[Orthostatic transient unresponsiveness in an elderly patient with severe cerebral arteriosclerosis under antihypertensive medication].

An 80-year-old man who had was administered antihypertensive medication showed repeated transient unresponsiveness during standing and/or walking. Neurological examination showed no focal neurological signs except mild dementia. Head-up tilting examination induced unresponsiveness and a decrease of systolic blood pressure from 111 mmHg to 86 mmHg. This unresponsiveness disappeared 3 minutes later when the blood pressure recovered to 102/64 mmHg. Cerebral angiography demonstrated occlusion in the right internal carotid artery and the right vertebral artery. Severe stenosis was observed at the left internal carotid artery and the left vertebral artery. Discontinuance of the antihypertensive medication reduced the frequency of orthostatic transient unresponsiveness. Elastic stockings in the lower extremities completely prevented the attack; head-up tilting did not induce hypotension with elastic stockings. The transient unresponsiveness in the present case was probably correlated to hemodynamic failure under the condition of severe cerebral arteriosclerosis.