Acute Disseminated Encephalomyelitis Related to a Cytomegalovirus Infection in an Immunocompetent Patient.

Cytomegalovirus (CMV) infection can cause acute disseminated encephalomyelitis (ADEM). However, it is rare in immunocompetent people. We describe a 17-year-old patient who was brought with flu-like symptoms. After one week, she experienced rapidly progressive weakness in all four extremities, followed by coma. The neurologic examination showed no response to verbal and pain stimuli. A Babinski sign was noted in both lower extremities, along with clonus and hyperreflexia in all four limbs. Brain magnetic resonance imaging (MRI) demonstrated extensive areas of hyperintense signal on fluid-attenuated inversion recovery (FLAIR) sequences in the white matter which was asymmetrically distributed in both hemispheres, as well as in the brainstem and cerebellar peduncles, compatible with acute demyelinating lesions. Cerebrospinal fluid (CSF) showed mild lymphocytic pleocytosis and normal glucose levels. Polymerase chain reaction to herpes simplex virus was negative. Serum immunoglobulin G (IgG) and immunoglobulin M (IgM) were positive for cytomegalovirus. The patient was treated with methylprednisolone pulse therapy for five days. Subsequently, the patient showed neurologic improvement with the recovery of consciousness and muscle strength. In terms of prognosis, in patients with ADEM, the sooner the diagnosis, the better the outcome. The cornerstone of treatment is immunosuppression with steroids. Some patients require intravenous immunoglobulin G (IVIG) or plasmapheresis, and in refractory cases, cyclophosphamide is used.