Cerebrotendinous Xanthomatosis (CTX) 

Updated: Dec 08, 2021
Author: Austin Larson, MD; Chief Editor: Maria Descartes, MD 

Overview

Background

Cerebrotendinous xanthomatosis (CTX) is a rare genetic disorder of cholesterol and bile acid metabolism that results in systemic and neurologic abnormalities.[1] The disease may become apparent in infancy, with chronic diarrhea or through liver disease/jaundice. Cataracts can become evident in childhood or adolescence, and xanthomata can develop in the second and third decades of life. Significant neurologic impairment may also occur; this often includes seizures, dementia, spasticity, gait impairment, and cerebellar and extrapyramidal dysfunction, typically beginning in the third decade of life and progressing until premature death, often in the sixth decade of life if the condition goes untreated. The presentation and course vary widely, and treatment can dramatically alter the natural history, especially with early initiation.

The disease was first described in 1937 by Van Bogaert and colleagues and has since been characterized clinically, biochemically, and genetically.[2, 3] In 1968, Menkes et al described the accumulation of cholestanol, the primary metabolite found in elevated concentrations in CTX, in tissues of the CNS.[4] In 1971, Salen found that chenodeoxycholic acid (CDCA), an important bile acid, was virtually absent in patients with clinical symptoms of the disease.[5] This led to successful trials of therapy with CDCA replacement, in 1975 by Salen[6] and later with Berginer,[7] that was found to normalize the biochemical phenotype and prevent disease progression. In 1980, defects in mitochondrial sterol 27-hydroxylase were implicated in the biochemical pathophysiology of the disease by Oftebro et al.[8] In 1991, mutations in the gene CYP27A1 were determined to be the genetic cause of CTX.[9, 10, 11]  

Pathophysiology

The enzymatic defect that causes CTX is in mitochondrial sterol 27-hydroxylase, a key enzyme in the pathway necessary for synthesis of bile acids from cholesterol. Deficiency of the enzyme results in impaired synthesis of the mature bile acids CDCAoxycholic acid (CDCA) and cholic acid. The mature bile acids (primarily CDCA) are responsible for negative feedback on cholesterol 7-alpha-hydroxylase, which is the initial and rate-limiting step in bile acid synthesis. With no inhibition of flux into the metabolic pathway, cholesterol-derived bile acid precursors accumulate in tissues and are thought to cause the symptoms of CTX.

Cholestanol is formed in a pathway from the bile acid precursor 7-alpha-hydroxy-4-cholesten-3-one.[12] Deposition of cholestanol and other intermediate metabolites in the CNS (the brain and spinal cord), muscle (including the heart), blood vessels, eyes, and tendons results in progressive dysfunction unless treatment is initiated to prevent further accumulation of toxic metabolites. 

While the general framework of tissue dysfunction due to accumulation of toxic metabolites is settled, there is ongoing study of the specific mechanisms of neurotoxicity.[13, 14]  Patients with CTX appear to have a diffuse decrease in total brain volume, the decrease being predominantly in cortical grey matter rather than white matter. This finding provides additional evidence that CTX is a primary neuronal disorder.[15]

 

Epidemiology

Frequency

More than 300 cases have been published worldwide, with an estimated prevalence of 1 case per 50,000 individuals in populations of European descent.[10, 16] Populations with increased CYP27A1 mutation frequency exist due to founder effects; for example, there is an estimated disease prevalence of 1:440 for the Druze population in Israel.[17]

United States

Given the estimates of prevalence, as many as 8,000-14,000 people in the United States may have CTX. These are far more cases than have actually been diagnosed, and it is likely that the condition is underdiagnosed.

