title: Post-deep brain stimulation--gradual non-stimulation dependent decrease in strength with attenuation of multiple sclerosis tremor.
abstract: Tremor in multiple sclerosis is considered to be a persistent and progressive sign. We describe five patients with multiple sclerosis in whom upper limb tremor severity gradually decreased over a period of several years after deep brain stimulation. In every case this attenuation of tremor was accompanied by increasing pyramidal weakness in the relevant upper limb. In two patients this attenuation of tremor remained after stimulation was permanently switched off. In one other patient, where upper limb strength remained normal, tremor severity gradually worsened in spite of continuing stimulation. There was a highly significant difference (p = 0.0007) between the changes in intention tremor severities when the arms with increasing pyramidal weakness (n = 9) were compared to those in which normal strength was retained throughout follow-up period (n = 3); intention tremor decreased in the former and increased in the latter by means of -3.66 and +4.0 points of a 0-10 tremor scale respectively. There was also a significant correlation (0.699; p = 0.0359) between decreasing upper limb strength and decreasing intention tremor severity for the upper limbs of patients that had undergone contralateral DBS.
authors: Department of Neurosurgery, West London Neurosciences Centre Charing Cross Hospital, London, UK.
authors: Jonathan A
authors: JA
authors: Hyam
authors: Tipu Z
authors: TZ
authors: Aziz
authors: Peter G
authors: PG
authors: Bain
mesh_terms: D000328:Adult; D046690:Deep Brain Stimulation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009103:Multiple Sclerosis / Q000150:complications; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome; D014202:Tremor / Q000209:etiology / Q000473:pathology / Q000628:therapy*; D034941:Upper Extremity / Q000503:physiopathology