title: Steady or not following thalamic deep brain stimulation for essential tremor.
abstract: Deep brain stimulation (DBS) has become an important option for medication-refractory essential tremor (ET), but may contribute to worsened gait and falling. This study evaluates impaired gait in a cohort of patients treated with DBS with a retrospective review of ET patients before and after DBS implantation. Factors examined included: age, duration of symptoms, pre-morbid gait difficulties/falls, Fahn-Tolosa-Marin tremorrating scale (TRS) scores at baseline, 6 months post-unilateral DBS implantation, and 6 or 12 months post-bilateral implantation. All implantations targeted the nucleus ventralis intermediate (Vim). Thirty-eight patients (25 males, 13 females) were included. Twenty-five patients (65.8%) underwent unilateral DBS implantation and 13 (34.2%) bilateral. The mean age at surgery was 67.1 years ± 11.4 (range 34-81). The mean disease duration was 31 years ± 18.3 (range 6-67). Fifty-eight percent of patients had worsened gait post-operatively. Seventy percent of patients with unilateral Vim DBS experienced gait worsening while 55% of bilateral DBS patients experienced gait worsening. Patients with worsened gait post-DBS had higher baseline pre-operative TRS scores than those without worsened gait (43.1 points ± 8.4 vs. 33.1 points ± 10.1, p = 0.002) (odds ratio 2.5, p = 0.02). Gait/balance may worsen following DBS for medication refractory ET. Higher baseline TRS score may factor into these issues, although a larger prospective study will be required with a control population. The larger percentage of difficulties observed in unilateral versus bilateral cases likely reflected the bias not to proceed to second-sided surgery if gait/balance problems were encountered.
authors: Department of Neurology, McKnight Brain Institute, University of Florida, 100 S. Newell Drive, Rm L3-100, Gainesville, Fl, 32610, USA.
authors: Nelson
authors: N
authors: Hwynn
authors: Christopher J
authors: CJ
authors: Hass
authors: Pamela
authors: P
authors: Zeilman
authors: Janet
authors: J
authors: Romrell
authors: Yunfeng
authors: Y
authors: Dai
authors: Sam S
authors: SS
authors: Wu
authors: Kelly D
authors: KD
authors: Foote
authors: S H
authors: SH
authors: Subramony
authors: Genko
authors: G
authors: Oyama
authors: Frances
authors: F
authors: Velez-Lago
authors: Hubert H
authors: HH
authors: Fernandez
authors: Andrew S
authors: AS
authors: Resnick
authors: Irene A
authors: IA
authors: Malaty
authors: Michael S
authors: MS
authors: Okun
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D046690:Deep Brain Stimulation / Q000009:adverse effects* / Q000379:methods*; D020329:Essential Tremor / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D020233:Gait Disorders, Neurologic / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D011446:Prospective Studies; D012189:Retrospective Studies; D020651:Ventral Thalamic Nuclei / Q000473:pathology / Q000502:physiology / Q000601:surgery*