It
is self-evident that Alzheimer’s Disease (AD) is one of the most prevalent
disease among the older population and also the fourth leading cause of death
in the U.S, plaguing over 5.5 million people. It is projected that halfway
through 21st century the figure will rise to three times as many AD
patients. Alzheimer’s also happens to be one of the saddest and worst kind of
disease to be diagnosed with, as this disease attacks the hippocampal neurons in
most patients, which results in patient losing their cherished memories. Dr.
Roberto Fernandez’s study Early
Alzheimer’s disease blocks responses to accelerating self-movement began
by giving background information about the disease itself, he explained that
this disease is most common in population older then 65 and is also the most
common form of dementia. This disease has early symptoms of impairment of recent
episodic memories; there is no cure yet, no preventative measure to slow the disease
down, or even an effective method to diagnose or prescreen this disease. These
are some of the reasons given by Dr. Fernandez’s introduction which outlines
the importance of the research of the Alzheimer’s disease.
Dr.
Fernandez explained that AD occurs with presence and accumulation of Amyloid
Beta plaques which serve as the hallmark of this disease as well as genetic
risk factors, selective vulnerability, and why some group of people are
predisposed at greater rate to AD. Dr. Fernandez’s study concentrates on
relationship of the visual motion. Dr. Fernandez described exactly what his
research has focused on by discussing the posterior cortical distribution of AD
pathology. The reason why Dr. Fernandez chose to do this study was due to there
being certain selective vulnerability of specific neuronal populations and the
spread of pathological functional networks that are associated with the
Alzheimer’s Disease. He specifically chose to perform detail study on the
parietal lobe function and the perceptual base of navigation because it is very
ideal to study in the aging population and the correlation with AD. Lastly, AD
is known for its notorious association with the posterior cortical atrophy and
this research focuses on those effects in the AD patients.
I greatly appreciated the way Dr.
Fernandez set up his lab experiment. The experiment was set up in a visual
reality driving test stimulation which was focused on the optic flow and the
optic motion that is present during movement and self-movement. The visual
reality driving test was tested and the test subjects were as followed: a younger
group of subjects without the AD, an older group of subjects without AD, and
finally another older group of subjects with AD. The study was testing what is
known as Event Related Potentials (ERPs), which are accumulation of stimuli
that result in firing of a neurotransmitter. The ERPs, involve horizontal
moving dot patterns which induce a negative wave peaking at around 200ms and
the driving simulations tested the presence of the N200 response. The results
of the study were predictable and as hypothesized by Dr. Fernandez. There was a
greater motion consistency and quicker optic flow which produced great N200
peaks; this was seen in the younger population because they did not suffer from
the AD. However, the study proved that AD is involved in smaller optic flow and
reduced N200 peaks in the older group of subjects with AD. It was also
interesting to see that age difference had little effect on the N200 peaks as
the both younger and older test subjects without AD had very little difference
in their N200 peaks but compared to subjects who suffered from AD had
significantly reduced N200 peaks.
I also came across another study; Lack of sleep may be linked to risk factor
for Alzheimer's disease: Preliminary study shows increased levels of
beta-amyloid, however, there is currently less known about the impact in
the human brain as this study was done on mice. As a student who has to stay
awake for long periods of time due to studying for exams and other academic
related work, it is a bit concerning and scary reading about this. The study
gives new insight about potentially harmful effects of lack of sleep on the
brain which tells us even more about the pathology of AD. This study was led by
Dr. Ehsan Shokri-Kojori and Nora D. Volkow of the National Institute on Alcohol
Abuse and Alcoholism (NIAAA) and Dr. Volkow who is also the director of the
National Institute on Drug Abuse at NIH.
To
understand the possible correlation between the sleep and Amyloid Beta build
up, PET scans were taken from 20 healthy subjects ranging from age 22 to 72, after
a night of rested sleep and then after sleep deprivation (being awake for about
31 hours). They found beta-amyloid increases of about 5 percent after losing a
night of sleep in brain regions including the thalamus and hippocampus, regions
especially vulnerable to damage in the early stages of Alzheimer's disease.
However, the study does not answer whether the increase in Amyloid Beta may
possibly subside following a night of rest. Although, this sample size was
small for the demonstration of this type study but the preliminary assessments do
point in the direction that there might be some correlation between sleep and
Amyloid Beta accumulation.
In retrospect of both studies,
looking at Alzheimer’s Disease and the rate at which it is rising in population
is scary and especially the detrimental effect it has on the people that are
diagnosed with AD. It is evident that patients with late onset AD, are
completely dependent on family and nursing homes to carry on day to day tasks.
I learned from Dr. Fernandez that AD patients lose the ability to function in
motion related tasks, which in his study concentrated on driving simulation. AD
is a very pressing, important and aforementioned is in fact a very sad disease
because patients are simply unable to take care of themselves which can have a
huge emotional and physical toll on their loved ones and themselves. However,
going back to the dynamics of the study which clearly showed the decrease in
ability to drive safely in patients with dementia, it is of paramount
importance to educate people and state legislations to take effective measures
to prevent AD patients from driving after a certain time period in their
disease state without stigmatizing them. This initiative will not only decrease
the number vehicle related accidents of AD patients but also spread awareness about
the disease itself.
Work Cited
1) Early Alzheimer’s disease blocks
responses to accelerating self-movement
https://loyolauniversitychicago-my.sharepoint.com/personal/rmorrison_luc_edu/Documents/Forms/All.aspx?slrid=0b66629e%2D3002%2D5000%2Dcfcc%2D24d288cc413e&FolderCTID=0x01200052F973E683B96F4F97B49148A837C07C&id=%2Fpersonal%2Frmorrison%5Fluc%5Fedu%2FDocuments%2FNEUR%20300%2F%2803%2E27%2E18%29%20%2D%20Roberto%20Fernandez%2DRomero%2FNBA2012%2Epdf&parent=%2Fpersonal%2Frmorrison%5Fluc%5Fedu%2FDocuments%2FNEUR%20300%2F%2803%2E27%2E18%29%20%2D%20Roberto%20Fernandez%2DRomero
2) Lack
of sleep may be linked to risk factor for Alzheimer's disease: Preliminary
study shows increased levels of beta-amyloid
https://www.sciencedaily.com/releases/2018/04/180413155301.htm
3) https://www.cdc.gov/aging/aginginfo/alzheimers.htm
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