Thursday, April 26, 2018

The Forgettable Killer: Alzheimer’s and the prevalence in reaction times


Alzheimer’s is one of the most prevalent diseases among the older population in the United States and worldwide, and also one of the saddest. According to the Alzheimer’s association, over 5.7 million people are living with Alzheimer’s, with this number projected to be 14 million by 2050. I myself have had experience with Alzheimer’s disease – my grandfather, who recently passed away, was diagnosed with both Alzheimer’s and Parkinson’s. Seeing him go from an inspiring and intelligent man to being a shell of his formal self within the last two years was one of the hardest things for me to witness. Because of these circumstances, I was very interested in Dr. Roberto Fernandez’s study on Alzheimer’s and how it relates to visual motion.
Dr. Fernandez started off his lecture discussing Alzheimer’s overall, and why it is so important to study. Alzheimer’s is the most common form of dementia after the age of 65. It impairs recent episodic memory, and this serves as the earliest symptom. It currently has no cure, preventative measures, and also has no way to be effectively treated. There are genetic risk factors, and seen pattern of progressions for the disease itself.
With all of that being said, Dr. Fernandez went into detail about the things unknown about Alzheimer’s disease (AD). For starters, he talked briefly about changes in amyloid/tau markers that are prevalent with the disease; furthermore, selective vulnerability, or why some groups are predisposed to greater rates of getting the disease.
Going off of this, Dr. Fernandez went into exactly what his research project focused on. He briefly discussed the posterior cortical distribution of AD pathology. There is selective vulnerability of specific neuronal populations and the spread of pathological functional networks associated with the disease. This is why Dr. Fernandez chose to study the parietal lobe function – it’s perceptual base of navigation are ideal model to study aging and AD. AD is heavily associated with posterior cortical atrophy, and Dr. Fernandez’s research focused greatly on the effects in AD patients.
Dr. Fernandez’s research focused on optic flow – the visual motion that is present during self-movement. More specifically, his research looked at direction and focus of expansion in driving. His lab set up a visual reality driving test that tested several different aspects in younger test subjects without Alzheimer’s, older test subjects without Alzheimer’s, as well as older subjects who suffered from AD. The research focuses on visual motion testing involving event related potentials (ERPs), that have horizontally moving dot patterns/gratings that evoke a negative wave peaking at around 200 ms after onset (N200 response). The research design focused on creating a driving simulation that subjects participated in, that involved testing the presence of N200 response.
The research overall provided data that Dr. Fernandez hypothesized. Greater motion coherence and faster optic flow produced greater N200 peaks, especially in younger subjects who did not suffer from the disease. Furthermore, it was also confirmed that AD is associated with overall smaller optic flow N200 peaks. Aging has little effect on N200 peaks, as shown between regular subjects both old and young, but AD had a significant effect on diminishing N200 peaks.
Breaking this information down, the big picture is that Alzheimer’s disease is very detrimental to people diagnosed with the disease – they cannot live on their own, and must rely on family/nursing home’s to be able to survive. One of the take home messages of Dr. Fernandez’s research is the strong effect that AD has on a patient’s ability to function in motion related tasks, especially with the driving simulations. His research found that AD has significant implications for real world navigation, including an increased risk for motor vehicle accidents.AD has significant implications for real world navigation, including an increased risk for motor vehicle accidents.
Indeed, this data is very pressing and important in relation to the stigmatization around drivers with dementia, and those who are starting to suffer from dementia. In an article published by the Alzheimer’s association discussing Alzheimer’s and when a person should stop driving states that driving deaths for rivers aged 75-84 is 3 per 1 million miles driven – very similar to teen driving deaths. For over the age of 85, this rate quadruples – with over 2 million drivers in this category, and the chance of dementia increasing with increasing age, it is very important to educate people on the dangers of driving with Alzheimer’s/dementia, and  when to stop driving. I believe that if Dr. Fernandez’s research were put on the Alzheimer’s association website and was further advocated, it would help decrease the number of crashes related to older drivers, especially those with dementia.
Overall, I thoroughly enjoyed Dr. Fernandez’s presentation. I think that the work is very important, especially since it relates to real world issues such as motor fatality related to old age. While there may be no cure yet, the steps taken towards Alzheimer’s research serve as important steps to a safer future.
 Bibliography
Cramer, Luciana. “When Is It Time to Stop Driving?” Caregiver Tips and Tools, no. 26, www.alz.org/documents/centralcoast/Safety_26_When_to_stop_driving.pdf.
“Latest Alzheimer's Facts and Figures.” Latest Facts & Figures Report | Alzheimer's Association, 19 Mar. 2018, www.alz.org/facts/.

No comments:

Post a Comment