A 44-year-old patient with a new-onset seizure disorder after vaccination against Japanese encephalitis: a case report

INTRODUCTION Seizure disorders can have a wide variety of causes. In many cases, however, the underlying cause remains unknown. Vaccinations, for example, can trigger seizures, especially during childhood. In the literature, many cases have been reported in which febrile convulsions occurred after the administration of different types of vaccines, such as the measles, mumps and rubella vaccine or the tetanus and diphtheria vaccine. Only a few cases of epilepsy after vaccination have thus far been described in adults. CASE PRESENTATION In the case reported here, a 44-year-old German Caucasian man working as a soldier had a seizure the day after he received a third dose of Japanese encephalitis vaccine. Before this vaccination, he had received multiple vaccines that he had tolerated well. He underwent several drug therapies at various institutions but has continued to experience different forms of seizures for more than 18 months. The intervals between seizures were approximately six weeks in length. The present work discusses our patient's history, including all diagnostic procedures and results, as well as treatment approaches. None of the examinations revealed a possible cause for the seizures. Since no structural or genetic causes were detected, the seizures were deemed most likely to have been caused by the vaccinations, especially vaccination against Japanese encephalitis. To date, no medication has prevented our patient from having repeated attacks. CONCLUSIONS To the best of our knowledge there have been no previous cases reported in the literature where seizures occurred after multiple vaccinations in general or after vaccinations against Japanese encephalitis in particular. Although vaccines are tested before release, the appearance of new adverse reactions cannot be prevented in all cases. Seizure after vaccination is difficult to treat. In our patient's case, different approaches have not led to a satisfying result to date.