Stroke; a journal of cerebral circulation
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Transcranial Doppler sonography (TCD) can evaluate noninvasively the blood flow velocities and patency of the main trunk of the middle cerebral artery (MCA). Using TCD we evaluated MCA patency and patterns of flow through the circle of Willis in patients with acute stroke. ⋯ TCD allows early differentiation of patency and natural history of MCA thromboembolic events. This may have important implications in the decision for thrombolytic therapy.
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Stroke scales are intended to measure stroke severity for the purpose of clinical trials. Scores have been used to determine trial entry, to compare patient groups within or between trials, or as a secondary end point. The use of scores as an end point in meta-analysis has not been validated, but such analyses have nevertheless been performed when equivocal results have been obtained using the main outcome measure. The different scale designs suggest that conversion of scores may not be possible. We sought to determine whether scores on different scales could be interconverted. ⋯ The Canadian Neurological Scale and the middle cerebral artery Neurological Score may reliably be converted. The National Institutes of Health scale cannot be used to predict these scores reliably, even with reweighting of the motor score. Interconversion is poorest for patients with dysphasia and total anterior circulation strokes. These results suggest that there will be more general difficulty in interconverting scales that use different test items and weighting. Meta-analysis using sequential changes in averaged scores from various stroke scales is not valid.
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The goal of this study was to determine the causes of mortality and morbidity after subarachnoid hemorrhage. ⋯ Most deaths after subarachnoid hemorrhage occur very rapidly and are due to the initial hemorrhage. Rebleeding is the most important preventable cause of death in hospitalized patients. In a large representative metropolitan population, delayed arterial vasospasm plays a very minor role in mortality caused by subarachnoid hemorrhage.
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Hypothermia to core temperatures ranging from 16 degrees C to 24 degrees C has become an established procedure to extend the "safe" interval of cardiac arrest during open heart surgery in human infants. The present experiment was designed to ascertain whether differences in core (rectal) temperature during hypothermic circulatory arrest influence the presence and extent of ischemic brain damage in newborn dogs. ⋯ The findings indicate that differences in intraischemic core temperature during deep hypothermic circulatory arrest influence the severity of damage to the cerebral cortex of newborn dogs. Specifically, the lower the temperature below 24 degrees C, the more protected the structure from ischemic injury. Furthermore, the greater the cortical damage, the more severe the neurobehavioral deficits. Such was not the case for the amygdaloid nucleus and especially for the caudate nucleus. Accordingly, differences in core temperature, even at very low levels, appear critical for optimal protection of the newborn brain during hypothermic circulatory arrest.
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We determined the effect of chronic hyperglycemia associated with diabetes on recovery of cerebral pH after global incomplete cerebral ischemia. ⋯ This study shows that cerebral pH recovery after global incomplete ischemia is improved in chronic hyperglycemia compared with acute hyperglycemia, despite similar decreases in blood flow and pH during ischemia and similar levels of blood flow and glucose levels during ischemia and reperfusion. In addition, cerebral pH recovery in chronic hyperglycemic dogs was not different from that in normoglycemic controls. These results suggest that an adaptation occurs with chronic hyperglycemia that improves recovery of cerebral pH during reperfusion and that is associated with better maintenance of energy metabolism and evoked potentials and with less edema over 3 hours of reperfusion compared with acute hyperglycemia.