From the Departments of Neurology (S.P., J.F., J.B., S.H., H.H., K.W., G.D.) and Neurosurgery (A.-K.H.), Christian-Albrechts-University; Division of Neurological Pain Research and Therapy (J.F.), Department of Neurology, University Hospital Schleswig-Holstein, Kiel; and Department of Neurology (K.W.), School of Medicine and Health Sciences-European Medical School, University Oldenburg and Research Center Neurosensory Science, Carl von Ossietzky University, Oldenburg, Germany.
Neurology. 2019 Mar 19;92(12):e1378-e1386. doi: 10.1212/WNL.0000000000007134. Epub 2019 Feb 20.
Deep brain stimulation (DBS) of the ventral intermediate thalamic nucleus (Vim) is established for medically refractory severe essential tremor (ET), but long-term efficacy is controversial.
Twenty patients with ET with DBS had standardized video-documented examinations at baseline, in the stimulation-on condition at short term (13.1 ± 1.9 months since surgery, mean ± SEM), and in the stimulator switched on and off (stim-ON/OFF) at long term; all assessments were done between 32 and 120 months (71.9 ± 6.9 months) after implantation. The primary outcome was the Tremor Rating Scale (TRS) blindly assessed by 2 trained movement disorder neurologists. Secondary outcomes were TRS subscores A, B, and C; Archimedes spiral score; and activities of daily living score. At long-term follow-up, tremor was additionally recorded with accelerometry. The rebound effect after switching the stimulator off was assessed for 1 hour in a subgroup.
Tremor severity worsened considerably over time in both in the nonstimulated and stimulated conditions. Vim-DBS improved the TRS in the short term and long term significantly. The spiral score and functional measures showed similar improvements. All changes were highly significant. However, the stimulation effect was negatively correlated with time since surgery (ρ = -0.78, < 0.001). This was also true for the secondary outcomes. Only one-third of the patients had a rebound effect terminated 60 minutes after the stimulator was switched off. Long-term worsening of the TRS was more profound during stim-ON than in the stim-OFF condition, indicating habituation to stimulation.
Vim-DBS loses efficacy over the long term. Efforts are needed to improve the long-term efficacy of Vim-DBS.
This study provides Class IV evidence that for patients with medically refractory severe ET, the efficacy of Vim-DBS severely decreases over 10 years.
深部脑刺激（DBS）于腹侧中间丘脑核（Vim）治疗药物难治性严重特发性震颤（ET）已有应用，但长期疗效仍有争议。
20 例 ET 患者接受 DBS 治疗，在基线、短期刺激开启时（术后 13.1±1.9 个月，均值±SEM）和长期刺激开启/关闭（刺激 ON/OFF）时进行标准化视频记录检查；所有评估均在植入后 32-120 个月（71.9±6.9 个月）进行。主要结局是由 2 位经过培训的运动障碍神经科医生进行盲法评估的震颤评定量表（TRS）。次要结局包括 TRS 子量表 A、B 和 C、阿基米德螺旋评分和日常生活活动评分。在长期随访中，用加速度计记录震颤。在亚组中评估刺激关闭后 1 小时的反弹效应。
在非刺激和刺激条件下，震颤严重度随时间推移显著恶化。Vim-DBS 可显著改善短期和长期 TRS。螺旋评分和功能测量也显示出相似的改善。所有变化均具有高度显著性。然而，刺激效果与手术时间呈负相关（ρ=-0.78， < 0.001）。这对于次要结局也是如此。只有三分之一的患者在刺激关闭 60 分钟后出现反弹效应终止。与刺激关闭相比，TRS 在刺激开启时的长期恶化更明显，表明对刺激的适应。
Vim-DBS 的长期疗效丧失。需要努力提高 Vim-DBS 的长期疗效。
本研究提供了 IV 级证据，表明对于药物难治性严重 ET 患者，Vim-DBS 的疗效在 10 年内严重下降。
