation in adults has no significant effects on the structure of major sensory or motor pathways contralateral to the amputation. Our results are consistent with the organization of these white matter tracts being robust to changes in activity once mature or that continued use of the residual limb (with or without a prosthesis) provides stimulation sufficient to maintain tract integrity.
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Affiliation(s)
- Huiling Peng
- Department of Psychology, Temple University , Philadelphia, Pennsylvania
| | - Carmen M Cirstea
- Department of Physical Medicine and Rehabilitation, University of Missouri , Columbia, Missouri
| | | | - Scott H Frey
- Department of Physical Medicine and Rehabilitation, University of Missouri , Columbia, Missouri.,Department of Psychological Sciences, University of Missouri , Columbia, Missouri
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10
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Burke MW, Ptito M. Introductory Chapter: Primates - What the Monkey Brain Tells the Human Brain. Primates 2018. [DOI: 10.5772/intechopen.76482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Wang AC, Ibrahim GM, Poliakov AV, Wang PI, Fallah A, Mathern GW, Buckley RT, Collins K, Weil AG, Shurtleff HA, Warner MH, Perez FA, Shaw DW, Wright JN, Saneto RP, Novotny EJ, Lee A, Browd SR, Ojemann JG. Corticospinal tract atrophy and motor fMRI predict motor preservation after functional cerebral hemispherectomy. J Neurosurg Pediatr 2018; 21:81-89. [PMID: 29099351 DOI: 10.3171/2017.7.peds17137] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECTIVE The potential loss of motor function after cerebral hemispherectomy is a common cause of anguish for patients, their families, and their physicians. The deficits these patients face are individually unique, but as a whole they provide a framework to understand the mechanisms underlying cortical reorganization of motor function. This study investigated whether preoperative functional MRI (fMRI) and diffusion tensor imaging (DTI) could predict the postoperative preservation of hand motor function. METHODS Thirteen independent reviewers analyzed sensorimotor fMRI and colored fractional anisotropy (CoFA)-DTI maps in 25 patients undergoing functional hemispherectomy for treatment of intractable seizures. Pre- and postoperative gross hand motor function were categorized and correlated with fMRI and DTI findings, specifically, abnormally located motor activation on fMRI and corticospinal tract atrophy on DTI. RESULTS Normal sensorimotor cortical activation on preoperative fMRI was significantly associated with severe decline in postoperative motor function, demonstrating 92.9% sensitivity (95% CI 0.661-0.998) and 100% specificity (95% CI 0.715-1.00). Bilaterally robust, symmetric corticospinal tracts on CoFA-DTI maps were significantly associated with severe postoperative motor decline, demonstrating 85.7% sensitivity (95% CI 0.572-0.982) and 100% specificity (95% CI 0.715-1.00). Interpreting the fMR images, the reviewers achieved a Fleiss' kappa coefficient (κ) for interrater agreement of κ = 0.69, indicating good agreement (p < 0.01). When interpreting the CoFA-DTI maps, the reviewers achieved κ = 0.64, again indicating good agreement (p < 0.01). CONCLUSIONS Functional hemispherectomy offers a high potential for seizure freedom without debilitating functional deficits in certain instances. Patients likely to retain preoperative motor function can be identified prior to hemispherectomy, where fMRI or DTI suggests that cortical reorganization of motor function has occurred prior to the operation.
