Stroke; a journal of cerebral circulation
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Case Reports Comparative Study Clinical Trial
Altered hemodynamic responses in patients after subcortical stroke measured by functional MRI.
Blood oxygenation level-dependent (BOLD) functional MRI (fMRI) is a promising method for defining brain recovery after stroke quantitatively. Applications thus far have assumed that the BOLD hemodynamic response in patients after stroke is identical to that in healthy controls. However, because of local vascular compromise or more diffuse vascular disease predisposing to infarction, this assumption may not be justified after stroke. We sought to test whether patients who have suffered a lacunar stroke show BOLD fMRI response characteristics identical to those of healthy controls. ⋯ The magnitude of the BOLD fMRI response can be reduced in stroke patients even if infarcts do not involve the cortex. This may be a consequence of the stroke, but the observation that the BOLD signal time course is similar in the affected and unaffected hemispheres suggests that it also could result from preexisting pathophysiological changes in the cerebral microvasculature.
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Guidelines for intravenous tissue plasminogen activator (tPA) use in stroke emphasize the importance of limiting its use to facilities with imaging capabilities and stroke expertise. This prospective case series set out to evaluate the safety of tPA use in patients referred from rural communities to a tertiary center. ⋯ This prospective study suggests that it is feasible and safe to treat rural patients referred to a tertiary care center with tPA, thus extending the benefits of thrombolysis for acute stroke to a wider population.
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Intravenous tissue plasminogen activator improves outcome after ischemic stroke when given within 3 hours of symptoms onset in carefully selected patients. However, only a small proportion of acute stroke patients are currently eligible for thrombolysis, mainly because of excessive delay to hospital presentation. We sought to determine the factors associated with early admission in a French stroke unit. ⋯ The present study shows that hospital arrival within the first hours of stroke is feasible in a French stroke unit. As many as 75% of the patients are admitted within the first 6 hours of stroke. This is the first study demonstrating that stroke unit admission in France is fastest in patients brought to the hospital by EMS or FD ambulances. However, only 35% of stroke patients activate the emergency telephone system and are currently transported by EMS or FD ambulances. French stroke patients should be encouraged to seek immediate medical attention by using the emergency telephone system, and stroke management should be reprioritized in the French EMS as a time-dependent medical emergency, with the same level of organization and expertise currently applied to myocardial infarction.
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Comparative Study Clinical Trial
Basilar vasospasm diagnosis: investigation of a modified "Lindegaard Index" based on imaging studies and blood velocity measurements of the basilar artery.
Numerous studies have shown that cerebral vasospasm is one of the leading causes of death and neurological disability after subarachnoid hemorrhage. Most of these studies, however, have focused on anterior circulation vessels. Since the introduction of the transcranial Doppler (TCD), increasing attention has been given to basilar artery (BA) vasospasm, especially in traumatic subarachnoid hemorrhage. As shown for the anterior circulation, however, the significance of elevated flow velocities (FVs) in the posterior vessels may be ambiguous, so vasospasm may not be reliably differentiated from hyperemia. The purpose of the present study was to evaluate the potential additional value of an intracranial/extracranial FV ratio in the posterior circulation to cope with this shortcoming of the TCD in the diagnosis of BA vasospasm. ⋯ The results of the present study showed that the BA/EVA ratio may contribute to an improved discrimination between BA vasospasm and vertebrobasilar hyperemia and enhance the accuracy and reliability of TCD in the diagnosis of BA vasospasm. Our data further suggest that the BA/EVA ratio may provide an approximation of vasospasm severity and help in identifying patients who are likely to suffer from hemodynamically significant vasospasm.
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Clinical Trial
Effects of hypertonic (10%) saline in patients with raised intracranial pressure after stroke.
The aim of this study was to evaluate the effects of hypertonic saline in stroke patients with increased intracranial pressure (ICP) after conventional therapy with mannitol had failed. ⋯ Infusion of 75 mL hypertonic (10%) saline decreases elevated ICP and increases cerebral perfusion pressure in stroke patients in whom mannitol had failed. The effect on the ICP and cerebral perfusion pressure reaches its maximum after the end of infusion and is seen for 4 hours.