Earhart Gammon M, Clark B Ruth, Tabbal Samer D, Perlmutter Joel S
Program in Physical Therapy, Washington University, St. Louis, Missouri 63108, USA.
Mov Disord. 2009 Feb 15;24(3):386-91. doi: 10.1002/mds.22356.
Essential tremor (ET) is a multi-faceted condition best known for postural and action tremor but also may include disordered gait and postural instability. Deep brain stimulation (DBS) of the ventral intermediate nucleus (VIM) of the thalamus provides substantial tremor reduction yet some patients with bilateral VIM DBS have gait and balance impairment. This study examines gait and balance performance in 13 participants with ET who have bilateral VIM DBS compared with a matched control group. Participants with ET were tested with their stimulators off (DBS OFF) and on (DBS ON). For both standard and tandem walking, participants with ET walked significantly more slowly than controls, with significantly lower cadence, spending a lower percentage of the gait cycle in single limb support and a higher percentage in double support compared with controls. Participants with ET also had significantly lower tandem and one leg stance times, Berg balance scores, balance confidence, and required significantly greater time to perform the Timed Up-and-Go relative to controls. There were no significant differences in any gait or balance measures in the DBS OFF versus DBS ON conditions, but the effects of DBS on gait and balance were highly variable among individuals. Future studies are needed to determine why some individuals experience gait and balance difficulties after bilateral thalamic DBS and others do not. A better understanding of the mechanisms underlying gait and balance impairments in those with bilateral DBS is critical to reduce falls and fractures in this group.
特发性震颤（ET）是一种多方面的病症，最以姿势性和动作性震颤而闻名，但也可能包括步态紊乱和姿势不稳。丘脑腹中间核（VIM）的深部脑刺激（DBS）可显著减轻震颤，但一些接受双侧VIM DBS治疗的患者存在步态和平衡障碍。本研究比较了13名接受双侧VIM DBS治疗的ET患者与匹配的对照组的步态和平衡表现。ET患者在刺激器关闭（DBS关闭）和打开（DBS打开）的情况下接受测试。对于标准行走和串联行走，ET患者的行走速度明显比对照组慢，步频显著更低，单腿支撑期在步态周期中所占百分比更低，双腿支撑期所占百分比更高。ET患者的串联站立和单腿站立时间、伯格平衡评分、平衡信心也显著更低，相对于对照组，完成定时起立行走测试所需时间显著更长。在DBS关闭与DBS打开状态下，任何步态或平衡测量指标均无显著差异，但DBS对步态和平衡的影响在个体间差异很大。未来需要开展研究，以确定为何一些个体在双侧丘脑DBS后会出现步态和平衡困难，而另一些个体则不会。更好地理解双侧DBS患者步态和平衡障碍的潜在机制，对于减少该群体的跌倒和骨折至关重要。
