Effect of simvastatin in addition to chenodeoxycholic acid in patients with cerebrotendinous xanthomatosis.

The effects of combination therapy with chenodeoxycholic acid (CDCA) and simvastatin on serum cholestanol, low-density lipoprotein (LDL) cholesterol, and lathosterol levels were investigated in seven adult patients with cerebrotendinous xanthomatosis (CTX) who were on long-term treatment with CDCA. The patients were treated with a combination of CDCA 750 mg daily and an increasing dose of simvastatin from 10 mg to 40 mg daily for a period of 6 months. We found a significant effect of this combination therapy compared with CDCA alone in terms of decreasing the serum cholestanol and LDL cholesterol levels, particularly with a daily dose of 40 mg simvastatin. The mean cholestanol level decreased from 9.27 micromol/L (baseline) to 6.69 micromol/L (40 mg simvastatin), while the mean LDL cholesterol level decreased from 5.08 mmol/L (baseline) to 3.04 mmol/L (40 mg simvastatin). No side effects were reported, and there were no effects on the clinical condition, cerebral magnetic resonance imaging (MRI), visual evoked potentials, and electroencephalographic features. We conclude that a combination of 750 mg CDCA and 40 mg simvastatin daily is effective to further reduce serum cholestanol, LDL cholesterol, and lathosterol in adult CTX patients treated with long-term CDCA. Whether this combination treatment will be effective for the long-term prevention of neurological deterioration and atherosclerosis remains to be established.

Ocular and systemic manifestations of cerebrotendinous xanthomatosis.

PURPOSE: Cerebrotendinous xanthomatosis is a storage disease that usually leads to severe mental and neurologic deterioration before the diagnosis and start of treatment are established. We identified major ocular and systemic characteristics that may enable a diagnosis to be made earlier. METHODS: Ten patients (group 1) of the University Hospital Nijmegen, with a diagnosis of cerebrotendinous xanthomatosis, were re-examined for detailed ocular and major clinical manifestations. Meanwhile, we looked for similar but undiagnosed cases in patients (group 2) who visited the Institute of Ophthalmology during a 12-month period. RESULTS: A diagnosis of cerebrotendinous xanthomatosis had been made in the patients of group 1 at an average age of 40 years (range, 33 to 48 years). Subsequently, six new cases (group 2) were diagnosed in patients 7 to 37 years old (average age, 18 years). Bilateral cataract was the major ocular manifestation in all 16 patients. Small irregular corticonuclear opacities, anterior polar cataracts, and dense posterior subcapsular cataracts were diagnosed at various ages (mean, 18 years; range, 4 to 40 years). Four patients showed clinical signs of optic neuropathy, whereas retinal function was normal in all patients. Other major clinical signs included a history of chronic diarrhea (since childhood), mental deterioration (mean age, 23 years), neurologic deterioration (mean age, 31 years), and tendon xanthomas (mean age, 37 years). CONCLUSIONS: Appropriate biochemical investigations for cerebrotendinous xanthomatosis should be performed in patients with unexplained juvenile or early-onset adult cataracts, especially if these cataracts are associated with chronic diarrhea since infancy, mental retardation or deterioration, neurologic dysfunction, or xanthomas.

Neuroaxonal pathology of central and peripheral nervous systems in cerebrotendinous xanthomatosis (CTX).

We studied three siblings and one unrelated patient with cerebrotendinous xanthomatosis (CTX). Of two unrelated patients, we examined biopsies of sural nerve, soleus muscle, and achilles tendon. We also performed neurophysiologic investigations. Another patient died, and a postmortem examination of both brain and spinal cord was made. It was concluded that both the central and the peripheral nervous system were involved in CTX, but the peripheral system only to a slight degree, and that the pathology was predominantly neuroaxonal rather than demyelinating in character.

Cerebrotendinous xanthomatosis: a review of biochemical findings of the patient population in The Netherlands.

This study gives a review of the results obtained from biochemical investigations of 20 patients in The Netherlands suffering from cerebrotendinous xanthomatosis, an inborn error of metabolism in bile acid synthesis. Diagnosis can best be established by determining the excretion of urinary bile alcohols, in particular 5 beta-cholestane-3 alpha, 7 alpha, 12 alpha,23,25-pentol, in urine by means of capillary gas chromatography. Measurement of serum cholestanol levels or serum cholestanol/cholesterol ratios, commonly used for establishing cerebrotendinous xanthomatosis, are not reliable. The effectiveness of the different therapies, i.e. administration of bile acids, can be evaluated by monitoring the urinary excretion of bile alcohols. From such investigations it was concluded that cholic acid especially, but also chenodeoxycholic acid are the therapies of choice for the treatment of cerebrotendinous xanthomatosis. All patients, until now diagnosed in The Netherlands were not discovered before the third or fourth decade of life because the characteristic signs only then become manifest clearly. Unfortunately, because sterol storage is almost irreversible, therapy only results in minor improvements of the patient's condition. Therefore early detection of the presence of cerebrotendinous xanthomatosis is desirable so that treatment can start before extensive storage of sterols is a fact. We developed some laboratory assays with the purpose of early detection. One consists of the detection of cerebrotendinous xanthomatosis carriers by subjecting them to oral cholestyramine administration and monitoring the urinary excretion of the bile alcohol 5 beta-cholestane-3 alpha,7 alpha,12 alpha,23,25-pentol before and after treatment. Secondly, a relatively simple screening test for cerebrotendinous xanthomatosis was developed based on an enzymatic assay of 7 alpha-hydroxylated steroids in urine. After suitable modification this assay in principle allows the screening of large populations for the existence of cerebrotendinous xanthomatosis and thus to detect the disease at an earlier stage of life.