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Huang Y, Sadeghzadeh S, Li AHY, Schonfeld E, Ramayya AG, Buch VP. Rates and Predictors of Pain Reduction With Intracranial Stimulation for Intractable Pain Disorders. Neurosurgery 2024:00006123-990000000-01186. [PMID: 38836613 DOI: 10.1227/neu.0000000000003006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2023] [Accepted: 04/01/2024] [Indexed: 06/06/2024] Open
Abstract
BACKGROUND AND OBJECTIVES Intracranial modulation paradigms, namely deep brain stimulation (DBS) and motor cortex stimulation (MCS), have been used to treat intractable pain disorders. However, treatment efficacy remains heterogeneous, and factors associated with pain reduction are not completely understood. METHODS We performed an individual patient review of pain outcomes (visual analog scale, quality-of-life measures, complications, pulse generator implant rate, cessation of stimulation) after implantation of DBS or MCS devices. We evaluated 663 patients from 36 study groups and stratified outcomes by pain etiology and implantation targets. RESULTS Included studies comprised primarily retrospective cohort studies. MCS patients had a similar externalized trial success rate compared with DBS patients (86% vs 81%; P = .16), whereas patients with peripheral pain had a higher trial success rate compared with patients with central pain (88% vs 79%; P = .004). Complication rates were similar for MCS and DBS patients (12% vs 15%; P = .79). Patients with peripheral pain had lower likelihood of device cessation compared with those with central pain (5.7% vs 10%; P = .03). Of all implanted patients, mean pain reduction at last follow-up was 45.8% (95% CI: 40.3-51.2) with a 31.2% (95% CI: 12.4-50.1) improvement in quality of life. No difference was seen between MCS patients (43.8%; 95% CI: 36.7-58.2) and DBS patients (48.6%; 95% CI: 39.2-58) or central (41.5%; 95% CI: 34.8-48.2) and peripheral (46.7%; 95% CI: 38.9-54.5) etiologies. Multivariate analysis identified the anterior cingulate cortex target to be associated with worse pain reduction, while postherpetic neuralgia was a positive prognostic factor. CONCLUSION Both DBS and MCS have similar efficacy and complication rates in the treatment of intractable pain. Patients with central pain disorders tended to have lower trial success and higher rates of device cessation. Additional prognostic factors include anterior cingulate cortex targeting and postherpetic neuralgia diagnosis. These findings underscore intracranial neurostimulation as an important modality for treatment of intractable pain disorders.
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Affiliation(s)
- Yuhao Huang
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Sina Sadeghzadeh
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Alice Huai-Yu Li
- Department of Anesthesia, Stanford University School of Medicine, Palo Alto, California, USA
| | - Ethan Schonfeld
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Ashwin G Ramayya
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
| | - Vivek P Buch
- Department of Neurosurgery, Stanford University School of Medicine, Palo Alto, California, USA
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2
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Castillo Rangel C, Marin G, Diaz Chiguer DL, Villegas López FA, Ramírez-Rodríguez R, Gómez Ibarra A, Aguilar-Velazquez R, Soto Abraham JE. Radiofrequency Cingulotomy as a Treatment for Incoercible Pain: Follow-Up for 6 Months. Healthcare (Basel) 2023; 11:2607. [PMID: 37830644 PMCID: PMC10573053 DOI: 10.3390/healthcare11192607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/18/2023] [Accepted: 09/19/2023] [Indexed: 10/14/2023] Open
Abstract
Incoercible or intractable pain is defined as pain that is refractory to pharmacological treatment to such an extent that opioid and analgesic adverse effects outweigh the therapeutic effects. The anterior cingulate cortex (ACC) is involved in the perception of pain, especially emotional pain, so it is logical that cingulotomy has an effective therapeutic effect. Therefore, we evaluated the effectiveness of cingulotomy for the treatment of incoercible pain. An observational, longitudinal, retrospective, and analytical study was carried out on a series of cases in which bilateral cingulotomy was performed for incoercible pain, and follow-up was performed 6 months after neurosurgery in the outpatient clinic at the Neurotraumatology Clinic. A positive correlation was observed between pain intensity and medication use, indicating that an increase in pain was associated with a greater requirement for analgesics. The result was a significant reduction in pain, as measured by the visual analog scale of pain, and decreased drug use after cingulotomy. We concluded that cingulotomy reduces incoercible pain and the need for medication.
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Affiliation(s)
- Carlos Castillo Rangel
- Department of Neurosurgery, “Hospital Regional 1° de Octubre”, Institute of Social Security and Services for State Workers (ISSSTE), Mexico City 07300, Mexico;
| | - Gerardo Marin
- Neural Dynamics and Modulation Lab, Cleveland Clinic, Cleveland, OH 44195, USA; (D.L.D.C.); (A.G.I.)
| | - Dylan Lucia Diaz Chiguer
- Neural Dynamics and Modulation Lab, Cleveland Clinic, Cleveland, OH 44195, USA; (D.L.D.C.); (A.G.I.)
| | | | | | - Alejandro Gómez Ibarra
- Neural Dynamics and Modulation Lab, Cleveland Clinic, Cleveland, OH 44195, USA; (D.L.D.C.); (A.G.I.)
