The pathogenesis of delayed
cerebral ischemia (DCI) is multifactorial and not completely elucidated. Our objective was to determine if episodes of spreading depolarization (SD) are reflected in compromised levels of extracellular
glucose monitored by bedside microdialysis (MD) in
aneurysmal subarachnoid hemorrhage (aSAH) patients. Patients with aSAH, prospectively included in the COSBID (CoOperative Study on
Brain Injury Depolarisations) protocol (Berlin, Heidelberg), had hourly monitoring of cerebral
glucose by MD and in parallel electrocorticographic (ECoG) monitoring for SD detection on day of admission until days 10-14 after aSAH. Cerebral MD probes were placed in the vascular territory at risk for DCI. Twenty-one aSAH patients (53.3 ± 9.1 years; mean ± standard deviation), classified according to the World Federation of Neurosurgical Societies (WFNS) in low (I-III, 11) and high (IV-V, 10) grades, were studied. Of these, 13 patients (62%) presented with DCI. Median
glucose was 1.48 (0.00-8.79). Median occurrence of SD was 7 (0-66)/patients. High WFNS grade (WFNS grades IV-V) patients had more SDs (p = 0.027), while the overall
glucose level did not differ. In high-grade SAH patients, SDs were more frequent. Individually, the occurrence of SD was not linked to local deviations (neither high nor low) from the LOWESS (locally weighted scatterplot smoothing) trend curve for extracellular
glucose concentrations. Rapid-sampling MD techniques and analyses of SD clusters may elucidate more detail of the relationship between SD and brain energy metabolism.