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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A clinical usefulness of computed tomography was reviewed in 38 consecutive patients with subarachnoid haemorrhage and multiple intracranial aneurysms. CT helped in identification of ruptured aneurysm in more than 70% of cases (it pinpointed source of bleeding in 55% of patients and showed region of haemorrhage in 15% of cases). Its main limitation was inability to detect blood in subarachnoid space (SAS) in patients who were diagnosed later after bleeding (23%). Intracerebral haematoma or localized blood accumulated in SAS showed unequivocally the burst aneurysm. Symmetrical and especially asymmetrical distribution of blood in SAS were also helpful, though the former was misleading in two cases. Moreover, CT detected hypodense lesion of brain in 2 cases, widening of ventricular system in 12 patients and directly visualized aneurysm in 3 cases.
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PMID:A clinical evaluation of computed tomography in patients with subarachnoid haemorrhage and multiple intracranial aneurysms. 264 27

Since inert gas washout techniques for cerebral blood flow (CBF) measurement are not applicable to asymmetrical pathological states where assumptions about constancy of distribution, volume, and partition coefficients cannot be held to be valid, a new approach to regional and global CBF is described. Regional volume and regional mean transit time are measured independently to give regional volume flow in ml/min. In a pilot study, this noninvasive, quantitative technique has been applied to 37 patients with various clinical responses to subarachnoid hemorrhage. Global CBF and clinical grading were significantly associated. Reduction of regional CBF and spasm of the relevant arterial supply were also significantly associated in these patients.
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PMID:Global and regional cerebral blood flow. Noninvasive quantitation in patients with subarachnoid hemorrhage. 700 Sep 82

We experienced a case with sudden unexpected death caused by rupture of an intracranial aneurysm, which was confirmed by autopsy. Depending on this case, we reported the significance of the cerebellar tonsillar herniation on the cause of sudden death of ruptured cerebral aneurysm. A 58-year-old man was admitted to us for treatment of subarachnoid hemorrhage (SAH). The CT scanning showed diffuse SAH in the whole cistern. Cerebral angiography on admission revealed an aneurysm at the bifurcation of the left middle cerebral artery in association with bleb like configuration. The aneurysmal neck was clipped on the day of admission. The postoperative course was uneventful. In the early morning of postoperative 23rd day, he was found being expired. To clarify the cause of death, an autopsy was done, disclosing diffuse SAH in association with tonsillar herniation more marked on the left. Thus, the distortion of the spinomedullary junction due to asymmetrical herniation was considered to be responsible for unexpected sudden death in this case. Examination of the major cerebral artery disclosed a ruptured anterior communicating artery aneurysm.
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PMID:[The significance of the cerebellar tonsillar herniation on the cause of sudden death of ruptured cerebral aneurysm]. 962 66

Takayasu's arteritis is a chronic inflammatory disease that produces a narrowing of the aorta and its major branches. Fibrosis and thickening of the arterial wall often occur in later stages, resulting in a cerebrovascular accident. The authors report two young women patients who presented with subarachnoid hemorrhage (SAH) and occlusive cerebrovasular disease associated with Takayasu's arteritis. Both patients had sudden headache and hemiparesis. Physical examination showed weak radial pulse, carotid bruit, and asymmetrical blood pressure. Erythrocyte sedimentation rate (ESR) was elevated in both patients. SAH was confirmed by brain computerized tomography (CT) or lumbar puncture. Occlusive cerebrovascular disease was diagnosed by brain magnetic resonance imaging (MRI), brain magnetic resonance angiography (MRA), and cerebral angiography. The findings of aortography and cerebral angiography were compatible with Takayasu's arteritis, but intracranial aneurysm was not found in either patient.
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PMID:Takayasu's arteritis presented with subarachnoid hemorrhage: report of two cases. 1237 26

The vertebrobasilar system is a part of the cerebral arterial circle (circle of Willis), which forms the collateral circulation of the brain. A 75-year-old Caucasian female was admitted to hospital because of a strong headache radiating to the neck. On the basis of a neurological examination, the patient was classified into group III of the Hunt and Hess scale. Subarachnoid haemorrhage and 2 aneurysms of the cerebral arteries were diagnosed during multidetector 64-row computed tomography and angiography. An asymmetrical fenestration of the proximal part of the basilar artery was also observed. The bleeding aneurysm locating at anterior communicating artery was diagnosed and clipped surgically by right fronto-parietal craniotomy. The second aneurysm was located just after the junction of the vertebral arteries on the wall of the basilar artery. The presented case firstly illustrates the asymmetric fenestration of the proximal part of the basilar artery coexisting with subarachnoid haemorrhage and 2 aneurysms of brain arteries. Such observation should increase diagnostic attention in the detection of possible associated aneurysms and can help in preventing complications during all endovascular treatment procedures.
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PMID:An asymmetrical fenestration of the basilar artery coexisting with two aneurysms in a patient with subarachnoid haemorrhage: case report and review of the literature. 2490 4

Physiologically, neurovascular coupling (NVC) matches focal increases in neuronal activity with local arteriolar dilation. Astrocytes participate in NVC by sensing increased neurotransmission and releasing vasoactive agents (e.g., K(+)) from perivascular endfeet surrounding parenchymal arterioles. Previously, we demonstrated an increase in the amplitude of spontaneous Ca(2+) events in astrocyte endfeet and inversion of NVC from vasodilation to vasoconstriction in brain slices obtained from subarachnoid hemorrhage (SAH) model rats. However, the role of spontaneous astrocyte Ca(2+) signaling in determining the polarity of the NVC response remains unclear. Here, we used two-photon imaging of Fluo-4-loaded rat brain slices to determine whether altered endfoot Ca(2+) signaling underlies SAH-induced inversion of NVC. We report a time-dependent emergence of endfoot high-amplitude Ca(2+) signals (eHACSs) after SAH that were not observed in endfeet from unoperated animals. Furthermore, the percentage of endfeet with eHACSs varied with time and paralleled the development of inversion of NVC. Endfeet with eHACSs were present only around arterioles exhibiting inversion of NVC. Importantly, depletion of intracellular Ca(2+) stores using cyclopiazonic acid abolished SAH-induced eHACSs and restored arteriolar dilation in SAH brain slices to two mediators of NVC (a rise in endfoot Ca(2+) and elevation of extracellular K(+)). These data indicate a causal link between SAH-induced eHACSs and inversion of NVC. Ultrastructural examination using transmission electron microscopy indicated that a similar proportion of endfeet exhibiting eHACSs also exhibited asymmetrical enlargement. Our results demonstrate that subarachnoid blood causes a delayed increase in the amplitude of spontaneous intracellular Ca(2+) release events leading to inversion of NVC. Significance statement: Aneurysmal subarachnoid hemorrhage (SAH)--strokes involving cerebral aneurysm rupture and release of blood onto the brain surface--are associated with high rates of morbidity and mortality. A common complication observed after SAH is the development of delayed cerebral ischemia at sites often remote from the site of rupture. Here, we provide evidence that SAH-induced changes in astrocyte Ca(2+) signaling lead to a switch in the polarity of the neurovascular coupling response from vasodilation to vasoconstriction. Thus, after SAH, signaling events that normally lead to vasodilation and enhanced delivery of blood to active brain regions cause vasoconstriction that would limit cerebral blood flow. These findings identify astrocytes as a key player in SAH-induced decreased cortical blood flow.
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PMID:Astrocyte Ca2+ Signaling Drives Inversion of Neurovascular Coupling after Subarachnoid Hemorrhage. 2642 85