A retrospective population‐based study on seizures related to childhood vaccination

Abstract

Summary Purpose: Cases of severe childhood epilepsies in temporal association with vaccination have great impact on the acceptance of vaccination programs by parents and health care providers. However, little is known about the type and frequency of seizures and epilepsy syndromes following vaccination. This study aims to describe the clinical features of children presenting with seizures after vaccination using a register‐based cohort. Methods: We surveyed the national German database of adverse events following immunization (AEFI) for reported seizures and epilepsies in children aged 0–6 years. All cases reported in 2006–2008 were analyzed retrospectively; available clinical information was reevaluated and classified by seizure type and epilepsy syndrome. Key Findings: In total, 328 cases reported between 2006 and 2008 were included. Data supportive of seizures or epilepsy were present in 247 (75.3%) of 328 patients with a mean interval between the vaccination and the epileptic event of 24 h and 7.5 days for inactivated and attenuated vaccines, respectively. Fifty‐one (15.5%) of 328 patients presented with syncope, hypotonic–hyporesponsive episodes, or other nonepileptic events. Information was insufficient for classification into epileptic versus nonepileptic events in 30 (11.3%) of 328 patients. For cases with confirmed seizures, febrile seizures were present in 121 (49%) of 247 cases, and 38 (15.4%) of 247 patients had single afebrile seizures. Status epilepticus was described in 21 (8.5%) of 247 patients. Thirty‐one (12.6%) of 247 patients presented with various pediatric epilepsy syndromes. Severe childhood epilepsies (Dravet syndrome, West syndrome, Lennox–Gastaut syndrome, or Doose syndrome) were diagnosed in 29 (11.7%) of 247 patients, with the vaccination‐associated event being the first documented seizure in 15 (51.7%) of 29 patients. Significance: Vaccination‐associated seizures present in the setting of various epilepsy syndromes, including severe childhood epilepsies in >10% of cases. Early diagnosis of the corresponding epilepsy syndromes and confirmation of an underlying etiology is important for treatment decisions, genetic counseling, and public health evaluation of vaccine safety.

Etiologies for Seizures Around the Time of Vaccination

“…10 In our study, West syndrome was a much less frequently identified epilepsy syndrome after vaccination, in contrast to another study, 18 probably because we used strict criteria for a temporal relation between vaccination and seizures.…”

“…13,14 The detection of a pathogenic SCN1A mutation in children with alleged vaccination encephalopathy proved that, although the vaccination might have triggered the first seizure, the epilepsy and subsequent intellectual disability were caused by a genetic defect. 10 Most published case series and retrospective cohort studies confirming SCN1A-related Dravet syndrome as a cause of alleged vaccination encephalopathy [15][16][17][18] have focused on epileptic encephalopathy. Only a few case reports have shown that occasionally other genetic causes of epilepsy also present with seizures after vaccination.…”

Risk of febrile seizures after first dose of measles–mumps–rubella–varicella vaccine: a population-based cohort study

“…4,37 It is a matter for debate whether the choice of separate versus combination vaccine is a policy decision or a choice for parents to make in consultation with their vaccination provider. If MMRV continues to be offered for first-dose administration, it might be advisable to counsel parents regarding antipyretic use if children experience a fever within the peak risk period.…”

Mitteilungen der Deutschen Gesellschaft für Epileptologie e.V.

“…Bei gehäuften Anfällen oder während einer medikamentösen Umstellung sollte eine nicht unbedingt erforderliche Impfung sicherheitshalber zurückgestellt werden. Bei Kindern mit epileptischen Fieberanfällen (Fieberkrämpfen) in der Vorgeschichte kann bei solchen Impfungen, die häufig mit einer fieberhaften Allgemeinreaktion einhergehen, vorsorglich eine Gabe fiebersenkender Medikamente (Paracetamol) erfolgen und gegebenenfalls ein Medikament zum Abbruch länger andauernder Anfälle bereitgehalten werden [5].…”