Post-vaccination encephalomyelitis: literature review and illustrative case

Abstract

Acute disseminated encephalomyelitis (ADEM) is an inflammatory demyelinating disease of the central nervous system that is usually considered a monophasic disease. ADEM forms one of several categories of primary inflammatory demyelinating disorders of the central nervous system including multiple sclerosis, optic neuropathy, acute transverse myelitis, and neuromyelitis optica (Devic's disease). Post-infectious and post-immunisation encephalomyelitis make up about three-quarters of cases, where the timing of a febrile event is associated with the onset of neurological disease. Post-vaccination ADEM has been associated with several vaccines such as rabies, diphtheria-tetanus-polio, smallpox, measles, mumps, rubella, Japanese B encephalitis, pertussis, influenza, hepatitis B, and the Hog vaccine. We review ADEM with particular emphasis on vaccination as the precipitating factor. We performed a literature search using Medline (1976-2007) with search terms including "ADEM", "acute disseminated encephalomyelitis", "encephalomyelitis", "vaccination", and "immunisation". A patient presenting with bilateral optic neuropathies within 3 weeks of "inactivated" influenza vaccination followed by delayed onset of ADEM 3 months post-vaccination is described.

Fig. 1

Images of the patient’s optic nerves (see Illustrative case report) taken about 4 weeks after his influenza vaccination showing bilateral optic atrophy, more marked in the right eye (lower image).

Fig. 2

MRI (a–c) Axial fluid attenuated inversion recovery (FLAIR) images and (d) sagittal FLAIR images performed in October 2005 about 3 months post-influenza vaccination showing involvement of central grey matter including (a) the left pons, (b) centromedial thalami, and (c) right and left globus pallidus.