Muller Jennifer, Alizadeh Mahdi, Mohamed Feroze B, Riley Jonathan, Pearce John J, Trieu Benjamin, Liang Tsao-Wei, Romo Victor, Sharan Ashwini, Wu Chengyuan
Departments of1Radiology.
2Neurosurgery.
J Neurosurg. 2018 Dec 14;131(5):1520-1531. doi: 10.3171/2018.7.JNS18541. Print 2019 Nov 1.
Deep brain stimulation (DBS) is an effective procedure in improving motor symptoms for patients with advanced Parkinson's disease (PD) through the use of high-frequency stimulation. Although one of the most commonly used target sites for DBS, sensorimotor regions of the globus pallidus interna (GPi) have yet to be thoroughly described with advanced neuroimaging analysis in vivo for human subjects. Furthermore, many imaging studies to date have been performed in a research setting and bring into question the feasibility of their applications in a clinical setting, such as for surgical planning. This study compares two different tractography methods applied to clinically feasible acquisition sequences in identifying sensorimotor regions of the GPi and the subthalamic nucleus (STN) in patients with advanced PD selected to undergo DBS.
Seven patients with refractory PD selected for DBS were examined by MRI. Diffusion images were acquired with an average acquisition time of 15 minutes. Probabilistic and deterministic tractography methods were applied to each diffusion-weighted data set using FSL and MRtrix, respectively. Fiber assignment was performed using combined sensorimotor areas as initiation seeds and the STN and GPi, separately, as inclusion masks. Corticospinal tracts were excluded by setting the cerebral peduncles as exclusion masks. Variability between proposed techniques was shown using center of gravity (CoG) coordinates.
Deterministic and probabilistic corticopallidal and corticosubthalamic pathways were successfully reconstructed for all subjects across all target sites (bilaterally). Both techniques displayed large connections between the sensorimotor cortex with the posterolateral aspect of the ipsilateral GPi and the posterosuperolateral aspect of the ipsilateral STN. The average variability was 2.67 mm, with the probabilistic method identifying the CoG consistently more posterior and more lateral than the deterministic method.
Successful delineation of the sensorimotor regions in both the GPi and STN is achievable within a clinically reasonable timeframe. The techniques described in this paper may enhance presurgical planning with increased accuracy and improvement of patient outcomes in patients undergoing DBS. The variability found between tracking techniques warrants the use of the probabilistic tractography method over the deterministic method for presurgical planning. Probabilistic tractography was found to have an advantage over deterministic tractography in its sensitivity, in accurately describing previously described tracts, and in its ability to detect a larger number of fibers.
脑深部电刺激（DBS）是一种通过高频刺激改善晚期帕金森病（PD）患者运动症状的有效方法。虽然苍白球内侧部（GPi）的感觉运动区域是DBS最常用的靶点部位之一，但尚未通过先进的神经影像学分析在人体活体中进行全面描述。此外，迄今为止的许多影像学研究都是在研究环境中进行的，其在临床环境中的应用可行性受到质疑，例如用于手术规划。本研究比较了两种不同的纤维束成像方法应用于临床可行的采集序列，以识别选择接受DBS的晚期PD患者的GPi和丘脑底核（STN）的感觉运动区域。
对7例选择接受DBS的难治性PD患者进行MRI检查。采集扩散图像，平均采集时间为15分钟。分别使用FSL和MRtrix将概率性和确定性纤维束成像方法应用于每个扩散加权数据集。使用联合感觉运动区域作为起始种子，并分别将STN和GPi作为包含掩码进行纤维分配。通过将大脑脚设置为排除掩码来排除皮质脊髓束。使用重心（CoG）坐标显示所提出技术之间的变异性。
在所有靶点部位（双侧）为所有受试者成功重建了确定性和概率性的皮质苍白球和皮质丘脑底核通路。两种技术均显示感觉运动皮层与同侧GPi的后外侧以及同侧STN的后上外侧之间有大量连接。平均变异性为2.67毫米，概率性方法确定的CoG始终比确定性方法更靠后且更靠外侧。
在临床合理的时间范围内，可以成功描绘出GPi和STN中的感觉运动区域。本文所述技术可能会提高术前规划的准确性，并改善接受DBS患者的治疗效果。在术前规划中，两种追踪技术之间的变异性使得概率性纤维束成像方法比确定性方法更具优势。发现概率性纤维束成像在敏感性、准确描述先前描述的纤维束以及检测更多纤维的能力方面优于确定性纤维束成像。
