In a representative series of 53 females with Rett syndrome (RS), aged 5–55 y, a history of epilepsy was present in 50 (94%), 45 of whom had 5-y active epilepsy. Compared with severe mental retardation in general, the median age of seizure onset was significantly later (4 vs 0.8 y) and partial complex seizures were more frequent (54% vs 23%). Neonatal seizures had occurred in only one and infantile spasms in none compared with 26% and 12%. After teenage, the severity of epilepsy tended to decrease, i.e. lower seizure frequency and relatively more partial seizures. The rate of being seizure-free for 1 y was 8% after 10 y and 40% after 27 y of epilepsy duration. Frequent seizures were associated with smaller head circumference.
Conclusion: This epilepsy profile could fit in with present-day knowledge of RS as a form of dendrito-synaptogenic developmental failure with mainly late postnatal consequences, as well as being a relatively stationary condition in adulthood.