Abstract
Objectives Oligoepilepsy is a poorly defined syndrome characterised by infrequent seizures. Oligoepilepsy poses a management dilemma with regards to the role of anti-seizure medication (ASM) and driving advice. The clinical, EEG and imaging characteristics of oligoepilepsy have not been well described.
Methods Patients were identified from a prospective database of adults with first-ever seizure. Oligoepilepsy was defined as patients who were not treated with ASM, and had ≥2 unprovoked seizures, with ≤1 seizure per year over ≥3 years follow-up. The comparator group comprised the remaining epilepsy patients.
Results Of 810 patients with ≥2 unprovoked seizures, 33 (4%) met the definition of oligoepilepsy (45% female, median age 36 years, range 17–90 with no difference in age or sex to the epilepsy group). Median time to second seizure was 1343 days, as opposed to 107 days in the comparator group (p<0.001). Patients with oligoepilepsy were less likely to have a first seizure from sleep, remote symptomatic aetiology and/or epileptogenic lesion on neuroimaging and focal onset seizure. There was no difference in the rate of presentation with clusters of seizures or status epilepticus and the proportion of patients with EEG epileptiform abnormalities (21%) was the same in the patients with epilepsy and oligoepilepsy.
Conclusion Oligoepilepsy is characterised by a longer interval between the first and second seizure and a lower frequency of remote symptomatic aetiology, focal seizures and seizures from sleep. Identification of this rare subgroup of epilepsy may have an impact on management.
