Status epilepticus in a population-based Virginia twin sample.
OBJECTIVE
To characterize status epilepticus (SE) and estimate its frequency of first occurrence, as well as to assess the contribution of genetic factors to risk of SE occurrence in a sample of Virginia-born twins ascertained from the population-based Mid-Atlantic Twin Registry.


METHODS
The occurrence of SE was determined in 13,506 unselected Virginia-born twin pairs ascertained from birth records. Twins included in the study were between ages 2 and 75 years when surveyed. History of seizures and SE was validated through medical records and by detailed personal or parental interviews.


RESULTS
Among 381 twins included in 332 pairs with a verified history of seizures, 70 (18.4%) were validated to have had at least one episode of SE. The frequency of first SE in this sample was 309 per 100,000 twins. First SE occurred in conjunction with 21 of 158 febrile and 49 of 223 afebrile seizure cases, respectively. Mean length of SE episode was 76.2 +/- 14.9 min. Age at first SE occurrence ranged from 2 months to 59 years. All concordant twin pairs in the sample were monozygotic (MZ), with a proband-wise concordance rate estimated for SE in this population of 0.31 [95% confidence interval (CI), 0.14-0.52) overall, and 0.67 (95% CI, 0.35-0.90) in pairs concordant for epilepsy.


CONCLUSIONS
These results provide a direct estimate of the frequency of SE in a defined population of twins and afford further evidence for a genetic contribution to risk for SE.
Corey
Linda A
LA
Virginia Institute for Psychiatric and Behavior Genetics, Department of Human Genetics, Virginia Commonwealth University, Richmond, Virginia 23298-0003, USA. corey@mail2.vcu.edu
Pellock
John M
JM
DeLorenzo
Robert J
RJ
D000293:Adolescent; D000328:Adult; D001722:Birth Order; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D012042:Registries; D012307:Risk Factors; D013226:Status Epilepticus / Q000453:epidemiology* / Q000235:genetics*; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic; D014768:Virginia / Q000453:epidemiology