This case was reported in a literature article and described the occurrence of acute disseminated encephalomyelitis in a 16-year-old male subject who was vaccinated with DTPa (with small D + P) (manufacturer unspecified) and Meningococcal polysaccharide vaccine groups A, C, W and Y. On an unspecified date, the subject received an unspecified dose of DTPa (with small D + P) (administration site and route unknown, batch number not provided) and an unspecified dose of Meningococcal polysaccharide vaccine groups A, C, W, and Y (administration site and route unknown, batch number not provided). 15 days after vaccination with DTPa (with small D + P) and Meningococcal polysaccharide vaccine groups A, C, W and Y, the subject experienced urinary retention, decreased sensation, photophobia, headache and progressive weakness. At an unspecified time after vaccination with DTPa (with small D + P) and Meningococcal polysaccharide vaccine groups A, C, W and Y, the subject experienced loss of consciousness and lethargy. This case was assessed as medically serious by GSK. Laboratory studies revealed cerebrospinal fluid pleocytosis and an abnormal magnetic resonance imaging brain identified diffuse parenchymal signal changes above and below the tentorium, compatible with acute disseminated encephalomyelitis. After approximately 7 weeks after vaccination, the events were resolved. This is one of the 11 cases created from the same literature article. Summary of the literature article: Pre-licensure clinical trials for two licensed tetanus toxoid, reduced diphtheria toxoid and acellular pertussis (Tdap) vaccines did not reveal any major safety concerns. However, routine use in large adolescent and adult populations could reveal rare and potentially serious adverse events (AEs). To characterize reported AEs following Tdap vaccination and identify potential safety concerns warranting further evaluation, we analyzed data from the Vaccine Adverse Event Reporting System (VAERS) and assessed the frequency and proportions of AEs and reporting rates (reports per 100,000 vaccine doses distributed). A total of 2090 reports (7% were serious; 55% listed Tdap alone) involving Tdap vaccines were submitted to VAERS May 2005 - June 2007. The crude reporting rate was 10.2 per 100,000 vaccine doses distributed. The median age of vaccinees was 22 years, and the female to male ratio was about 2 to 1. The majority of reports described common local and systemic signs and symptoms, such as injection site reactions, fever, and headache. Rarely reported AEs included myopericarditis, demyelinating diseases of the central nervous system, Guillain-Barre Syndrome, syncope, encephalopathy/encephalitis, seizure, Bell's palsy, anaphylaxis, and thrombocytopenia. The author's conclusion stated that because adolescents and adults were not routinely vaccinated against pertussis in the past, this surveillance summary provides important - and reassuring - information about the use of Tdap in these age groups. Although subject to the limitations of passive surveillance, the findings of this VAERS review support the pre-licensure clinical trial data with regard to the safety of the licensed Tdap vaccines. Continued monitoring of clinically significant AEs that are temporally associated with Tdap vaccination and further assessment of such events using controlled observational studies may provide additional information about the safety of these vaccines.