Abstract

SCOPE OF THE PROBLEM

Epilepsy is common. About 3% of individuals develop epilepsy during a lifetime of 70 years, and about 0.5–0.9% of the population have epilepsy at any given time. For the majority, the prognosis is favourable: about two-thirds of those who develop epilepsy will – at some stage – attain freedom from seizures for at least 5 years, and about one-third will become free of seizures for 5 years or more, and off medication (Cockerell et al. 1997). While these figures predate the ‘new’ antiepileptic drugs (AEDs) and the vagal nerve stimulator, there is no evidence that any of these interventions have diminished the proportion of patients with medically refractory seizures, somewhat arbitrarily defined as the recurrence of seizures despite a trial of two or more AEDs.

Given the estimate that about 1 in 1000 of the population have monthly seizures, and about 60% of patients have partial seizures