QEEG prognostic value in acute stroke.

The objective of our study is to determine the predictive value of QEEG in patients suffering from an acute ischemic cerebral stroke. Twenty-eight patients were studied within the first 72 hours of clinical evolution of middle cerebral artery territory ischemic stroke. Thirty-seven QEEG recordings were obtained: 13 in the first 24 hours after cerebral stroke onset, 9 between 24-48 hours and 15 between 48-72 hours. Absolute Energies (AE) were the QEEG selected variables for statistical analysis: first, AE Z values were calculated using the Cuban QEEG norms, then the maximum and minimum AE Z values were selected within each frequency band and total power. The medians of the five neighboring Z values were also chosen. Regression models were estimated using the RANKIN scores as dependent variables and the selected QEEG variables as independent, then outcome predictions at hospital discharge and 3 months later were calculated. Percentages of concordance and errors between the estimated and real outcome scores were obtained. Alpha and theta AE were the best predictor for short-term outcome and delta AE for long-term outcome. We conclude that QEEG performed within the first 72 hours of ischemic stroke might be a powerful tool predicting short- and long-term outcome.

Predicting outcome in acute stroke: a comparison between QEEG and the Canadian Neurological Scale.

OBJECTIVE: To determine and compare the predictive value of quantitative EEG (QEEG) and the Canadian Neurological Scale (CaNS), in patients with an acute cerebral stroke. METHODOLOGY: Twenty-eight patients were studied with the diagnosis of acute ischemic middle cerebral artery stroke, within the first 72 hours of clinical evolution. Thirty-seven EEGs and clinical evaluations were collected: 13 during the first 24 hours after stroke onset, 9 between 24-48 hours and 15 between 48-72 hours. The QEEG studied variables were: the Z values (maximum, minimum and the Z medians from the 5 nearest points to each one) of absolute energies (AE) from the 4 classic frequencies bands. The clinical scale showed a smaller percent of correct prognosis than QEEG variables. CONCLUSIONS: QEEG was demonstrated to be a powerful tool to predict the degree of residual functional disabilities after an acute ischemic stroke and showed a higher prognostic value than CaNS when they are performed within the first 72 hours of brain infarct.