Departments of1Neurosurgery.
2David Geffen School of Medicine at UCLA, Los Angeles, California.
J Neurosurg. 2018 Jan;128(1):215-221. doi: 10.3171/2016.10.JNS161603. Epub 2017 Feb 24.
Essential tremor and Parkinson's disease-associated tremor are extremely prevalent within the field of movement disorders. The ventral intermediate (VIM) nucleus of the thalamus has been commonly used as both a neuromodulatory and neuroablative target for the treatment of these forms of tremor. With both deep brain stimulation and Gamma Knife radiosurgery, there is an abundance of literature regarding the surgical planning, targeting, and outcomes of these methodologies. To date, there have been no reports of frameless, linear accelerator (LINAC)-based thalomotomies for tremor. The authors report the case of a patient with tremor-dominant Parkinson's disease, with poor tremor improvement with medication, who was offered LINAC-based thalamotomy. High-resolution 0.9-mm isotropic MR images were obtained, and simulation was performed via CT with 1.5-mm contiguous slices. The VIM thalamic nucleus was determined using diffusion tensor imaging (DTI)-based segmentation on FSL using probabilistic tractography. The supplemental motor and premotor areas were the cortical target masks. The authors centered their isocenter within the region of the DTI-determined target and treated the patient with 140 Gy in a single fraction. The DTI-determined target had coordinates of 14.2 mm lateral and 8.36 mm anterior to the posterior commissure (PC), and 3 mm superior to the anterior commissure (AC)-PC line, which differed by 3.30 mm from the original target determined by anatomical considerations (15.5 mm lateral and 7 mm anterior to the PC, and 0 mm superior to the AC-PC line). There was faint radiographic evidence of lesioning at the 3-month follow-up within the target zone, which continued to consolidate on subsequent scans. The patient experienced continued right upper-extremity resting tremor improvement starting at 10 months until it was completely resolved at 22 months of follow-up. Frameless LINAC-based thalamotomy guided by DTI-based thalamic segmentation is a feasible method for achieving radiosurgical lesions of the VIM thalamus to treat tremor.
特发性震颤和帕金森病相关震颤在运动障碍领域极为常见。丘脑腹中间核（VIM）已被广泛用作治疗这些震颤形式的神经调节和神经消融靶点。对于深部脑刺激和伽玛刀放射外科手术，有大量关于这些方法的手术规划、靶向和结果的文献。迄今为止，尚无关于无框架、线性加速器（LINAC）基底丘脑切开术治疗震颤的报告。作者报告了一例以震颤为主的帕金森病患者，药物治疗震颤改善不佳，患者接受了 LINAC 基底丘脑切开术。获得了高分辨率 0.9 毫米各向同性磁共振成像，并通过 CT 进行了 1.5 毫米连续切片的模拟。使用基于扩散张量成像（DTI）的 FSL 分割，通过概率追踪确定 VIM 丘脑核。辅助运动区和运动前区是皮质靶掩模。作者将等中心点置于 DTI 确定的靶区中心，并对患者进行 140 Gy 单次分割治疗。DTI 确定的目标坐标为后联合（PC）后外侧 14.2 毫米和前侧 8.36 毫米，前联合（AC）-PC 线上方 3 毫米，与解剖学考虑确定的原始目标相差 3.30 毫米（PC 后外侧 15.5 毫米和前侧 7 毫米，AC-PC 线上方 0 毫米）。在 3 个月的随访中，在靶区范围内有轻微的放射影像学证据显示病变，随后的扫描显示病变继续巩固。患者从 10 个月开始持续出现右侧上肢静止性震颤改善，直到 22 个月的随访时完全缓解。基于 DTI 丘脑分割的无框架 LINAC 基底丘脑切开术是一种可行的方法，可以实现 VIM 丘脑的放射外科损伤，以治疗震颤。
