[Cerebral ischemia manifested as recurrent loss of consciousness]

To demonstrate the clinical characteristics of cerebral ischemia that mainly manifested as recurrent loss of consciousness and to explore the pathogenesis of these incidents.

Twelve patients who had cerebral ischemia that manifested mainly as recurrent loss of consciousness were retrospectively studied. Their risk factors, clinical characteristics, cranial MRIs, angiograms and perfusion images were recorded in detail. The patients were followed up for at least 90 days.

Every patient had at least one risk factor for cerebrovascular disease. The clinical manifestations in most of the patients are syncope-like incidents, but the duration was longer, lasting for minutes to hours, but mostly less than 24 hours. These patients could be sorted into three types according to the angiographic data: type A severe stenosis in anterior circulation (mostly on both sides); type B severe stenosis in posterior circulation; and type C multiple severe stenosis (in both anterior and posterior circulation). Cerebral blood flow was severely reduced in the stenotic arteries as shown by angiogram. The perfusion studies in type A patients also showed diffuse hypoperfusion of cerebrum. In one case, the patient lost his consciousness when the Angioguard (a protective guidewire) passed through the stenosis, and he regained consciousness when the stent was fully-opened in a few minutes. All the 12 patients received medical therapy. Four patients who were ineffective with medical treatment along received stent angioplasty and there was no incident during the follow-up. Six of the remaining eight patients with medical treatment alone had ischemic strokes within 90 days, including two with disabling strokes.

Recurrent loss of consciousness is a rare manifestation of large cerebral artery stenosis. The probable mechanism may be diffuse hypoperfusion in cerebrum or brainstem. These patients are in high risk of stroke. Interventional therapy to revascularize the cerebral circulation may be a rational treatment.