Abstract

SUMMARY: CTX is a rare lipid-storage disease. Novel MRS findings from 3 patients, using a short TE, were the presence of lipid peaks at 0.9 and 1.3 ppm in the depth of the cerebellar hemisphere; this might represent an additional marker of disease that is CNS-specific and noninvasive. A decrease in NAA concentration was also detected and attributed to neuroaxonal damage. One patient presented an increase in mIns concentration, pointing to gliosis and astrocytic proliferation. ABBREVIATIONS: a.u. arbitrary unit; Cho choline-containing compounds; CNS central ner-vous system; Cr creatine/phosphocreatine; CTX cerebrotendinous xanthomatosis; Lip lipid; Lip09 lipid signals at 0.9 ppm; Lip13 lipid signals at 1.3 ppm; mIns myo-inositol; MRS MR spectroscopy; NAA N-acetylaspartate; PRESS point-resolved spectroscopy sequence; STEAM short echo time stimulated echo acquisition mode; VOI volume of interest CTX is a rare metabolic disorder whose main clinical man-ifestations are juvenile cataracts, chronic diarrhea, and tendinous xanthomas.1-5 It is caused by mutations in the CYP27A1 gene, which codes for sterol 27-hydroxylase, an en-zyme essential for bile acid synthesis.2,4 This defect leads to abnormally high levels of cholestanol in various tissues—the biochemical hallmark of CTX.1-5 Treatment is oral adminis-tration of chenodeoxycholic acid, which inhibits cholestanol synthesis.5 The most distinctive MR imaging abnormalities are bilat-eral T2 hyperintensity in the dentate nuclei and adjacent cer-ebellar white matter.1,6 A previous MRS study disclosed a re-duction of the NAA peak and the presence of a lactate peak.6 We studied 3 patients with CTX, attempting to assess possible novel MRS findings, focusing on short-TE acquisitions.