A three-year old female born at 39 weeks presented to the clinic with developmental delay, abnormal gait, and abnormal brain MRI. At her initial presentation, her height and weight were less than fifth percentile and head circumference was less than second percentile. She had a history of gross motor delay and fine motor delay, with normal language and social skills. On exam, she had bilateral lower extremity hyperreflexia, clonus and was unable to walk without using a gait trainer. Her initial MRI brain without contrast showed areas of polymicrogyria and multiple scattered asymmetric T2/FLAIR hyperintensities in the bilateral supratentorial deep and subcortical white matter. Due to hyperintensities that were confined to the white matter, these findings were concerning for leukodystrophy. Genetic testing included leukodystrophy panel that revealed multiple variants of unknown significance but no pathological abnormalities. Trio-whole exome sequencing and chromosomal microarray did not reveal any abnormalities. MRI brain repeated after six months did not reveal new abnormalities and a first-time brain MR-spectroscopy was unremarkable. CMV testing was IgG positive and IgM negative. At 3-month follow-up, she did not show signs of regression, was gaining milestones and her neurological exam remained unchanged. Although her diagnosis remains unclear, if the CMV infection was congenital or postnatal, clinical history at the time was reassuring.