The incidence of unprovoked seizures and occurrence of neurodevelopmental comorbidities in children at the time of their first epileptic seizure and during the subsequent six months

•The incidence of first epileptic seizures in children was 67/100,000 person years.•One third of the new seizure-patients had one or more of the defined comorbidities.•A combination of defined comorbidities was highly suspected in 11% of the subjects.•Among new seizure-patients younger than 6 years ESSENCE (Early Symptomatic Syndromes Eliciting Neurodevelopmental Clinical Examinations) was highly suspected in 34%.

SummaryPurposeTo evaluate the incidence of unprovoked seizures in children and the prevalence of related neurodevelopmental comorbidities at the time of the presumed first seizure and six months thereafter.MethodsThe medical records of all children (0-18 years of age) seeking medical attention as the result of a first unprovoked seizure between September 1, 2001 and December 31, 2006, and registered in the population-based Stockholm Incidence Registry of Epilepsy (SIRE) were reviewed. Neurodevelopmental comorbidities were evaluated on the basis of the medical records from this first visit and from other healthcare during the following six months.ResultsThe incidence of unprovoked seizures was between 30 and 204/100,000 person years (n = 766) in the different age groups. It was highest among the youngest children and lowest among the 18-year-olds with small gender differences. The most common neurodevelopment comorbidities were developmental delay (22%, CI: 19-25%), speech/language and learning difficulties (23%, CI: 20-26%) and intellectual disability (16%, CI: 13-18%). The types of neurodevelopmental comorbidity varied by age at the time of seizure onset, with cerebral palsy being more common among the 0-5-year-olds, attention deficits among the 6-16-year-olds, and autism and psychiatric diagnosis among the older children. An associated neurodevelopmental comorbidity was more common among those experiencing recurrent than single seizures during follow-up six months from the index seizure (42% versus 66%). In 68% (CI: 64-71%) of the children there was no known or suspected neurodevelopmental comorbidity.ConclusionThe incidence of unprovoked, non-febrile seizures among 0-18-year-olds included in the SIRE was 67/100,000 person-years. Neurodevelopmental comorbidities were common already at the time of onset of the seizure disorder, indicating that neither seizure treatment nor seizures were the underlying cause of other neurodevelopmental symptoms in these patients during the period studied.