International

Cases have been reported in China, Canada, Belgium, Brazil, Saudi Arabia, India, Germany, Taiwan, France, Switzerland, South Africa, Australia, Israel, and Argentina; a large representation has been reported among Spanish[18] and Scandinavian populations, as well as in Italy and Japan. A nationwide survey in Japan revealed an average 16.5-year diagnostic delay after onset of the presenting symptom, providing further evidence that CTX may be underdiagnosed.[19] A founder effect and high rate of consanguineous marriages are responsible for a high prevalence of CTX in the Druze population.[17, 20]

Mutation analysis internationally reveals the following high frequency alleles: T339M in Dutch patients, R474(Q-W) in Japanese patients, and A216P in Italian patients.[10]  The prevalence of CTX has been estimated in different populations based on the allele frequency of known mutations and presumed deleterious genetic variants in a large cohort of individuals that have undergone exome sequencing.[21]

Mortality/Morbidity

Life expectancy is lowered; however, no formal epidemiologic studies have been published. One analysis found that 14/194 (7%) of published patients had died with a cumulative incidence of death of 50% at age 60 years.[22] Causes of death reported in the literature include myocardial infarction and progressive neurological deterioration.[23]  

Morbidity begins with intractable diarrhea. Presenile cataracts result in vision abnormalities. Xanthomas can cause motor restriction and joint deformities, resulting in various orthopedic sequelae. Vascular abnormalities such as premature atherosclerosis (especially in the carotid and coronary vessels) can lead to stroke and myocardial infarction. The primary neurologic manifestations of the disease are associated with complications that range from treatable seizures to neurologic devastation. The severity of disease widely varies.

Race

Series of patients have been described in the Netherlands, Italy, Spain and Japan, with scattered case reports around the world (see International). No specific data on minority populations in the United States are available. 

Sex

No sex predilection has been reported for this autosomal recessive disorder, although animal models exhibit sex differences.

Age

Cerebrotendinous xanthomatosis can present at any age, from the neonatal period to the sixth decade of life or later with certain symptoms being more common at different ages. 

Prognosis

If CTX is untreated, life expectancy is into the fifth and sixth decades; however, confirmed deaths have been reported as early as age 4 months. This is a progressive and terminal disease if left untreated. Treated patients may have a normal lifespan.

 

Presentation

History

Untreated CTX usually follows a progressive course. Mignarri and colleagues proposed a suspicion index for earlier diagnosis of CTX with weighted scores assigned to indicators of disease.[24] Four clinical criteria are used in diagnosis; the presence of any two of the criteria warrants testing for CTX, although because this is a treatable disorder, testing when only one criterion is present is reasonable. The criteria include intractable diarrhea, presenile cataracts, tendinous xanthomas, and neurologic abnormalities. The symptoms usually manifest themselves in that order, although atypical cases have been reported and the disease spectrum widely varies, even within families. To date, no genotype-phenotype correlation has been reported.

Common findings

Chronic diarrhea occurs in a significant portion of patients and the onset may be in infancy. The diarrhea may continue through adulthood if left untreated. Neonatal or infantile hepatitis and prolonged jaundice have been described.[9, 25, 26]

Juvenile cataracts are often the presenting sign of CTX.[27, 22]  A recent study found that the prevalence of CTX in a cohort of 170 patients presenting with juvenile cataracts was 1.8%.[28]  

The typical onset of ocular symptoms is in the first decade of life, though rarely earlier than age 5 years. The following ocular findings are noted:

  • Bilateral, presenile cataracts that may be corticonuclear, anterior pole, or dense posterior opacities [29, 30, 31, 27]
  • Optic disc pallor
  • Premature retinal senescence with retinal vessel sclerosis
  • Cholesterol-like deposits along vascular arcade
  • Myelinated retinal nerve fibers [32]
  • Rarely, palpebral xanthelasma and optic nerve atrophy
  • Unique bilateral fleck lenticular deposits have been described in affected children prior to development of capsular opacities [33]

Tendon xanthomas are rarely seen before age 20 years, although an early onset phenotype may be observed in patients with concurrent heterozygous familial hypercholesterolemia and CTX.[34] They are usually found on the Achilles tendon but may also be found on the patella, elbow, hand, and neck tendons. They have also been reported on the parenchyma of the lungs and brain, as well as in the bones. 

