Mahlknecht Philipp, Akram Harith, Georgiev Dejan, Tripoliti Elina, Candelario Joseph, Zacharia Andre, Zrinzo Ludvic, Hyam Jonathan, Hariz Marwan, Foltynie Thomas, Rothwell John C, Limousin Patricia
Sobell Department of Motor Neuroscience, UCL Institute of Neurology, National Hospital for Neurology and Neurosurgery, London, United Kingdom.
Department of Neurology, Innsbruck Medical University, Innsbruck, Austria.
Mov Disord. 2017 Aug;32(8):1174-1182. doi: 10.1002/mds.27042. Epub 2017 Jun 7.
Subthalamic deep brain stimulation (STN-DBS) is an effective treatment for Parkinson's disease (PD), but can have side effects caused by stimulus spread to structures outside the target volume such as the pyramidal tract.
To assess the relevance of pyramidal tract activation with STN-DBS in PD.
In a multimodal, blinded study in 20 STN-DBS patients, we measured stimulation thresholds for evoking electromyographic activity in orbicularis oris and first dorsal interosseous muscles at each of 150 electrode sites. We also modeled the electric field spread and calculated its overlap with the estimated anatomical location of corticospinal and corticobulbar tracts from primary motor cortex using 3 Tesla MRI probabilistic tractography.
Mean resting motor thresholds were significantly lower for the contralateral orbicularis oris (3.5 ± 1.0 mA) compared with ipsilaterally (4.1 ± 1.1 mA) and with the contralateral first dorsal interosseous (4.0 ± 1.2 mA). The modeled volumes of corticobulbar and corticospinal tract activated correlated inversely with the resting motor threshold of the contralateral orbicularis oris and first dorsal interosseous, respectively. Active motor thresholds were significantly lower compared with resting motor thresholds by around 30% to 35% and correlated with the clinically used stimulation amplitude. Backward multiple regression in 12 individuals with a "lateral-type" speech showed that stimulation amplitude, levodopa equivalent dose reduction postsurgery, preoperative speech intelligibility, and first dorsal interosseous resting motor thresholds explained 79.9% of the variance in postoperative speech intelligibility.
Direct pyramidal tract activation can occur at stimulation thresholds that are within the range used in clinical routine. This spread of current compromises increase in stimulation strengths and is related to the development of side effects such as speech disturbances with chronic stimulation. © 2017 International Parkinson and Movement Disorder Society.
丘脑底核深部脑刺激（STN-DBS）是治疗帕金森病（PD）的一种有效方法，但可能会因刺激扩散到目标体积之外的结构（如锥体束）而产生副作用。
评估PD患者中锥体束激活与STN-DBS的相关性。
在一项针对20例接受STN-DBS治疗患者的多模式、盲法研究中，我们测量了150个电极位点处诱发口轮匝肌和第一背侧骨间肌肌电图活动的刺激阈值。我们还对电场扩散进行了建模，并使用3特斯拉MRI概率性纤维束成像计算其与来自初级运动皮层的皮质脊髓束和皮质延髓束估计解剖位置的重叠情况。
与同侧（4.1±1.1 mA）和对侧第一背侧骨间肌（4.0±1.2 mA）相比，对侧口轮匝肌的平均静息运动阈值（3.5±1.0 mA）显著更低。所建模的皮质延髓束和皮质脊髓束激活体积分别与对侧口轮匝肌和第一背侧骨间肌的静息运动阈值呈负相关。主动运动阈值比静息运动阈值显著低约30%至35%，且与临床使用的刺激幅度相关。对12例具有“外侧型”言语的个体进行的向后多元回归显示，刺激幅度、术后左旋多巴等效剂量减少量、术前言语清晰度以及第一背侧骨间肌静息运动阈值解释了术后言语清晰度变异的79.9%。
在临床常规使用的刺激阈值范围内可发生直接的锥体束激活。这种电流扩散会影响刺激强度的增加，并与慢性刺激导致的言语障碍等副作用的发生有关。© 2017国际帕金森病和运动障碍协会
