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DESCRIPTION
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Young-onset
Alzheimer’s
disease
(YOAD) is the diagnosis of Alzheimer's disease (AD) for an individual younger than age 65,
and accounts for approximately 5-10% of all AD cases. AD is a degenerative, irreversible
brain disease that usually affects older individuals and causes a type of dementia
characterized by the gradual loss of cognitive abilities, such as memory, language,
judgment, and the ability to function.
YOAD is also known as familial AD (FAD) when associated with three specific genes:
presenilin 1, presenilin 2, and amyloid precursor
protein, which cause less than 5% of AD.
Hallmark changes in the brain include the development of beta-amyloid plaques and
neurofibrillary tangles (NFT), also known as tau tangles, which interrupt normal brain
activity and contribute to the eventual deterioration and death of brain cells.
The onset of YOAD is subtle; memory impairment is frequently its earliest manifestation,
quickly followed by learning and language impairments.
Because individuals with YOAD often are employed, it is not uncommon for the disease
to first manifest as a decline or loss in their ability to perform work-related activities.
YOAD affects each individual differently and symptoms will vary. However, problems
with memory, problem-solving, and depression are common complaints in the early stages
of YOAD. In later stages, agitation, changes in personality and behavior, restlessness,
and withdrawal become evident.
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DIAGNOSTIC TESTING, PHYSICAL FINDINGS, AND
ICD-9-CM/ICD-10-CM
CODING
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Diagnostic testing: There is no single test used to diagnose YOAD. The diagnosis is made using the individual's
medical history and other diagnostic tools, including:
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History of onset and description of cognitive and functional impairments at home and
at work;
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Results of neurological examinations;
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Cognitive and functional assessments including, but not limited to mini-mental status
examination (MMSE), best if recorded over time to document any decline;
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Neuroimaging such as magnetic resonance imaging (MRI), computed tomography (CT), and
positron emission tomography (PET) scans to observe changes in the brain and exclude
other causes of dementia;
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Cerebrospinal fluid (CSF) analysis; or
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Blood testing to detect the presence of amyloid plaques.
Physical findings: The non-memory impairment symptoms of YOAD are variable and may include:
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Balance and coordination problems;
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Difficulty with fine motor skills; and
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Difficulty walking, speaking, or swallowing.
ICD-9: 290.0; 290.1; 290.10; 290.11; 290.12; 290.13; 294.1; 331.0
ICD-10: G30.0; G30.8; G30.9
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PROGRESSION
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Individuals with YOAD experience gradual cognitive decline until death. As the condition
progresses, brain cells die and connections among cells are lost, causing cognitive
symptoms to worsen. An individual’s quality of life may also be impacted by a variety
of behavioral and psychological symptoms that accompany dementia, such as sleep disturbances,
agitation, hallucinations, and delusions. Death usually results from pneumonia, malnutrition,
or general body wasting. The average time of survival after diagnosis of YOAD varies
but generally is 8-10 years, and many individuals with YOAD require long-term care
in a medical facility or in-home care from caregivers.
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TREATMENT
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There is no cure for YOAD. The current modalities for treatment for this condition
may include cholinesterase inhibitors, N-methyl D-aspartate (NMDA) receptor antagonist
(memantine), combination therapy, and supportive therapies.
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* 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.
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