Neurologic manifestations of CTX
Early neurologic signs and symptoms of CTX are often present by the time xanthomas develop, but may be subtle and mistaken for other problems.
In a systematic review of selected case series, the prevalence of tendon xanthomas in patients with CTX were 69%.1 Tendon xanthomas often present in the second decade, and most often affect the Achilles tendons.2,3 Tendon xanthomas occur in CTX when foamy macrophages containing cholestanol, cholesterol, and other lipids infiltrate the tendon, disrupting collagen fibers in the connective tissue.4
Tendon xanthomas are rare and warrant further investigation.4 They are typically associated with lipid disorders, including sitosterolemia and familial hypercholesterolemia.1,3,4 However, sitosterolemia and familial hypercholesterolemia are associated with high plasma lipid levels,1,4 while in patients with CTX, plasma cholesterol and lipid levels are usually normal or near normal.4 Biochemical analysis of tendon xanthomas in patients with CTX characteristically shows high amounts of cholestanol and little cholesterol.3
CTX should be suspected in all patients with tendon xanthomas and normal serum triglycerides and cholesterol.4
