G Saposnik1, L R Caplan. 1. Servicio de Stroke; Beth Israel Deaconess Medical Center, Boston, MA, 02215, USA. gsaposnik@intramed.net.ar
Abstract
OBJECTIVE: We first review historic, anatomic, and epidemiological aspects involving the vertebrobasilar territory ischemia. We describe the development of ideas regarding the stroke mechanisms and treatment in the posterior circulation. Key authors and their contributions are also mentioned. DEVELOPMENT: Several new diagnostic and therapeutic strategies have emerged during the last few decades in cerebrovascular disease. The comprehension of the ischemic stroke in the posterior circulation is more difficult than carotid circulation. Thus, vertebrobasilar stroke represents a microcosm. Several mechanisms may explain the ischemic process (large artery disease, penetrating vessel disease, cardioembolism, unusual causes of stroke, and combined or undetermined causes). One of the most common is large artery atherosclerosis. Transient ischemic attacks, usually stereotyped, may be the clue for the earliest recognition. Correct diagnosis may improve the chance of effective therapy. Some practical considerations may help to identify the underlying cause of the stroke. CONCLUSIONS: The prognosis in patients with vertebrobasilar ischemia depends on: a) the mechanism of the stroke, b) site of the vessel occlusion, c) thrombus propagation, d) collateral circulation, e) hemodynamic (hypertension, cardiac output, etc.), and hemorreologic factors (viscosity, hypercoagulable state, etc.), f) neurologic status, g) time to treatment. The accurate the diagnosis of the mechanism, the better the prognosis.
OBJECTIVE: We first review historic, anatomic, and epidemiological aspects involving the vertebrobasilar territory ischemia. We describe the development of ideas regarding the stroke mechanisms and treatment in the posterior circulation. Key authors and their contributions are also mentioned. DEVELOPMENT: Several new diagnostic and therapeutic strategies have emerged during the last few decades in cerebrovascular disease. The comprehension of the ischemic stroke in the posterior circulation is more difficult than carotid circulation. Thus, vertebrobasilar stroke represents a microcosm. Several mechanisms may explain the ischemic process (large artery disease, penetrating vessel disease, cardioembolism, unusual causes of stroke, and combined or undetermined causes). One of the most common is large artery atherosclerosis. Transient ischemic attacks, usually stereotyped, may be the clue for the earliest recognition. Correct diagnosis may improve the chance of effective therapy. Some practical considerations may help to identify the underlying cause of the stroke. CONCLUSIONS: The prognosis in patients with vertebrobasilar ischemia depends on: a) the mechanism of the stroke, b) site of the vessel occlusion, c) thrombus propagation, d) collateral circulation, e) hemodynamic (hypertension, cardiac output, etc.), and hemorreologic factors (viscosity, hypercoagulable state, etc.), f) neurologic status, g) time to treatment. The accurate the diagnosis of the mechanism, the better the prognosis.