Down Syndrome and Epilepsy

Down syndrome (DS) is associated with many neurological complications including cognitive deficits, early-onset dementia -which resembles Alzheimer’s diseaseand seizures. Although seizures and epilepsy were not mentioned in the original description of DS (Down, 1866) the prevalence of seizures in individuals with DS is now known to be higher than in the general population, but lower than in patients with some other types of mental retardation (Corvett et al., 1975). Reported rates of epilepsy in DS range from 1 to 13% (see table 1) (Tatsumo et al., 1984). Individual series are difficult to compare because of differences in inclusion criteria and study populations. The increased seizure susceptibility in DS has been attributed to inherent structural and molecular anomalies of the brain or to associated medical complications, such as cardiovascular abnormalities and recurrent infections. Medical interventions in DS have resulted in increased longevity, with estimated life expectancy of people with DS in developed countries increasing from an average of 12 years in the 1940s to an average of 57,8 years for women and 61,1 years for men (Bittles et al., 2007). Epilepsy onset in people with DS is age-specific; therefore, because certain complications will arise in childhood and others in adulthood, their occurrence is relevant to paediatric and adult neurologists. This chapter will provide a critical overview of epilepsy in DS.