UNUSUAL CAUSES OF CEREBRAL-ISCHEMIA

Among arteriosclerotic lesions of the extracranial brain supplying arteries, occlusion of the internal carotid artery (ICA) represents a diagnostic and therapeutic problem. Segmental occlusions and pseudoocclusions, which potentially can by treated surgically, are difficult to diagnose by noninvasive ultrasound methods. The prognosis of asymptomatic patients with occlusion of the ICA is not benign. Dissections of the ICA, which seem to be more frequent than earlier assumed, can be reliably diagnosed by non-invasive Doppler ultrasound. The subclavian-steal phenomenon characterized by an inversed flow direction of the vertebral artery is a frequent disorder with rare neurological deficits. Intracranial obstructive lesions and dolichoectatic intracranial vessels are rare findings, which also can reliably be diagnosed by noninvasive testing.