Ataxic hemiparesis--ventrolateral nucleus of the thalamus: yet another site of lesion.

Letters to the Editor will be published, if suitable, as space permits. They should not exceed 1,000 words (typed double-spaced) in length, and may be subject to editing or abridgement. To the Editor: Thalamic vascular lesions usually produce objective sensory disturbances and sometimes may be associated with aphasia, amnesia, and neglect. Rarely ataxia and choreoathetotic movements can be seen. 12 1 describe a patient with ataxic hemiparesis in whom computed tomog-raphy (CT scan) showed an isolated hypodense area in the thalamus compatible with lacunar infarct. A 60-year-old man, a known hypertensive, suddenly experienced clumsiness of his left arm and leg associated with weakness and heavi-ness. He was conscious and well-oriented without any memory or other higher function abnormalities; there was minimal left-sided weakness. Tendon reflexes were hyperactive on that side with upgoing plantar. He had difficulty in accomplishing finger-nose and heel-shin tests on the left side with dysdiadochokinesia and intention tremor. Touch and pain sensations were mildly impaired. CT scan showed a small hypodense lesion in the thalamus on the right side (Figure 1). His pyramidal weakness and sensory disturbances improved within 5 days, his ataxia in 10 days. Garcin 3 and Garcin and Lapresele 4 described two cases with unilateral cerebellar ataxia in whom infarction of the contralateral thalamus was demonstrated at autopsy. One patient had associated numbness and paresis of the lower limb. 4 Cases of thalamic lesion presenting as painful ataxic hemiparesis 5 and hypesthetic ataxic hemiparesis 6 have been documented. Ataxia is due to the involvement of the dentatorubro tha-lamic fibers in the ventrolateral nucleus of the thalamus. Hemiparesis is due to extension of the lesion to the adjacent internal capsule. Syndrome cer£bello-thalamique par lesion localisee du thalamus: Avec une digression sur le "signe de la main creuse" et son interet semiologuique. J: Incoordination cdrebelleuse du membre infer-ieur par lesion localisee de la region interne du thalamus contralat-eral. To the Editor: The article by Ernst et al' throws some light on an important area of hemorheologic research. Leukocyte rheology in vascular disease is now, in fact, a burning question. In their conclusions, Ernst et al suggest that further studies are needed on the filtration pattern of individual leukocyte subpopulations. Here, at our hemorheologic unit, we have begun studying the filtration of white blood cells and, in particular, of leukocyte subpopulations in stroke patients using a simple separation method 2 and a new filtration technique. 3 This …