Neurogenerative Diseases - 5

The existence of clear genetic and toxicologic etiologies alongside apparently idiopathic neurodegenerative diseases suggests that, like
many cancers, what appears to be a single disease may in fact be several distinguishable illnesses. Image from Dreamstime.

Age is not the only risk factor for Parkinson's, as the
lifetime risk for developing the disease is 4.4% for
men and 3.7% for women. A recent paper suggested
that "sex might constitute an important factor for
AD [Alzheimer's disease] patient stratification and
personalized treatment."

more susceptible to vascular dementia.
The underlying mechanisms of these differences
are still unknown. Part of the answer might lie in the
physiological differences in gray matter composition
that persist between the sexes from birth throughout
life. Females have a higher gray matter density than
men but significantly lower gray matter volume and
mass, and these differences prevail in all relevant
regions of the brain.

Sex differences related to immune responses to
neurodegeneration, affecting both susceptibility
and disease progression, are also apparent in
multiple sclerosis, which women develop more
frequently than men, but which progresses more
slowly and less frequently in females.

Underlying causes
However, to say that age and sex are risk factors
for NDDs, or even that these disorders are a result
of neuronal cell death, is to duck the question of
etiology. Considerable debate centers on the relative
contributions of nature and nurture, or genes and
environment.

Similarly, a 2018 article reviewing nearly 300
papers on sex differences and cognitive decline in
Alzheimer's disease confirmed that women "are at
significantly higher risk of developing" Alzheimer's,
and that their cognitive outcomes were poorer than
men's. Moreover, the degree to which underlying
health issues such as obesity, cardiovascular disease,
and lifestyle factors affect the course of various
dementias also varies by sex. While females are at
greater risk for developing Alzheimer's, men are

Huntington's disease, as well as several rare
neurologic disorders, are clearly inherited as an
autosomal dominant trait, while other NDDs occur
as autosomal recessive, X-linked, or maternally

https://www.ncbi.nlm.nih.gov/pubmed/11781119 https://www.ncbi.nlm.nih.gov/pubmed/11781119 https://www.ncbi.nlm.nih.gov/pubmed/29985474 https://www.jneurosci.org/content/37/20/5065/tab-figures-data https://onlinelibrary.wiley.com/doi/full/10.1002/jnr.23955 https://onlinelibrary.wiley.com/doi/full/10.1002/jnr.23955 https://www.ingentaconnect.com/content/wk/yco/2018/00000031/00000002/art00011 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5286729/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC151843/#__sec2title

Neurogenerative Diseases

Table of Contents for the Digital Edition of Neurogenerative Diseases