Relationship of pertussis immunization to the onset of epilepsy, febrile convulsions and central nervous system infections: a retrospective epidemiologic study.

A change in the pertussis immunization schedule in Denmark allowed a retrospective study examining the relationship of the time of onset of selected neurologic disorders with the time of pertussis immunization in two core cohorts of children. Records of 2,199 children with febrile seizures were reviewed and a significant association between first febrile seizures and the scheduled age of pertussis immunization was noted (p = 0.004). The occurrence of epilepsy and CNS infections did not appear to be related to the time of pertussis immunization.