RESUMO
Arterial dissection is the result of blood entering along the intima-media plane through a breach produced either spontaneously or traumatically. Cervical arterial dissections are an important cause of acute ischemic stroke in children, young adults, and patients with cranio-cervical traumatic injuries. Arterial dissections occur either spontaneously, in genetic diseases, the most important association being with fibromuscular dysplasia. In most of the cases dissection involve the extracranial portions of the internal carotid and vertebral arteries. Magnetic resonance with T1 fat-saturation (T1 FS) sequence of the cervical region or computed tomography (CT) with computed tomography angiography (CTA) shows a very high sensitivity and specificity in the diagnosis of cervical artery dissections. Therapeutic options are still debatable in patients with acute ischemic stroke and vertebral or carotid artery dissection.
RESUMO
Watershed strokes have been described previously as ischemic strokes located in vulnerable border zones between brain tissue supplied by the anterior, posterior, and middle cerebral arteries in the distal junction between two non-anastomotic arterial territories. Ischemic strokes in border zones are well-recognized entities and well-described in terms of imaging features, but the pathophysiological mechanism of brain injury production is not fully defined. Border zone ischemia is caused by cerebral hypoperfusion through decreased cerebral blood flow and arterial embolism in unstable atheroma plaque. It is often difficult to say which mechanisms are fully responsible for producing cerebral ischemic lesions. This review aimed to highlight the imaging aspect of watershed strokes and to correlate the clinical characteristics of this type of stroke with the diagnostic algorithm for optimal therapeutic management. Neurologists should promptly recognize this type of stroke and investigate its etiology in the shortest possible time.
