Dom Pedro I of Brazil and IV of Portugal: epilepsy and peculiar behavior.

We present medical issues related to Dom Pedro de Alcântara Bragança e Bourbon (1798-1834), first Emperor of Brazil. This is made by means of narrative revision on historical facts starting from primary and secondary sources. Dom Pedro presented familiar incidence of epilepsy. His seizures were relatively benign and scattered, supposedly started at the age of 13: idiophatic epilepsy with generalized tonic-clonic seizures only or juvenile myoclonic epilepsy. He also had behavioral disorder characterized by hypersexuality, agitation and impulsiveness. It could have facilitated his opportunistic behavior necessary for daring to transgress the conservatism of the Portuguese crown, to create the constitutional monarchism in Brazil and in Portugal.