AUTOSOMAL DOMINANT NOCTURNAL FRONTAL LOBE EPILEPSY

OVERVIEW

Autosomal dominant nocturnal frontal lobe epilepsy is a familial epilepsy with focal seizures beginning most commonly in childhood, although sporadic cases may occur. Brief nocturnal frontal lobe seizures with hyperkinetic, tonic or dystonic motor features are seen. Treatment with low dose carbamazepine is effective, however 30% of cases are resistant to treatment. Interictal EEG is often normal but may show anterior epileptiform abnormalities, typically in sleep. Mutations have been identified in genes coding for different subunits of the neuronal nicotinic acetylcholine receptors in 15% of familial cases, and in some sporadic cases.

Clinical context

This syndrome is characterized by onset of seizures at a mean age of 9 years (ranges from infancy to the sixth decade of life), 85% of cases have onset of seizures by 20 years of age. Both sexes are equally affected. Antecedent and birth history is normal. Head size and neurological examination are usually normal. Development prior to onset of seizures is typically normal, cognitive disturbances (executive dysfunction and memory impairment) and psychiatric disorders have been described in some families. Cognitive decline has been reported with time in rare individuals.