The commonest time for fits to begin is between 18 and 24 months of age, often associated with a fever. A variety of anticonvulsants have been used to control fits with sodium valproate and clonazepam being some of the more successful. Each child needs treating individually, however, and when fits are difficult to control referral to a paediatric neurologist is important. The fits are often episodic in nature and interspersed with relatively fit-free periods. Common types of seizures include drop attacks, petit mal absences and myoclonic jerks.
Fits are less frequent as the children grow older and often cease completely.
During a severe period of fitting regression in development may occur with the loss of some previously acquired skills. The regression is reversible, however, and the skills are regained at a later date. The EEG tracing is almost always abnormal in AS and has a specific pattern which has been studied in detail. The EEGs need to be carried out under specified conditions to show up all the relevant features and the changes are more prominent in younger children. The skin is pale and burns easily on exposure to sunlight.