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3
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Kim NY, Taylor JJ, Kim YW, Borsook D, Joutsa J, Li J, Quesada C, Peyron R, Fox MD. Network Effects of Brain Lesions Causing Central Poststroke Pain. Ann Neurol 2022; 92:834-845. [PMID: 36271755 DOI: 10.1002/ana.26468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/31/2022] [Accepted: 08/01/2022] [Indexed: 01/07/2023]
Abstract
OBJECTIVE This study was undertaken to test whether lesions causing central poststroke pain (CPSP) are associated with a specific connectivity profile, whether these connections are associated with metabolic changes, and whether this network aligns with neuromodulation targets for pain. METHODS Two independent lesion datasets were utilized: (1) subcortical lesions from published case reports and (2) thalamic lesions with metabolic imaging using 18F- fluorodeoxyglucose positron emission tomography-computed tomography. Functional connectivity between each lesion location and the rest of the brain was assessed using a normative connectome (n = 1,000), and connections specific to CPSP were identified. Metabolic changes specific to CPSP were also identified and related to differences in lesion connectivity. Therapeutic relevance of the network was explored by testing for alignment with existing brain stimulation data and by prospectively targeting the network with repetitive transcranial magnetic stimulation (rTMS) in 7 patients with CPSP. RESULTS Lesion locations causing CPSP showed a specific pattern of brain connectivity that was consistent across two independent lesion datasets (spatial r = 0.82, p < 0.0001). Connectivity differences were correlated with postlesion metabolism (r = -0.48, p < 0.001). The topography of this lesion-based pain network aligned with variability in pain improvement across 12 prior neuromodulation targets and across 32 patients who received rTMS to primary motor cortex (p < 0.05). Prospectively targeting this network with rTMS improved CPSP in 6 of 7 patients. INTERPRETATION Lesions causing pain are connected to a specific brain network that shows metabolic abnormalities and promise as a neuromodulation target. ANN NEUROL 2022;92:834-845.
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Affiliation(s)
- Na Young Kim
- Department and Research, Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.,Department of Rehabilitation Medicine, Yongin Severance Hospital, Yongin, Republic of Korea.,Center for Digital Heath, Yongin Severance Hospital, Yongin, Republic of Korea
| | - Joseph J Taylor
- Center for Brain Circuit Therapeutics, Departments of Neurology, Psychiatry, Radiology, and Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA.,Department of Psychiatry, Brigham and Women's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Yong Wook Kim
- Department and Research, Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - David Borsook
- Harvard Medical School, Boston, MA, USA.,Departments of Psychiatry and Radiology, Massachusetts General Hospital, Boston, MA, USA
| | - Juho Joutsa
- Turku Brain and Mind Center, Clinical Neurosciences, University of Turku, Turku, Finland.,Turku PET Center, Neurocenter, Turku University Hospital, Turku, Finland
| | - Jing Li
- Harvard Medical School, Boston, MA, USA.,Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
| | - Charles Quesada
- Central Integration of Pain (NeuroPain) Laboratory-Lyon Neurosciences Research Center, National Institute of Health and Medical Research U1028, Lyon, France.,Stephanois Pain Center, Saint-Etienne Regional University Hospital Center, Saint-Etienne, France.,Department of Physical Therapy, Claude Bernard Lyon-1 University, Lyon, France
| | - Roland Peyron
- Central Integration of Pain (NeuroPain) Laboratory-Lyon Neurosciences Research Center, National Institute of Health and Medical Research U1028, Lyon, France.,Department of Physical Therapy, Claude Bernard Lyon-1 University, Lyon, France.,Neurology Department, Saint-Etienne Regional University Hospital Center, Saint-Etienne, France
| | - Michael D Fox
- Center for Brain Circuit Therapeutics, Departments of Neurology, Psychiatry, Radiology, and Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA.,Department of Psychiatry, Brigham and Women's Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Neurology, Brigham and Women's Hospital, Boston, MA, USA
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4
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Deep Brain Stimulation, Stereotactic Radiosurgery and High-Intensity Focused Ultrasound Targeting the Limbic Pain Matrix: A Comprehensive Review. Pain Ther 2022; 11:459-476. [PMID: 35471626 PMCID: PMC9098763 DOI: 10.1007/s40122-022-00381-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 03/24/2022] [Indexed: 11/04/2022] Open
Abstract
Chronic pain (CP) represents a socio-economic burden for affected patients along with therapeutic challenges for currently available therapies. When conventional therapies fail, modulation of the affective pain matrix using reversible deep brain stimulation (DBS) or targeted irreversible thalamotomy by stereotactic radiosurgery (SRS) and magnetic resonance (MR)-guided focused ultrasound (MRgFUS) appear to be considerable treatment options. We performed a literature search for clinical trials targeting the affective pain circuits (thalamus, anterior cingulate cortex [ACC], ventral striatum [VS]/internal capsule [IC]). PubMed, Ovid, MEDLINE and Scopus were searched (1990–2021) using the terms “chronic pain”, “deep brain stimulation”, “stereotactic radiosurgery”, “radioneuromodulation”, “MR-guided focused ultrasound”, “affective pain modulation”, “pain attention”. In patients with CP treated with DBS, SRS or MRgFUS the somatosensory thalamus and periventricular/periaquaeductal grey was the target of choice in most treated subjects, while affective pain transmission was targeted in a considerably lower number (DBS, SRS) consisting of the following nodi of the limbic pain matrix: the anterior cingulate cortex; centromedian-parafascicularis of the thalamus, pars posterior of the central lateral nucleus and internal capsule/ventral striatum. Although DBS, SRS and MRgFUS promoted a meaningful and sustained pain relief, an effective, evidence-based comparative analysis is biased by heterogeneity of the observation period varying between 3 months and 5 years with different stimulation patterns (monopolar/bipolar contact configuration; frequency 10–130 Hz; intensity 0.8–5 V; amplitude 90–330 μs), source and occurrence of lesioning (radiation versus ultrasound) and chronic pain ethology (poststroke pain, plexus injury, facial pain, phantom limb pain, back pain). The advancement of neurotherapeutics (MRgFUS) and novel DBS targets (ACC, IC/VS), along with established and effective stereotactic therapies (DBS–SRS), increases therapeutic options to impact CP by modulating affective, pain-attentional neural transmission. Differences in trial concept, outcome measures, targets and applied technique promote conflicting findings and limited evidence. Hence, we advocate to raise awareness of the potential therapeutic usefulness of each approach covering their advantages and disadvantages, including such parameters as invasiveness, risk–benefit ratio, reversibility and responsiveness.