Sixteen-year-old male with cerebrotendinous xantho Sixteen-year-old male with cerebrotendinous xanthomatosis. Note the xanthomas on his knuckles.
Sixteen-year-old male with cerebrotendinous xantho Sixteen-year-old male with cerebrotendinous xanthomatosis.
Xanthomas of the Achilles tendon. Photo courtesy o Xanthomas of the Achilles tendon. Photo courtesy of William Connor, MD, Oregon Health and Science University.
Xanthomas on the knees in a patient with cerebrote Xanthomas on the knees in a patient with cerebrotendinous xanthomatosis. Photo courtesy of William Connor, MD, Oregon Health and Science University.

Neurologic symptoms tend to manifest in the third decade of life; however, children and young adults may have below-average intelligence, occasionally severe intellectual disability, with worsening and deterioration in the third decade of life. In one study, neurologic symptoms were broken down into extrapyramidal (81%), cognitive impairment (66%), and cerebellar signs (56%).[24] Peripheral neuropathy was present in 31% of patients, and 16% of patients had seizures, although seizures can be the presenting symptom in rare cases.[35]  Importantly, all of these symptoms are progressive and age-dependent, so the cumulative incidence by age of each symptom is an informative way to understand the natural history of CTX.[22]

Other symptoms include the following:

  • Fronto-temporal dementia [11, 32]
  • Spasticity (both periventricular white matter and isolated spinal cord disease)
  • Cerebellar symptoms and ataxia (with other neurologic signs or isolated) [36]
  • Extrapyramidal symptoms, including dystonia and oromandibular dyskinesia [37]
  • Early-onset  Parkinson disease  [38]
  • Seizures
  • Peripheral neuropathy

Muscular symptoms may include myopathic facies and generalized feelings of weakness.[39]

Less common findings

Neonatal cholestasis has been observed repeatedly.[40] Cerebrotendinous xanthomatosis has been associated with marked cardiovascular findings, including coronary and carotid vascular disease[23, 41] and atrial septal hypertrophy[42, 43]

Granulomatous bone lesions, osteopenia, osteoporosis, and pathologic fractures have been well described. The granulomas are typically in the femur and lumbar vertebrae; thoracic kyphosis has been described.[44]

Granulomatous lung disease has been reported based on bronchoalveolar lavage findings.[45] These patients did not have correlating clinical symptoms. Pulmonary xanthomas have also been described.

Although hypothyroidism is not a common manifestation, it appears to be one of the few endocrinologic complications. In one particular series, the proband case had an ectopic thyroid gland and typical neurologic changes associated with CTX; four patients in this study had CTX and hypothyroidism.[46]

A single case report described a case of "minimal change" nephrotic syndrome and CTX in a Japanese adult.[47]

Osteoporosis, tooth loss, cataracts, dementia and parkinsonism, and heart disease can mimic signs of aging at an earlier age.[48]

 

Physical

See History.

Causes

Cerebrotendinous xanthomatosis is a defect in bile acid synthesis, with subsequent overproduction and accumulation of cholestanol in multiple tissues of the body. It is caused by a defect in the CYP27A1 gene that codes for sterol 27-hydoxylase. It is an autosomal recessive disorder.

A recent review and update by Gallus et al identified mutations in exons 1-8 of the CYP27A1 gene but none in exon 9.[10] More than 50 different mutations have been identified. Half of these are found in exons 6 to 8, and many have effects on enzyme heme-binding and adrenodoxin-binding sites. In one study, mutation analysis revealed mutations of all types, including missense (45%), nonsense (20%), splice site (18%), deletion (14%), and insertion (2%).[10]

Affected individuals have mutations in both alleles; although sometimes homozygous, a substantial number of compound heterozygote patients have been described. Two heterozygous patients with clinical disease and decreased enzyme function have been reported, but no second mutation was identified despite an extensive search.[11, 49]

CYP27A1 was recently identified as a candidate gene for sporadic amyotrophic lateral sclerosis (ALS).[50] This is of interest as CTX can present as a clinical mimic of ALS with progressive upper motor neuron loss.

