Duration of Pupillary Unresponsiveness to Light: A Physiological Adjunct to Electroencephalography and Motor Seizure Duration Monitoring During Electroconvulsive Therapy

Abstract

Background: During electroconvulsive therapy (ECT) sessions, we observed that the time taken for the return of pupillary response to light (ROPL) outlasted both the electroencephalography (EEG) and the motor seizure duration after the delivery of the electrical stimulus to produce convulsions.

Objective: The objective of this study was to investigate whether ROPL can be used as a marker of cessation of seizure activity in the brain after ECT and also to study the effect of atropine premedication on seizure activity during ECT.

Methods: Forty-one patients underwent 82 sessions of ECT in a cross-over design study. The duration of motor seizure, EEG seizure, and time for ROPL was observed and compared.

Results: The ROPL consistently outlasted EEG and motor seizures; the difference in their mean durations was statistically significant P < 0.05. There was good correlation among the 3 parameters. Atropine premedication did not alter the seizure activity and ROPL after ECT.

Conclusions: The ROPL after ECT stimulus is a good bedside monitor for termination of seizure activity and can be a valuable adjunct to surface EEG in monitoring the duration of epileptic activity after delivery of ECT.