Department of Biomedical Engineering, Schulich School of Engineering, University of Calgary, Calgary, Alberta, Canada.
Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada.
Mov Disord. 2023 May;38(5):831-842. doi: 10.1002/mds.29350. Epub 2023 Mar 22.
Magnetic resonance-guided focused-ultrasound (MRgFUS) thalamotomy is an effective treatment for essential and other tremors. It targets the ventrointermedius (Vim) nucleus, which is the thalamic relay in a proprioceptive pathway, and contains kinesthetic cells. Although MRgFUS thalamotomy reduces some risks associated with more invasive surgeries, it still has side effects, such as balance and gait disturbances; these may be caused by the lesion impacting proprioception.
Our aim was to quantitatively measure the effects of MRgFUS on proprioception and limb use in essential tremor patients. We hypothesized that this thalamotomy alters proprioception, because the sensorimotor Vim thalamus is lesioned.
Proprioception was measured using the Kinarm exoskeleton robot in 18 patients. Data were collected pre-operatively, and then 1 day, 3 months, and 1 year after surgery. Patients completed four tasks, assessing motor coordination and postural control, goal-directed movement and bimanual planning, position sense, and kinesthesia.
Immediately after surgery there were changes in posture speed (indicating tremor improvement), and in bimanual hand use, with the untreated limb being preferred. However, these measures returned to pre-operative baseline over time. There were no changes in parameters related to proprioception. None of these measures correlated with lesion size or lesion-overlap with the dentato-rubro-thalamic tract.
This is the first quantitative assessment of proprioception and limb preference following MRgFUS thalamotomy. Our results suggest that focused-ultrasound lesioning of the Vim thalamus does not degrade proprioception but alters limb preference. This change may indicate a required "relearning" in the treated limb, because the effect is transient. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
磁共振引导聚焦超声（MRgFUS）丘脑切开术是治疗原发性震颤和其他震颤的有效方法。它的目标是腹侧中间核（Vim），这是本体感觉通路中的丘脑中继核，包含运动觉细胞。虽然 MRgFUS 丘脑切开术降低了一些与更具侵袭性手术相关的风险，但它仍然存在副作用，例如平衡和步态障碍；这些可能是由于病灶影响本体感觉。
我们的目的是定量测量 MRgFUS 对原发性震颤患者本体感觉和肢体使用的影响。我们假设这种丘脑切开术改变了本体感觉，因为感觉运动 Vim 丘脑被损伤。
使用 Kinarm 外骨骼机器人测量 18 例患者的本体感觉。数据在术前收集，然后在术后 1 天、3 个月和 1 年收集。患者完成四项任务，评估运动协调和姿势控制、目标导向运动和双手规划、位置感和运动觉。
手术后立即出现姿势速度的变化（表明震颤改善），以及未治疗侧手的使用偏好增加。然而，这些措施随着时间的推移恢复到术前基线。与本体感觉相关的参数没有变化。这些措施与病灶大小或病灶与齿状红核丘脑束的重叠均无相关性。
这是首次对 MRgFUS 丘脑切开术后本体感觉和肢体偏好进行定量评估。我们的结果表明，Vim 丘脑的聚焦超声损伤不会降低本体感觉，但会改变肢体偏好。这种变化可能表明治疗侧需要“重新学习”，因为这种影响是暂时的。© 2023 作者。运动障碍由 Wiley 期刊公司代表国际帕金森和运动障碍学会出版。
