PREVALENCE OF EPILEPSY IN PATIENTS DIAGNOSED WITH NON-EPILEPTIC SEIZURES
Abstract number :
1.023
Submission category :
Year :
2003
Submission ID :
935
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Eric M. Jeffries, Allan Krumholz, Tricia Y. Ting, Elizabeth Barry, Charles Simpson Department of Neurology, University of Maryland Medical System, Baltimore, MD
Nonepileptic seizures (NES) are a common problem, accounting for approximately 20% of all intractable seizure disorders referred to comprehensive epilepsy centers and presenting with an annual incidence of about 4% that of epileptic seizures. Epileptic and nonepileptic seizures are not mutually exclusive phenomena and can co-exist in the same patient. How commonly NES and epileptic seizures co-exist is not established, with reports varying from a high of more than 50% to a low of about 2%. Some of the differences in reported incidence may relate to how these NES and epilepsy are defined.
We addressed this issue by reviewing our database of all patients diagnosed with NES between 1989 and 1998 in the Maryland Epilepsy Center Monitoring Unit to identify those diagnosed to have co-existing epilepsy as well. We then assessed the criteria on which those judgments were made.
From 1989 to 1998, we identified 215 patients with video-EEG documented NES. Their ages ranged from 9 to 79 years of age and 68 percent were women.
Of these, data on 164 was available regarding the co-existence of epilepsy and NES. Of these 164, 46 (28%) were judged to have both epilepsy and NES. The clinical diagnosis of NES in all patients was confirmed by video-EEG monitoring.
Adequate data was available on exactly how the determination of epilepsy was made in 38 (83%) of these patients. In 20 of the 38 (53%) the determination of epilepsy was based solely on the clinical history. In 17 of 38 (45%), the diagnosis of epilepsy was based on history and epileptiform abnormalities on interictal EEG. In only 1 of the 38 (3%) was the presence of epilepsy confirmed by recording an EEG-documented epileptic seizure in addition to coexisting NES.
NES and epilepsy coexist. The exact incidence depends to a large degree on how one determines the diagnosis of epilepsy in patients diagnosed to have NES. Using a strict diagnosis of video-EEG documented epilepsy actively co-existing with similarly documented NES, the incidence is low and in the range of 3%.
[Supported by: The Harry and Jeanette Weinberg Foundation]