Clinical Guidance

Cerebrotendinous xanthomatosis (CTX) is a lipid storage disease characterized by infantile-onset diarrhea, childhood-onset cataract, adolescent- to young adult-onset tendon xanthomas, and adult-onset progressive neurologic dysfunction (dementia, psychiatric disturbances, pyramidal and/or cerebellar signs, dystonia, atypical parkinsonism, peripheral neuropathy, and seizures). Intrafamilial variability is considerable. A suspicion index for diagnosis has been reported based on clinical and laboratory findings .

Diagnostic Criteria

A consensus paper on the diagnostic criteria and management of cerebrotendinous xanthomatosis (CTX) has been published (full text). Suggestive Findings CTX, a lipid storage disease, should be suspected in individuals with the following clinical, laboratory, imaging, and family history findings. Clinical findings • Neonatal cholestasis • Infantile-onset diarrhea • Childhood-onset cataract • Adolescent- to young adult-onset tendon xanthomas • Adult-onset progressive neurologic dysfunction (dementia, psychiatric disturbances, pyramidal and/or cerebellar signs, and seizures) Laboratory findings • High plasma and tissue cholestanol concentration • Normal-to-low plasma cholesterol concentration • Markedly decreased formation of chenodeoxycholic acid as a result of impaired primary bile acid synthesis • Increased concentration of bile alcohols and their glyconjugates in bile, urine, and plasma • Increased concentration of cholestanol and apolipoprotein B in cerebrospinal fluid • Increased plasma lactate concentration Table 1. Biochemical Abnormalities in Cerebrotendinous Xanthomatosis

Management Guidelines

A clinical practice guideline on the diagnosis, treatment, and management of cerebrotendinous xanthomatosis (CTX) has been published, based on expert opinion collected with the Delphi method (full text). Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with CTX, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 5. Cerebrotendinous Xanthomatosis: Recommended Evaluations Following Initial Diagnosis

Surveillance Guidelines

Table 8.

Cerebrotendinous Xanthomatosis: Recommended Surveillance

System/Concern | Evaluation | Frequency

cholestanol levels | Cholestanol plasma concentration | Annually

Neurologic

neuropsychologic issues | Neurologic neuropsychologic eval