Alzheimer’s disease

By Jia Jing & Kris Goh

In 2022, 1 in 10 adults aged 60 and above have been diagnosed with dementia. How is this relevant to us? Alzheimer’s disease is commonly known as the memory loss disease of aging individuals. With increasing life expectancy and aging population in Singapore, this number is presumed to rise (MOH, 2022). Individuals who suffer from this disease have the inability to carry out daily tasks on their own and are placed in care facilities. The disease was first found by Dr. Alois Alzheimer who studied the brain structure of a patient who died of symptoms such as memory loss and unpredictable behavior. In her brain, he found abnormalities in parts of the brain involved in memory, particularly the hippocampus and entorhinal cortex. Subsequently, the cerebral cortex – in charge of higher order thinking, language and reasoning – becomes damaged as well (National Institute on Aging, 2021). The abnormalities found in these regions of the brain explains why the symptoms of Alzheimer’s are primarily memory loss followed by unexplainable behavior.

Symptoms of Alzheimer’s

Alzheimer’s progresses clinically in multiple stages – preclinical, mild, moderate, and severe, with each phase presenting distinct symptoms (National Institute of Aging, 2022). The preclinical stage is found to have complex brain changes associated with Alzheimer’s as far back as 10 years before any symptoms appear. However, it is worth noting that such brain changes may not necessarily signify the onset of the illness. As one starts to develop mild Alzheimer’s, the illness may present itself as memory loss that disrupts daily life, losing track of dates or one’s current location, wandering and getting lost, misplacing items in odd places as well as mood and personality changes. These symptoms would typically result in the diagnosis of Alzheimer’s at the mild stage. As the illness progresses, moderate Alzheimer’s would require more supervision and vigilance from the caretaker, and the patient may display difficulty with language and carrying out familiar tasks, delusions, paranoia, occasional problems recognizing people, and inappropriate emotional outbursts with continued cognitive decline. At the last stage, patients are completely reliant on caretakers and are unable to communicate with others. They experience significant weight loss due to disinterest in eating, general physical decline, inability to control bowel movements, and even seizures (National Institute of Aging, 2022). Overall, there is a continued cognitive decline of patients suffering from Alzheimer’s. While it may not be easy to care for patients with Alzheimer’s, it is also important for us to remember that they are unable to gain control of their moods and actions, hence we empathize and seek to discover their unmet needs.

Types and causes of Alzheimer’s

There are 2 main types of Alzheimer’s: early-onset and late-onset. Late-onset Alzheimer’s is the more common type which becomes symptomatic in one’s mid-sixties. Early-onset Alzheimer’s only affects about 10 percent of all Alzheimer’s patients and they mostly become symptomatic from their thirties to mid-sixties. The specific gene which has a direct effect on late-onset Alzheimer’s has not been discovered. However, a genetic risk factor of Alzheimer’s disease is having the apolipoprotein E (APOE) gene on chromosome 19 of the human genome (National Institute on Aging, 2019). The APOE gene works in the bloodstream by transporting cholesterol and other fats. Interestingly, the various forms of APOE gene either protects or increases risk for Alzheimer’s. While APOE ε4 increases the risk, APOE ε2 has a preventative effect. Although there are increased risks with the presence of the APOE gene, it does not equate to developing the disease. In addition to the APOE gene, presence of amyloid precursor protein (APP) on chromosome 21, presenilin 1 (PSEN1) on chromosome 14 and presenilin 2 (PSEN2) on chromosome 1 increases the risk of early-onset Alzheimer’s (National Institute on Aging, 2023). In addition, the presence of amyloid plaques and neurofibrillary tangles cause dementia. Amyloids are a normal phenomenon of the brain. However, in an Alzheimer’s patient, these amyloid fragments no longer break down and eventually form hard insoluble plaques which build up between neurons. This is usually caused by the inefficiency of the enzyme that cuts these amyloids. These plaques cause neurons to die and trigger an immune response. Neurofibrillary tangles are twisted fibers found within the brain. They are formed by tau proteins which form a larger microtubule structure. Their main function is for transportation. In Alzheimer’s, the tau protein is abnormal and thus the microtubule structure does not form naturally and falls apart. These tangles form inside the cell and disrupt the creation and recycling of proteins, eventually killing the cell. Thus, they both work together to eventually cause Alzheimer’s. Thus far, there has not been a preventative measure to stop these from forming (Alzheimer’s Disease Research, 2015). Therefore, the combination of these with the APOE gene increases the risk for dementia.

Alzheimer’s vs Dementia

Alzheimer’s may not be as familiar to the layman as the term ‘dementia’, which can be easily found in our day-to-day vocabulary when it comes to any deterioration of memory. So what exactly is the difference between Alzheimer’s and dementia? Dementia is not an actual illness but a broad term that describes certain symptoms, some of which include a decline in memory, poor judgment and reasoning skills, as well as decreased focus and attention among other symptoms (Graff-Radford, 2022). Alzheimer’s is just one of the most common types of dementia, however, there are many other forms and causes of dementia. Mixed dementia could also develop, where brain changes of more than one type of dementia occur together (Alzheimer’s Association, n.d.-a). One myth that should be debunked is that dementia may not necessarily be the result of old age, and other factors can also lead to its development. One example is Huntington’s disease, where a defective gene causes a progressive brain disorder. The disorder leads to brain changes that cause abnormal involuntary movements, a severe decline in thinking and reasoning skills, and irritability, depression, and other mood changes (Alzheimer’s Association, n.d.-b).

