title: Thalamic stimulation in multiple sclerosis: evidence for a 'demyelinative thalamotomy'.
abstract: The mechanism of action of deep brain stimulation (DBS) in the alleviation of tremor in multiple sclerosis (MS) and other neurological disorders is unknown. Moreover, whether the trauma accompanying this surgery is responsible for the induction of new MS plaques is controversial. Here we report the first description of the post-mortem imaging and pathologic findings in the brain of a MS patient who underwent thalamic DBS for the treatment of MS-induced tremor. MR imaging of formalin-fixed brain slices was carried out at 1.5, 3 and 7 Tesla and correlated with the histopathology. There were numerous demyelinative plaques in the white mater, cortex and deep gray matter. There were no plaques along the DBS tract within the sections that sampled the deep hemispheric white matter. However, deep within the thalamus focal demyelination approximated the tract, particularly in the region corresponding to the electrical field. The findings in this single case raise the possibility that focal demyelination may be induced by the electrical field and this may be responsible for long-lasting alleviation of tremor in the absence of continued electrostimulation.
authors.affiliation: Department of Pathology and Laboratory Medicine (Neuropathology), University of British Columbia, Vancouver, British Columbia, Canada. wayne.moore@vch.ca
authors.forename: G R Wayne
authors.initials: GR
authors.lastname: Moore
authors.forename: Aleksander M
authors.initials: AM
authors.lastname: Vitali
authors.forename: Esther
authors.initials: E
authors.lastname: Leung
authors.forename: Cornelia
authors.initials: C
authors.lastname: Laule
authors.forename: Piotr
authors.initials: P
authors.lastname: Kozlowski
authors.forename: Alex L
authors.initials: AL
authors.lastname: Mackay
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Honey
mesh_terms: D001921:Brain / Q000473:pathology; D046690:Deep Brain Stimulation / Q000009:adverse effects*; D003711:Demyelinating Diseases / Q000209:etiology* / Q000473:pathology*; D004567:Electrodes, Implanted / Q000009:adverse effects; D005260:Female; D006801:Humans; D007370:Interferon Type I / Q000627:therapeutic use; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000473:pathology* / Q000628:therapy*; D011183:Postoperative Complications / Q000473:pathology*; D011994:Recombinant Proteins; D013788:Thalamus / Q000473:pathology* / Q000502:physiology*; D016610:Tissue Embedding; D016707:Tissue Fixation
chemical_list: D007370:Interferon Type I; D011994:Recombinant Proteins