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Wu C, Ferreira F, Fox M, Harel N, Hattangadi-Gluth J, Horn A, Jbabdi S, Kahan J, Oswal A, Sheth SA, Tie Y, Vakharia V, Zrinzo L, Akram H. Clinical applications of magnetic resonance imaging based functional and structural connectivity. Neuroimage 2021; 244:118649. [PMID: 34648960 DOI: 10.1016/j.neuroimage.2021.118649] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2021] [Revised: 09/24/2021] [Accepted: 10/10/2021] [Indexed: 12/23/2022] Open
Abstract
Advances in computational neuroimaging techniques have expanded the armamentarium of imaging tools available for clinical applications in clinical neuroscience. Non-invasive, in vivo brain MRI structural and functional network mapping has been used to identify therapeutic targets, define eloquent brain regions to preserve, and gain insight into pathological processes and treatments as well as prognostic biomarkers. These tools have the real potential to inform patient-specific treatment strategies. Nevertheless, a realistic appraisal of clinical utility is needed that balances the growing excitement and interest in the field with important limitations associated with these techniques. Quality of the raw data, minutiae of the processing methodology, and the statistical models applied can all impact on the results and their interpretation. A lack of standardization in data acquisition and processing has also resulted in issues with reproducibility. This limitation has had a direct impact on the reliability of these tools and ultimately, confidence in their clinical use. Advances in MRI technology and computational power as well as automation and standardization of processing methods, including machine learning approaches, may help address some of these issues and make these tools more reliable in clinical use. In this review, we will highlight the current clinical uses of MRI connectomics in the diagnosis and treatment of neurological disorders; balancing emerging applications and technologies with limitations of connectivity analytic approaches to present an encompassing and appropriate perspective.
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Affiliation(s)
- Chengyuan Wu
- Department of Neurological Surgery, Vickie and Jack Farber Institute for Neuroscience, Thomas Jefferson University, 909 Walnut Street, Third Floor, Philadelphia, PA 19107, USA; Jefferson Integrated Magnetic Resonance Imaging Center, Department of Radiology, Thomas Jefferson University, 909 Walnut Street, First Floor, Philadelphia, PA 19107, USA.
| | - Francisca Ferreira
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, 33 Queen Square, London WC1N 3BG, UK; Unit of Functional Neurosurgery, UCL Queen Square Institute of Neurology, 33 Queen Square, London WC1N 3BG, UK.
| | - Michael Fox
- Center for Brain Circuit Therapeutics, Departments of Neurology, Psychiatry, Radiology, and Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA.
| | - Noam Harel
- Center for Magnetic Resonance Research, University of Minnesota, 2021 Sixth Street S.E., Minneapolis, MN 55455, USA.
| | - Jona Hattangadi-Gluth
- Department of Radiation Medicine and Applied Sciences, Center for Precision Radiation Medicine, University of California, San Diego, 3855 Health Sciences Drive, La Jolla, CA 92037, USA.
| | - Andreas Horn
- Neurology Department, Movement Disorders and Neuromodulation Section, Charité - University Medicine Berlin, Charitéplatz 1, D-10117, Berlin, Germany.
| | - Saad Jbabdi
- Wellcome Centre for Integrative Neuroimaging, Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, UK.
| | - Joshua Kahan
- Department of Neurology, Weill Cornell Medicine, 525 East 68th Street, New York, NY, 10065, USA.
| | - Ashwini Oswal
- Medical Research Council Brain Network Dynamics Unit, University of Oxford, Mansfield Rd, Oxford OX1 3TH, UK.
| | - Sameer A Sheth
- Department of Neurosurgery, Baylor College of Medicine, 7200 Cambridge, Ninth Floor, Houston, TX 77030, USA.
