Prolonged cortical silent period but normal sensorimotor plasticity in spinocerebellar ataxia 6
Prolonged cortical silent period but normal sensorimotor plasticity in spinocerebellar ataxia 6
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DOI：
10.1002/mds.21847
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发表时间：
2008-02-15
影响因子：
8.6
通讯作者：
Bhatia, Kailash P.
中科院分区：
文献类型：
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作者：
Teo, James T. H.;Schneider, Susanne A.;Bhatia, Kailash P.
脊髓小脑性共济失调6(SCA6)是一种以CACNA1A基因三核苷酸重复扩增和迟发性双侧小脑萎缩为特征的遗传性疾病。目前尚不清楚小脑以外是否存在显著的病理改变。我们使用经颅磁刺激来评估8名SCA6患者和8名年龄匹配的对照组的感觉运动皮质环路和皮质可塑性。通过有节奏的敲击任务来评估行为表现。SCA6患者的神经生理学检查显示皮层静默期延长，但MEP募集曲线正常，短潜伏期传入抑制，长潜伏期传入抑制和同侧静默期。正常情况下，配对-联想刺激诱导也会增加运动诱发电位。SCA6患者线索节律性敲击的变异性比正常人更大，去掉线索后变异性更大；相比之下，正常受试者在线索和非线索节律性敲击之间的变异性相似。用Wing-Kristofferson计时模型分析表明，时钟变化和电机延迟变化都是异常的。结论。在SCA6中，感觉运动整合回路和感觉运动皮质LTP样可塑性机制未受损害。SCA6的CSP延长，就像其他小脑萎缩一样，表明这种神经生理学变化是小脑功能障碍的典型表现。(C)2007年运动无序协会。
Spinocerebellar ataxia 6 (SCA6) is a hereditary disease characterized by a trinucleotide repeat expansion in the CACNA1A gene and late-onset bilateral cerebellar atrophy. It is unclear if there is significant pathology outside of the cerebellum. We used transcranial magnetic stimulation to assess sensorimotor cortical circuits and cortical plasticity in 8 SCA6 patients and 8 age-matched controls. Behavioral performance was assessed using a rhythmic tapping task. Neurophysiological measures of SCA6 patients showed a prolonged cortical silent period (CSP) but normal MEP recruitment curve, short-latency afferent inhibition, long-latency afferent inhibition and ipsilateral silent period. Paired-associative stimulation induction also increased motor-evoked potentials normally. SCA6 patients had greater variability with cued rhythmic tapping than normals and deteriorated when the cue was removed; in comparison, normal subjects had similar variability between cued and uncued rhythmic tapping. Analysis using a Wing-Kristofferson timing model indicated that both clock variance and motor delay variance were abnormal. Conclusion. In SCA6, the circuits for sensorimotor integration and the mechanisms for LTP-like plasticity in the sensorimotor cortex are unimpaired. A prolonged CSP in SCA6 just like in other cerebellar atrophies would suggest that this neurophysiological change typifies cerebellar dysfunction. (c) 2007 Movement Disorder Society.