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Affiliation(s)
| | - George M Ibrahim
- 3Division of Neurosurgery, Hospital for Sick Children and Toronto Western Hospital, Toronto, Ontario, Canada; Departments of
| | | | | | | | - Gary W Mathern
- Departments of1Neurosurgery and.,2Psychiatry and BioBehavioral Sciences, The Brain Research Institute, University of California, Los Angeles, California
| | | | | | - Alexander G Weil
- 7Division of Pediatric Neurosurgery, Department of Surgery, Sainte Justine Hospital, University of Montreal, Quebec, Canada
| | | | | | - Francisco A Perez
- 6Radiology, University of Washington, Seattle Children's Hospital, Seattle, Washington; and
| | - Dennis W Shaw
- 6Radiology, University of Washington, Seattle Children's Hospital, Seattle, Washington; and
| | - Jason N Wright
- 6Radiology, University of Washington, Seattle Children's Hospital, Seattle, Washington; and
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Sebastianelli L, Versace V, Taylor A, Brigo F, Nothdurfter W, Saltuari L, Trinka E, Nardone R. Functional reorganization after hemispherectomy in humans and animal models: What can we learn about the brain's resilience to extensive unilateral lesions? Brain Res Bull 2017; 131:156-167. [PMID: 28414105 DOI: 10.1016/j.brainresbull.2017.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Revised: 04/05/2017] [Accepted: 04/11/2017] [Indexed: 01/18/2023]
Abstract
Hemispherectomy (HS) is an effective surgical procedure aimed at managing otherwise intractable epilepsy in cases of diffuse unihemispheric pathologies. Neurological recovery in subjects treated with HS is not limited to seizure reduction, rather, sensory-motor and behavioral improvement is often observed. This outcome highlights the considerable capability of the brain to react to such an extensive lesion, by functionally reorganizing and rewiring the cerebral cortex, especially early in life. In this narrative review, we summarize the animal studies as well as the human neurophysiological and neuroimaging studies dealing with the reorganizational processes that occur after HS. These topics are of particular interest in understanding mechanisms of functional recovery after brain injury. HS offers the chance to investigate contralesional hemisphere activity in controlling ipsilateral limb movements, and the role of transcallosal interactions, before and after the surgical procedure. These post-injury neuroplastic phenomena actually differ from those observed after less extensive brain damage. Therefore, they illustrate how different lesions could lead the contralesional hemisphere to play the "good" or "bad" role in functional recovery. These issues may have clinical implications and could inform rehabilitation strategies aiming to improve functional recovery following unilateral hemispheric lesions. Future studies, involving large cohorts of hemispherectomized patients, will be necessary in order to obtain a greater understanding of how cerebral reorganization can contribute to residual sensorimotor, visual and auditory functions.
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Affiliation(s)
- Luca Sebastianelli
- Department of Neurorehabilitation, Hospital of Vipiteno, Italy, and Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy
| | - Viviana Versace
- Department of Neurorehabilitation, Hospital of Vipiteno, Italy, and Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy
| | - Alexandra Taylor
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria
| | - Francesco Brigo
- Department of Neurology, Franz Tappeiner Hospital, Merano, Italy; Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Wolfgang Nothdurfter
- Department of Neurorehabilitation, Hospital of Vipiteno, Italy, and Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy
| | - Leopold Saltuari
- Department of Neurorehabilitation, Hospital of Vipiteno, Italy, and Research Unit for Neurorehabilitation of South Tyrol, Bolzano, Italy
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Centre of Cognitive Neuroscience, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria
| | - Raffaele Nardone
- Department of Neurology, Christian Doppler Klinik, Paracelsus Medical University, Salzburg, Austria; Department of Neurology, Franz Tappeiner Hospital, Merano, Italy.
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Meoded A, Faria AV, Hartman AL, Jallo GI, Mori S, Johnston MV, Huisman TAGM, Poretti A. Cerebral Reorganization after Hemispherectomy: A DTI Study. AJNR Am J Neuroradiol 2016; 37:924-31. [PMID: 26767710 DOI: 10.3174/ajnr.a4647] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Accepted: 11/03/2015] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Hemispherectomy is a neurosurgical procedure to treat children with intractable seizures. Postsurgical improvement of cognitive and behavioral functions is observed in children after hemispherectomy suggesting plastic reorganization of the brain. Our aim was to characterize changes in DTI scalars in WM tracts of the remaining hemisphere in children after hemispherectomy, assess the associations between WM DTI scalars and age at the operation and time since the operation, and evaluate the changes in GM fractional anisotropy values in patients compared with controls. MATERIALS AND METHODS Patients with congenital or acquired neurologic diseases who required hemispherectomy and had high-quality postsurgical DTI data available were included in this study. Atlas- and voxel-based analyses of DTI raw data of the remaining hemisphere were performed. Fractional anisotropy and mean, axial, and radial diffusivity values were calculated for WM and GM regions. A linear regression model was used for correlation between DTI scalars and age at and time since the operation. RESULTS Nineteen patients after hemispherectomy and 21 controls were included. In patients, a decrease in fractional anisotropy and axial diffusivity values and an increase in mean diffusivity and radial diffusivity values of WM regions were observed compared with controls (P < .05, corrected for multiple comparisons). In patients with acquired pathologies, time since the operation had a significant positive correlation with white matter fractional anisotropy values. In all patients, an increase in cortical GM fractional anisotropy values was found compared with controls (P < .05). CONCLUSIONS Changes in DTI metrics likely reflect Wallerian and/or transneuronal degeneration of the WM tracts within the remaining hemisphere. In patients with acquired pathologies, postsurgical fractional anisotropy values correlated positively with elapsed time since the operation, suggesting a higher ability to recover compared with patients with congenital pathologies leading to hemispherectomy.
