Department of Neurology and Neuropsychiatry, Assiut University Hospital, Assiut, Egypt.
Neurophysiol Clin. 2011 Jul;41(3):107-13. doi: 10.1016/j.neucli.2011.03.002. Epub 2011 Apr 19.
In Alzheimer's disease (AD), transcranial magnetic stimulation (TMS) studies have been limited to test motor cortical excitability. The aim of this study was to investigate the inhibitory circuits of the motor cortex and to relate these to measures of cognitive function in AD patients. Results were compared with those of a control group of healthy subjects matched for age, sex and education.
Forty-five AD patients and 37 healthy volunteers were included in the study. Each participant received a neurological evaluation, Mini-Mental State Examination (MMSE), and Clinical Dementia Rating (CDR). Neurophysiological evaluations included resting and active motor threshold (rMT and aMT), motor evoked potential (MEP), cortical silent period (CSP), and transcallosal inhibition (TI).
AD patients showed significantly reduced rMT, aMT and shorter MEP onset latency; in addition there was a prolongation of both CSP and TI. There was a significant positive correlation between the MMSE and CDR, on the one hand, and aMT and rMT, on the other hand, whereas the correlation was negative with CSP and TI durations.
AD is associated with hyperexcitability of the motor cortex, which supports the hypothesis that changes in GABAb and glutamate function are important factors in cognitive impairment.
在阿尔茨海默病（AD）中，经颅磁刺激（TMS）研究仅限于测试运动皮质兴奋性。本研究的目的是研究运动皮质的抑制性回路，并将这些回路与 AD 患者的认知功能测量相关联。结果与年龄、性别和教育相匹配的健康对照组的结果进行了比较。
45 名 AD 患者和 37 名健康志愿者被纳入研究。每位参与者都接受了神经学评估、简易精神状态检查（MMSE）和临床痴呆评定量表（CDR）。神经生理学评估包括静息和活动运动阈值（rMT 和 aMT）、运动诱发电位（MEP）、皮质静息期（CSP）和皮质间抑制（TI）。
AD 患者的 rMT、aMT 明显降低，MEP 起始潜伏期缩短；此外，CSP 和 TI 均延长。MMSE 和 CDR 与 aMT 和 rMT 呈正相关，而与 CSP 和 TI 持续时间呈负相关。
AD 与运动皮质的过度兴奋有关，这支持了 GABA 和谷氨酸功能变化是认知障碍的重要因素的假说。
