The development of white matter signal abnormalities on magnetic resonance brain imaging (MRI) in children and young adults with congenital adrenal hyperplasia has been well documented. Existing theories regarding the development of these findings include effects of electrolyte imbalances, effects of disease-related hormone abnormalities, and non-physiologic long-term administration of corticosteroids. Many of the patients previously described were normal neurologically. We describe the case of white matter signal abnormalities in a neonate with salt-wasting congenital adrenal hyperplasia who presented with seizures during the first week of life, possibly due to a transient blood calcium disturbance. This case suggests that white matter changes are not simply the result of chronic insults and that they may not always be subclinical.