Ataxia in Thalamic Stroke

Yoon, Sung sang; Chang, Dae il; Chung, Kyung cheon

Abstract

BACKGROUND & PURPOSE: Of thalamic stroke syndrome, according to previous reports, the syndrome of hemiataxia and hemisensory loss (thalamic ataxia syndrome) is known to have localizing value confined to the lesion of posterolateral thalamus. And ataxia in thalamic ataxia syndrome is due to interruption of cerebellar outflow pathways. We observed the clinical characteristics of cerebellar manifestations in patients with thalamic ataxia syndrome to clarify intrathalamic cerebellar pathways because it is known that parts of cerebellar efferent fibers do not pass through the thalamus.
METHODS
Ten patients with ataxia (5 men, 5 women ; mean age 64), out of 47 thalamic stroke patients admitted to Kyung Hee University Hospital from Jan. 1994 to May. 1995, were selected. The localization of the lesion was based on CT or MR imaging and ataxia was characterized in view of cerebellar functions - coordination of movement, regulation of equilibrium and muscle tone.
RESULTS
Out of 10 patients, 4 patients were thalamic hematoma, 4 patients thalamic hematoma with intraventricular hemorrhage, 2 patients thalamic infarction. Four patients were hemiataxia-hemiparesis-hemisensory loss, 4 patients hemiataxia-hemisensory loss, 2 patients hemiataxia-hemiparesis. Posterolateral thalamus was involved in 4 patients, dorsal thalamus in 3 patients, posterolateral and dorsal thalamus in 3 patients. All patients had dysmetria, dysdiadochokinesia, kinetic tremor. Two patient has gait ataxia. Speech and ocular motility disturbances were not noted.
CONCLUSION
Thalamic ataxia syndrome appeared in the lesion of posterolateral and dorsal thalamus. Common cerebellar manifestations symptoms of incoordination.