Acute disseminated encephalomyelitis in the Arabian Peninsula: A retrospective study from Oman

Acute disseminated encephalomyelitis is typically a monophasic multifocal autoimmune demyelinating disease of the central nervous system, which generally follows a febrile infection or a vaccination. It presents with a variety of clinical features reflecting the multifocal nature of the disease. The study was carried out at Sultan Qaboos University Hospital Oman, which is a tertiary care hospital, to see the pattern in this country. A review of inpatients files' records was done with the diagnosis of acute disseminated encephalomyelitis. Inclusion criteria were acute onset, a preceding infection or vaccination, hyperattenuated lesions seen on T2 weighted magnetic resonance imaging, or computerized tomography findings consistent with white matter changes and rapid response to corticosteroids upon therapy. Twenty-three children met the clinical and imaging criteria. Fifteen (65%) were males and eight (35%) were females giving a ratio of 2:1. Their ages ranged from 9 months to 11 years with median age of 5 years. Eleven (48%) patients had a history of an acute respiratory tract infection two to 20 days before presentation. Two (9%) patients had chickenpox, and another two (9%) patients had fever with a rash. One (4%) patient had pneumonia with positive IgM for Mycoplasma pneumonia. None had received a vaccine prior to presentation. Pyramidal signs were seen in the majority of children (83%). Most children had involvement of the subcortical white matter (74%) followed by basal ganglia (24%) and thalamic lesions (24%). Corticosteroids were administered to 21 (91%) children. Eight (35%) of these children had received intravenous immunoglobulin after failure to respond adequately to steroid therapy. Full recovery was seen in 16 (70%) of the patients. The average period of recovery was around 3 weeks. Seven (30%) patients had persistent neurological deficits upon discharge as well as on follow up two years later. The clinical features, outcome and response to treatment were similar to other reported studies. This is the first study to show a clear-cut male predilection of 2:1.