Absence epilepsy beyond adolescence: an outcome analysis after 45 years of follow-up

Depending on patient age at onset, absence epilepsy is subdivided into childhood and juvenile forms. Absence seizures can occur several times per day (pyknoleptic course) or less frequently than daily (non-pyknoleptic course). Seizures typically terminate before adulthood, but a quarter of patients need ongoing treatment beyond adolescence. Little is known about their long-term seizure and psychosocial outcome.

Files of 135 outpatients with absence epilepsy (76 females; 123 had additional generalised tonic-clonic seizures) were retrospectively analysed after a median follow-up of 45.4 years (IQR: 31.9-56.2). Eighty-two subjects completed an additional interview. Patients were dichotomised according to age at epilepsy onset (childhood: n=82; juvenile: n=53) and course of absence seizures (pyknoleptic: n=80; non-pyknoleptic: n=55).

Among all patients, 53% achieved 5-year terminal seizure remission, 16% without antiepileptic medication. Median age at last seizure was lower in patients with childhood onset of absence epilepsy (37.7 years) versus juvenile onset (44.4 years; P≤0.01). However, rates and duration of terminal seizure remission were similar. Pyknoleptic versus non-pyknoleptic course of absence seizures made no difference for long-term seizure outcome. Multivariate analysis identified only higher age at investigation to be associated with terminal 5-year seizure remission. Regarding aspects of psychosocial outcome, there were no significant differences between the respective subgroups.

These data indicate that if absence epilepsy persists beyond adolescence, long-term seizure and psychosocial outcome do not differ between childhood and juvenile onset or between pyknoleptic and non-pyknoleptic course of absence epilepsy. However, higher patient age increases the chance of terminal seizure remission.