Epilepsy as Chronic Sequelae of Nonconvulsive Status Epilepticus.
Abstract number :
2.139
Submission category :
Year :
2001
Submission ID :
962
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
B.F. Shneker, MD, Neurology, University of Virginia, Charlottesville, VA; N.B. Fountain, MD, Neurology, University of Virginia, Charlottesville, VA
RATIONALE: Nonconvulsive status epilepticus (NCSE) may cause epilepsy by excitotoxic mechanisms similar to generalized convulsive status epilepticus but the frequency of epilepsy following NCSE is unknown. We reviewed patients with definite NCSE to determine the proportion developing epilepsy and whether there were identifiable risk factors.
METHODS: We identified cases of NCSE through review of EEG reports with confirmation through review of original EEGs. Medical records were examined for patient and EEG characteristics, etiology of NCSE, acute complications, subsequent development of seizures or recurrent NCSE, and duration of follow up. Phone follow-up was attempted if no record was available. Fisher[ssquote]s exact or t-tests were used to determine whether the following factors were associated with development of epilepsy; age, gender, general etiology of NCSE (after a single GTC seizure, due to acute medical problem, or cryptogenic), or EEG characteristics (discharge type and frequency, level of consciousness, and clinical and EEG response to benzodiazepines).
RESULTS: We identified 100 cases of NCSE, but 42 had preexisting epilepsy, 14 died during hospitalization and 22 did not have follow-up, yielding 22 patients for analysis. Epileptic sequelae developed in 10/22 (45%) patients who survived and had follow-up; 4/22 (18%) had subsequent seizures, and 6/22 (27%) had recurrent NCSE. Epilepsy developed in 1/2 with NCSE following a GTC, in 4/11 with NCSE due to an acute medical problem, and in 5/9 with cryptogenic NCSE. Of the 10 patients who developed epilepsy, 4 (40%) had acute complications during hospitalization, 7 (70%) had spike-wave type discharges, and 9 (90%) had only mild encephalopathy during EEG. Mean age was 61[plusminus] 20 years, 18 (82%) were female, and mean duration of follow up was 4.7 [plusminus] 4 years. Differences in all parameters between the patients who did and who did not develop epilepsy were not statistically significant.
CONCLUSIONS: Epilepsy follows NCSE in 45%, including recurrent NCSE in 27%, therefore NCSE is often either the first sign of epilepsy or causes it. No statistically significant characteristics were found for the group developing epilepsy but the numbers examined are small.