[Limb shaking and loss of consciousness: a carotid-basilar artery syndrome].

We describe the brain MRI and cerebral blood flow characteristics in a patient with hypertension, severe bilateral carotid artery disease and moderate vertebrobasilar atheromatosis. When standing, the patient experienced short repetitive episodes of loss of consciousness and involuntary shaking of the lower extremities. We believe that, in this patient, the combination of bilateral perfusion insufficiency through the carotid artery, the local effects of atheromatosis of the penetrating branches arising from the basilar artery and the systemic effects of orthostatic hypotension may have caused ischemic lesions in the terminal zones of the paramedian branches of the basilar artery.