Acute disseminated encephalomyelitis in middle-aged or elderly patients.

Acute disseminated encephalomyelitis (ADEM) in middle-aged or elderly adults is rarely reported. We present here three ADEM patients of these age groups, who manifested behavioral changes, mutism or psychosis. Single clinical episodes, widespread encephalopathic disturbances and magnetic resonance imaging (MRI) findings favored the diagnosis of ADEM. However, no obvious preceding infections could be discovered. Two of them had traveled to mainland China prior to admission to psychiatric wards. All three patients had fair-to-good recovery after steroid treatment. A review of the literature showed that clinical and neuroimage findings of ADEM in the elderly group did not differ from those in the younger group. However, ADEM has rarely been reported in older age groups, probably due to: (1) differences between the elderly and young people in susceptibility or immune response to infectious agents, and (2) lack of a sensitive tool to examine patients prior to the wide-spread use of MRI. We suggest ADEM as one of the possible etiologies of acute or subacute onset of psychosis in adult patients, especially in those with a history of traveling.