| | - Yanmei Tie
- Center for Brain Circuit Therapeutics, Departments of Neurology, Psychiatry, Radiology, and Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA; Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, 60 Fenwood Road, Boston, MA 02115, USA.
| | - Vejay Vakharia
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, 33 Queen Square, London WC1N 3BG, UK.
| | - Ludvic Zrinzo
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, 33 Queen Square, London WC1N 3BG, UK; Unit of Functional Neurosurgery, UCL Queen Square Institute of Neurology, 33 Queen Square, London WC1N 3BG, UK.
| | - Harith Akram
- Victor Horsley Department of Neurosurgery, National Hospital for Neurology and Neurosurgery, 33 Queen Square, London WC1N 3BG, UK; Unit of Functional Neurosurgery, UCL Queen Square Institute of Neurology, 33 Queen Square, London WC1N 3BG, UK.
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Role of the Anterior Cingulate Cortex in Translational Pain Research. Neurosci Bull 2021; 37:405-422. [PMID: 33566301 DOI: 10.1007/s12264-020-00615-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 06/03/2020] [Indexed: 02/06/2023] Open
Abstract
As the most common symptomatic reason to seek medical consultation, pain is a complex experience that has been classified into different categories and stages. In pain processing, noxious stimuli may activate the anterior cingulate cortex (ACC). But the function of ACC in the different pain conditions is not well discussed. In this review, we elaborate the commonalities and differences from accumulated evidence by a variety of pain assays for physiological pain and pathological pain including inflammatory pain, neuropathic pain, and cancer pain in the ACC, and discuss the cellular receptors and signaling molecules from animal studies. We further summarize the ACC as a new central neuromodulation target for invasive and non-invasive stimulation techniques in clinical pain management. The comprehensive understanding of pain processing in the ACC may lead to bridging the gap in translational research between basic and clinical studies and to develop new therapies.
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7
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Samsir MS, Zakaria R, Razak SA, Ismail MS, Rahim MZA, Lin CS, Osman NMFN, Asri MA, Mohd NH, Ahmad AH. Six Months Guided Exercise Therapy Improves Motor Abilities and White Matter Connectivity in Children with Cerebral Palsy. Malays J Med Sci 2020; 27:90-100. [PMID: 33154705 PMCID: PMC7605833 DOI: 10.21315/mjms2020.27.5.9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 07/23/2020] [Indexed: 01/22/2023] Open
Abstract
Background Diffusion magnetic resonance imaging (dMRI) provides the state of putative connectivity from lesioned areas to other brain areas and is potentially beneficial to monitor intervention outcomes. This study assessed the effect of a 6 months guided exercise therapy on motor abilities and white matter diffusivity in the brains of cerebral palsy (CP) children. Methods This is a single arm pre-and post-test research design involving 10 spastic CP children, aged 8–18 years and whose Gross Motor Function Classification System Expanded and Revised (GMFCS-E & R) at least Level 21 with the ability to ambulate independently. They were recruited from Paediatric Neurology Clinic, Hospital Universiti Sains Malaysia (HUSM) from December 2015–December 2016. All participants underwent 6 months of therapist-guided exercise session comprising progressive strength training at a frequency of twice a week, 1 h duration per session. The effect of exercise on motor abilities was assessed using the Gross Motor Function Measures (GMFM)-88. Six out of the 10 children consented for dMRI. Probabilistic tractography of the corticospinal tract (CST) was performed to determine the connectivity index of the tracts pre-and post-intervention. Results All the participants displayed statistically significant increment in GMFM-88 scores pre-to post-exercise intervention. This improvement was concurrent with increased connectivity index in the CST of upper limbs and lower limbs in the brain of these children. Conclusion Our findings demonstrated that 6 months guided exercise therapy improves motor abilities of CP children concurrent with strengthening the connectivities of the motor pathways in the brain.
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Affiliation(s)
- Md Safwan Samsir
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Faculty of Psychology and Education, Universiti Malaysia Sabah, Malaysia
| | - Rahimah Zakaria
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Salmi Abdul Razak
- Department of Paediatrics, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.,Hospital Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Mohamed Saat Ismail
- School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | | | - Chia-Shu Lin
- Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan
| | - Nik Mohammad Faez Nik Osman
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Mohammad Afiq Asri
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Nor Haslina Mohd
- School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
| | - Asma Hayati Ahmad
- Department of Physiology, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia
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8
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Abstract
Deep brain stimulation is the most advanced and effective neuromodulation therapy for Parkinson disease, essential tremor, and generalized dystonia. This article discusses how imaging improves surgical techniques and outcomes and widens possibilities in translational neuroscience in Parkinson disease, essential tremor, generalized dystonia, and epilepsy. In movement disorders diffusion tensor imaging allows anatomic segment of cortical areas and different functional subregions within deep-seated targets to understand the side effects of stimulation and gain more data to describe the therapeutic mechanism of action. The introduction of visualization of white matter tracks increases the safety of neurosurgical techniques in functional neurosurgery and neuro-oncology.
