HORNERS-SYNDROME AND THALAMIC LESIONS - REPORT OF 2 CASES

The authors report two cases with Horner's syndrome and thalamic lesio ns documented by CT and MRI. There is evidence of a right posterolater al thalamic hemorrhage in one case and a left anterior thalamic infarc tion in the other. The possible mechanisms of sympathetic pathway invo lvement in these cases are discussed. In the first case, Homer's syndr ome could be due to compression of the posterior hypothalamic area-whe re the sympathetic pathway's superior center is supposed to be located -or of the posterior longitudinal fasciculus, by edema resulting from the hemorrhage. In the second case, there is evidence of a small infar ction, which appears to be limited to the tuberothalamic territory. In this case, the authors postulate a possible role of the thalamus in t he development of a Homer's syndrome, perhaps by way of thalamic proje ctions to the hypothalamic sympathetic center.