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Affiliation(s)
- A Meoded
- From the Section of Pediatric Neuroradiology (A.M., T.A.G.M.H., A.P.)
| | - A V Faria
- Division of Pediatric Radiology, Russell H. Morgan Department of Radiology and Radiological Sciences (A.V.F., S.M.)
| | | | - G I Jallo
- Neurosurgery (G.I.J.), The Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - S Mori
- Division of Pediatric Radiology, Russell H. Morgan Department of Radiology and Radiological Sciences (A.V.F., S.M.) F.M. Kirby Research Center for Functional Brain Imaging (S.M.)
| | - M V Johnston
- Departments of Neurology (A.L.H., M.V.J.) Kennedy Krieger Institute (M.V.J.), Baltimore, Maryland
| | - T A G M Huisman
- From the Section of Pediatric Neuroradiology (A.M., T.A.G.M.H., A.P.)
| | - A Poretti
- From the Section of Pediatric Neuroradiology (A.M., T.A.G.M.H., A.P.)
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Nelles M, Urbach H, Sassen R, Schöne-Bake JC, Tschampa H, Träber F, Delev D, Elger CE, Jurcoane A, Hattingen E. Functional hemispherectomy: postoperative motor state and correlation to preoperative DTI. Neuroradiology 2015; 57:1093-102. [PMID: 26263839 DOI: 10.1007/s00234-015-1564-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/12/2015] [Indexed: 10/23/2022]
Abstract
INTRODUCTION Functional hemispherectomy (FH) is an infrequent method to reduce seizure frequency in patients with intractable epilepsy. The risk that hemispherotomy injures brain structures involved in residual motor function is challenging to predict. Our purpose was to evaluate MR diffusion tensor imaging (DTI) to preoperatively assess residual ipsilateral motor function prior to FH. METHODS We applied DTI in 34 patients scheduled for FH to perform fiber tracking in healthy and damaged hemispheres of the corticospinal tracts (CSTs) and of the corpus callosum. We assessed the CSTs and the commissural fibers for streamline count, for fractional anisotropy (FA), and for respective ratios (affected/unaffected side). We correlated these DTI values to post-to-prior changes of muscle strength and evaluated their diagnostic accuracy. RESULTS FA of the affected CSTs and of commissural fibers was significantly higher in patients with postoperative loss of muscle strength compared to patients without (p = 0.014 and p = 0.008). In contrast, CST FA from healthy hemispheres was not different between both groups. Ratios of streamline counts and FA from CSTs were higher in patients with postoperative reduced muscle strength compared to those without (1.14 ± 0.22 vs. 0.58 ± 0.14, p = 0.040; 0.93 ± 0.05 vs. 0.74 ± 0.03, p = 0.003). CSTs' normalized FA ratio greater than -0.085 predicted loss of muscle strength with 80 % sensitivity and 69.6 % specificity. CONCLUSION Preoperative tracking of the CST and of commissural fibers contributes to the prediction of postoperative motor outcome after functional hemispherectomy.
