Predictive value of neurochemical monitoring in large middle cerebral artery infarction

Background and Purpose-Space-occupying brain edema is a life-threatening co mplication in patients with large hemispheric stroke. Early identification of patients at risk is necessary to decide on invasive therapies such as de compressive hemicraniectomy or hypothermia. To assess potential predictors of malignant brain edema by measurement of intracranial pressure (ICP) and microdialysis in patients with large hemispheric stroke and different clini cal course. Methods-In an ongoing prospective clinical study, an ICP and microdialysis probe were placed into the parenchyma of the ipsilateral frontal lobe of 10 patients. Extracellular concentrations of glutamate, lactate, pyruvate, an d glycerol were measured continuously. Repeated cranial CT scans were scrut inized for size of infarction and presence of mass effect. Results-The dynamics of the different substances varied in accordance with the clinical course, size of infarction, and local brain edema: Increase in ICP and in glutamate concentration and lactate-pyruvate ratio was followed by massive edema and large infarcts; generally low and stable ICP and subs trate concentrations were found in patients without progressive space-occup ying infarcts. Conclusions-In patients with large hemispheric infarction, bedside monitori ng with microdialysis is feasible and might be helpful together with ICP re cording to follow the development of malignant brain edema.