Cranial computed tomography in acute disseminated encephalomyelitis.

Acute disseminated encephalomyelitis (ADEM) is an uncommon inflammatory disorder of the nervous system. The appearance of ADEM on cranial CT scans has rarely been reported. The author reports seven cases in two institutions during a period of seven years. Only four of the seven patients had hypodense lesions in the white matter and six patients showed spotty, nodular, or gyral enhancement after contrast injections. The enhancement resolved with steroid therapy, leaving some persistent hypoattenuated areas even after 10 months follow-up, these findings support the dual components of the pathogenesis of ADEM. The vasculitic component may be responsive to steroids, nevertheless the demyelinating or necrotic areas may not, and the latter may be responsible for the sequelae of ADEM.