Childhood absence epilepsy

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By C P Panayiotopoulos MD PhD

Childhood absence epilepsy is also known as or subsumes Pyknolepsy and Petit mal seizures. -ed.

Childhood absence epilepsy is the prototype idiopathic generalized epilepsy syndrome of typical absence seizures. It is common, genetically determined, age related, and affects otherwise normal children. It manifests with severe and frequent (pyknoleptic) absence seizures of around 10 seconds each for many times per day. EEG shows classical generalized 3 Hz spike-and-slow wave discharges. Prognosis of childhood absence epilepsy is excellent if properly diagnosed and treated. In this update, C P Panayiotopoulos MD PhD FRCP, Consultant Emeritus in Clinical Neurophysiology and Epilepsy at St. Thomas’ Hospital in London, England, details recent developments in the pathophysiology, genetics, and pharmacological treatment of childhood absence epilepsy. The focus is on the current understanding of its clinical and EEG phenotype, epidemiology, and outcome along with the differential diagnosis associated with other idiopathic generalized epilepsies involving absence seizures. Dr. Panayiotopoulos particularly emphasizes that most of the older and newer antiepileptic drugs are contraindicated for the treatment of childhood absence epilepsy.

Key Points

  • Childhood absence epilepsy is the most characteristic and classic example of an idiopathic generalized epilepsy characterized by typical absence seizures of high daily frequency and severe impairment of consciousness.
  • Probably any other types of seizure in the active period of childhood absence epilepsy are incompatible with this diagnosis. Mild impairment of consciousness in untreated patients is an exclusion criterion.
  • Differential diagnosis includes other types of syndromes manifesting with typical absence seizures; “epilepsy with absences seizures of childhood onset” is not synonymous with childhood absence epilepsy.
  • Prognosis is usually excellent for patients diagnosed on strict inclusion and exclusion criteria for childhood absence epilepsy.
  • Ethosuximide, sodium valproate, and lamotrigine are the most effective antiepileptic drugs.