Cerebrovascular diseases
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Cerebrovascular diseases · Jan 2001
Clinically silent circulating microemboli in 20 patients with carotid or vertebral artery dissection.
Carotid and vertebral artery dissections are frequently complicated by cerebral embolism. Detection of clinically silent circulating microemboli by transcranial Doppler sonography (TCD) is now widely investigated in patients with carotid artery disease in the hope to identify patients at increased risk for stroke. ⋯ Microembolic signals occur in patients with high-grade stenosis or occlusion due to acute cervical artery dissection. Patients with microemboli seem to be at increased macroembolic risk, i.e. stroke recurrence, and may require close-meshed clinical follow-up and possibly stronger antithrombotic treatment.
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Cerebrovascular diseases · Jan 2001
Historical ArticlePerfusion thresholds in human cerebral ischemia: historical perspective and therapeutic implications.
After middle cerebral artery occlusion (MCAO) in the laboratory animal, the ischemic penumbra has been documented as a severely hypoperfused, functionally impaired, but still viable cortex which can regain its function and escape infarction if it is reperfused before a certain time has elapsed. The penumbra surrounds the ischemic core of already irreversibly damaged tissue, and is progressively recruited into the core with increasing MCAO duration. In the animal, the threshold of cerebral blood flow (CBF) below which neuronal function is impaired and the tissue is at risk of infarction is around 22 ml/100 g/min (approximately 40% of normal) in the awake or lightly anesthetized monkey, and around 30--35 ml/100 g/min in the cat and the rat. ⋯ In the remaining patients, there was evidence of early extensive damage or early spontaneous reperfusion, which would make them inappropriate candidates for neuroprotective therapy. Recent evidence from PET studies of relative perfusion performed within 3 h of onset suggests that early thrombolysis indeed saves the tissue with CBF below a critical threshold of 12 ml/ 100 g/min, with a correlation between the volume of such tissue escaping infarction and subsequent neurological recovery. Thus, mapping the penumbra in the individual patient with physiologic imaging should allow to formulate a pathophysiological diagnosis, and in turn to design a rational management of the stroke patient and to increase the sensitivity of drug trials by appropriate patient selection.
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Cerebrovascular diseases · Sep 2000
Case ReportsEpileptic seizures attributed to cerebral hyperperfusion after percutaneous transluminal angioplasty and stenting of the internal carotid artery.
Cerebral hyperperfusion syndrome as a complication of carotid endarterectomy (CEA) has been widely reported in the surgical literature. It may occur within hours to 3 weeks after CEA and is characterized by symptoms ranging from headaches, fits, confusion, focal neurological signs to intracerebral hemorrhage. Although percutaneous transluminal angioplasty (PTA) and stenting are increasingly performed as an alternative to CEA in the treatment of carotid artery stenosis, few cases of cerebral hyperperfusion injury following carotid stenting have been reported. ⋯ Both patients fully recovered without any intracerebral hemorrhage or infarction. To our knowledge, this is the first report of cerebral hyperperfusion injury after carotid stenting without associated intracranial hemorrhage and with full recovery. In the patient with neurological symptoms following carotid stenting, it is important to consider cerebral hyperperfusion syndrome as a differential diagnosis to embolic or hemorrhagic stroke since early recognition and meticulous control of blood pressure may prevent progression to cerebral hemorrhage and death.
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Cerebrovascular diseases · Jul 2000
Are all cardio-embolic strokes embolic? An autopsy study of 100 consecutive acute ischaemic strokes.
Estimates of the frequency of different types of ischaemic stroke vary widely, particularly those said to be of embolic aetiology. This retrospective autopsy study of 100 acute ischaemic strokes was undertaken to clarify the incidence of cardio-embolic stroke. ⋯ A significantly higher incidence of non-hypertensive cardiac disease was found in the group in whom no thrombus or thrombo-embolus was found at autopsy, suggesting that some of these strokes may have been due to unrecognised cerebral hypoperfusion. Haemodynamic stroke is probably an important and underrecognised form of acute ischaemic stroke.
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Cerebrovascular diseases · May 2000
Review Case ReportsCerebral venous infarction following thrombosis of the draining vein of a venous angioma (developmental abnormality).
We report two cases of cerebral venous angioma presenting as venous infarction, one in the left parietal lobe, the other in the left frontal lobe. Cerebral imaging demonstrated thrombotic occlusion of the draining vein of the venous angioma associated in the latter case with thrombosis of the anterior part of the superior longitudinal sinus. Both patients were free of coagulopathy. ⋯ One completely recovered, while the other was left with slight residual disability. Thrombosis of the draining vein has been reported in only 6 previous cases, of whom only 2 received anticoagulant therapy. Discovery of a venous angioma in the diagnostic workup of a patient with recent neurological disorders should raise the question of a possible occlusion of the draining vein and lead to an appropriate therapy.