 

DDx

Differential Diagnoses

 

Workup

Laboratory Studies

Whole blood, serum, and plasma studies

Findings reveal elevated plasma and serum cholestanol levels and low-to-normal cholesterol levels (usually 115-220 mg/dL). The cholestanol level is typically 3 to 15 times higher than mean levels in unaffected individuals and can range from 1.3 mg/dL to 15 mg/dL.[23] The cholesterol-to-cholestanol ratio is a better indicator of disease than cholestanol concentration alone.[51] A low cholesterol-to-cholestanol ratio is diagnostic in the appropriate clinical setting; however, additional confirmatory testing is recommended if feasible.

Low-density lipoprotein and triglyceride levels are also usually normal. High-density lipoprotein and very-low density lipoprotein levels vary. Although not typically obtained, bile acid intermediate and other sterol levels are also elevated, such as 7-dehydrocholesterol,[52] 7-alpha-hydroxycholesterol, and lathosterol levels. Some serum bile acid levels themselves are low. Measurement of 7-alpha-hydroxy-4-cholesten-3-one facilitates rapid, convenient diagnostic testing for CTX and may be useful in monitoring biochemical response to treatment.[53, 54] Measurement of the bile acid precursor (7-alpha, 12-alpha-dihydroxy-4-cholesten-3-one) enables sensitive dried bloodspot testing for CTX, showing that dried bloodspot newborn screening is technically feasible.[55]  Additional studies are ongoing to determine the suitability of CTX for newborn screening programs. Recently, excellent diagnostic performance has been found for 5β-cholestane-3α,7α,12α,25-tetrol glucuronide in dried blood spots.[56]  

As is true for many other genetic diseases, CTX is increasingly being identified by exome or genome sequencing.[57]

Urine studies

Urine testing of bile alcohols (typically pentols) using fast ion bombardment–mass spectroscopy for pattern recognition of bile alcohol glucuronides is typically abnormal in patients with CTX.[58, 59]  Concurrent use of propofol may lead to false positive urine bile acid profile testing.[60]  

Bile analysis

HIgh levels of cholestanol are present in the bile of almost all individuals affected by CTX and concentrations of cholestanol decrease in response to treatment.[61, 62] As expected given the enzymatic defect, a low concentration of CDCA) is observed along with high concentrations of bile alcohols (conjugated with glucuronic acid).

Cerebrospinal fluid (CSF) studies

Salen et al have reported an increased cholesterol-to-cholestanol ratio (1.5-20 times the reference range); however, this is not routinely analyzed for diagnostic purposes.[63]

Mutation studies

CYP27A1 sequencing and copy number analysis is increasingly the initial test indicating a diagnosis of CTX. Biallelic mutations are detectable in the vast majority of patients with clinical features and biochemistry that are consistent with CTX.

Electrophysiology studies

Decreased nerve conduction velocities as well as somatosensory, motor, brainstem, and visual evoked potentials all relate to peripheral neuropathy.[64, 65] These abnormalities may improve with treatment.

Imaging Studies

The brains of individuals with CTX often show both supratentorial and infratentorial abnormalities on MRI. The findings on MRI and CT scanning include cortical and cerebellar atrophy of the brain, as well as focal lesions (including demyelinating lesions and, rarely, xanthomata) in the cerebellum, basal ganglia, and cerebrum. T2/FLAIR hyperintensity of the subcortical, periventricular, cerebellar white matter, brainstem, and dentate nuclei are characteristic of CTX.[66, 67] T2 abnormalities are also found in the globus pallidus, substantia nigra, and inferior olives with extension into the surrounding white matter in later years of the disease. Cerebrotendinous xanthomatosis should be considered in the differential diagnosis of leukodystrophies.[68]

A 2017 study showed T1/FLAIR hypointensity consistent with cerebellar vacuolation and T1/FLAIR/SW hypointense alterations compatible with calcification in a subgroup of patients with CTX. Long-term follow-up showed that clinical and neuroradiological stability or progression were almost invariably associated. In patients with cerebellar vacuolation at baseline, worsening over time was observed, while patients lacking vacuoles were clinically and neuroradiologically stable at follow-up. Infratentorial abnormalities on MRI are related to clinical disability. The presence of cerebellar vacuolation may be regarded as a useful biomarker of disease progression and unsatisfactory response to therapy. Conversely, the absence of dentate nuclei signal alteration should be considered an indicator of better prognosis.[67]

