[Imaging appearance of acute disseminated encephalomyelitis: a study of 22 cases]

Acute disseminated encephalomyelitis (ADEM) is a rare cause of encephalitis in adults, characterized by inflammatory lesions in the white substance of the central nervous system (CNS). Initial clinical presentation may mimic severe CNS infection with fever, encephalopathy, seizures, or multiple sclerosis. The purpose of our study was to report the epidemiological, clinical, radiological, therapeutic and evolutionary features of ADEM and to determine the role of MRI sequences in the diagnosis, monitoring and prognosis of this disease. We conducted a retrospective study of the clinical and radiological records of 22 patients with ADEM followed up in the Department of Neurology over a period of 11 years (January 2006- January 2017). These patients underwent medical imaging at the Mohammed V Military Teaching Hospital, de Rabat. The average age of patients was 35 years (12-57 years). A recent infection was found in 31% of patients, while 4% of patients had recently undergone vaccination. Symptoms were dominated by focal neurologic deficit (72%). CT scan was normal in 78%. MRI showed hyperintense subtentorial and supratentorial white substance on FLAIR sequences in 70% of patients, without diffusion restriction in all cases, with enhancement of the lesions in 27% of cases and involvement of the cervical spinal cord in 68% of cases. Clinical and radiological outcome was favorable in all cases.