苍白球切开术对抽动秽语综合征病人脑代谢的影响

Effect of pallidotomy on cerebral metabolism in patients with Tourette syndrome

目的分析与抽动秽语综合征(TS)关系最为密切的运动通路和边缘通路的代谢特点及苍白球腹后部切开术(PVP)对其影响。方法在术前1周和术后3个月,对6例TS病人进行18F脱氧葡萄糖正电子发射断层显像(18FDG-PET)脑代谢成像,分析运动和边缘通路的葡萄糖代谢特点,比较手术前后的代谢变化。结果TS病人运动通路中的皮质结构糖代谢增高,边缘通路中的扣带回、颞叶内侧皮质和尾状核代谢低于正常。术后运动通路中的高代谢区较术前下降,边缘通路中的低代谢区变化不明显;抽动评分改善率与运动通路结构放射性计数比值改善率有相关关系,与边缘通路无明显的相关性。结论TS病人运动通路相关皮质葡萄糖代谢率增高,边缘通路代谢率降低;推测两个通路的功能异常、代谢活性相反可能是TS的病理生理学基础。PVP对运动通路和边缘通路的功能异常具有调节作用。

Objective To study the cerebral metabolism of the motor circuit and anterior cingulate circuit closely associated with Tourette syndrome (TS) and observe their metabolic changes following pallidotomy. Methods Six patients with TS receiving pallidotomy underwent examination with positron emission tomography with 18-fluorodeoxyglucose (FDG-PET) 1 week before and 3 months after operation respectively, to evaluate the changes in the metabolic rate of the motor and anterior cingulated circuits in comparison with normal control subjects. The radioactivity ratio (RAR) in the areas with metabolic abnormalities in the two circuits was measured, and compared with the same areas in normal control subjects. The severity of the symptom was assessed in relation to RAR. Results Before operation, hypermetabolism was observed in the cortical regions in the motor circuit, whereas hypometabolism was detected in the cingulate cortex, temporal neocortex and caudate of the anterior cingulate circuit. The hypermetabolic areas in the motor circuit were decreased after the operation, but the hypometabolic areas remained unchanged in the anterior cingulated circuit. The Yale Global Tic Severity Scale (YGTSS) scores were found to relate to RAR. Conclusions Hypermetabolism in the cortical structures of the motor circuit and hypometabolism of the anterior cingulated circuit defined by PET characterize patients with TS. Abnormal metabolism in the two circuits may constitute the pathophysiological basis of TS. Pallidotomy serves as an effective intervention to regulate the abnormal metabolism in the two circuits.