Miyagishima Takaaki, Takahashi Akio, Kikuchi Senichiro, Watanabe Katsushige, Hirato Masafumi, Saito Nobuhito, Yoshimoto Yuhei
Department of Neurosurgery, Gunma University School of Medicine, Maebashi, Japan.
Stereotact Funct Neurosurg. 2007;85(5):225-34. doi: 10.1159/000103261. Epub 2007 May 25.
Stereotactic ventralis intermedius (Vim) thalamotomy is effective for essential tremor (ET) of the limb, but the effect on the activity of the sensorimotor cortex is still unclear. The functional changes in this cortical area of patients with ET after Vim thalamotomy were investigated using functional magnetic resonance (fMR) imaging. Six patients underwent Vim thalamotomy for medically intractable ET, predominantly in the right hand. 1.5-tesla fMR imaging was performed using the blood oxygenation level-dependent sequence, before and after Vim thalamotomy, during passive movements with right wrist flexion and extension. Before and after images were analyzed using SPM99 software. Activation in the sensorimotor cortex and supplementary motor area evoked by wrist passive movement was observed both before and after surgery. Group analysis of changes in the blood oxygenation level-dependent response revealed a significantly smaller activated area postoperatively. Activation at the fundus of the central sulcus was characteristically decreased. All patients showed marked improvement in tremor after Vim thalamotomy. No patient experienced neurological deficits. fMR imaging showed that activation at the fundus of the central sulcus evoked by passive wrist movement was suppressed after Vim thalamotomy in ET patients, probably due to disruption of the thalamocortical pathway. The fundus of the central sulcus (Brodmann area 3a) is likely to be one of the key relays in the tremor circuit.
立体定向腹中间核（Vim）丘脑切开术对肢体特发性震颤（ET）有效，但对感觉运动皮层活动的影响仍不清楚。利用功能磁共振（fMR）成像研究了Vim丘脑切开术后ET患者该皮层区域的功能变化。6例患者因药物难治性ET接受了Vim丘脑切开术，主要累及右手。在Vim丘脑切开术前和术后，于右手腕屈伸的被动运动期间，采用血氧水平依赖序列进行1.5特斯拉fMR成像。使用SPM99软件分析术前和术后图像。手术前后均观察到腕部被动运动诱发的感觉运动皮层和辅助运动区激活。对血氧水平依赖反应变化的组分析显示，术后激活区域明显变小。中央沟底部的激活明显减少。所有患者在Vim丘脑切开术后震颤均有明显改善。无患者出现神经功能缺损。fMR成像显示，ET患者Vim丘脑切开术后，被动腕部运动诱发的中央沟底部激活受到抑制，这可能是由于丘脑皮质通路中断所致。中央沟底部（布罗德曼3a区）可能是震颤环路中的关键中继站之一。
