Long-term prognosis for symptomatic (secondarily) generalized epilepsies: a population-based study.
OBJECTIVE
To describe the long-term outcome of childhood-onset secondarily generalized epilepsies (SGEs).


METHODS
Children were identified from the Nova Scotia population-based epilepsy study (n=692). Onset of epilepsy was between 1977 and 1985, and follow-up was mainly in 2003. SGE was defined as having a mixture of more than one generalized seizure types including myoclonus, akinetic/atonic, tonic, or atypical absence, plus an interictal EEG with generalized spike-wave (irregular or slow) and/or multifocal spikes.


RESULTS
SGE was identified in 80 children, 11.6% (80 of 692) of all childhood epilepsy. Forty percent did not fit into a currently accepted syndrome (such as Lennox-Gastaut, myoclonic-astatic or West). Seizure onset was in the first year of life in 60%, with only 9% later free of intellectual or physical handicap. Sixty-five percent (11 of 17) with Lennox-Gastaut had preceding West syndrome. During a median follow-up of 20 years, mortality was 24% (n=19), and 53% (n=42) had persistently intractable seizures. Surprisingly, 22 (28%) had >or=5 years of terminal remission (West, 31%, 10 of 32; Lennox-Gastaut, 0, none of four; myoclonic-astatic, 56%, five of nine; undefined, 31%, 10 of 32). At the end of follow-up, nearly 90% of patients fell into one of three outcome categories: death, 19 (24%); alive with intractable epilepsy, 31 (39%); or in remission for >or=5 years, 21 (26%).


CONCLUSIONS
Many children with SGE have ill-defined epilepsy syndromes. SGE is characterized by early age at onset, high rates of handicap, intractability, and death, although one third achieve complete seizure control with a long terminal remission.
Camfield
Peter
P
Department of Pediatrics, Dalhousie University and the IWK Health Centre, Halifax, Nova Scotia, Canada. pcamfiel@dal.ca
Camfield
Carol
C
D000293:Adolescent; D017668:Age of Onset; D002423:Cause of Death; D002648:Child; D002675:Child, Preschool; D015897:Comorbidity; D003625:Data Collection; D004185:Disability Evaluation; D004831:Epilepsies, Myoclonic / Q000175:diagnosis / Q000453:epidemiology; D004832:Epilepsy, Absence / Q000175:diagnosis / Q000453:epidemiology; D004829:Epilepsy, Generalized / Q000175:diagnosis* / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008137:Longitudinal Studies; D008297:Male; D009674:Nova Scotia / Q000453:epidemiology; D017063:Outcome Assessment, Health Care; D011379:Prognosis; D013577:Syndrome