Risk factors of infantile spasms compared with other seizures in children under 2 years of age.

To analyze the magnitude of the risk factors for infantile spasms, we evaluated the records of 80 children with infantile spasms, 474 children with other types of epilepsy, 2,196 children with febrile seizures, and 262 children with CNS infections. There was a family history of seizures in 13.8% of children with infaNtile spasms, 28.5% of children with other forms of epilepsy, 25.5% of children with febrile seizures, and 5.3% of children with CNS infections. Children with a family history of seizures were 2.82 times more likely to have infantile spasms, 7.05 time more likely to have other epilepsy, and 6.08 time more likely to have febrile seizures than controls (children with CNS infections). However, a family history of seizures increased the risk for infantile spasms only in the cryptogenic group. Children with infantile spasms were significantly more likely to have cerebral palsy, microcephaly, hydrocephaly, CNS malformations, neonatal hypoxia, or neonatal seizures than children with other types of epilepsy, febrile seizures, or CNS infections. There was a modest genetic predisposition to seizures in children with infantile spasms. However, our data suggest a much stronger association with underlying neurologic abnormalities, mainly neonatal seizures, neonatal hypoxia, and CNS malformations.