In an experimental stroke model, the frequency of peri-infarct depolarisations demonstrated a highly significant inverse relationship with plasma glucose (P<0.001).
In an experimental stroke model, peri-infarct depolarisations are associated with progressive cortical glucose depletion, highlighting potential risks of using insulin to control plasma glucose in brain injury.
p-value: p=<0.001
Peri-infarct depolarisations (PIDs) contribute to infarct expansion in experimental focal ischaemia; furthermore, depolarisations propagate in the injured human brain. Glucose utilisation is increased under both conditions, and depletion of brain glucose carries a poor prognosis. We studied dynamics of cerebral glucose and lactate in relation to PID patterns in experimental stroke. The middle cerebral artery was occluded for 3 h in 23 cats under terminal chloralose anaesthesia. We used fluorescence imaging to detect occurrence of PIDs, and rapid-sampling online microdialysis (rsMD), coupled to a flow-injection assay, to examine changes in cerebral cortical extracellular glucose and lactate at intervals of 30 sec each. After 30 min' ischaemia, lactate had increased by 43.6+/-s.d. 45.9 micromol/L, and stabilised in that range for 3 h. In contrast, glucose fell only slightly initially (11.9+/-9.7 micromol/L), but progressively decreased to a reduction of 56.7+/-47.2 micromol/L at 3 h, with no evidence of stabilisation. There was a highly significant inverse relationship of frequency of PIDs with plasma glucose (P<0.001). The results also characterise a metabolic signature for PIDs for possible application in clinical work, and emphasise potential risks in the use of insulin to control plasma glucose in patients with brain injury.
Hopwood et al. (Wed,) conducted a other in Experimental stroke (n=23). Middle cerebral artery occlusion was evaluated on Changes in cerebral cortical extracellular glucose and lactate (p=<0.001). In an experimental stroke model, the frequency of peri-infarct depolarisations demonstrated a highly significant inverse relationship with plasma glucose (P<0.001).