Stroke; a journal of cerebral circulation
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The mechanisms of perihematomal injury in primary intracerebral hemorrhage (ICH) are incompletely understood. An MRI study was designed to elucidate the nature of edema and blood flow changes after ICH. ⋯ Acute perihematomal oligemia occurs in acute ICH but is not associated with MRI markers of ischemia and is unrelated to edema formation. Increased rates of water diffusion in the perihematomal region independently predict edema volume, suggesting the latter is plasma derived.
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Development of a method to continuously assess cerebrovascular autoregulation of patients with traumatic brain injury would facilitate therapeutic intervention and thus reduce secondary complications. ⋯ Evaluation of changes of the HMF of cerebrovascular pressure transmission with respect to CPP changes permits continuous monitoring of cerebral autoregulation.
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The clinical and hemodynamic impacts of basilar artery (BA) vasospasm (VS) after aneurysmal subarachnoid hemorrhage (SAH) are ill-defined. The purpose of the present study was to evaluate the relationship between BA-VS and regional cerebral blood flow (rCBF) with posterior circulation after aneurysmal SAH. ⋯ These findings suggest for the first time that BA-VS after aneurysmal SAH is associated with hypoperfusion to BS and other posterior circulation territories. The risk for delayed BS ischemia increased significantly when TCD BA-FVs were >115 cm/s.
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The differentiation of reversible from irreversible ischemic damage is essential for identifying patients with acute ischemic deficits who may benefit from therapeutic interventions. Diffusion-weighted imaging (DWI) has become the method of choice to detect ischemic lesions. Positron emission tomography (PET) of the central benzodiazepine receptor ligand 11C flumazenil (FMZ) has been shown to be a reliable marker of neuronal integrity. These 2 imaging parameters were compared with respect to the probability to predict cortical infarction in early ischemic stroke. ⋯ These results indicate that FMZ-PET and DWI are comparable in the prediction of probability of ischemic cortical infarction, but FMZ-PET carries a lower probability of false-positive prediction. The final infarcts include tissue not identified by these imaging modalities; at the time of the study, these tissue compartments are viable and could benefit from treatment. The discrepancy in predictive probability could be related to the fundamental difference of the measured variables: benzodiazepine receptor activity is a reliable marker of neuronal integrity in the cortex, and movement of water molecules in the extracellular space might be a more variable indicator of tissue damage.
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Clinical and radiologic predictors of cerebral infarction occurrence and location after aneurysmal subarachnoid hemorrhage have been seldom studied. ⋯ Evidence of vasospasm on TCD and angiogram is predictive of cerebral infarction on CT scan but sensitivity and specificity are suboptimal. Cerebral infarction location cannot be predicted in one quarter to one third of patients by any of the studied clinical or radiological variables.