共济失调患者手运动时脑激活区域的定量分析

Quantitative analysis of the hand motor cortex in ataxia patients using blood oxygen level dependent functional magnetic resonance imaging

目的 利用血氧水平依赖性功能性磁共振成像（BOLD-fMRI）技术,探讨共济失调患者在主动与被动复杂对指运动模式下关键脑功能区激活体积和强度的变化.方法 选取共济失调患者16例作为病例组,另选10名健康志愿者作为正常组.入选者均进行主动与被动复杂对指运动,在这两种运动模式下进行BOLD-fMRl检查,记录相应脑运动功能区的激活体积和强度并进行定量分析.采用共济失调量表（ICARS）对共济失调患者的共济运动进行评分.结果 病例组患手主动运动时,同侧辅助运动区（SMA）激活体积大于正常组同侧手的测定结果,激活强度也高于正常组;同侧小脑的激活体积和激活强度则小于正常组,小脑激活区的出现率也低于正常组.病例组患手主动运动时,同侧小脑激活区的体积、激活强度与共济失调量表评分无相关性.结论 共济失调患者患侧小脑功能下降,而同侧SMA可以发挥代偿作用,临床共济失调量表的评分尚不能准确反映小脑功能情况.

Objective To study the characteristics of the hand motor cortex in ataxia patients during active and passive finger-to-thumb opposition movements using bold oxygenation level dependent functional magnetic resonance imaging （BOLD-fMRI）. Methods Ten right-handed healthy volunteers and 16 ataxia patients with motor cortex lesions were selected, and whole-brain BOLD-fMRI examinations were made while the subjects were performing the active and passive movements. Activated volume and intensity were recorded from the corresponding motor cortex and analyzed quantitatively. Meanwhile, the patients＇ coordination was evaluated using the international cooperative ataxia rating scale （ICARS）. Results During passive movement of the ataxia patient＇s affected hands, the ipsilateral supplementary motor area （SMA） activated volume was larger than that during normal ipsilateral hand movement, and the activation intensity was also higher than that in the healthy controls. The ipsilateral cerebellum activated volume and intensity were significantly lower than those in the control group, and the frequency of appearance of the cerebellum was also less. The patients＇ activated volume and intensity in the ipsilateral cerebellum showed no correlation with ICARS scores. Conclusions When the ataxia patients＇ affected side cerebellum was dysfunctional, the ipsilateral SMA could compensate for the weak cerebellum function. The ICARS does not reflect cerebellum function.