Cicinelli P, Traversa R, Bassi A, Scivoletto G, Rossini P M
I.R.C.C.S. Ospedale di Riabilitazione S. Lucia, Rome, Italy.
Muscle Nerve. 1997 May;20(5):535-42. doi: 10.1002/(sici)1097-4598(199705)20:5<535::aid-mus1>3.0.co;2-a.
Focal magnetic transcranial stimulation (TCS) is employed for mapping of the motor cortical output to abductor digiti minimi (ADM) muscle. The aim of this study was to evaluate the interhemispheric asymmetries in normals. Motor maps were obtained through motor evoked potentials (MEPs) recordings from ADM muscle in 20 healthy subjects in right and left hemispheres TCS. Measurement of several indexes such as excitability threshold, MEPs amplitude, MEPs latency, and silent period duration did not show differences between the hemispheres. Moreover, no interhemispheric asymmetries were found when the amplitude ratio values were analyzed. The hand motor cortical area, as represented by the number of responsive sites (3.6 vs. 3.5) and the "hot spot" site localization presented a fairly symmetrical organization. Absolute values displayed a relatively wide intersubject variability, while their interhemispheric differences were extremely restricted. This observation can offer a new tool in diagnosing and following up neurological disorders affecting the central motor system, mainly for those concerning monohemispheric lesions.
局灶性磁刺激经颅刺激（TCS）用于绘制运动皮质至小指展肌（ADM）的输出图。本研究的目的是评估正常人群的半球间不对称性。通过对20名健康受试者左右半球TCS刺激下ADM肌肉运动诱发电位（MEP）记录来获得运动图谱。对兴奋性阈值、MEP波幅、MEP潜伏期和静息期持续时间等多个指标的测量未显示半球间存在差异。此外，分析波幅比值时也未发现半球间不对称性。以反应位点数量（3.6对3.5）和“热点”位点定位所代表的手部运动皮质区域呈现出相当对称的组织结构。绝对值显示出相对较大的个体间变异性，而它们的半球间差异则极为有限。这一观察结果可为诊断和随访影响中枢运动系统的神经系统疾病提供一种新工具，主要针对那些涉及单半球病变的疾病。