Brain MRI fluid attenuation inversion recovery (FLAIR) sequences in one patient revealed cortical and subcortical hyperintensities in the temporal lobes) and globus pallidus. T2-weighted MRI revealed cerebellar hyperintensities within the dentate nucleus. Hypointensities were seen on T1-weighted and susceptibility MRI scans within the cerebellum at the level of the midbrain.[66]

Magnetic resonance spectroscopy reveals diffuse mitochondrial dysfunction and axonal damage, with large amounts of lactate and decreased N -acetylaspartate in the periventricular white matter and cerebellar hemispheres.[66]

Diffusion tensor imaging (DTI) may show abnormalities despite normal conventional brain MRI findings. DTI showed reduced fractional anisotropy (FA) and tract-density in the cerebellum and widespread cerebral reductions of FA. DTI after therapy initiation showed progressive increases in cerebellar tract density and cerebral FA.[69]

Isolated spinal cord white matter disease has been described.[70, 71] MRI may reveal increased intensity in the lateral and dorsal columns.[66] Magnetization transfer imaging has been found to be a reliable quantitative indicator of the extent of damage in the brain parenchyma.[71] MRI can also be used to evaluate for tendon xanthomata.

Other Tests

Other studies include electrophysiologic testing, prenatal testing (only performed if a family member is affected), and population-wide newborn screening (not yet implemented).[72, 73] Electrophysiological testing may reveal motor or sensorimotor peripheral neuropathy (demyelinating, axonal, or mixed). Somatosensory evoked potentials (SSEPs) are commonly affected. Delayed brainstem auditory evoked potentials are common, and visual evoked potentials are often abnormal.[74]

Histologic Findings

CNS findings

Xanthomas and granulomas are found in multiple areas of the brain, including the cerebellar hemispheres, cerebellar peduncles, and globus pallidus. Further studies have reported more involvement of gray matter and have also described pathognomonic lesions of spindle-shaped lipid crystal clefts, fibrosis, and hemosiderin deposition in the dentate nucleus.[75] Neuropathologic findings described include lipid crystal clefts, neuronal loss, demyelination, reactive astrocytosis, and perivascular macrophages, suggesting the limited reversibility of the disease and poor prognosis if treatment is not started early.

CNS findings

Xanthomas and granulomas are found in multiple areas of the brain, including the cerebellar hemispheres, cerebellar peduncles, and globus pallidus. Further studies have reported more involvement of gray matter and have also described pathognomonic lesions of spindle-shaped lipid crystal clefts, fibrosis, and hemosiderin deposition in the dentate nucleus.[72] Neuropathologic findings described include lipid crystal clefts, neuronal loss, demyelination, reactive astrocytosis, and perivascular macrophages, suggesting the limited reversibility of the disease and poor prognosis if treatment is not started early.

Peripheral nerve findings

“Onion bulbs” have been described; this suggests that the process is chronic and demyelinating. Demyelination, remyelination, and primary axonal degeneration have been reported. Whether or not the process is a primary neuroaxonal process is unclear.

Muscular findings

Atrophy and pyknotic nuclei have been reported. Mitochondrial dysfunction has also been noted, as revealed by decreased respiratory chain activity and increased levels of pyruvate and lactate in the serum and cerebrospinal fluid.[39]

Liver findings

Typical findings include amorphous pigment and crystalloid forms associated with smooth endoplasmic reticulum, with some free-floating in the cytoplasm.[61]

Xanthomas

Birefringent crystals are surrounded by giant cells with foamy cytoplasm.

 

Treatment

Medical Care

Early diagnosis of CTX is imperative because it is a treatable disease. This early diagnosis depends on recognition of early signs and symptoms, specifically the combination of diarrhea and cataracts. A recent publication has compiled expert opinion on best practices for patient management.[76]

 

 

Surgical Care

Lensectomy and intraocular lens placement may be indicated for patients with visually significant cataracts. Surgical removal of tendon xanthomas is not recommended. One patient is reported to have undergone liver transplantation in infancy due to liver failure.[73]

 

Consultations

Consultation with the following may be indicated:

  • Gastroenterologist
  • Ophthalmologist
  • Metabolic and genetic disease specialist
  • Developmental specialist
  • Neurologist
  • Orthopedist
  • Cardiologist
  • Lipid disorder specialist

Diet

A diet low in cholestanol containing foods (eg, egg yolk, butter, cheddar cheese) can significantly reduce plasma cholestanol and cholesterol levels; however, true clinical benefit is not seen unless pharmacologic therapy is also started. Dietary restriction probably is not necessary if pharmacologic treatment is commenced (see below).

