Stroke; a journal of cerebral circulation
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An extradurally located cavernous sinus dural arteriovenous fistula (CSDAVF) exhibits different clinical behavior from other dural arteriovenous fistulas (DAVFs) located between 2 dural leaves. The aim of this study is to define angiographic types of CSDAVF associated with presenting symptom (Sx) and venous drainage patterns. ⋯ CSDAVF presents as 3 distinctive angiographic types and is associated with presenting Sxs and venous drainage patterns.
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The Echoplanar Imaging Thrombolysis Evaluation Trial (EPITHET) tests the hypothesis that perfusion-weighted imaging (PWI)-diffusion-weighted imaging (DWI) mismatch predicts the response to thrombolysis. There is no accepted standardized definition of PWI-DWI mismatch. We compared common mismatch definitions in the initial 40 EPITHET patients. ⋯ Deconvolution and application of PWI thresholds provide more conservative estimates of tissue at risk and decrease the frequency of mismatch accordingly. The precise definition may not be critical; however, because reperfusion alters tissue fate irrespective of mismatch.
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Case Reports
Reduction of diffusion-weighted MRI lesion volume after early moderate hypothermia in ischemic stroke.
Large areas of restricted diffusion in the middle cerebral artery (MCA) territory are highly predictive of severe and potentially space-occupying MCA stroke. A reduction of diffusion-weighted MRI (DWI) lesions occurs in 20% to 40% of acute stroke patients with early reperfusion. ⋯ This case describes an unexpected reduction of a DWI lesion after early moderate hypothermia and spontaneous recanalization 3 days after stroke onset. We discuss potential reasons for the unexpected DWI lesion reduction.
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Spreading depression (SD)-like depolarizations may augment neuronal damage in neurovascular disorders such as stroke and traumatic brain injury. Spreading ischemia (SI), a particularly malignant variant of SD-like depolarization, is characterized by inverse coupling between the spreading depolarization wave and cerebral blood flow. SI has been implicated in particular in the pathophysiology of subarachnoid hemorrhage. Under physiological conditions, SD is blocked by N-methyl-D-aspartate receptor (NMDAR) antagonists. However, because both SD-like depolarizations and SI occur in presence of an increased extracellular K+ concentration ([K+]o), we tested whether this increase in baseline [K+]o would reduce the efficacy of NMDAR antagonists. ⋯ Our data suggest that elevated baseline [K+]o reduces the efficacy of NMDAR antagonists on SD-like depolarizations and SI. In conditions of moderate energy depletion, as in the ischemic penumbra, or after subarachnoid hemorrhage, NMDAR inhibition may not be sufficient to block these depolarizations.