van der Kamp W, Maertens de Noordhout A, Thompson P D, Rothwell J C, Day B L, Marsden C D
MRC Human Movement and Balance Unit, National Hospital for Nervous Diseases, London, UK.
Ann Neurol. 1991 Jan;29(1):6-12. doi: 10.1002/ana.410290104.
Central motor conduction times for the adductor pollicis muscle, the twitch force of that muscle to scalp magnetic motor cortex stimulation, and the maximum force of phasic voluntary contraction of the same muscle were measured in 15 patients with multiple sclerosis. Two tests of manual dexterity of the same hand also were studied: the Purdue pegboard test, and the maximal frequency of a scissors movement of the thumb and index finger. The patients had normal strength or minimal weakness of the intrinsic muscles of the hand on clinical examination. The mean central motor conduction times for the adductor pollicis muscle for the patients were longer than normal, the peak twitch force of the adductor pollicis muscle evoked by cortical stimulation and the maximum force of a phasic voluntary contraction of the adductor pollicis muscle were smaller than normal. There were strong correlations between all these measures. Central motor conduction time in the patients was inversely correlated with voluntary phasic force and the twitch force after cortical stimulation. That is, the longer the central motor conduction time, the weaker the force. Prolonged central motor conduction time is likely to be accompanied by conduction block in corticomotoneuron pathways. The correlation of central motor conduction time with voluntary phasic force and the twitch force most likely reflects the degree of conduction block and temporal dispersion rather than delay in conduction per se. These results indicate that objective assessments of phasic muscle strength may reveal correlations with central motor conduction time that are not evident on conventional clinical examination which assesses tonic muscle contraction strength.(ABSTRACT TRUNCATED AT 250 WORDS)
对15例多发性硬化症患者测量了拇内收肌的中枢运动传导时间、该肌肉对头皮磁运动皮层刺激的抽搐力以及同一肌肉的相位性随意收缩最大力。还研究了同一只手的两项手动灵巧性测试：普渡钉板测试以及拇指和食指剪刀式运动的最大频率。临床检查时，这些患者手部固有肌肉力量正常或仅有轻微无力。患者拇内收肌的平均中枢运动传导时间长于正常，皮层刺激诱发的拇内收肌抽搐力峰值以及拇内收肌相位性随意收缩最大力均小于正常。所有这些测量值之间存在强相关性。患者的中枢运动传导时间与随意相位力以及皮层刺激后的抽搐力呈负相关。也就是说，中枢运动传导时间越长，力量越弱。中枢运动传导时间延长可能伴有皮质运动神经元通路的传导阻滞。中枢运动传导时间与随意相位力和抽搐力的相关性很可能反映了传导阻滞程度和时间离散，而非传导本身的延迟。这些结果表明，对相位性肌肉力量的客观评估可能揭示与中枢运动传导时间的相关性，而这在评估紧张性肌肉收缩力量的传统临床检查中并不明显。（摘要截短于250词）
