The aetiology of the learning difficulty in tuberous sclerosis is debated. It may be related to the amount of tubers in the brain or caused by the infantile spasms that occur in early life.
Department of Paediatric Neurology, Bristol Royal Hospital for Children, Institute of Child Health, Upper Maudlin Street, Bristol BS2 8BJ, UK. finbar.ocallaghan@ubht.nhs.swest.uk