Urban P P, Wicht S, Hopf H C, Fleischer S, Nickel O
Department of Neurology, University of Mainz, Germany.
J Neurol Neurosurg Psychiatry. 1999 Apr;66(4):495-501. doi: 10.1136/jnnp.66.4.495.
The pathophysiology of dysarthria can preferentially be studied in patients with the rare lacunar stroke syndrome of "isolated dysarthria".
A single study was carried out on seven consecutive patients with sudden onset of isolated dysarthria due to single ischaemic lesion. The localisation of the lesion was identified using MRI. The corticolingual, cortico-orofacial, and corticospinal tract functions were investigated using transcranial magnetic stimulation. Corticopontocerebellar tract function was assessed using 99mTc hexamethylpropylene amine oxime-single photon emission computerised tomography (HMPAO-SPECT) in six patients. Sensory functions were evaluated clinically and by somatosensory evoked potentials.
Brain MRI showed the lesions to be located in the corona radiata (n=4) and the internal capsule (n=2). No morphological lesion was identified in one patient. Corticolingual tract function was impaired in all patients. In four patients with additional cortico-orofacial tract dysfunction, dysarthria did not differ from that in patients with isolated corticolingual tract dysfunction. Corticospinal tract functions were normal in all patients. HMPAO-SPECT showed no cerebellar diaschisis, suggesting unimpaired corticopontocerebellar tract function. Sensory functions were not affected.
Interruption of the corticolingual pathways to the tongue is crucial in the pathogenesis of isolated dysarthria after extracerebellar lacunar stroke.
构音障碍的病理生理学可优先在患有罕见的“孤立性构音障碍”腔隙性卒中综合征的患者中进行研究。
对7例因单一缺血性病变突然出现孤立性构音障碍的连续患者进行了一项研究。使用MRI确定病变的位置。使用经颅磁刺激研究皮质舌、皮质口面部和皮质脊髓束功能。6例患者使用99mTc六甲基丙烯胺肟单光子发射计算机断层扫描（HMPAO-SPECT）评估皮质脑桥小脑束功能。通过临床检查和体感诱发电位评估感觉功能。
脑部MRI显示病变位于放射冠（n = 4）和内囊（n = 2）。1例患者未发现形态学病变。所有患者的皮质舌束功能均受损。在另外4例伴有皮质口面部束功能障碍的患者中，构音障碍与孤立性皮质舌束功能障碍患者的构音障碍无差异。所有患者的皮质脊髓束功能均正常。HMPAO-SPECT显示无小脑失联络，提示皮质脑桥小脑束功能未受损。感觉功能未受影响。
小脑外腔隙性卒中后孤立性构音障碍的发病机制中，通向舌部的皮质舌通路中断至关重要。
