A 2-year-old child with a...

A child of 2 and eight months of age presented to the hospital to investigate the acute onset of ataxia without encephalopathy. Her birth history and early development were unremarkable. However, at the age of 2 years and one month, her brain MRI revealed extensive white matter lesions, mainly the periventricular and subcortical white matter. In addition, the cerebellar white matter with patchy and incomplete rim enhancement of some of these lesions was shown in the figure. 

She was given high-dose IV methylprednisolone for five days. A week later, she presented again with an ataxic gait. 

Other investigations included an average CSF analysis except for an elevated MBP, negative testing for OCB and NMO IgG antibody titers.  However, extensive metabolic and mitochondrial studies, including lysosomal enzyme estimations, were standard. Twenty-four months after initial presentation, a repeat MRI of the brain showed two new white matter lesions.