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Affiliation(s)
- M Nelles
- Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, D - 53105, Bonn, Germany.
| | - H Urbach
- Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, D - 53105, Bonn, Germany
| | - R Sassen
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - J C Schöne-Bake
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - H Tschampa
- Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, D - 53105, Bonn, Germany
| | - F Träber
- Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, D - 53105, Bonn, Germany
| | - D Delev
- Department of Neurosurgery, University of Bonn Medical Center, Bonn, Germany
| | - C E Elger
- Department of Epileptology, University of Bonn Medical Center, Bonn, Germany
| | - A Jurcoane
- Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, D - 53105, Bonn, Germany
| | - E Hattingen
- Department of Radiology, University of Bonn Medical Center, Sigmund Freud Str. 25, D - 53105, Bonn, Germany
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Altered contralateral sensorimotor system organization after experimental hemispherectomy: a structural and functional connectivity study. J Cereb Blood Flow Metab 2015; 35:1358-67. [PMID: 25966942 PMCID: PMC4527994 DOI: 10.1038/jcbfm.2015.101] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 04/10/2015] [Indexed: 12/18/2022]
Abstract
Hemispherectomy is often followed by remarkable recovery of cognitive and motor functions. This reflects plastic capacities of the remaining hemisphere, involving large-scale structural and functional adaptations. Better understanding of these adaptations may (1) provide new insights in the neuronal configuration and rewiring that underlies sensorimotor outcome restoration, and (2) guide development of rehabilitation strategies to enhance recovery after hemispheric lesioning. We assessed brain structure and function in a hemispherectomy model. With MRI we mapped changes in white matter structural integrity and gray matter functional connectivity in eight hemispherectomized rats, compared with 12 controls. Behavioral testing involved sensorimotor performance scoring. Diffusion tensor imaging and resting-state functional magnetic resonance imaging were acquired 7 and 49 days post surgery. Hemispherectomy caused significant sensorimotor deficits that largely recovered within 2 weeks. During the recovery period, fractional anisotropy was maintained and white matter volume and axial diffusivity increased in the contralateral cerebral peduncle, suggestive of preserved or improved white matter integrity despite overall reduced white matter volume. This was accompanied by functional adaptations in the contralateral sensorimotor network. The observed white matter modifications and reorganization of functional network regions may provide handles for rehabilitation strategies improving functional recovery following large lesions.
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Clowry GJ, Basuodan R, Chan F. What are the Best Animal Models for Testing Early Intervention in Cerebral Palsy? Front Neurol 2014; 5:258. [PMID: 25538677 PMCID: PMC4255621 DOI: 10.3389/fneur.2014.00258] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 11/21/2014] [Indexed: 11/13/2022] Open
Abstract
Interventions to treat cerebral palsy should be initiated as soon as possible in order to restore the nervous system to the correct developmental trajectory. One drawback to this approach is that interventions have to undergo exceptionally rigorous assessment for both safety and efficacy prior to use in infants. Part of this process should involve research using animals but how good are our animal models? Part of the problem is that cerebral palsy is an umbrella term that covers a number of conditions. There are also many causal pathways to cerebral palsy, such as periventricular white matter injury in premature babies, perinatal infarcts of the middle cerebral artery, or generalized anoxia at the time of birth, indeed multiple causes, including intra-uterine infection or a genetic predisposition to infarction, may need to interact to produce a clinically significant injury. In this review, we consider which animal models best reproduce certain aspects of the condition, and the extent to which the multifactorial nature of cerebral palsy has been modeled. The degree to which the corticospinal system of various animal models human corticospinal system function and development is also explored. Where attempts have already been made to test early intervention in animal models, the outcomes are evaluated in light of the suitability of the model.