Prevention

Therapy with CDCA can halt and reverse symptoms of the illness, including GI and neurologic complications.

Parents who both are known to be carriers for mutations in CYP27A1 can undergo in vitro fertilization with preimplantation genetic diagnosis to exclude implantation of embryos with biallelic mutations in CYP27A1. 

Long-Term Monitoring

The annual examination in patients with CTX should consist of the following[7] :

  • Neurologic and neuropsychologic evaluation
  • Cholestanol plasma concentration assessment. Elevated cholestanol results (or changes in clinical status) may warrant further investigation and potential treatment modification. Other biomarkers may be useful to more rapidly monitor treatment efficacy compared to cholestanol.
  • Liver enzymes
  • Brain MRI in selected cases
  • Echocardiography when indicated
  • Bone mineral density assessment when indicated
 

Medication

Medication Summary

The treatment of choice in CTX is CDCA replacement therapy to inhibit the flux of cholesterol into the bile acid synthesis pathway and reduce the generation of toxic metabolites. Rarely, patients have been treated with cholic acid as opposed to CDCA and have had a similar biochemical and clinical response to therapy, though the number of patients treated with cholic acid is too small to draw firm conclusions from these reports.[77]

If hypercholesterolemia is not controlled with CDCA treatment alone, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitors may be added. HMG-CoA reductase inhibitors (ie, statins) have well-established efficacy and safety in patients with hypercholesterolemia and have also been used alone and in combination with CDCA to treat CTX.

Dotti et al examined treatment with CDCA, simvastatin, and low-density lipoprotein apheresis in several combinations.[74] Although the established treatments performed well, low-density lipoprotein apheresis was not associated with a clinical benefit and possibly put the patient at risk for treatment complications.

Other medical treatment modalities typically used in the treatment of disorders of bile and cholesterol metabolism, specifically hydrophilic 7 beta-hydroxy bile acids and cholestyramine, have been ineffective.[75]

 

Bile Acids

Class Summary

The primary treatment is CDCA, which was initially used for treatment of gallstones. In the United States, CDCA is available with the brand name Chenodal. The typical adult dose is 750 mg/d or 10-15 mg/kg/d orally divided 3 times daily.[7]

Treatment with CDCA has been found to normalize bile acid metabolism and to slow, halt, and even reverse problems associated withCTX. In several studies, the bile acids and metabolites in plasma, bile, urine, and cerebrospinal fluid concentrations of cholestanol have normalized after as little as 4 months of treatment.[7]

Clinically, neuropsychologic and peripheral neurologic symptoms improve, as do effects on bone mineralization.

In a landmark study, dementia was found to improve in 10 of 12 patients with CTX after initiating treatment with CDCA, with strong improvements in mentation, speech, orientation, and memory.[7]  Corresponding improvements were seen in MRI and EEG findings. Xanthoma and cataract development were nonprogressive but have not reversed with CDCA administration. Biochemical changes include reduced serum cholestanol levels and increased CDCA levels.[78]  Further studies have confirmed and expanded on these findings.[64]

Pharmacologic treatment may be initiated at any stage of disease, though some neurological symptoms are irreversible.[64]  Multiple studies have demonstrated that patients who started treatment later had a worse outcome than those who started treatment earlier.[79, 80]  A subset of patients continue to deteriorate despite treatment.[81]  Even late institution of treatment may lead to some clinical improvement.[82, 17, 79]  The effect of treatment on cataract progression is described in one study.[83]

Generally, CDCA appears to be well tolerated, although hepatoxicity has been reported in at least one infant. In that case, dose reduction was successful in resolving hepatotoxicity.[84]

  

In March 2015, cholic acid (Cholbam) was approved by the FDA for bile acid synthesis disorders caused by a single enzyme defect. Cholic acid has been rarely used an alternative to CDCA to treat individuals withCTX.[72, 77] Currently, there is insufficient evidence to recommend its routine use inCTX.