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Affiliation(s)
- Lorand Eross
- Department of Functional Neurosurgery, Center of Neuromodulation, National Institute of Clinical Neurosciences, Amerikai út 57, Budapest 1145, Hungary.
| | - Jonathan Riley
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University Buffalo Medical, 955 Main Street, Buffalo, NY 14203, USA
| | - Elad I Levy
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University Buffalo, 955 Main Street, Buffalo, NY 14203, USA
| | - Kunal Vakharia
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University Buffalo, 955 Main Street, Buffalo, NY 14203, USA
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Neuroimaging of Pain: Human Evidence and Clinical Relevance of Central Nervous System Processes and Modulation. Anesthesiology 2019; 128:1241-1254. [PMID: 29494401 DOI: 10.1097/aln.0000000000002137] [Citation(s) in RCA: 97] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Neuroimaging research has demonstrated definitive involvement of the central nervous system in the development, maintenance, and experience of chronic pain. Structural and functional neuroimaging has helped elucidate central nervous system contributors to chronic pain in humans. Neuroimaging of pain has provided a tool for increasing our understanding of how pharmacologic and psychologic therapies improve chronic pain. To date, findings from neuroimaging pain research have benefitted clinical practice by providing clinicians with an educational framework to discuss the biopsychosocial nature of pain with patients. Future advances in neuroimaging-based therapeutics (e.g., transcranial magnetic stimulation, real-time functional magnetic resonance imaging neurofeedback) may provide additional benefits for clinical practice. In the future, with standardization and validation, brain imaging could provide objective biomarkers of chronic pain, and guide treatment for personalized pain management. Similarly, brain-based biomarkers may provide an additional predictor of perioperative prognoses.
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10
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Samsir S, Zakaria R, Razak SA, Ismail MS, Rahim MZA, Lin CS, Osman NMFN, Asri MA, Ahmad AH. Characterisation of the Corticospinal Tract Using Diffusion Magnetic Resonance Imaging in Unilateral and Bilateral Cerebral Palsy Patients. Malays J Med Sci 2019; 25:68-78. [PMID: 30914864 PMCID: PMC6419886 DOI: 10.21315/mjms2018.25.5.7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Accepted: 08/05/2018] [Indexed: 11/06/2022] Open
Abstract
Background Neuroimaging is increasingly used to locate the lesion that causes cerebral palsy (CP) and its extent in the brains of CP patients. Conventional structural magnetic resonance imaging (MRI) does not indicate the connectional pattern of white matter; however, with the help of diffusion MRI, fibre tracking of white matter can be done. Methods We used diffusion MRI and probabilistic tractography to identify the putative white matter connectivity in the brains of 10 CP patients. We tracked the corticospinal tract (CST) of the patients’ upper and lower limbs and calculated the white matter connectivity, as indexed by streamlines representing the probability of connection of the CST. Results Our results show that diffusion MRI with probabilistic tractography, while having some relation with the clinical diagnosis of CP, reveals a high degree of individual variation in the streamlines representing the CST for upper and lower limbs. Conclusion Diffusion MRI with probabilistic tractography provides the state of connectivity from lesioned areas to other parts of the brain and is potentially beneficial to be used as an adjunct to the clinical management of CP, providing a means to monitor intervention outcomes.
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Affiliation(s)
- Safwan Samsir
- Faculty of Psychology & Education, Universiti Malaysia Sabah, Sabah, Malaysia.,Department of Physiology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Rahimah Zakaria
- Department of Physiology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Salmi Abdul Razak
- Department of Paediatrics, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Mohamed Saat Ismail
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Mohd Zulkifli Abdul Rahim
- School of Health Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Chia-Shu Lin
- Department of Dentistry, School of Dentistry, National Yang-Ming University, Taipei, Taiwan
| | - Nik Mohammad Faez Nik Osman
- Department of Physiology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Mohammad Afiq Asri
- Department of Physiology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Asma Hayati Ahmad
- Department of Physiology, School of Medical Sciences, Health Campus, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan, Malaysia
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Weiss AR, Gillies MJ, Philiastides MG, Apps MA, Whittington MA, FitzGerald JJ, Boccard SG, Aziz TZ, Green AL. Dorsal Anterior Cingulate Cortices Differentially Lateralize Prediction Errors and Outcome Valence in a Decision-Making Task. Front Hum Neurosci 2018; 12:203. [PMID: 29872384 PMCID: PMC5972193 DOI: 10.3389/fnhum.2018.00203] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 04/30/2018] [Indexed: 11/13/2022] Open
Abstract
The dorsal anterior cingulate cortex (dACC) is proposed to facilitate learning by signaling mismatches between the expected outcome of decisions and the actual outcomes in the form of prediction errors. The dACC is also proposed to discriminate outcome valence-whether a result has positive (either expected or desirable) or negative (either unexpected or undesirable) value. However, direct electrophysiological recordings from human dACC to validate these separate, but integrated, dimensions have not been previously performed. We hypothesized that local field potentials (LFPs) would reveal changes in the dACC related to prediction error and valence and used the unique opportunity offered by deep brain stimulation (DBS) surgery in the dACC of three human subjects to test this hypothesis. We used a cognitive task that involved the presentation of object pairs, a motor response, and audiovisual feedback to guide future object selection choices. The dACC displayed distinctly lateralized theta frequency (3-8 Hz) event-related potential responses-the left hemisphere dACC signaled outcome valence and prediction errors while the right hemisphere dACC was involved in prediction formation. Multivariate analyses provided evidence that the human dACC response to decision outcomes reflects two spatiotemporally distinct early and late systems that are consistent with both our lateralized electrophysiological results and the involvement of the theta frequency oscillatory activity in dACC cognitive processing. Further findings suggested that dACC does not respond to other phases of action-outcome-feedback tasks such as the motor response which supports the notion that dACC primarily signals information that is crucial for behavioral monitoring and not for motor control.
