2.5 Hz generalised spike-wave discharges. Atypical absence seizures: - Occur only in the context of mainly severe symptomatic or cryptogenic epilepsies of children with learning difficulties who also suffer from frequent seizures of other types such as atonic, tonic and myoclonic - Onset and termination is not so abrupt and changes in tone are more pronounced - Ictal EEG is of slow less than 2.5 Hz spike and slow wave. - The discharge is heterogeneous, often asymmetrical and may include irregular spike and slow wave complexes, fast and other paroxysmal activity. - Background interictal EEG is usually abnormal. Treatment of patients with absence seizures only is mainly with sodium valproate or ethosuximide, which are of equal efficacy controlling absences in around 75% of patients. Sodium valproate as a single drug is the DOC if tonic clonic seizures are also present or emerge during the therapy with ethosuximide Lamotrigine monotherapy is less effective with nearly half of the patients becoming seizure free.">