Summary

Although there is strong evidence that genetic factors contribute to risk for epilepsy, their role in the determination of syndrome type is less clear. This study was undertaken to address this question. Information related to epilepsy was obtained from twins included in 455 monozygotic and 868 dizygotic pairs ascertained from population-based twin registries in Denmark, Norway and the United States. Syndrome type was determined based on medical record information and detailed clinical interviews and classified using the International Classification Systems for the Epilepsies and Epileptic Syndromes. Concordance rates were significantly increased in monozygotic versus dizygotic pairs for all major syndrome groups except localization-related cryptogenic epilepsy. Among generalized epilepsies, genetic factors were found to play an important role in the determination of childhood absence, juvenile absence, juvenile myoclonic, and idiopathic generalized epilepsy; and to a lesser degree for epilepsies with grand mal seizures on awakening. Among localization-related epilepsies, genetic factors contributed to risk for localization-related idiopathic and symptomatic syndromes overall, but did not appear to play an important role in determining risk for frontal, occipital or temporal lobe epilepsy. These results suggest that, while genetic factors contribute to risk for major syndrome types, determined when possible, their contribution to risk for localization-related syndrome sub-types, as defined by specific focality, may be modest.

Background

Infantile spasms (IS; West syndrome) is a severe form of encephalopathy that typically affects infants younger than 2 years old. Pediatricians, pediatric neurologists, and other pediatric health care providers are all potentially key early contacts for families who have an infant with IS. The objective of this article is to assist pediatric health care providers in the detection of the disease and in the counseling and guidance of families who have an infant with IS.

Methods

Treatment guidelines, consensus reports, and original research studies are reviewed to provide an update regarding the diagnosis and treatment of infants with IS. Web sites were searched for educational and supportive resource content relevant to providers and families of patients with IS.

Results

Early detection of IS and pediatrician referral to a pediatric neurologist for further evaluation and initiation of treatment may improve prognosis. Family education and the establishment of a multidisciplinary continuum of care are important components of care for the majority of patients with IS. The focus of the continuum of care varies across diagnosis, initiation of treatment, and short- and long-term needs. Several on-line educational and supportive resources for families and caregivers of patients with IS were identified.

Conclusions

Given the possibility of poor developmental outcomes in IS, including the emergence of other seizure disorders and cognitive and developmental problems, early recognition, referral, and treatment of IS are important for optimal patient outcomes. Dissemination of and access to educational and supportive resources for families and caregivers across the lifespan of the child with IS is an urgent need. Pediatric health care providers are well positioned to address these needs.

Summary

Questionnaire surveys provide an efficient means of identifying potential seizure cases in large population-based cohorts. Concerns exist, however, with regard to the reliability of self-reported information both with respect to the validity of the results obtained and with regard to the usefulness of this approach in identifying true cases. Information on history of seizures obtained by questionnaire from members of 47,626 twin pairs included in the Mid-Atlantic (MATR), Danish (DTR) and Norwegian (NTR) Twin Registries was verified using medical records and detailed clinical and family interviews. The accuracy of these reports was assessed. Self-reported epilepsy was verified in 81.9% of twins overall (86.1% (DTR), 75.6% (NTR) and 80.7% (MATR)). However, when both pair members reported a history of epilepsy in the affected pair member, epilepsy was verified in >90% of cases. Among MATR twins with a verified history of epilepsy, 21.5% reported other seizures but not epilepsy and 18.5% of verified Norwegian epilepsy cases reported no history of epilepsy themselves and were identified only through their co-twin. The results of this study indicate that the accuracy of self-reported epilepsy and febrile seizures among those who provided information on health history was high across all populations. However, the relatively large percentage of twins with a verified diagnosis who did not acknowledge epilepsy suggests that the frequency of epilepsy may be under-estimated in self-reported samples.