Abstract：
BACKGROUND: Magnetic resonance guided focused ultrasound (MRgFUS) thalamotomy is an effective treatment for drug-resistant tremor. The most frequent side effects are ataxia, gait disturbance, paresthesias, dysgeusia, and hemiparesis. Here, we report the first case of thalamic hand dystonia rapidly occurring after MRgFUS thalamotomy of the ventral intermediate nucleus (V.im).
METHODS: MRgFUS thalamotomy was performed in a 60-year-old left-handed patient for his disabling medically refractory essential tremor. The intervention resulted in a marked reduction of his action tremor. However, the patient developed an unvoluntary abnormal posture in his left hand a few days after the procedure with difficulty holding a cigarette between his fingers. Brain MRI revealed the expected MRgFUS lesion within the right V.im as well as an extension of the lesion anteriorly to the V.im in the ventro-oralis nucleus. Tractography showed that the lesion disrupted the dentato-rubro-thalamic tract as expected with a lesion suppressing tremor. However, the lesion also was interrupted fibers connecting to the superior frontal and pre-central cortices (primary motor cortex, premotor cortex, and supplementary area). We hypothesized that the interventional MRgFUS thalamotomy was slightly off target, which induced a dysfunction within the cortico-striato-thalamo-cortical network and the cerebello-thalamo-cortical pathway reaching a sufficient threshold of basal ganglia/cerebellum circuitry interference to induce dystonia.
CONCLUSIONS: This rare side effect emphasizes the risk of imbalance within the dystonia network (i.e., basal ganglia-cerebello-thalamo-cortical circuit) secondary to V.im thalamotomy.
METHODS: MRgFUS thalamotomy was performed in a 60-year-old left-handed patient for his disabling medically refractory essential tremor. The intervention resulted in a marked reduction of his action tremor. However, the patient developed an unvoluntary abnormal posture in his left hand a few days after the procedure with difficulty holding a cigarette between his fingers. Brain MRI revealed the expected MRgFUS lesion within the right V.im as well as an extension of the lesion anteriorly to the V.im in the ventro-oralis nucleus. Tractography showed that the lesion disrupted the dentato-rubro-thalamic tract as expected with a lesion suppressing tremor. However, the lesion also was interrupted fibers connecting to the superior frontal and pre-central cortices (primary motor cortex, premotor cortex, and supplementary area). We hypothesized that the interventional MRgFUS thalamotomy was slightly off target, which induced a dysfunction within the cortico-striato-thalamo-cortical network and the cerebello-thalamo-cortical pathway reaching a sufficient threshold of basal ganglia/cerebellum circuitry interference to induce dystonia.
CONCLUSIONS: This rare side effect emphasizes the risk of imbalance within the dystonia network (i.e., basal ganglia-cerebello-thalamo-cortical circuit) secondary to V.im thalamotomy.
摘要：
背景：磁共振引导下聚焦超声（MRgFUS）丘脑切开术是一种有效的耐药性震颤治疗方法。最常见的副作用是共济失调，步态紊乱,感觉异常,熟食症,和偏瘫.这里,我们报告了首例在MRgFUS丘脑腹侧中间核切开术后迅速发生的丘脑手部肌张力障碍（V。im).
方法：对一名60岁的左撇子患者进行了MRgFUS丘脑切开术，因为他的医学难治性特发性震颤致残。干预导致他的动作震颤明显减少。然而,手术后几天，患者的左手出现了非自愿的异常姿势，手指之间很难握住香烟。脑部MRI显示右侧V.im内预期的MRgFUS病变，以及前口核V.im的病变向前延伸。气管造影显示，病变如预期的那样破坏了牙本质-红斑-丘脑束，并抑制了震颤。然而,病变也是连接到上额叶和中央前皮质(初级运动皮质，运动前皮质,和补充区域)。我们假设介入MRgFUS丘脑切开术稍微偏离目标，它在皮质-纹状体-丘脑-皮层网络和小脑-丘脑-皮层通路内引起功能障碍，达到足够的基底神经节/小脑电路干扰阈值，以诱导肌张力障碍。
结论：这种罕见的副作用强调了肌张力障碍网络内失衡的风险（即，基底神经节-小脑-丘脑-皮层回路）继发于丘脑切开术。
方法：对一名60岁的左撇子患者进行了MRgFUS丘脑切开术，因为他的医学难治性特发性震颤致残。干预导致他的动作震颤明显减少。然而,手术后几天，患者的左手出现了非自愿的异常姿势，手指之间很难握住香烟。脑部MRI显示右侧V.im内预期的MRgFUS病变，以及前口核V.im的病变向前延伸。气管造影显示，病变如预期的那样破坏了牙本质-红斑-丘脑束，并抑制了震颤。然而,病变也是连接到上额叶和中央前皮质(初级运动皮质，运动前皮质,和补充区域)。我们假设介入MRgFUS丘脑切开术稍微偏离目标，它在皮质-纹状体-丘脑-皮层网络和小脑-丘脑-皮层通路内引起功能障碍，达到足够的基底神经节/小脑电路干扰阈值，以诱导肌张力障碍。
结论：这种罕见的副作用强调了肌张力障碍网络内失衡的风险（即，基底神经节-小脑-丘脑-皮层回路）继发于丘脑切开术。
