Acute demyelinating encephalomyelitis presenting with a mass lesion
Acute disseminated encephalomyelitis (ADEM) is usually a monophasic disease that may follow many infections or vaccines. Neuroimaging plays a key role in the differential diagnosis of ADEM. We reported a female patient with ADEM mimicking a mass lesion in the pons. On physical examination, the patient was drowsy but there were no signs of meningeal irritation. Initial magnetic resonance imaging revealed hyperintense signals on fluid attenuated inversion recovery and T2-weighted sequence over distal area of bilateral mesencephalon and pons with involvement of cerebellar pedunculus. The patient was treated intravenous methylprednisolone for 3 days followed by oral prednisolone for another 7 days. The child remained ataxic for 20 days but recovered slowly following 4 months. At the 6th months of follow-up neurological findings of the patient completely recovered, physical examination was normal findings, and control magnetic resonance imaging scanning was also normal. It should be kept in mind that early diagnosis and appropriate treatment of the ADEM could prevent serious neurological sequelae and it is important to make differential diagnosis with other demyelinating diseases and intracranial mass. © 2011 - IOS Press and the authors. All rights reserved.