Neurogenerative Diseases - 4

Neurodegenerative Disease
Research Update
As molecular techniques advance, NDD knowledge is increasing,
informing the development of new therapies and diagnostics.

Angelo DePalma, Ph.D.
Neurodegenerative diseases (NDDs) comprise
perhaps half a dozen well-known and hundreds of
rare conditions characterized by the loss of function
over time and the eventual death of nerve cells.
Manifestations of NDDs include cognitive deficits,
sensory-motor decline, or both.

neuron disease, spinocerebellar ataxia, and spinal
muscular dystrophy are examples of less common
neurodegenerative diseases.

Risk factors
Virtually every review article on NDDs cites age as a
significant risk factor for developing these disorders.
For example, Alzheimer's disease is rare in individuals
younger than 50 but prevalence begins rising an
additional 0.5% per year after age 65, increasing
to about 8% per year after age 85. Similarly rare
before the sixth decade of life, Parkinson's disease
prevalence may be as high as 2% for individuals over
age 65, increasing every year thereafter.

According to the National Institutes of Neurological
Disorders and Stroke, more than 600 diseases of the
nervous system affect 50 million Americans every
year. Assuming an annual cost of about $46,000 to
care for a single patient, the societal cost of NDDs in
the U.S. alone is $243 billion.
Approximately 5.4 million Americans live with
Alzheimer's disease, and close to a million are
affected by Parkinson's disease, the two most
prevalent neurodegenerative disorders. Alzheimer's
represents approximately 70% of all dementias.

Recent evidence suggests that the accumulation
of senescent nervous system cells, a natural
consequence of aging, may predispose individuals
toward developing NDDs or accelerate progression
of these diseases once they take hold. Investigating
the link between senescence and NDDs has been
hindered by the lack of universal markers for
senescent neuronal cells.

Other common neurodegenerative diseases
include multiple sclerosis (400,000 patients),
amyotrophic lateral sclerosis (ALS) and Huntington's
disease (30,000 cases each). Prion diseases, motor

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https://www.niehs.nih.gov/research/supported/health/neurodegenerative/index.cfm https://www.niehs.nih.gov/research/supported/health/neurodegenerative/index.cfm https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4489962/ https://www.ncbi.nlm.nih.gov/pubmed/16360788 https://onlinelibrary.wiley.com/doi/abs/10.1002/ana.24897 https://www.ncbi.nlm.nih.gov/pubmed/11781119 https://www.ncbi.nlm.nih.gov/pubmed/30261683 https://www.ncbi.nlm.nih.gov/pubmed/30261683

Neurogenerative Diseases

Table of Contents for the Digital Edition of Neurogenerative Diseases