Nonconvulsive status epilepticus as a possible cause of coma in neurosurgical intensive care.

Nonconvulsive status epilepticus (NCSE) can occur in comatose patients without clinical signs of seizure activity. We evaluated the occurrence of NCSE in patients who were admitted to our neurosurgical intensive care unit between 1998 and 2000. EEGs were obtained from 158 patients with head trauma, spontaneous bleeding or brain tumour. Patients with clinically apparent seizure activity or no electrophysiological signs of seizure activity were excluded from the study. Epileptiform activity was seen in 28 out of 158 patients. 11/28 of these patients had a Glasgow-Coma-Scale (GCS) Score below 9 and showed continuous epileptiform discharge without clinical signs of seizure activity (NCSE). The clinical status of 4 of these 11 NCSE patients improved after initiation of anticonvulsive medication. NCSE may be an under-recognised cause of coma in neurosurgical intensive medicine. EEG should be included in the routine evaluation of comatose patients, even if clinical seizure activity is not apparent.