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Affiliation(s)
- Alexander R Weiss
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom.,Neurophysiological Pharmacology Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States
| | - Martin J Gillies
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Marios G Philiastides
- Institute of Neuroscience and Psychology, University of Glasgow, Glasgow, United Kingdom
| | - Matthew A Apps
- Department of Experimental Psychology, University of Oxford, Oxford, United Kingdom
| | | | - James J FitzGerald
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Sandra G Boccard
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Tipu Z Aziz
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
| | - Alexander L Green
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom
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12
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See AAQ, King NKK. Improving Surgical Outcome Using Diffusion Tensor Imaging Techniques in Deep Brain Stimulation. Front Surg 2017; 4:54. [PMID: 29034243 PMCID: PMC5625016 DOI: 10.3389/fsurg.2017.00054] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 09/06/2017] [Indexed: 12/16/2022] Open
Abstract
Introduction Recent advances in surgical imaging include the use of diffusion tensor imaging (DTI) in deep brain stimulation (DBS) and provide a detailed view of the white matter tracts and their connections which are not seen with conventional magnetic resonance imaging. Given that the efficacy of DBS depends on the precise and accurate targeting of these circuits, better surgical planning using information obtained from DTI may lead to improved surgical outcome. We aim to review the available literature to evaluate the efficacy of such a strategy. Methods A search of PubMed was performed to identify all articles using the search terms “(diffusion tractography OR diffusion tensor imaging OR DTI) AND (deep brain stimulation OR DBS).” Studies were included if DTI was used and clinical outcomes were reported. Results We identified 35 studies where the use of DTI in DBS was evaluated. The most studied pathology was movement disorders (17 studies), psychiatric disorders (11 studies), and pain (7 studies). The overall responder rates for tremor reduction was 70.0% (SD = 26.1%) in 69 patients, 36.5% (SD = 19.1%) for obsessive–compulsive disorder in 9 patients, 48.3% (SD = 40.0%) for depression in 40 patients, and 49.7% (SD = 35.1%) for chronic pain in 23 patients. Discussion The studies reviewed show that the use of DTI for surgical planning is feasible, provide additional information over conventional targeting methods, and can improve surgical outcome. Patients in whom the DBS electrodes were within the DTI targets experienced better outcomes than those in whom the electrodes were not. Many current studies are limited by their small sample size or retrospective nature. The use of DTI in DBS planning appears underutilized and further studies are warranted given that surgical outcome can be optimized using this non-invasive technique.
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Affiliation(s)
- Angela An Qi See
- Department of Neurosurgery, National Neuroscience Institute, Singapore, Singapore
| | - Nicolas Kon Kam King
- Department of Neurosurgery, National Neuroscience Institute, Singapore, Singapore.,Duke-NUS Medical School, Singapore, Singapore
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13
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Ward M, Mammis A. Deep Brain Stimulation for the Treatment of Dejerine-Roussy Syndrome. Stereotact Funct Neurosurg 2017; 95:298-306. [PMID: 28848107 DOI: 10.1159/000479526] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 07/11/2017] [Indexed: 01/09/2023]
Abstract
BACKGROUND/AIMS Patients who suffer from Dejerine-Roussy syndrome commonly experience severe poststroke hemibody pain which has historically been attributed to thalamic lesions. Despite pharmacological treatment, a significant proportion of the population is resistant to traditional therapy. Deep brain stimulation is often appropriate for the treatment of resistant populations. In this review we aim to summarize the targets that are used to treat Dejerine-Roussy syndrome and provide insight into their clinical efficacy. METHODS In reviewing the literature, we defined stimulation success as achievement of a minimum of 50% pain relief. RESULTS Contemporary targets for deep brain stimulation are the ventral posterior medial/ventral posterior lateral thalamic nuclei, periaqueductal/periventricular gray matter, the ventral striatum/anterior limb of the internal capsule, left centromedian thalamic nuclei, the nucleus ventrocaudalis parvocellularis internis, and the posterior limb of the internal capsule. CONCLUSIONS Due to technological advancements in deep brain stimulation, its therapeutic effects must be reevaluated. Despite a lack of controlled evidence, deep brain stimulation has been effectively used as a therapeutic in clinical pain management. Further clinical investigation is needed to definitively evaluate the therapeutic efficacy of deep brain stimulation in treating the drug-resistant patient population.
