Motor evoked potentials (MEPs) during intracranial vascular surgeries are used as surrogate endpoints to predict the efficacy of interventions to avoid new postoperative deficits.

The probability of a new postoperative deficit was reduced by 60% for reversible, as compared to irreversible, MEP deteriorations in a meta-analysis of recent studies.

The efficacy of interventions in recovering MEP deteriorations was negatively correlated with new postoperative deficits in motor strength.