Atypical presentations of acute disseminated encephalomyelitis (ADEM) in HIV infection.

Acute disseminated encephalomyelitis is a monophasic demyelinating disorder of the central nervous system associated with various viral infections including HIV infection. We present the findings of seven HIV-infected patients with mild to moderate immunosuppression presenting with atypical features. Four patients had a multiphasic course; three patients had tumefactive lesions, and two patients had corpus callosum lesions. Two patients with the multiphasic course also had tumefactive lesions. Their clinical and radiological findings are presented. Despite the few cases, we propose that the dysimmune process lying between marked immunosuppression (CD4 < 200 cells/μL) and normal CD4 counts (CD4 > 500 cells/μL) might be responsible for these atypical presentations.