Intracranial dissecting

Intracranial dissection is much rarer. It may present with subarachnoid hemorrhage owing to rupture of a pseudo-aneurysm, as well as with ischemic stroke, and is less often diagnosed during life (Farrell et al. 1985 de Bray et al. 1997 Chaves et al. 2002). 

Dissection of the internal carotid and vertebral arteries is a common cause of stroke, particularly in young patients. Although many occur due to trauma, it is estimated that over half occur spontaneously. The mechanism of stroke following arterial dissection is either by artery-to-artery embolism, by thrombosis in situ, or by dissection-induced lumenal stenosis with secondary cerebral hypoperfusion and low-flow watershed infarction. Occasionally, dissection may lead to the formation of a pseudoaneurysm as a source of thrombus formation. Vertebrobasilar dissections that extend intracranially have a higher risk of rupture leading to subarachnoid hemorrhage (SAH). ° ... 

Endo S, Nishijima M, Nomura H, Takaku A, Okada E. A pathological study of intracranial posterior circulation dissecting aneurysms with subarachnoid hemorrhage report of three autopsied cases and review of the literature. Neurosurgery 1993 33 732-738. 

Lylyk R Cohen JE, Ceratto R, Eerrario A, Miranda C. Angioplasty and stent placement in intracranial atherosclerotic stenoses and dissections. AJNR Am J Neuroradiol 2002 23 430 36. 

Absolute contraindications to fibrinolytic therapy include (1) active internal bleeding (2) previous ICH at anytime (3) ischemic stroke within 3 months (4) known intracranial neoplasm (5) known structural vascular lesion (6) suspected aortic dissection and (7) significant closed head or facial trauma within 3 months. Primary PCI is preferred in these situations. 

Lamy C, Giarmesini C, Zuber M et al. (2002). Clinical and imaging findings in cryptogenic stroke patients with and without patent foramen ovale the PFO-ASA Study (Atrial Septal Aneurysm). Stroke 33 706-711 Leung SY, Ng THK, Yuen ST et al. (1993). Pattern of cerebral atherosclerosis in Hong Kong Chinese severity in intracranial and extracranial vessels. Stroke 24 779-786 Leys D, Moulin Th, Stojkovic T et al. (1995). Follow-up of patients with history of cervical artery dissection. Cerebrovascular Diseases 5 43-49... 

The main clinical indications for imaging the cerebral circulation are TIA (e.g. to identify arterial stenosis), acute ischemic stroke (e.g. to identify vessel occlusion), intracerebral hemorrhage (e.g. to identify an underlying vascular malformation) and possible arterial dissection, flbromuscular dysplasia or other arteriopathies, cerebral aneurysm, intracranial venous thrombosis or cerebral vasculitis. 

A systematic review of all prospective studies of the risks associated with spinal manipulation included five primary investigations (150). The most valid studies suggested that about half of all patients who see a chiropractor will have adverse effects, which are usually mild and transient. No reliable data about serious adverse events were uncovered. However, a review of recent case reports has shown that spinal manipulation was associated with several serious adverse effects, including dissection of the vertebral and internal carotid arteries, resulting in strokes and at least one death (151). Other instances relate to epidural hematoma, intracranial aneurysm, cauda equina syndrome, contusion of the spinal cord, myelopathy, radiculopathy, and palsy of the long thoracic nerve. 

Extracranial carotid atherosclerosis or intimal hyperplasia Intracranial atherosclerosis Aortic atherosclerosis Extracranial arterial dissection... 

Infrequently, cervical artery dissection can lead to subarachnoid hemorrhage, usually when the dissection extends to the intracranial part of the vessel, with pseudoaneurysm formation and rupture (1% of cervical artery dissection cases in the large hospital-based series) [36, 37], Rupture of dissected vertebral arteries into the subarachnoid space is more common in children. Rupture of dissected carotid artery pseudoaneurysms into the neck or nasal sinuses is generally rare. Dissection can occur intracraiually and, on rare occasions, can spread intracraniaUy from a primary extracranial origin. 

Vasculitis affecting the central nervous system (CNS) represents a heterogeneous group of inflammatory diseases that may be idiopathic or associated with autoimmune diseases, infections, drug exposure, radiation, or cancer. Inflammatory cells invade vessel walls, and neuropeptide release increases vasomotor reactivity. These properties lead to vessel narrowing. There is also loss of normal endothelial anticoagulant properties and vessels have increased susceptibility to thrombosis. Consequently, patients with vasculitis develop ischemic and thrombotic infarctions. There is also altered wall competence, which can result in dissection or vessel wall disruption with intracranial hemorrhage. MRA is clinically used to screen for vasculitis, but is less sensitive than DSA (Fig. 6.20). One study of 14 patients with suspected vasculitis reported that MRA can detect distal stenoses in vasculitis with a... 

B. Complications. Severe hypertension can result In Intracranial hemorrhage, aortic dissection, myocardial infarction, and congestive heart failure. 

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