Motor evoked potentials in unilateral lingual paralysis after monohemispheric ischaemia
Motor evoked potentials in unilateral lingual paralysis after monohemispheric ischaemia
复制标题
单侧半球缺血后单侧舌麻痹的运动诱发电位
DOI：
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发表时间：
1998
影响因子：
11
通讯作者：
B. Mamoli
中科院分区：
文献类型：
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作者：
W. Muellbacher;Christa Artner;B. Mamoli
单侧上运动神经元损伤后舌麻痹的发生是一种罕见的临床现象，其潜在的病理生理机制尚不清楚。我们研究了健康对照组和一组选定的中风患者的同侧和对侧舌肌的皮质运动表征，以澄清最近单半球缺血后舌麻痹的可变发生率。方法采用特殊的双极表面电极，经颅磁刺激（TMS）人运动皮层和外周电刺激（PES）舌下神经下颌角内侧后，记录同侧和对侧舌肌复合肌肉动作电位（CMAP）。研究了4例单半球首次卒中后舌麻痹患者（组1）和4例对称性舌运动患者（组2），并与40名健康对照者进行了比较。结果对照组两侧大脑半球TMS均能在同侧和对侧舌肌产生CAMPs，分别通过交叉和非交叉的中枢运动通路。在40名健康对照者中，与同侧反应相比，两侧半球的TMS从对侧肌肉引起的CMAP的幅度显著更大，起始时间更短（p<0.0001）。在患者组中，受影响半球的TMS未能从舌侧唤起任何CMAP;未切断半球的TMS总是产生正常的同侧和对侧反应，无论同侧肌肉是否麻痹。结论：人双侧皮质核投射存在交叉和非交叉投射。在这些通路单侧中断后，有些人确实表现出舌麻痹，而另一些人则没有。中枢性舌麻痹的发展很可能依赖于未切断的半球利用先前存在的未交叉运动投射的能力。个体受试者中这些通路的可变可用性与限制性单半球病变后舌麻痹的不稳定发生非常一致。
OBJECTIVES The occurrence of a lingual paralysis after unilateral upper motor neuron lesions is an infrequent clinical phenomenon, and the underlying pathophysiological mechanisms are poorly understood. We studied the cortical motor representations of ipsilateral and contralateral lingual muscles in healthy controls and in a selected group of stroke patients, to clarify the variable occurrence of a lingual paralysis after recent monohemispheric ischaemia. METHODS A special bipolar surface electrode was used to record the ipsilateral and contralateral compound muscle action potentials (CMAPs) from the lingual muscles after transcranial magnetic stimulation (TMS) of the human motor cortex and peripheral electrical stimulation (PES) of the hypoglossal nerve medial to the angle of the jaw. Four patients with a lingual paralysis (group 1) and four patients with symmetric lingual movements (group 2) after monohemispheric first ever stroke were studied and compared with 40 healthy controls. RESULTS In controls, TMS of either hemisphere invariably produces CAMPs in the ipsilateral and contralateral lingual muscles, elicited through crossed and uncrossed central motor pathways, respectively. In the 40 healthy controls, TMS of either hemisphere elicited CMAPs of significantly greater amplitudes and shorter onset latencies from the contralateral muscles compared with the ipsilateral responses (p<0.0001). In the patient groups, TMS of the affected hemisphere failed to evoke any CMAP from either lingual side; TMS of the unsevered hemisphere always produced normal ipsilateral and contralateral responses, irrespective of whether the ipsilateral muscles were paralysed or not. CONCLUSIONS Bilateral crossed and uncrossed corticonuclear projections are invariably existent in humans. After unilateral interruption of these pathways, some people do exhibit a lingual paralysis whereas others do not. The development of a central lingual paralysis is most likely dependent on the ability of the unsevered hemisphere to utilise the pre-existent uncrossed motor projections. The variable availability of these pathways among individual subjects is in good agreement with the inconstant occurrence of a lingual paralysis after restricted monohemispheric lesions.