Diagnosis and management of seizures and myoclonus after cardiac arrest.

Cardiac arrest may lead to postanoxic brain injury. In approximately one third of the patients who remain in coma, myoclonus or status myoclonus is seen. Clinically manifest or electrographic epileptic seizures or status epilepticus are less common. Both status myoclonus and electrographic seizures indicate severe brain injury. Electroencephalography can contribute to discrimination between epileptic seizures and postanoxic myoclonus, as well as to identification of patients that may have a good outcome or can benefit from treatment. Accumulating data suggest that extensive anti-seizure treatment is futile in case of general periodic discharges. On the other hand, the small subgroup of patients with EEG patterns closely resembling electrographic seizures or status epilepticus may benefit from anti-seizure treatment, but the evidence of efficacy is weak. Medication to suppress clinically manifest myoclonus may be necessary for general ICU care and mechanical ventilation, but does not improve a patient's prognosis.