Movement Disorders Section, Department of Neurology, Hannover Medical School, Hannover, Germany.
Neurology. 2011 Aug 2;77(5):483-8. doi: 10.1212/WNL.0b013e318227b19e. Epub 2011 Jul 20.
Stimulation-induced hypokinetic gait disorders with freezing of gait (FOG) have been reported only recently as adverse effects of deep brain stimulation (DBS) of the globus pallidus internus (GPi) in patients with dystonia. The aim of this work was to determine the frequency and the nature of this GPi-DBS-induced phenomenon.
We retrospectively screened our database of patients with dystonia who underwent DBS. Patients with focal, segmental, or generalized dystonia of primary or tardive origin and no gait disorder due to lower limb dystonia before DBS, bilateral pallidal stimulation, and a follow-up for more than 6 months were included. Reports of adverse events were analyzed, and gait abnormalities were scored by comparing preoperative and postoperative video recordings using Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) items 3.10 (gait) and 3.11 (FOG). To assess the role of GPi-DBS in gait abnormalities, DBS was paused for 24 hours. Gait and FOG were assessed 30 minutes, 2 hours, and 24 hours after restarting DBS. Finally, a standardized adjustment algorithm was performed trying to eliminate the gait disorder.
Of a collective of 71 patients with dystonia, 6 presented with a new gait disorder (8.5%; 2 men, 4 women, mean age 61.3 years [48-69 years], 2 craniocervical, 1 DYT-1 segmental, 1 truncal, 2 tardive dystonia). GPi-DBS improved Burke-Fahn-Marsden Dystonia Rating Scale motor score by 54% and disability score by 52%. MDS-UPDRS item 3.10 worsened from 0.5 (±0.8) to 2.0 (±0.9) and item 3.11 from 0 to 2.5 (±0.5). The gait disorder displayed shuffling steps and difficulties with gait initiation and turning. Increasing voltages improved dystonia but triggered FOG, sometimes worsening over a period of a few hours. It vanished within minutes after ceasing DBS. Electrode misplacement was ruled out. In all but one patient, no optimal configuration was found despite extensive testing of settings (monopolar, bipolar, pulse width 60-210 μs, frequency 60-180 Hz). Nevertheless, a compromise between optimal stimulation for dystonia and eliciting FOG was achieved in each case.
A hypokinetic gait disorder with FOG can be a complication of GPi-DBS.
深部脑刺激（DBS）治疗苍白球 internus（GPi）后出现运动减少性步态障碍伴冻结步态（FOG），这是一种新发现的不良反应，目前仅见于部分局灶性、节段性或全身性肌张力障碍患者。本研究旨在确定这种由 GPi-DBS 引起的现象的频率和性质。
我们回顾性筛查了接受 DBS 的肌张力障碍患者的数据库。纳入标准为原发性或迟发性肌张力障碍患者，下肢肌张力障碍无步态障碍，双侧苍白球刺激，随访时间超过 6 个月。分析不良事件报告，并通过比较术前和术后视频记录，使用运动障碍协会修订的统一帕金森病评定量表（MDS-UPDRS）项目 3.10（步态）和 3.11（FOG）进行步态异常评分。为评估 GPi-DBS 在步态异常中的作用，暂停 DBS 24 小时。在重新开始 DBS 后 30 分钟、2 小时和 24 小时评估步态和 FOG。最后，尝试通过标准化调整算法消除步态障碍。
在 71 例肌张力障碍患者中，有 6 例出现新的步态障碍（8.5%；2 例男性，4 例女性，平均年龄 61.3 岁[48-69 岁]，2 例颅颈，1 例 DYT-1 节段性，1 例躯干，2 例迟发性肌张力障碍）。GPi-DBS 使 Burke-Fahn-Marsden 肌张力障碍评定量表运动评分改善 54%，残疾评分改善 52%。MDS-UPDRS 项目 3.10 从 0.5（±0.8）恶化至 2.0（±0.9），项目 3.11 从 0 恶化至 2.5（±0.5）。步态障碍表现为拖曳步态和步态起始及转弯困难。增加电压可改善肌张力障碍，但会引发 FOG，有时在数小时内加重。停止 DBS 后几分钟内消失。排除了电极放置不当。尽管对设置（单极、双极、脉冲宽度 60-210 μs、频率 60-180 Hz）进行了广泛测试，但除 1 例患者外，在所有患者中均未找到最佳配置。然而，在每种情况下，都可以在为肌张力障碍提供最佳刺激和引发 FOG 之间找到一个折衷方案。
GPi-DBS 后可能会出现运动减少性步态障碍伴 FOG。