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Affiliation(s)
- Max Ward
- Department of Neurological Surgery, Rutgers New Jersey Medical School, Newark, NJ, USA
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14
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Long-Term Results of Deep Brain Stimulation of the Anterior Cingulate Cortex for Neuropathic Pain. World Neurosurg 2017; 106:625-637. [PMID: 28710048 DOI: 10.1016/j.wneu.2017.06.173] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Revised: 06/28/2017] [Accepted: 06/30/2017] [Indexed: 12/18/2022]
Abstract
BACKGROUND Deep brain stimulation (DBS) of the anterior cingulate cortex (ACC) is a recent technique that has shown some promising short-term results in patients with chronic refractory neuropathic pain. Three years after the first case series, we assessed its efficacy on a larger cohort, with longer follow-up. METHODS Twenty-four patients (19 males; average age, 49.1 years) with neuropathic pain underwent bilateral ACC DBS. Patient-reported outcome measures were collected before and after surgery, using the Numerical Rating Scale (NRS), Short-Form 36 quality of life (SF-36), McGill Pain Questionnaire (MPQ), and EuroQol 5-domain quality of life (EQ-5D) questionnaire. RESULTS Twenty-two patients after a trial week were fully internalized and 12 had a mean follow-up of 38.9 months. Six months after surgery the mean NRS score decreased from 8.0 to 4.27 (P = 0.004). There was a significant improvement in the MPQ (mean, -36%; P = 0.021) and EQ-5D score significantly decreased (mean, -21%; P = 0.036). The physical functioning domain of SF-36 was significantly improved (mean, +54.2%; P = 0.01). Furthermore, in 83% of these patients, at 6 months, NRS score was improved by 60% (P < 0.001) and MPQ decreased by 47% (P < 0.01). After 1 year, NRS score decreased by 43% (P < 0.01), EQ-5D was significantly reduced (mean, -30.8; P = 0.05) and significant improvements were also observed for different domains of the SF-36. At longer follow-ups, efficacy was sustained up to 42 months in some patients, with an NRS score as low as 3. CONCLUSIONS Follow-up results confirm that ACC DBS alleviates chronic neuropathic pain refractory to pharmacotherapy and improves quality of life in many patients.
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15
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Murga I, Guillen V, Lafuente JV. Cerebral magnetic resonance changes associated with fibromyalgia syndrome. Med Clin (Barc) 2017; 148:511-516. [PMID: 28450073 DOI: 10.1016/j.medcli.2017.01.034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2017] [Revised: 01/31/2017] [Accepted: 01/31/2017] [Indexed: 01/06/2023]
Abstract
Fibromyalgia syndrome is a chronic disease, of unknown origin, whose diagnostic criteria were established in 1990 by the American College of Rheumatology. New criteria were proposed in 2010 that have not yet been validated. It is characterized by a generalized chronic musculoskeletal pain, accompanied by hyperalgesia and allodynia, as well as other motor, vegetative, cognitive and affective symptoms and signs. We have reviewed a set of studies with cerebral magnetic resonance (morphometry, connectivity and spectroscopy) that refer to changes in areas involved in pain processing. Modifications in gray and white matter volume, as well as in levels of N-acetylaspartate, choline or glutamate, among other metabolites, have been observed in the hippocampus, insula, prefrontal and cingular cortex. Neuroradiological findings are nonspecific and similar to those found in other examples of chronic pain. An increase in the sample size and a standardized methodology would facilitate comparison, allowing the drawing of general conclusions.
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Affiliation(s)
- Iñigo Murga
- LaNCE, Departamento de Neurociencia, Universidad del País Vasco, Leioa, Bizkaia, España.
| | - Virginia Guillen
- LaNCE, Departamento de Neurociencia, Universidad del País Vasco, Leioa, Bizkaia, España
| | - José-Vicente Lafuente
- LaNCE, Departamento de Neurociencia, Universidad del País Vasco, Leioa, Bizkaia, España; Grupo de Nanoneurocirugía, Instituto de Investigación Sanitaria BioCruces, Barakaldo, Bizkaia, España; Facultad de Ciencias de la Salud, Universidad Autónoma de Chile, Santiago de Chile, Chile
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16
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Boccard SGJ, Rebelo P, Cheeran B, Green A, FitzGerald JJ, Aziz TZ. Post-Traumatic Tremor and Thalamic Deep Brain Stimulation: Evidence for Use of Diffusion Tensor Imaging. World Neurosurg 2016; 96:607.e7-607.e11. [PMID: 27693821 DOI: 10.1016/j.wneu.2016.09.079] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2016] [Revised: 09/16/2016] [Accepted: 09/20/2016] [Indexed: 01/11/2023]
Abstract
BACKGROUND Deep brain stimulation (DBS) is a well-established treatment to reduce tremor, notably in Parkinson disease. DBS may also be effective in post-traumatic tremor, one of the most common movement disorders caused by head injury. However, the cohorts of patients often have multiple lesions that may impact the outcome depending on which fiber tracts are affected. CASE DESCRIPTION A 20-year-old man presented after road traffic accident with severe closed head injury and polytrauma. Computed tomography scan showed left frontal and basal ganglia hemorrhagic contusions and intraventricular hemorrhage. A disabling tremor evolved in step with motor recovery. Despite high-intensity signals in the intended thalamic target, a visual analysis of the preoperative diffusion tensor imaging revealed preservation of connectivity of the intended target, ventralis oralis posterior thalamic nucleus (VOP). This was confirmed by the postoperative tractography study presented here. DBS of the VOP/zona incerta was performed. Six months postimplant, marked improvement of action (postural, kinetic, and intention) tremor was achieved. CONCLUSIONS We demonstrated a strong connectivity between the VOP and the superior frontal gyrus containing the premotor cortex and other central brain areas responsible for movement control. In spite of an existing lesion in the target, the preservation of these tracts may be relevant to the improvement of the patient's symptoms by DBS.