Early treatment and prevention of Alzheimer’s

Measures to manage Alzheimer’s in Singapore

Singapore’s first dementia-friendly neighborhood is in Yishun, established in 2019 to aid those with dementia to find their way home. Buildings are colored in primary colors — red, green and blue — to help with identifying their homes. Signages and fonts are made larger on directional signages to ensure clear visuals for those who suffer from dementia. Block numbers are larger and painted at high points to ensure visibility even from a distance. Singapore has teamed up with people suffering from dementia to aid in designing signages. Nostalgic murals like the white rabbit candy and Ang Ku Kuehs have been utilized in Kebun Baru, another housing estate. Other than visuals, staff working in nearby stores in Yishun have been trained to aid those with dementia.

In addition to building friendly neighborhoods, Singapore has stepped up its transport with identifying murals and directions on the floors and berths. Using nostalgic images which have been encoded in their long-term memory allow for easier recognition and identification of their buses and their respective berths.

It puts one’s mind at ease when there are measures to help those who cannot remember their way back home find their way more easily. With the rise in population suffering from dementia and Alzheimer's, it is important for Singapore to take a step in this direction.

Mahjong as a preventative measure in Singapore?

One popular way of combating dementia in Singapore – at least according to the older generation, is through the game of Mahjong. Mahjong, a popular Chinese tile-matching game, originated in China around the mid-to-late 1800s and has since taken the world by storm as one of the most trendy pastimes in both the East as well as the West today (Lang, 2021). However, does this beloved game aid in the prevention of dementia, or is that just a widespread myth? One longitudinal study done by Tian et al. (2022) found that through observing a group of elderly over 10 years, participants who engaged in Mahjong playing almost daily throughout the study had a significantly lower risk of dementia as compared to those who did not. One other study found that after 12 weeks of playing Mahjong, elderly participants’ executive function of the brain greatly increased, which refers to the advanced cognitive function for completing tasks and overcoming difficulties involving working memory and reflection, planning, organization, and management (Zhang et al., 2020). A study by Chu-Man et al. (2015) found that Mahjong may be seen as an effective prevention for dementia through enhancing short-term memory, attention, and logical reasoning capability, which improves cognitive reserve and restores cognitive function, effectively reducing the risk of Alzheimer’s in the elderly. Although further research on the effects of Mahjong is still needed, such studies highlight its potential benefits on brain deterioration and demonstrate how this unassuming game may incidentally aid one in preventing Alzheimer’s, while bringing joy and comfort to the older crowd.

With a growing aging population and an increase in Alzheimer’s disease, it is important for Singapore to take the necessary actions to aid these people. Be it infrastructure or activities for the elderly to allow them to better identify and improve on their ability to remember.

References

Alzheimer’s Disease Research (2015, July 1). Amyloid plaques and neurofibrillary tangles [Infographic]. BrightFocus Foundation. https://www.brightfocus.org/news/amyloid-plaques-and-neurofibrillary-tangles

Ang, S. (2022, February 7). Murals at bus interchanges, MRT stations to help people with dementia find their way home. The Straits Times. https://www.straitstimes.com/singapore/transport/murals-at-bus-interchanges-mrt-stations-to-help-people-with-dementia-find-their-way-home

Chu‐Man, L., Chang, M., & Chu, M. (2015, July 29). Effects of mahjong on the cognitive function of middle‐aged and older people. International Journal of Geriatric Psychiatry, 30(9), 995–997. https://doi.org/10.1002/gps.4307

Lang, C. (2021, May 4). What the surprising history of mah-jongg can teach us about America. Time. https://time.com/6045817/mahjongg-history/

Ministry of Health. (2022, April 25). Speech by associate professor kenneth mak, director of medical services, minstry of health and member, lee kong chian school of medicine governing board, at the launch of the dementia research centre Singapore, 25 april 2022, 10.30am. https://www.moh.gov.sg/news-highlights/details/speech-by-associate-professor-kenneth-mak-director-of-medical-services-ministry-of-health-and-member-lee-kong-chian-school-of-medicine-governing-board-at-the-launch-of-the-dementia-research-centre-singapore-25-april-2022-10.30am#:~:text=The%20ongoing%20efforts%20to%20tackle%20dementia&text=As%20had%20been%20shared%2C%20around,expected%20to%20continue%20to%20rise.

Nanda, A., Chua, C. & Pazos, R. (2022, September 21). How Singapore builds its dementia-friendly neighbourhoods. The Straits Times. https://www.straitstimes.com/multimedia/graphics/2022/09/dementia-neighbourhoods-singapore/index.html?shell

National Institute on Aging. (2019). What causes alzheimer’s disease? https://www.nia.nih.gov/health/what-causes-alzheimers-disease#:~:text=There%20are%20two%20types%20of,types%20have%20a%20genetic%20component.

National Institute on Aging. (2021). What is alzheimer’s disease? https://www.nia.nih.gov/health/what-alzheimers-disease

National Institute on Aging. (2023). Alzheimer’s disease genetics fact sheet https://www.nia.nih.gov/health/alzheimers-disease-genetics-fact-sheet

Tian, G., Shuai, J., Li, R., Zhou, T., Shi, Y., Cheng, G. & Yan, Y. (2022). Association between playing cards/mahjong and risk of incident dementia among the Chinese older adults: a prospective cohort study. Frontiers Aging Neuroscience, 14. https://doi.org/10.3389/fnagi.2022.966647

Zhang, H., Peng, Y., Li, C., Lan, H., Xing, G., Chen, Z., Zhang, B. (2020). Playing mahjong for 12 weeks improved executive function of elderly people with mild cognitive impairment: A study of implications for TBI-induced cognitive deficits. Frontiers in Neurology, 11. https://doi.org/10.3389/fneur.2020.00178