Abstracts

RATIONALE: Nonconvulsive status epilepticus (NCSE) is an epileptiform encephalopathy that benefits from antiepileptic treatment but can be difficult to distinguish from other such encephalopathies that do not. Jacob-Creutzfeldt disease is one such severe irreversible encephalopathy that can present with epileptiform electroencephalographic (EEG) patterns, including periodic spikes and sharp waves, and may be mistaken for NCSE, but does not improve with antiepileptic drug treatment and is uniformly fatal. We reviewed all patients diagnosed and treated for NCSE who later proved to have Jacob-Creutzfeldt disease to determine the extent and nature of this problem.
METHODS: We reviewed all patients referred at the University of Maryland Epilepsy Center over the past 10 years who, based on their clinical and EEG findings, were diagnosed and treated for suspected NCSE and identified those who later proved, on the basis of specific antigen studies, biopsy, or autopsy to have Jacob-Creutzfeldt disease. We reviewed the clinical histories, laboratory studies, electroencephalograms, and available pathology for all patients.
RESULTS: We indentified four patients initially diagnosed with NCSE who were later proven to have Jacob-Creutzfeldt disease. There were 2 men and 2 women, and their average age was 64 years (range 58-71 years). All presented with acute or subacute changes in mental status. Two were reported to have had previous convulsive events. Electroencephalograms in all patients showed continuous spikes or sharp waves suggestive of NCSE. In all patients periodic epileptiform discharges were reported with a frequency of 1 to 2 cycles per second. In three patients these were bilateral and in one focal. In one patient, the epileptiform EEG pattern improved after administration of a test dose of intravenous benzodiazepines. All patients were aggressively treated with antiepileptic therapy, and two were subjected to barbiturate coma. None of the patients showed clinical improvement with antiepileptic drug therapy despite improvement in their EEGs. Diagnosis of Jacob-Creutzfeld disease was eventually made with brain biopsy or autopsy in three patients, and by antigen studies in one. All patients died within three months of their initial presentation.
CONCLUSIONS: Jacob-Creutzfeldt disease can be mistaken for NCSE resulting in inappropriate therapy and delayed diagnosis for some patients. Jacob-Creutzfeldt disease is a subacute encephalopathy which because of its association with altered mental status and a continuous epileptiform EEG pattern must be carefully distinguished from NCSE.
Support: The Rosen Fund for Neurological Research