Acute disseminated encephalomyelitis: a comprehensive review

Abstract

Acute disseminated encephalomyelitis (ADEM) is a disease that is characterized by an immune-mediated inflammatory reaction and demyelination in the central nervous system, including optic nerve, brain and spinal cord, which is common in children, but also appears in adults. ADEM happens probably with a causative relationship to viral diseases or prior vaccinations. It can also occur without any cause. The clinical symptoms of ADEM can begin with fever, headache and meningeal signs, followed by abnormal mental status, seizures and focal neurological signs, such as limb pareses, visual decline and speech disturbances. And their clinical courses may be monophasic, recurrent or multiphasic, mild but also very aggressive. Neuroimaging may be characterized by large demyelinating lesions in the brain involving both the white and the grey matter, and spinal cord. Lesions in ADEM are typically large globular lesions, multiple, and asymmetric, partially with diffuse or ring-like gadolinium enhancement. The diagnosis of ADEM requires both multifocal involvement and encephalopathy by consensus criteria. The differential diagnoses of ADEM include a variety of disorders, such as viral encephalitis, multiple sclerosis, neuromyelitis optica spectrum disorders and primary central nervous system vasculitis, etc. Treatments of ADEM include corticosteroids, intravenous immunoglobulin, plasmapheresis and other immunosuppressive agents.