ADULT ONSET HUNTINGTON DISEASE
|
ALTERNATE NAMES
|
Huntington’s chorea; Huntington’s Disease; Huntington chorea; Huntington chronic progressive
hereditary chorea
|
DESCRIPTION
|
Huntington disease (HD) is a hereditary neurodegenerative disorder that is characterized by progressively
worsening motor, cognitive, behavioral, and psychiatric symptoms. HD is caused by
a mutation of the Huntington gene called a “CAG repeat expansion.” The mutation results
in gradual neuronal degeneration in the basal ganglia of the brain, and progresses
to involve other regions of the brain responsible for coordination of movements, thoughts,
and emotions. Neuronal degeneration causes diffuse and severe brain atrophy that is
comparable to late stage Alzheimer disease.
|
DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND ICD-9-CM/ICD-10-CM CODING
|
Diagnostic testing: The diagnosis of HD is made by:
-
•
Clinical history documenting changes in motor, behavioral and cognitive function;
-
-
•
Abnormal neurological exam findings;
-
•
Abnormal neuropsychological test results; and
-
•
HD gene test with abnormal results (40 or more CAG repeats).
Brain imaging is optional, but if performed may show atrophy of the caudate nucleus
or diffuse brain atrophy.
Physical findings: Clinical presentation of HD may include:
-
•
Changes in personality, behavior, cognition, speech, and coordination;
-
•
Random uncoordinated extremity movements (chorea);
-
-
-
-
-
-
As the disease progresses, concentration on cognitive tasks becomes increasingly difficult,
and an individual may have difficulty swallowing and feeding himself. Family history
of HD is usually but not always positive.
ICD-9: 333.4
ICD-10: G10
|
PROGRESSION
|
The average onset age is around 40, plus or minus 10 years; however, onset has been
documented as young as age 5 (see Juvenile HD) and as old as age 90. Death usually
occurs at about 15 to 20 years after onset of symptoms, and is due to complications
of the disease.
|
TREATMENT
|
There is no cure or treatment to stop, slow or reverse the progression of HD. Claimant’s
medical source(s) may prescribe medications to manage symptoms. A psychiatrist or
behavior management specialist may address behavior disorders. A speech language pathologist
may evaluate communication and swallowing problems. A nutritionist may be consulted
to address nutritional needs as the disease progresses. Assistive devices such as
wheelchairs, helmets, and communication boards may be used for safety, and to improve
quality of life.
|
SUGGESTED PROGRAMMATIC ASSESSMENT*
|
Suggested MER for Evaluation:
-
•
Claimant’s medical source(s) records documenting progression of motor, cognitive,
and psychiatric symptoms and signs; family history of HD, and abnormal neurological
exam findings consistent with HD;
-
•
Laboratory testing showing a CAG repeat expansion in the HD gene (40 or more CAG repeats);
-
•
Brain imaging may provide supporting evidence; and
-
•
Psychological or psychiatric reports including neurocognitive testing.
|
Suggested Listings for Evaluation:
|
DETERMINATION
|
LISTING
|
REMARKS
|
Meets
|
11.17
|
|
Equals
|
12.02
|
|
* Adjudicators may, at their discretion, use the Medical Evidence of Record or the
listings suggested to evaluate the claim. However, the decision to allow or deny the
claim rests with the adjudicator.
|