Immunization stress-related responses presenting as psychogenic non-epileptic seizures following HPV vaccination in Rio Branco, Brazil

Abstract Importance The absence of a positive diagnosis of psychogenic non-epileptic seizures (PNES) in immunization stress-related response (ISRR) clusters may have not only a direct impact on affected patients’ health but may also reduce compliance to national vaccination programs. It is therefore crucial to develop efficient diagnostic tools and a feasible proposal for proper communication and treatment of ISRR. Purpose To explore the psychogenic nature of patients’ convulsive seizures in a suspected outbreak of an ISRR cluster following human papillomavirus vaccination in Rio Branco, Brazil. Methods Twelve patients with convulsive seizures were submitted to prolonged intensive video-electroencephalography monitoring, brain magnetic resonance imaging, cerebrospinal fluid diagnostic testing, laboratory subsidiary examinations, and complete neurological and psychiatric evaluations. Results Ten patients received the positive diagnosis of PNES, and two patients received the diagnosis of idiopathic generalized epilepsy. No biological association was found between the HPV vaccine and the clinical problems presented by the patients. Conclusions Prolonged VEEG monitoring can contribute significantly to the positive diagnosis of PNES in ISRR clusters and to avoid hesitancy to vaccinate.