Chenodiol (Chenodal)

Primary bile acid synthesized by the liver. Available as an orphan drug in the United States for treatment of CTX. Generally appears to be safe, although hepatoxicity has been reported in at least one infant. In that case, dose reduction was successful in resolving hepatotoxicity.

 

Questions & Answers

Overview

What is cerebrotendinous xanthomatosis (CTX)?

What is the pathophysiology of cerebrotendinous xanthomatosis (CTX)?

What is the prevalence of cerebrotendinous xanthomatosis (CTX) in white populations?

What is the prevalence of cerebrotendinous xanthomatosis (CTX) in the US?

What is the global prevalence of cerebrotendinous xanthomatosis (CTX)?

What is the mortality associated with cerebrotendinous xanthomatosis (CTX)?

What is the morbidity associated with cerebrotendinous xanthomatosis (CTX)?

What are the racial predilections of cerebrotendinous xanthomatosis (CTX)?

What is the sexual predilection of cerebrotendinous xanthomatosis (CTX)?

At what age does cerebrotendinous xanthomatosis (CTX) typically present?

What is the prognosis of cerebrotendinous xanthomatosis (CTX)?

Presentation

How is cerebrotendinous xanthomatosis (CTX) diagnosed?

What are the signs and symptoms of cerebrotendinous xanthomatosis (CTX)?

What are the neurologic signs and symptoms of cerebrotendinous xanthomatosis (CTX)?

What are the muscular signs and symptoms of cerebrotendinous xanthomatosis (CTX)?

What are the less common manifestations of cerebrotendinous xanthomatosis (CTX)?

What causes cerebrotendinous xanthomatosis (CTX)?

DDX

What are the differential diagnoses for Cerebrotendinous Xanthomatosis (CTX)?

Workup

What is the role of lab tests in the workup of cerebrotendinous xanthomatosis (CTX)?

What is the role of urine testing in the workup of cerebrotendinous xanthomatosis (CTX)?

What is the role of bile analysis in the workup of cerebrotendinous xanthomatosis (CTX)?

What is the role of CSF analysis in the workup of cerebrotendinous xanthomatosis (CTX)?

What is the role of genetic tests in the workup of cerebrotendinous xanthomatosis (CTX)?

What is the role of EMG in the workup of cerebrotendinous xanthomatosis (CTX)?

What is the role of imaging studies in the workup of cerebrotendinous xanthomatosis (CTX)?

Which studies may be helpful in the workup of cerebrotendinous xanthomatosis (CTX)?

Which CNS findings are characteristic of cerebrotendinous xanthomatosis (CTX)?

Which peripheral nerve findings are characteristic of cerebrotendinous xanthomatosis (CTX)?

Which muscular findings are characteristic of cerebrotendinous xanthomatosis (CTX)?

Which histologic findings of the liver are characteristic of cerebrotendinous xanthomatosis (CTX)?

Which histologic xanthoma findings are characteristic of cerebrotendinous xanthomatosis (CTX)

Treatment

How is cerebrotendinous xanthomatosis (CTX) treated?

What is the role of surgery in the treatment of cerebrotendinous xanthomatosis (CTX)?

Which specialist consultations are beneficial to patients with cerebrotendinous xanthomatosis (CTX)?

Which dietary modifications are used in the treatment of cerebrotendinous xanthomatosis (CTX)?

What is the role of chenodeoxycholic acid (CDCA) in the treatment of cerebrotendinous xanthomatosis (CTX)?

What is included in the long-term monitoring of cerebrotendinous xanthomatosis (CTX)?

Medications

What is the role of medications in the treatment of cerebrotendinous xanthomatosis (CTX)?

Which medications in the drug class Bile Acids are used in the treatment of Cerebrotendinous Xanthomatosis (CTX)?