Early-onset of multiple sclerosis in a 5-year-old girl.

Childhood multiple sclerosis is a rare demyelinating autoimmune disease with particular features. Onset of multiple sclerosis is extremely uncommon in early childhood, particularly before 6 years of age. We report the case of a 5-year-old girl admitted to the hospital for altered consciousness and rapid onset of right hemiparaplegia. Magnetic resonance imaging (MRI) of the brain showed multifocal white matter disease with T2 hyperintense oval lesions in subcortical, periventricular, and cerebellar hemispheres. Treatment with high dose intravenous methylprednisolone (30 mg/kg/day for 3 days) improved symptoms. Intravenous corticosteroid therapy was followed by 1mg/kg/day of oral prednisone. A second MRI, 40 days later, revealed new disseminated T2 hyperintense lesions in the frontal periventricular white matter, corpus callosum, left middle cerebellar peduncle, and dorsal spinal cord, leading to the diagnosis of multiple sclerosis. Azathioprine (2.5 mg/kg/day) was started and the steroid dose was tapered before being stopped after 3 months. After 2 years of follow-up, the patient has remained asymptomatic with a normal neurological exam and with no relapse or side effects of azathioprine. This work shows the particularities in clinical and radiological features of multiple sclerosis in a child aged less than 6 years.