COMPASSIONATE ALLOWANCE INFORMATION

CREUTZFELDT-JAKOB DISEASE (CJD) - Adult

DESCRIPTION

Creutzfeldt-Jakob disease (CJD) is a rare, rapidly progressive, invariably fatal brain disorder primarily characterized by mental deterioration, although motor problems can be significant in many cases. CJD belongs to a group of human and animal diseases known as transmissible spongiform encephalopathies (TSE) or prion diseases. Spongiform refers to the characteristic appearance of infected brains, which become filled with holes until they resemble sponges under a microscope. Typically, onset of symptoms occurs at about age 60 and runs a rapid course. There are four major categories of CJD: sporadic CJD, hereditary CJD, acquired or iatrogenic CJD and variant CJD.
Sporadic CJD is the most common form of the disease. It accounts for 85% of cases. The cause of sporadic CJD is unknown, but it is believed that a normal cellular protein undergoes a spontaneous change in conformation (prion protein) that results in the disease. This form of the disease is believed to be spontaneous and not the result of an infection.
Hereditary or familial CJD is a very uncommon disease and the consequence of a mutation in the gene that encodes the prion protein. About 5 to 10 percent of cases of CJD in the United States are hereditary.
Acquired or Iatrogenic CJD is also very rare accounting for less than 1% of cases. It results from the accidental transmission during the course of medical interventions. Examples include transmission in cases of corneal transplantation, dural grafts, or treatment with Human Growth Hormone isolated from cadaveric pituitary glands.
Variant CJD was first reported in 1996. It is believed to be the result of eating meat from cattle with bovine spongiform encephalopathy (BSE or mad cow disease). In contrast with sporadic CJD which affects older people, the variant form primarily affects young subjects (i.e., in the late 20s) and may have a longer course, between one and two years.

ALTERNATE NAMES

Jakob-Creutzfeldt Disease, Jakobs Disease, Subacute Spongiform Encephalopathy, Variant (V-CJD) Bovine Spongiform Encephalopathy (BSE), Fatal Familial Insomnia (FFI), Gerstmann-Straussler-Scheinker (GSS) Disease, Prion disease

DIAGNOSTIC TESTING AND CODING

The diagnosis of CJD is suspected when there are typical clinical symptoms such as rapidly progressing dementia with myoclonus (twitching). Currently, there is no single diagnostic test for CJD except for brain biopsy. The first concern is to rule out treatable forms of dementia such as encephalitis or chronic meningitis. The following investigations can be performed to support the diagnosis:

• Electroencephalography - often has characteristic triphasic spikes

• MRI of the brain - often shows high signal intensity in the caudate nucleus and putamen bilaterally on T2-weighted images

• Cerebrospinal fluid analysis for 14-3-3 protein. The presence of this protein supports the diagnosis of CJD, but is not specific

• Tonsil biopsy is helpful in the diagnosis of variant CJD, but less so in other forms of the disease.

Brain biopsy is the definite diagnostic test, but is performed only in selected cases because the procedure may be dangerous to the individual. Since a correct diagnosis of CJD does not help the individual, brain biopsy is discouraged unless it is needed to rule out a treatable disorder.

TREATMENT

There is no treatment that can cure or control CJD. Current treatment is aimed at alleviating symptoms and making the patient as comfortable as possible. Opiate drugs can help relieve pain, and the drugs clonazepam and sodium valproate may help relieve involuntary muscle jerks.

PROGRESSION

About 90 percent of patients die within 1 year. In the early stages of disease, patients may have failing memory, behavioral changes, lack of coordination and visual disturbances. As the illness progresses, mental deterioration becomes pronounced and involuntary movements, blindness, weakness of extremities, and coma may occur.

SUGGESTED PROGRAMMATIC ASSESSMENT*

Suggested MER for Evaluation: Clinical notes and results of neurological examination that establish the presence of rapidly progressive dementia or neurodegenerative illness.

If available, ancillary studies, i.e., spinal tap, cerebrospinal fluid analysis, detection of 14-3-3 protein in spinal fluid, electroencephalogram (EEG) and brain biopsy are helpful as supportive evidence.

Suggested Listings for Evaluation:

DETERMINATION

LISTING

REMARKS

Meets Listing

11.17

Clinical diagnosis of CJD resulting in marked restrictions of activities of daily living and social interactions and

11.17

Clinical diagnosis of CJD with significant and persistent disorganization of motor function in two extremities as described in 11.04 B.

Medical Equals

* Adjudicators may, at their discretion, use the Medical Evidence of Record or Listings suggested to evaluate the claim. However, the decision to allow or deny the claim rests with the adjudicator.