Abstracts

Rationale: Comatose patients from cardiac arrest may represent severe permanent brain damage. Multiple factors play a role for prognostication. Anoxic myoclonus has been a great debate with its association with anoxic brain injury. Anoxic myoclonus reflects hyper excitability of the central nervous system and represents underlying disturbances of reticular loops. Whether anoxic myoclonus is epileptic or nonepileptic remains debatable, although anoxic myoclonus has been considered an independent prognostic factor to predict outcome. We studied anoxic myoclonus in patients with cardiac arrest to evaluate outcome as independent prognostic determinant. Methods: After IRB approval, we identified patients with anoxic brain injury who presented with anoxic myoclonus. Due to trial design, strict criteria were used to define status myoclonus and myoclonic jerks. Primary end point of the study was outcome measured. Results: 42 patients were identified who had anoxic myoclonus. 16/42 (38%) had anoxic myoclonus status epilepticus. Only 2/16(12%) were among the survivors. All patients had bi-hemispheric periodic lateralizing electrographic discharges. The remaining 26/42 had myoclonic jerks. All of them were followed by a clinical seizure. All these patients were started on intravenous sedative drips that have stopped clinical myoclonus. These patients were not included in status myoclonus due to the nature of the clinical trial. 4/26 (15%) were among the survivors. All EEGs in this group showed grade IV findings which correlated with generalized slowing and suppression. Overall 6/42(14%) survived in both group. Surprisingly, among all patients who died, the duration of cardiac arrest did not affect the outcome. (1 minute to 45 minutes) Conclusions: Anoxic myoclonus, seizure and anoxic myoclonus status epilepticus remain independent factors to determine high mortality. Our study’s reported outcome was the same as other clinical trials. Due to the retrospective nature and strict criteria of this study, it may under-represent anoxic myoclonus. Further prospective studies may be helpful for better understanding of outcome in patients with anoxic brain injury.