Cerebral embolism and hyperthyroidism.

Three different cases of cerebral embolism occurring in combination with hyperthyroidism are reported. Case 1; a healthy 37-year-old woman presented with sudden onset of left hemiparesis and left sided hypoesthesia of all modalities. Embolism in area of the right middle cerebral artery was confirmed by angiography and CT scan. Laboratory examination revealed hyperthyroidism and anemia. Antithyroid treatment brought about euthyroid function while slight hemiparesis remained present. Case 2; a 79-year-old woman who suffered from hypertension for one year had sudden onset of disorientation and left hemiparesis. Electrocardiogram showed atrial fibrillation. The CT scan indicated infarction in the right anterior and middle cerebral artery. The patient was diagnosed as having masked hyperthyroidism. Although antithyroid medication reduced it to euthyroid condition, the patient is now bedridden with hemiparesis. Case 3; a 45-year-old man who had partial thyroidectomy for Basedow's disease and had been treated with antithyroid and antiarrhythmic therapy for 10 years. Suddenly, he was in coma with dilated right pupil and left hemiplegia. Atrial fibrillation and hypothyroid function were observed. CT scan indicated hemorrhagic infarction in the territory of the middle cerebral artery with transtentorial herniation. He died on the 59th day of hospitalization following an episode of bronchopneumonia. On the basis of the cases presented here as well as on the basis of those described in the literature it appears that thyrotoxic patients with atrial fibrillation exhibit high incidence of cerebral embolism, and prophylactic anticoagulant therapy may be recommended.