Nonconvulsive status epilepticus associated with cephalosporins in patients with renal failure

PURPOSE: Nonconvulsive status epilepticus is an unusual complication of cep halosporin therapy, with only a few isolated cases reported. SUBJECTS AND METHODS: We reviewed the clinical and electroencephalographic (EEG) characteristics of 10 patients with renal failure in whom developed a lteration of consciousness without convulsions associated with continuous e pileptiform EEG activity while being treated with cephalosporins. RESULTS: Nonconvulsive status epilepticus developed in 5 men and 5 women, w ith a mean ( SD) age of 69 +/- 14 years, while receiving intravenous cephal osporins (ceftriaxone, 2 patients; ceftazidime, 2; and cefepime, 6). All pa tients had renal failure; I also had hepatic failure. Patients presented wi th progressive disorientation or agitation, sometimes associated with mild facial or limb myoclonus, that had begun 1 to 10 days (mean, 5 +/- 2 days) after starting cephalosporin treatment. The EEG showed continuous or interm ittent bursts of generalized, high-voltage, 1 to 2 Hz sharp wave activity o r sharp and slow wave activity that resembled, but could be differentiated from, the triphasic waves seen in metabolic encephalopathies. Intravenous c lonazepam suppressed the epileptiform activity completely in 5 patients and partially in the other 5. Cephalosporins were withdrawn, and antiepileptic therapy was started for all patients. All patients improved, 2 in less tha n 24 hours and the remainder within 2 to 7 days. CONCLUSIONS: Cephalosporins can cause nonconvulsive status epilepticus in p atients with renal failure. The clinical picture is difficult to differenti ate from a that of metabolic encephalopathy unless an EEG is obtained. Phys icians should be aware of this potentially dangerous complication. (C) 2001 by Excerpta Medica, Inc.