Cerebrotendinous xanthomatosis: Imaging clues to an underdiagnosed disorder

Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive lipid storage disorder resulting from defective bile acid synthesis, causing soft tissue deposition of cholesterol and cholestanol. It manifests with a wide spectrum of neurological as well as non-neurological features, leading to delayed diagnosis. We report a case of a 34-year-old male who presented with a 10-year history of seizures, followed by progressive neurological deterioration culminating in akinetic mutism. Magnetic resonance imaging (MRI) of the brain revealed characteristic signal abnormalities in bilateral dentate nuclei and surrounding cerebellar white matter. MRI of the ankle demonstrated marked enlargement and inhomogeneous infiltration of the Achilles tendon, consistent with tendon xanthoma. Genome sequencing confirmed the diagnosis of CTX. This case highlights the role of characteristic imaging findings in the early diagnosis and treatment of CTX.