Ikramuddin Salman S, Brinda Annemarie K, Butler Rebecca D, Hill Meghan E, Dharnipragada Rajiv, Aman Joshua E, Schrock Lauren E, Cooper Scott E, Palnitkar Tara, Patriat Rémi, Harel Noam, Vitek Jerrold L, Johnson Matthew D
Department of Neurology, University of Minnesota, Minneapolis, MN, United States.
Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN, United States.
Front Neurol. 2023 Nov 9;14:1258895. doi: 10.3389/fneur.2023.1258895. eCollection 2023.
To characterize how the proximity of deep brain stimulation (DBS) active contact locations relative to the cerebellothalamic tract (CTT) affect clinical outcomes in patients with essential tremor (ET).
DBS is an effective treatment for refractory ET. However, the role of the CTT in mediating the effect of DBS for ET is not well characterized. 7-Tesla (T) MRI-derived tractography provides a means to measure the distance between the active contact and the CTT more precisely.
A retrospective review was conducted of 12 brain hemispheres in 7 patients at a single center who underwent 7T MRI prior to ventral intermediate nucleus (VIM) DBS lead placement for ET following failed medical management. 7T-derived diffusion tractography imaging was used to identify the CTT and was merged with the post-operative CT to calculate the Euclidean distance from the active contact to the CTT. We collected optimized stimulation parameters at initial programing, 1- and 2-year follow up, as well as a baseline and postoperative Fahn-Tolosa-Marin (FTM) scores.
The therapeutic DBS current mean (SD) across implants was 1.8 mA (1.8) at initial programming, 2.5 mA (0.6) at 1 year, and 2.9 mA (1.1) at 2-year follow up. Proximity of the clinically-optimized active contact to the CTT was 3.1 mm (1.2), which correlated with lower current requirements at the time of initial programming (R = 0.458, = 0.009), but not at the 1- and 2-year follow up visits. Subjects achieved mean (SD) improvement in tremor control of 77.9% (14.5) at mean follow-up time of 22.2 (18.9) months. Active contact distance to the CTT did not predict post-operative tremor control at the time of the longer term clinical follow up (R = -0.073, = 0.58).
Active DBS contact proximity to the CTT was associated with lower therapeutic current requirement following DBS surgery for ET, but therapeutic current was increased over time. Distance to CTT did not predict the need for increased current over time, or longer term post-operative tremor control in this cohort. Further study is needed to characterize the role of the CTT in long-term DBS outcomes.
明确深部脑刺激（DBS）有效触点位置与小脑丘脑束（CTT）的接近程度如何影响特发性震颤（ET）患者的临床疗效。
DBS是治疗难治性ET的有效方法。然而，CTT在介导DBS对ET的作用方面尚未得到充分阐明。7特斯拉（T）磁共振成像（MRI）衍生的纤维束成像提供了一种更精确测量有效触点与CTT之间距离的方法。
对单一中心7例患者的12个脑半球进行回顾性研究，这些患者在药物治疗失败后接受丘脑腹中间核（VIM）DBS电极植入术前均进行了7T MRI检查。利用7T衍生的扩散纤维束成像来识别CTT，并将其与术后CT图像融合以计算有效触点到CTT的欧几里得距离。我们收集了初始程控、1年和2年随访时的优化刺激参数，以及基线和术后的法恩-托洛萨-马林（FTM）评分。
植入物的治疗性DBS电流均值（标准差）在初始程控时为1.8 mA（1.8），1年时为2.5 mA（0.6），2年随访时为2.9 mA（1.1）。临床优化的有效触点与CTT的接近程度为3.1 mm（1.2），这与初始程控时较低的电流需求相关（R = -0.458，P = 0.009），但在1年和2年随访时不相关。在平均随访时间22.2（18.9）个月时，受试者的震颤控制平均改善率（标准差）为77.9%（14.5）。在长期临床随访时，有效触点到CTT的距离不能预测术后震颤控制情况（R = -0.073，P = 0.58）。
ET患者DBS手术中，有效DBS触点与CTT的接近程度与较低的治疗电流需求相关，但治疗电流随时间增加。在该队列中，到CTT的距离不能预测随时间增加的电流需求或长期术后震颤控制情况。需要进一步研究以明确CTT在DBS长期疗效中的作用。
