Similarity of brain CT appearance in spongy degeneration to that of subacute necrotizing encephalomyelopathy.

Reports of brain computed tomography (CT) findings in spongy degeneration describe radiolucent changes of the cerebral white matter, but have not described changes in the posterior fossa. We describe an infant with spongy degeneration in whom CT scans detected brainstem, cerebellar, and cerebral white matter radiolucencies before the diagnosis was established. The posterior fossa CT findings resembled the periventricular changes described in subacute necrotizing encephalomyelopathy (SNE). As the patient's initial clinical findings were consistent with SNE, the similarity of the posterior fossa radiolucencies was misleading. Without basal ganglia or thalamic involvement, or without variability in their appearance over time, posterior fossa periventricular radiolucencies are not diagnostic of a specific degenerative disorder.