MRI brain in maple syrup urine disease

A neonate presented with vomiting, poor feeding, and progressive lethargy during the early neonatal period, with metabolic acidosis but otherwise unremarkable routine biochemistry. Magnetic resonance imaging (MRI) of the brain showed symmetrical areas of diffusion restriction and T2/FLAIR hyperintensity involving the cerebellar white matter, dorsal brainstem, cerebral peduncles, thalami, globus pallidi, posterior limb of the internal capsule, and perirolandic white matter, consistent with intramyelinic oedema. In the appropriate clinical context, these findings were characteristic of maple syrup urine disease (MSUD), a rare autosomal recessive disorder of branched-chain amino acid metabolism that causes dysmyelination and cerebral oedema. MRI thus enabled early diagnosis before confirmatory amino acid analysis and guided prompt initiation of dietary therapy aimed at restricting branched-chain amino acids. This case highlights the vital role of MRI, including diffusion-weighted imaging, in recognising the typical pattern of neonatal MSUD, allowing timely intervention to limit neurological injury and improve prognosis.