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Affiliation(s)
- Sandra G J Boccard
- Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery, University of Oxford, Oxford, United Kingdom.
| | - Pedro Rebelo
- Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery, University of Oxford, Oxford, United Kingdom
| | - Binith Cheeran
- Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery, University of Oxford, Oxford, United Kingdom
| | - Alexander Green
- Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery, University of Oxford, Oxford, United Kingdom
| | - James J FitzGerald
- Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery, University of Oxford, Oxford, United Kingdom
| | - Tipu Z Aziz
- Oxford Functional Neurosurgery and Experimental Neurology Group, Nuffield Departments of Clinical Neuroscience and Surgery, University of Oxford, Oxford, United Kingdom
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Sweet JA, Pace J, Girgis F, Miller JP. Computational Modeling and Neuroimaging Techniques for Targeting during Deep Brain Stimulation. Front Neuroanat 2016; 10:71. [PMID: 27445709 PMCID: PMC4927621 DOI: 10.3389/fnana.2016.00071] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2015] [Accepted: 06/09/2016] [Indexed: 12/15/2022] Open
Abstract
Accurate surgical localization of the varied targets for deep brain stimulation (DBS) is a process undergoing constant evolution, with increasingly sophisticated techniques to allow for highly precise targeting. However, despite the fastidious placement of electrodes into specific structures within the brain, there is increasing evidence to suggest that the clinical effects of DBS are likely due to the activation of widespread neuronal networks directly and indirectly influenced by the stimulation of a given target. Selective activation of these complex and inter-connected pathways may further improve the outcomes of currently treated diseases by targeting specific fiber tracts responsible for a particular symptom in a patient-specific manner. Moreover, the delivery of such focused stimulation may aid in the discovery of new targets for electrical stimulation to treat additional neurological, psychiatric, and even cognitive disorders. As such, advancements in surgical targeting, computational modeling, engineering designs, and neuroimaging techniques play a critical role in this process. This article reviews the progress of these applications, discussing the importance of target localization for DBS, and the role of computational modeling and novel neuroimaging in improving our understanding of the pathophysiology of diseases, and thus paving the way for improved selective target localization using DBS.
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Affiliation(s)
- Jennifer A Sweet
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
| | - Jonathan Pace
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
| | - Fady Girgis
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
| | - Jonathan P Miller
- Department of Neurosurgery, University Hospitals Case Medical Center, Case Western Reserve University Cleveland, OH, USA
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Pycroft L, Boccard SG, Owen SLF, Stein JF, Fitzgerald JJ, Green AL, Aziz TZ. Brainjacking: Implant Security Issues in Invasive Neuromodulation. World Neurosurg 2016; 92:454-462. [PMID: 27184896 DOI: 10.1016/j.wneu.2016.05.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 05/04/2016] [Accepted: 05/05/2016] [Indexed: 01/06/2023]
Abstract
The security of medical devices is critical to good patient care, especially when the devices are implanted. In light of recent developments in information security, there is reason to be concerned that medical implants are vulnerable to attack. The ability of attackers to exert malicious control over brain implants ("brainjacking") has unique challenges that we address in this review, with particular focus on deep brain stimulation implants. To illustrate the potential severity of this risk, we identify several mechanisms through which attackers could manipulate patients if unauthorized access to an implant can be achieved. These include blind attacks in which the attacker requires no patient-specific knowledge and targeted attacks that require patient-specific information. Blind attacks include cessation of stimulation, draining implant batteries, inducing tissue damage, and information theft. Targeted attacks include impairment of motor function, alteration of impulse control, modification of emotions or affect, induction of pain, and modulation of the reward system. We also discuss the limitations inherent in designing implants and the trade-offs that must be made to balance device security with battery life and practicality. We conclude that researchers, clinicians, manufacturers, and regulatory bodies should cooperate to minimize the risk posed by brainjacking.
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Affiliation(s)
- Laurie Pycroft
- Oxford Functional Neurosurgery, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom.
| | - Sandra G Boccard
- Oxford Functional Neurosurgery, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom
| | - Sarah L F Owen
- Department of Applied Health and Professional Development, Oxford Brookes University, Headington Campus, Oxford, United Kingdom
| | - John F Stein
- Department of Physiology, Anatomy, and Genetics, Sherrington Road, Oxford, United Kingdom
| | - James J Fitzgerald
- Oxford Functional Neurosurgery, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom
| | - Alexander L Green
- Oxford Functional Neurosurgery, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom
| | - Tipu Z Aziz
- Oxford Functional Neurosurgery, University of Oxford, John Radcliffe Hospital, Headington, Oxford, United Kingdom
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