Arterial dissection, causes stroke

Ischemic stroke has numerous causes. Cerebral infarction may result from large artery atherosclerosis, cardiac embolism, small artery lipohyalinosis, cryptogenic embolism, or, more rarely, from other diverse conditions such as arterial dissection, infective endocarditis, and sickle cell disease. Arterial occlusion is the cause of at least 80% of acute cerebral infarctions. " ... 

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). ° ... 

Arterial dissection is a common cause of ischemic stroke and TIA in young adults and may also occur in older people. Sometimes there is a predisposing cause (Schievink 2001 Rubinstein et al. 2005) (Table 6.4) but often there is no explanation. The artery may become occluded by the wall hematoma itself thrombosis and emboUsm may complicate occlusive or non-occlusive dissections, and aneurysmal bulging of the weakened wall may occur (O Connell et al. 1985). Arterial rupture is unusual. 

Previous strokes and/or TIAs in different vascular territories are more likely with a proximal embolic source in the heart, or arch of the aorta, than with a single arterial lesion. Attacks going back months or more make certain causes such as infective endocarditis and arterial dissection unlikely. 

Spontaneous arterial dissection has been well recognized at the cervical portion of the carotid artery and extracranial vertebral artery as an important cause of ischemic stroke in young adults. In contrast, intracranial or intradural dissections more... 

Spontaneous dissection of the internal carotid or the vertebral artery is an important cause of ischemic stroke in young adults (Fig. 1.3). In the late 1970s Fisher et al. (1978) and Mokri et al. (1979) described dissections of carotid and vertebral arteries as detected by modern diagnostic techniques rather than by post-mortem examination. This may occur... 

Brandt T, Steinke W, Thie A et al (2000) Posterior cerebral artery territory infarcts clinical features, infarct topography, causes and outcome. Multicenter results and a review of the literature. Cerebrovasc Dis 10 170-182 Cals N, Devuyst G, Afsar N et al (2002) Pure superficial posterior cerebral artery territory infarction in The Lausanne Stroke Registry. J Neurol 249 855-861 De Freitas GR, Carruzzo A, Tsiskaridze A et al (2001) Massive haemorrhagic transformation in cardioembolic stroke the role of arterial wall trauma and dissection. J Neurol Neurosurgery Psychiatry 70 672-674... 

Sometimes arterial occlusion is demonstrated by angiography in migrainous stroke and the cause is hypothesized to be in-situ thrombosis complicating vasospasm. No provoking factors are known. Other possible causes of stroke in the context of headache must be considered carotid dissection, mitochondrial cytopathy, ruptured vascular malformation, antiphospholipid antibody syndrome and CADASIL (cerebral autosomal dominant arterio-pathy with subcortical infarcts and leukoencephalopathy). Migraine auras without headache may be confused with TIA (Ch. 8). 

Neurological examination is primarily to localize the brain lesion but there may also be clues as to the cause of the stroke a Horner s syndrome ipsilateral to a carotid distribution infarct suggests dissection of the internal carotid artery or sometimes acute atherothrom-botic carotid occlusion. Lower cranial nerve lesions ipsilateral to a hemispheric cerebral infarct can also occur in carotid dissection. 

Innominate or proximal common carotid artery stenosis or occlusion is quite often seen on angiograms in symptomatic patients but, unless very severe, does not influence the decision about endarterectomy for any internal carotid artery stenosis. Although it is possible to bypass such lesions, it is highly doubtful whether this reduces the risk of stroke unless, perhaps, several major neck vessels are involved and the patient has low-flow cerebral or ocular symptoms. This very rare situation can be caused by atheroma, Takayasu s disease or aortic dissection. Clearly, close consultation between physicians and vascular surgeons is needed to sort out, on an individual patient basis, what to do for the best. 

Head Soft tissue injury Tender, thickened, or pulseless temporal artery Obliteration of flow through the trochlear artery with compression of the preauricular or supraorbital vessels Anhidrosis Tongue laceration Head trauma Temporal arteritis ICA occlusion or severe stenosis with retrograde ophthalmic flow CCA dissection with damage to sympathetic fibers or brainstem stroke with interruption of sympathetic tract Consider seizure as the cause of the neurologic deterioration... 

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