Inhibitory simple partial (non-convulsive) status epilepticus after intracranial surgery

Objectives-To report on five patients who developed, 2 to 4 days after an i ntracranial neurosurgical procedure, new, persistent, focal neurological de ficits which were due to inhibitory simple partial (nonconvulsive) status e pilepticus, and resolved with anticonvulsant treatment. Methods-The age range of the five patients was 15-74 years. The operations were: aneurysm clipping (three patients) and resections of an oligodendrogl ioma and a cavernous haemangioma (one patient each). The new focal deficits were: right hemiparesis and aphasia (two patients), aphasia alone (two pat ients), and left hemiparesis (one patient). The deficits were not explained by CT (obtained in all patients) or cerebral angiography (performed in two ). Results-Electroencephalography showed, in all patients, continuous or inter mittent focal seizures arising from cortex regionally relevant to the clini cal dysfunction. Subtle positive epileptic phenomena (jerking) occurred int ermittently in three patients as a late concommitant. Administration of ant iconvulsant drugs resulted in significant improvement within 24 hours in fo ur patients, with parallel resolution of ictal EEG activity. The fifth pati ent improved more slowly. Two patients relapsed when anticonvulsant concent rations fell, and improved again when they were raised. Conclusions-It is suggested that inhibitory simple partial (non-convulsive) status epilepticus be considered in the differential diagnosis when a new unexplained neurological deficit develops after an intracranial neurosurgic al procedure. An EEG may help to diagnose this condition, leading to defini tive treatment.