A Rare Form of Lipid Metabolic Encephalopathy

Abstract

A 27-year-old Asian man was found with painless masses of about 5.1 cm in diameter that appeared on both Achilles tendons 10 years ago. Two years prior, he had no obvious inducement and gradually developed indifference, glassy eyes, lethargy, and poor memory. One year prior, the patient's personality changed dramatically, with notably decreased memory formation but intact short-term memory. He was short-tempered, irritable, hyperactive, and exhibited slight balance instability while walking. On admission, physical examination showed unstable balance while walking in a straight line, positive ankle clonus bilaterally, positive Babinski sign bilaterally, positive Chaddock sign bilaterally, positive Romberg sign, and painless lumps of about 8.2 cm in diameter in both Achilles tendons. Routine laboratory test results showed that the patient's triglyceride level was elevated at 342.48 mg/dL (to convert to millimoles per liter, multiply by 0.0013 mg/dL; normal levels are considered to be 30.97-150.44 mg/dL). A brain magnetic resonance imaging (MRI) indicated multiple bilateral, symmetric abnormal signals in the genus of the internal capsules, posterior limbs of internal capsules, cerebral peduncles, pons, and cerebellar dentate nuclei (Figure, A). Genetic testing indicated a known pathogenic mutation c.1214G>A (p.Arg405Gln; Hom) in the CYP27A1 gene. An MRI of the ankle joints revealed an enlargement of the left Achilles tendon with abnormal signal, and the right Achilles tendon was circumscribed by a fusiform enlargement with abnormal signal (Figure, B).