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Affiliation(s)
- Gavin John Clowry
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , UK
| | - Reem Basuodan
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , UK
| | - Felix Chan
- Institute of Neuroscience, Newcastle University , Newcastle upon Tyne , UK
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17
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Umeda T, Funakoshi K. Reorganization of motor circuits after neonatal hemidecortication. Neurosci Res 2014; 78:30-7. [DOI: 10.1016/j.neures.2013.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/21/2013] [Accepted: 08/23/2013] [Indexed: 11/15/2022]
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18
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Ipsilateral and contralateral auditory brainstem response reorganization in hemispherectomized patients. Neural Plast 2013; 2013:832473. [PMID: 24455311 PMCID: PMC3884784 DOI: 10.1155/2013/832473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/06/2013] [Accepted: 11/20/2013] [Indexed: 11/20/2022] Open
Abstract
Background. Cortical hemispherectomy leads to degeneration of ipsilateral subcortical structures, which can be observed long term after the operation. Therefore, reorganization of the brainstem auditory pathway might occur. The aim of this study was to assess reorganization of brainstem auditory pathways by measuring the auditory brainstem response (ABR) in long-term hemispherectomized patients. Methods. We performed bilateral monaural stimulation and measured bilateral ABR in 8 patients ~20 years after hemispherectomy and 10 control subjects. Magnetic resonance imaging (MRI) was performed in patients to assess structural degeneration. Results. All patients showed degenerated ipsilateral brainstem structures by MRI but no significant differences in bilateral recording ABR wave latencies. However, nonsurgical-side stimulation elicited significantly longer wave V latencies compared to surgical-side stimulation. Differences in bilateral ABR were observed between hemispherectomized patients and control subjects. Waves III and V latencies elicited by nonsurgical-side stimulation were significantly longer than those in control subjects; surgical-side stimulation showed no significant differences. Conclusions. (1) Differences in ABR latency elicited by unilateral stimulation are predominantly due to bilateral brainstem auditory pathway activity rather than to changes in brainstem volume; (2) ABR Waves III and V originate predominantly in the contralateral brainstem; and (3) subcortical auditory pathways appear to reorganize after long term hemispherectomy.
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19
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Lindau NT, Bänninger BJ, Gullo M, Good NA, Bachmann LC, Starkey ML, Schwab ME. Rewiring of the corticospinal tract in the adult rat after unilateral stroke and anti-Nogo-A therapy. Brain 2013; 137:739-56. [DOI: 10.1093/brain/awt336] [Citation(s) in RCA: 123] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
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20
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Hamad AP, Caboclo LO, Centeno R, Costa LV, Ladeia-Frota C, Carrete H, Gomez NG, Marinho M, Yacubian EMT, Sakamoto AC. Hemispheric surgery for refractory epilepsy in children and adolescents: Outcome regarding seizures, motor skills and adaptive function. Seizure 2013; 22:752-6. [DOI: 10.1016/j.seizure.2013.06.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 05/31/2013] [Accepted: 06/03/2013] [Indexed: 11/26/2022] Open
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Cortex mapping of ipsilateral somatosensory area following anatomical hemispherectomy: a MEG study. Brain Dev 2013; 35:331-9. [PMID: 22770545 DOI: 10.1016/j.braindev.2012.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 05/08/2012] [Accepted: 06/13/2012] [Indexed: 11/23/2022]
Abstract
A remarkable preservation of sensorimotor function is observed in patients with refractory epilepsy who were treated by hemispherectomy. Cortical regions in the remaining hemisphere or contralateral subcortical region contribute to the residual sensorimotor function. Somatosensory evoked field (SEF) is used to investigate the residual sensory function in hemispherectomized patients. The SEFs are usually recorded with magnetoencephalography (MEG). The objective is to investigate the ipsilateral cortical regions associated with residual sensory function in hemispherectomized patients using somatosensory evoked field techniques. Six patients with anatomical hemispherectomy were included. Ipsilateral and contralateral sensory functions were assessed by physical examination. Somatosensory evoked fields to electrical stimulation of the bilateral median nerves were recorded by MEG in the hemispherectomized patients and six control subjects. The stimulus intensity was adjusted to the minimum threshold that elicited a thumb twitch. The presumed neuronal source was identified as the equivalent current dipole. Six patients demonstrated different degrees of residual sensory function. Three patients had somatosensory evoked field activation in the ipsilateral cortex upon electrical stimulation of the hemiplegic hand. In these patients the locations of the ipsilateral sensorimotor cortex activation were in the primary somatosensory cortex (SI). The latency of the reliable somatosensory evoked field after stimulation of the median nerve was significantly longer for responses from the hemiplegic side compared with responses to stimulation of the median nerve from the normal side. In conclusion, ipsilateral sensory function has a time-locked relation to the cortical electromagnetic activation in the SI area of hemispherectomized patients.
