Neurochemical Monitoring of Fatal Middle Cerebral Artery Infarction

Abstract

Background-Microdialysis is a method for neurochemical monitoring that has been applied more frequently over the past few years in patients suffering from subarachnoid hemorrhage, acute brain injury, and stroke. It is used to study the course of extracellular molecules of low molecular weight, such as excitatory amino acids or metabolic end products. Case Description-We report the case of a 43-year-old patient suffering from left hemispheric stroke with a space-occupying postischemic edema leading to a considerable mass effect on the contralateral side. For treatment of severe edema, hypothermia was initiated. The microdialysis and intracranial pressure probe were placed into the noninfarcted hemisphere. A massive increase in levels of glutamate, glycerine, and the lactate-pyruvate ratio was measured 24 hours before intracranial pressure elevation was observed and brain death occurred. Conclusions-Monitoring excitatory amino acids, glycerine as a membrane component, and lactate-pyruvate ratio as an energy marker by microdialysis is a useful tool to increase our understanding of biochemical events in secondary brain damage. For future prevention of secondary ischemia in patients with massive stroke, close neurochemical monitoring might be valuable to improve therapy, particularly in the critically ill. (Stroke. 1999;30:460-463.)Key Words: cerebral infarction Ⅲ cerebral ischemia Ⅲ glutamates Ⅲ microdialysis Ⅲ middle cerebral artery B rain ischemia is associated with an excessive release of excitatory amino acids, such as glutamate or aspartate, and with a shift of energy-related metabolites from the intracellular to the extracellular fluid. Intracerebral microdialysis 1 is a method by which these endogenous substances can be extracted from the extracellular fluid into a dialysate in which relative changes in concentration of these substances can be measured. Several animal studies applying microdialysis in neuronal injury models have been conducted. [2][3][4] More recently, microdialysis found its way into neurological intensive care units as a tool for monitoring metabolism and neuronal injury in subarachnoid hemorrhage 5 and severe head injury. 6 Only very limited data are present on microdialysis in ischemic stroke.In this case report, we demonstrate a massive increase in extracellular glutamate, glycerine, and the lactate-pyruvate ratio as a consequence of secondary brain damage in a patient with a fatal middle cerebral artery (MCA) infarction. Subjects and MethodsThis study was approved by the local Ethics Committee (approval number 34/97).A 10-mm flexible microdialysis probe with an external diameter of 0.5 mm (CMA/70 custom probe, CMA/Microdialysis), and an intracranial pressure (ICP) measuring device (Spiegelberg AG) were inserted into the parietal parenchyma of the healthy hemisphere. A thermistor attached to the ICP device allowed continuous recording of brain temperature. 7 A second microdialysis probe (CMA/60) placed into the abdominal subcutaneous tissue served as a reference.In the neurological criti...

Multimodal Online Monitoring in Middle Cerebral Artery Territory Stroke

“…To answer this question conclusively, more measurements must be performed and the monitoring perhaps be extended, for example, to microdialysis or CBF measurements, to better assess the "branches" of supply and demand of cerebral oxygen metabolism. 44 We found a pattern change in the PbrO 2 curve to occur between 6 to 18 hours before transtentorial herniation. Obviously, it is too soon and the number of such observations is too small at this moment to draw any conclusions.…”

Effects of Hypothermia on Excitatory Amino Acids and Metabolism in Stroke Patients

“…Patient 6, whose microdialysis results were published recently, 18 developed secondary neuronal ischemia in the noninfarcted hemisphere as a result of irretractable brain edema and herniation. Dialysate concentrations in the final stage were similar to those obtained from the infarct core.…”

Malignant Infarction in Cats After Prolonged Middle Cerebral Artery Occlusion

“…In the search for monitoring tools that permit early identification of such fatal outcome, microdialysis has recently been applied in the care of patients with severe stroke. 24,25 In the present study we investigated a model of transient focal ischemia in cats that has been shown to be prone to secondary deterioration during reperfusion if the duration of the ischemic episode is prolonged to 2 to 4 hours. 21 By choosing a 3-hour ischemic period followed by reperfusion, we expected that a significant number of experiments would lead to transtentorial herniation, and we hypothesized that glutamate elevation is involved in this process.…”