Arterial dissection, causes

Roig S, Gomez S, Fiol M et al. Spontaneous coronary artery dissection causing acute coronary syndrome an early diagnosis implies a good prognosis. Am J Emerg Med 2003 29 549. 

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). ° ... 

Spontaneous coronary artery dissection is an unusual cause of acute coronary syndrome. Only three other cases secondary to cocaine use have been described. 

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. 

Tenderness of the branches of the external carotid artery (occipital, facial, superficial temporal) points towards giant cell arteritis. Tenderness of the common carotid artery in the neck can occur in acute carotid occlusion but is more Ukely to be a sign of dissection, or arteritis. Absence of several neck and arm pulses in a young person occurs in Takayasu s arteritis (Ch. 6). Delayed or absent leg pulses suggest coarctation of the aorta or, much more commonly, peripheral vascular disease. Other causes of widespread disease of the aortic arch are atheroma, giant cell arteritis, syphihs, subintimal fibrosis, arterial dissection and trauma. 

Complications that can occur at the common femoral artery puncture site include formation of a hematoma, pseudoaneurysm, or arteriovenous fistula, dissection or thrombosis of the common femoral artery, and infection [53, 56]. Vessel perforation is even more unusual than arterial dissection but may be problematic in that it could either cause occlusion of the uterine artery prior to embolization or can cause bleeding from the perforated vessel which may itself require embolization as treatment (Fig. 10.4.4) [56],... 

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... 

The authors assert that spontaneous coronary dissection is a rare cause of acute coronary syndrome (ACS). Common risk factors for developing this condition were ruled out. No previous case of three-vessel coronary artery dissection related to carmabis use has been reported in the literature. However, previous reports have shoxvn a possible association between ACS and cannabis use. Cannabis is generally considered to be a drug of low toxicity but this and other cases highlight a need to exercise caution. 

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... 

Some congenital diseases such as Marfan syndrome or Ehlers Danlos syndrome (type 4) can cause arteriopathies of cranial cervical vessels. In Ehlers Danlos syndrome, elongations, dissections, dilatation and aneurysms, as well as fistula in large and mid-size arteries, are found. Cystic medial necrosis (Ueda et al. 1999) leads to aortic dissections which can include supraaortic vessels (Fig. 5.27)... 

MCA infarcts are mainly caused by cardioembolism, internal carotid artery (ICA) thrombosis, dissection or embolism and rarely (in Caucasians) by intrinsic MCA disease. MCA atherothrombotic territory infarctions related to intrinsic MCA disease often cause concomitant small cortical (territorial or borderzone) and subcortical infarcts (Min et al. 2000). 

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... 

Aortic arch dissection can cause profound hypotension, with global, and sometimes boundary zone, cerebral ischemia or focal cerebral ischemia if the dissection spreads up one of the neck arteries. Clues to this diagnosis are anterior chest or interscapular pain, along with diminished, unequal or absent arterial pulses in the arms or neck and a normal electrocardiogram, unlike acute myocardial infarction, acute aortic regurgitation and pericardial effusion. 

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. 

Two patients had oculosympathetic palsy after selftreatment with a shiatsu massager (169). A thorough diagnostic work-up, including MRI and MRA scans, identified dissection of the carotid artery as the cause of the problem. In the absence of other causes, the authors believed that the self-treatment had caused dissection. 

Coronary dissection (Figures 8.39-8.41) This is an ACS that occurs suddenly, usually in young multiparous women, during the postpartum period, and is due to a collagen abnormality that favours dissection. The LAD is the most frequently involved artery and it may be dissected from its origin, which commonly causes a quite large infarction. It is even more severe because it occurs in an area with no previous ischaemia and in which collateral circulation has not been developed. 

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... 

Fig. 4.3 Time course of ATP changes in a focal rat model of permanent ischemia. The inset indicates the four areas within the middle cerebral artery distribution that were dissected from lyophi-lized coronal sections and measured for ATP. The dorsolateral striatum (DS) is the core and the dorsolateral cortex (DC) is the penumbra with the other regions transitional between these two regions. In this figure, the border zone is the latertil cortex and the per-ischemic cortex (VC). The nomenclature of the transitional area is often variable and can cause problems with the interpretation of the results between studies. Control values were determined from the cerebral cortex of the contralateral hemisphere...

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