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Zhang J, Mei S, Liu Q, Liu W, Chen H, Xia H, Zhou Z, Wang L, Li Y. fMRI and DTI assessment of patients undergoing radical epilepsy surgery. Epilepsy Res 2013; 104:253-63. [PMID: 23340329 DOI: 10.1016/j.eplepsyres.2012.10.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 10/19/2012] [Accepted: 10/30/2012] [Indexed: 10/27/2022]
Abstract
Hemispherectomy is effective for young patients suffered from unilateral cortical disease and severe drug-resistant epilepsy, but a major concern for hemispherectomy is the remaining brain functions and function recovery in patients after such surgery. In this study, seven patients were evaluated with clinical and imaging assessment pre- and post-surgery. Among them, four underwent anatomic hemispherectomy (AH) and three underwent subtotal hemispherectomy (functional hemispherectomy, FH). After the surgery, 71.4% (5/7) patients [(4/4) with AH and (1/3) with FH] became seizure free (Engel class I). Motor function of the paretic upper extremity unchanged in 4 patients and deteriorated in 3. Functional imaging results indicated that relocation of hand motor function (to the ipsilateral hemisphere) could take place before or after the surgery, or did not occur. Similar observations were made in the motor cortex activation on the paretic foot movement. In addition, both the affected and unaffected hemispheres underwent post-surgical changes in the corticospinal tracks (CST) in various degrees, but significant reinforcement of the CST in the remaining unaffected hemisphere was not evident. Further research is needed to reveal the true functional and structural changes of the remaining brain after surgery and to explore the mechanisms of such functional relocation and reorganization in patients underwent hemispherectomy.
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Affiliation(s)
- Jing Zhang
- School of Biomedical Engineering, Capital Medical University, Beijing 100069, PR China.
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23
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DE BODE S, FRITZ S, MATHERN GW. Cerebral hemispherectomy: sensory scores before and after intensive mobility training. Brain Dev 2012; 34:625-31. [PMID: 22137579 PMCID: PMC3413311 DOI: 10.1016/j.braindev.2011.10.012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 10/26/2011] [Accepted: 10/28/2011] [Indexed: 10/14/2022]
Abstract
PURPOSE It is unclear whether sensory modalities can be modified by rehabilitation and if sensory functions vary on the affected side many years after cerebral hemispherectomy. This pilot, proof-of-concept study assessed light touch and proprioception before and after 10 days of intensive mobility training in individuals after hemispherectomy. METHODS Light touch and proprioception of the upper and lower extremity was measured using the Fugl-Meyer sensory subtest on the paretic side in 18 individuals with hemispherectomy before and after mobility training. Sensory scores and differences related to mobility training were compared with clinical variables. RESULTS Patients were 7.1±5.7 years from time of surgery to sensory assessment and mobility training. Light touch scores were 81±22% and proprioception values were 64±23% of normal (p=0.0022). Light touch did not correlate with proprioception scores, and differences comparing after with before mobility training did not correlate. In multivariate analysis, younger age at seizure onset correlated with better light touch scores, and older age at onset correlated with improvements in light touch scores with mobility training. By comparison, proprioception scores were better in individuals with perinatal infarcts compared with Rasmussen encephalitis and Sturge-Weber. Post-training, proprioception scores were better in Sturge-Weber cases. CONCLUSION Light touch was less affected than proprioception on the paretic side after cerebral hemispherectomy. Improvements with mobility training correlated with older age at seizure onset and etiology. These findings suggest that many years after epilepsy surgery sensory functions are not static supporting the notion of existing developmental neuroplasticity of the remaining cerebral cortex along with brain stem and spinal cord pathways.
