Outcome of seizures in the first year of life

Aim: To determine the frequency and natural history of seizures having an onset during the first year of life. Methods: A retrospective analysis of the files of all patients treated in the paediatric neurology clinic of our medical centre during 1975-1995. Results: Of our 482 patients with seizure onset prior to age 1 6 years, the first seizure occurred at age 1-12 months in 80 (16.6%). Of those, 38 (48%) had West syndrome and the rest were classified as follows - partial seizures with or without secondary generalization: 19%, generalized tonic seizures: 8.5%, generalized tonic-clonic seizures: 7.5%, myoclonic: 7.5%, unclassified: 7.5%, and mixed-type seizures: 2%. Follow-up was possible in 91% of the patients. Mean follow-up period from seizure onset was 10 years. Of the non-West syndrome patients who were followed, 19 (50%) were still experiencing seizures at follow-up. Eleven of the 15 patients (73%) with partial seizures and four of the 13 patients (31%) with generalized tonic or tonic-clonic seizures had symptomatic seizures. Of the 14 followed patients with partial seizures, 10 (71%) still had seizures at follow-up, as did three (25%) of the 12 followed patients with generalized tonic or tonic-clonic seizures (p = 0.023). Conclusions: The partial seizures were most often symptomatic with unfavourable prognosis, while the generalized seizures were either symptomatic and severe or cryptogenic and rapidly responsive to anti-epileptic drugs with good outcome.