Evaluation of lactate as a marker of metabolic stress and cause of secondary damage in acute ischemic stroke or TIA.

Background: Accumulation of lactate in ischemic regions has been documented in acute stroke. We evaluated the relation between lactate levels in blood and cerebrospinal fluid (CSF) and ischemic stroke evolution and outcome.

Methods: Lactate was measured in blood of 187 acute ischemic stroke and TIA patients at admission, 24 h, 72 h and 7 days after stroke onset. In a subpopulation of 85 stroke patients and in 51 controls, lactate was measured in CSF. Stroke evolution was evaluated by change in the NIHSS score within the first 72 h and by occurrence of progressing stroke. At 3 months after stroke, outcome was assessed on the basis of mortality rate and the modified Rankin Scale.

Results: We found no relation between lactate levels in blood and stroke evolution or outcome. Lactate in CSF was higher in stroke patients than in controls and correlated with stroke evolution and outcome. Multivariate regression analyses showed that CSF lactate levels, age and stroke severity are independent predictors for stroke evolution and outcome.

Conclusions: Lactate levels in CSF, but not in blood, are a reliable marker for metabolic crisis in acute ischemic stroke and correlate with the stroke evolution in the subacute phase and with long-term outcome.