Objective This study sought to compare the clinical course, seizure and developmental outcome of infantile spasms (IS) that start off as focal epilepsy (FE) with those who present with IS from the outset.
Method Ours was a retrospective observational study. The records review collected data regarding a wide range of parameters such as initial seizure types, initial EEGs, treatment of initial seizures, age at onset of infantile spasms, treatment of infantile spasms, MRI results, developmental outcome prior to onset of infantile spasms & after treatment of infantile spasms, period of follow up, seizure types at last follow up and aetiology of infantile spasms.
Results 26 (37.1%) out of 70 patients with IS presented with FE before evolving into IS and 6 (8.5%) with multifocal epilepsy. Majority from FE group had concordant electroencephalographic (EEG) changes. 20 (77%) out of 26 patients in FE group had an abnormal MRI compared to 22 out of 38 (58%) in IS group. Median age of diagnosis of IS was 24 weeks in FE group compared to 20 weeks of IS group. In 38 patients with IS as initial presentation, 37 showed hypsarrythmia and 1 showed modified hypsarrythmia. Patients with structural-metabolic abnormalities were more common in FE group than IS group. Infants with FE were more resistant to treatment for IS and had worse developmental outcome at the last follow-up.
Conclusion Our study looks at potential predictors in infants who initially present with FE before evolving into IS. This, in turn, could influence their early treatment to prevent epileptic encephalopathy. We have identified that patients with structural-metabolic aetiology presenting with FE in infancy are at an increased risk of developing IS, are more resistant to usual treatments and have worse developmental outcomes. This begs the question of treating this group of patients earlier with steroids before the emergence of IS to avoid the bad outcome (s) associated with epileptic encephalopathy.