Dysarthria in acute ischemic stroke: lesion topography, clinicoradiologic correlation, and etiology.

BACKGROUND AND PURPOSE: Although dysarthria is a frequent symptom in cerebral ischemia, there is little information on its anatomic specificity, spectrum of associated clinical characteristics, and etiologic mechanisms. METHODS: An investigation of 68 consecutive patients with sudden onset of dysarthria due to a single infarction confirmed by MRI or CT was conducted. RESULTS: Dysarthria was associated with a classic lacunar stroke syndrome in 52.9% of patients. Isolated dysarthria and dysarthria-central facial and lingual paresis occurred in 2.9% (n = 2) and 10.3% (n = 7), respectively. Dysarthria-clumsy hand syndrome was observed in 11.7% (n = 8) of patients and associated with pure motor hemiparesis and/or ataxic hemiparesis in 27.9% (n = 19). The lesions were due to small-vessel disease in 52.9% (n = 36), to cardioembolism in 11.8% (n = 8), and to large-vessel disease in only 4.4% (n = 3) of cases. Infarctions were located in the lower part of the primary motor cortex (5.9%; n = 4), middle part of the centrum semiovale (23.5%; n = 16), genu and ventral part of the dorsal segment of the internal capsule (8.8%; n = 6), cerebral peduncle (1.5%; n = 1), base of the pons (30.9%; n = 21), and ventral pontomedullary junction (1.5%; n = 1). Isolated cerebellar infarctions affected the rostral paravermal region in the superior cerebellar artery territory. CONCLUSIONS: Extracerebellar infarcts causing dysarthria were located in all patients along the course of the pyramidal tract. This finding correlates with the frequent occurrence of associated pyramidal tract signs in 90.7% (n = 62) of patients. Isolated cerebellar infarcts leading to dysarthria were in all cases located in the territory of the superior cerebellar artery.

[Not Available]. / Topodiagnostik ischämisch bedingter Dysarthrophonien.

In a prospective study we investigated 106 consecutive patients with sudden onset of dysarthria due to a single, not space-occupying infarction confirmed by MRI. Extracerebellar infarctions (81.1%) were located in the lower part of the primary motor cortex (3.8%), middle part of the centrum semiovale (23.6%), striatocapsular (5.7%), genu and dorsal segment of the internal capsule (11.4%), cerebral peduncle (0.9%), ventral ponto-mesencephalic region (1.9%), base of the pons (23.8%), and the ventral pontomedullary junction (1.9%). Isolated cerebellar infarctions affected the rostral paravermal region in the SCA-territory. Combined extracerebellar and cerebellar infarctions were present in 10.4% of our patients. In extracerebellar infarctions the lesions were more often localized in the left hemisphere as compared with the right hemisphere (77.5% vs 22.5%). Cerebellar infarctions, however, affected the right side in 4 and the left side in 2 patients.Correlating to clinical, electrophysiological, and fMRI-findings, the lesion topography of extracerebellar infarctions underlying dysarhria is consistent with an impairment of volitional movements due to a lesion of the corticobulbar pathways while cerebellar lesions result in impaired coordination of articulatory movements.