Department Stereotactic Neurosurgery, University Hospital Magdeburg, Leipziger Str. 44, 39120, Magdeburg, Germany.
Department of Neurology, OvGU-Magdeburg, Magdeburg, Germany.
Acta Neurochir (Wien). 2021 Jan;163(1):185-195. doi: 10.1007/s00701-020-04495-3. Epub 2020 Nov 10.
Therapeutic effects of deep brain stimulation (DBS) of the subthalamic nucleus (STN) in Parkinson's disease (PD) may in parts be attributed to the stimulation of white matter near the targeted structure. The dentato-rubro-thalamic (DRT) tract supposed to improve tremor control in patients with essential tremor could be one candidate structure. The aim of this study was to investigate the effect of stimulation proximity to the DRT on tremor control in PD patients treated with STN-DBS.
For this retrospective analysis, we included 36 consecutive patients (median age 65.5 years) treated with STN-DBS for disabling motor symptoms including tremor. Stereotactic implantation of DBS electrodes into the motor area of the STN was performed using direct MRI-based targeting and intraoperative microelectrode recording. Tremor severity was assessed preoperatively and at regular intervals postoperatively (Unified Parkinson's Disease Rating Scale III). The DRT was visualized in 60 hemispheres after probabilistic fiber tracking (3-T MRI). The position of active electrode contacts was verified on intraoperative stereotactic X-rays and postoperative CT images after co-registration with 3D treatment planning MRI/CT images. We determined the shortest distance of active contacts to the ipsilateral DRT tracts on perpendicular view slices and correlated this value with tremor change percentage.
Twelve patients had unilateral tremor only, and accordingly, 12 hemispheres were excluded from further imaging analysis. The remaining 60 hemispheres were associated with contralateral resting tremor. Active brain electrode contacts leading to resting tremor improvement (46 hemispheres) had a significantly shorter distance to the DRT (1.6 mm (0.9-2.1) [median (25th-75th percentiles)]) compared with contacts of non-responders (14 hemispheres, distance: 2.8 mm (2-4.6), p < 0.001).
This retrospective analysis suggests that in STN-DBS, better tremor control in PD patients correlates with the distance of active electrode contacts to the DRT. Tractography may optimize both individually DBS targeting and postoperative adjustment of stimulation parameters.
深部脑刺激（DBS）对丘脑底核（STN）的治疗效果部分归因于对目标结构附近的白质的刺激。齿状核红核丘脑束（DRT）被认为可以改善特发性震颤患者的震颤控制，它可能是候选结构之一。本研究旨在调查 STN-DBS 治疗的 PD 患者中刺激接近 DRT 对震颤控制的影响。
本回顾性分析纳入了 36 例连续接受 STN-DBS 治疗的患者（中位年龄 65.5 岁），这些患者因包括震颤在内的运动症状而接受治疗。使用直接基于 MRI 的靶向和术中微电极记录来进行 STN-DBS 电极的立体定向植入。在术前和术后定期（统一帕金森病评定量表 III）评估震颤严重程度。在 60 个半球中使用概率纤维追踪技术（3-T MRI）可视化 DRT。在术中立体定向 X 射线和术后 CT 图像上验证活性电极触点的位置，并与 3D 治疗计划 MRI/CT 图像进行配准。我们确定了在垂直视图切片上活性触点到同侧 DRT 束的最短距离，并将该值与震颤变化百分比相关联。
12 例患者仅单侧震颤，因此排除了 12 个半球的进一步成像分析。其余 60 个半球与对侧静止性震颤相关。导致静止性震颤改善的活性脑电极触点（46 个半球）与 DRT 的距离明显更近（1.6 毫米（0.9-2.1）[中位数（25 百分位数-75 百分位数）]），而无反应者的触点距离较远（14 个半球，距离：2.8 毫米（2-4.6），p<0.001）。
这项回顾性分析表明，在 STN-DBS 中，PD 患者更好的震颤控制与活性电极触点与 DRT 的距离相关。束追踪技术可能优化 DBS 靶向的个体性和术后刺激参数的调整。
