STATUS EPILEPTICUS IN A POPULATION-BASED TWIN SAMPLE
Abstract number :
2.002
Submission category :
Year :
2003
Submission ID :
3755
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Linda A. Corey, John M. Pellock, Robert J. DeLorenzo Human Genetics, Virginia Commonwealth University, Richmond, VA; Neurology, Virginia Commonwealth University, Richmond, VA
Although previous studies of status epilepticus (SE) have provided important insights about its incidence and demographics, there have been relatively few population-based studies of SE occurrence in the United States. This study was undertaken to characterize SE in a population-based sample of monozygotic (MZ) and dizygotic (DZ) twins and to examine the contribution of genetic factors to its risk of occurrence.
The occurrence of SE was determined 13,506 unselected Virginia-born twin pairs who were ascertained from birth records. Information on seizure history was collected either by mailed questionnaire or telephone interview. Twins included in the study were between two and 75 years of age when surveyed. History of SE was validated using medical records and by personal and/or parental interviews. Concordance rate analyses were used to assess the contribution of genetic factors to SE risk.
Among 381 twins included in 332 pairs with a verified history of seizures, a history of SE was validated in 70 individuals (18.4%). The frequency of first SE occurrence in this sample ranged from 277/100,000 to 493/100,000 in twins ascertained as adults and as children, respectively. The discrepancy in the frequency of SE observed in those ascertained as adults as compared to those ascertained as children is likely to be due to the small number of elderly twins included in a sample whose mean age is 37.1 years and the fact that suble forms of SE are likely to be under-represented. First SE occurred in conjunction with 21 of 158 febrile and 49 of 223 afebrile seizure cases, respectively. Mean SE length in this sample was 76.2 [plusmn] 14.9 minutes. Age at first SE occurrence ranged from two months to 59 years. Significant differences were observed both in the frequency of SE attributable to gender overall (p=0.047) and in the frequency of SE-affected male vs female members of opposite-sexed twin pairs (p[lt]0.01). All concordant twin pairs in the sample were MZ. Probandwise concordance rates estimated for SE in this sample were 0.31 for MZ and 0.00 for DZ twins. Among twin pairs who were concordant for seizures, probandwise concordance rates for MZ and DZ twins were 0.67 and 0.00, respectively.
These results characterize the demographics and frequency of first SE occurrence in a defined population of twins and provide further evidence of the contribution of genetic factors to risk for SE.
[Supported by: grants from the National Institutes of Health NINDS (NS25630 and NS31564).]