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Affiliation(s)
- Stella DE BODE
- University Medical Center Utrecht, Section Brain Function and Plasticity, The Netherlands
| | - Stacy FRITZ
- Department of Exercise Science, Physical Therapy Program, The Blanchard Machinery Company Rehabilitation Laboratory; Arnold School of Public Health, University of South Carolina, Columbia, SC, USA
| | - Gary W MATHERN
- Departments of Neurosurgery and Psychiatry & Biobehavioral Sciences, The Intellectual and Developmental Disabilities Research Center, and The Brain Research Institute; Mattel Children’s Hospital and David Geffen School of Medicine; University of California, Los Angeles, CA, USA
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Adaptive neuroplastic responses in early and late hemispherectomized monkeys. Neural Plast 2012; 2012:852423. [PMID: 22792495 PMCID: PMC3391903 DOI: 10.1155/2012/852423] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/29/2012] [Accepted: 04/12/2012] [Indexed: 11/18/2022] Open
Abstract
Behavioural recovery in children who undergo medically required hemispherectomy showcase the remarkable ability of the cerebral cortex to adapt and reorganize following insult early in life. Case study data suggest that lesions sustained early in childhood lead to better recovery compared to those that occur later in life. In these children, it is possible that neural reorganization had begun prior to surgery but was masked by the dysfunctional hemisphere. The degree of neural reorganization has been difficult to study systematically in human infants. Here we present a 20-year culmination of data on our nonhuman primate model (Chlorocebus sabeus) of early-life hemispherectomy in which behavioral recovery is interpreted in light of plastic processes that lead to the anatomical reorganization of the early-damaged brain. The model presented here suggests that significant functional recovery occurs after the removal of one hemisphere in monkeys with no preexisting neurological dysfunctions. Human and primate studies suggest a critical role for subcortical and brainstem structures as well as corticospinal tracts in the neuroanatomical reorganization which result in the remarkable behavioral recovery following hemispherectomy. The non-human primate model presented here offers a unique opportunity for studying the behavioral and functional neuroanatomical reorganization that underlies developmental plasticity.
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Chokshi FH, Poretti A, Meoded A, Huisman TAGM. Normal and abnormal development of the cerebellum and brainstem as depicted by diffusion tensor imaging. Semin Ultrasound CT MR 2012; 32:539-54. [PMID: 22108217 DOI: 10.1053/j.sult.2011.06.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Diffusion tensor imaging (DTI) is an advanced MRI technique that measures the microscopic molecular motion of water to gain information about the brain structure. This modality and its application to fiber tractography have been increasingly used in the last years to study the neuroanatomical background of brain malformations. This article aims to give an overview of the application of DTI and fiber tractography on pediatric posterior fossa including malformations, acquired disorders affecting the white matter, and posterior fossa involvement in phacomatoses. For every disorder, we show the additional information that DTI and fiber tractography are providing compared to conventional MR sequences and discuss their significance. Additionally, we show at the beginning normal DTI and fiber tractography findings of the pediatric posterior fossa. Finally, we briefly discuss potential future uses for DTI and fiber tractography to further understand the pathogenesis of posterior fossa malformations and the neuronal plasticity and connectivity of acquired lesions affecting the posterior fossa.
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Affiliation(s)
- Falgun H Chokshi
- Division of Neuroradiology, The Russell H. Morgan Department of Radiology and Radiological Science, The Johns Hopkins School of Medicine, Baltimore, MD, USA
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Starkey ML, Schwab ME. Anti-Nogo-A and training: can one plus one equal three? Exp Neurol 2011; 235:53-61. [PMID: 21530508 DOI: 10.1016/j.expneurol.2011.04.008] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 03/15/2011] [Accepted: 04/07/2011] [Indexed: 12/14/2022]
Abstract
Following spinal cord injury (SCI) the adult central nervous system (CNS) has a limited but substantial capacity for repair and plastic reorganisation. The degree of reorganisation is determined by a number of factors such as the extent and location of the lesion, the remaining circuit activity within the CNS and the age at injury. However, even in the best cases this spontaneous reorganisation does not lead to full recovery of the affected behaviour but instead often results in a functionally successful but compensatory strategy. Current SCI research focuses on enhancing fibre tract (re-)growth and recovery processes. Two currently promising approaches are the neutralisation of CNS growth inhibitory factors, and rehabilitative training of remaining networks. Independently, both approaches can lead to substantial functional recovery and anatomical reorganisation. In this review we focus on Nogo-A, a neurite growth inhibitory protein present in the adult CNS, and its role in regenerative and plastic growth following SCI. We then discuss the efforts of rehabilitative training and the potential combination of the two therapies.
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Affiliation(s)
- Michelle L Starkey
- Brain Research Institute, University of Zurich, Winterthurerstrasse 190, CH-8057, Zurich, Switzerland.
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