Dementia and Alzheimer's disease (by Abigail Wiederman)

The term Dementia is not a specific disease but is rather a general symptom of the impaired ability to remember information, and is associated with severe declines in thinking abilities, memory, and overall decision-making. Dementia is progressive and can affect abilities beyond memory such as thinking or making decisions for yourself. The progression of dementia can severely impact and interfere with everyday activities. There are many disorders associated with dementia that are not limited solely to Alzheimer’s disease. They include but are not limited to Parkinson’s disease, Korsakoff’s syndrome, Frontotemporal dementia, Vascular dementia, and Huntington’s disease. Alzheimer's disease is the most common type of dementia and primarily affects older adults, therefore, it is not part of routine aging.

Although patients with late-onset usually show their first symptoms in their mid-sixties or later on in life, it is also possible to see early onset which is when symptoms develop before age sixty-five and can rarely begin in a person's thirties. The severe impacts on the structure and function of the brain are why Alzheimer's disease can be so dangerous to a person's ability to function. Alzheimer's disease doesn’t necessarily kill a person, however, daily functions such as choking on food or not being able to use the restroom are usually the cause of death, as they would not have occurred without the presence of the disease.

Early onset typically shows faster cognitive decline and is less commonly diagnosed with only five percent of the cases being early onset. Additionally, there are many different tentative factors of early onset, however, experts don't know exactly what triggers the start of Alzheimer's disease. Researchers suspect that two proteins damage and kill nerve cells. Plaques are formed from the build-up of Beta-amyloid while the fibers of another protein, tau, twist, and form tangles. Amyloid-beta is a naturally occurring protein that builds up in the space between neurons which prevents efficient neuronal communication. The reasons why this happens are still not very well understood. Neurofibrillary tangles are caused by tau, another naturally occurring protein that builds up inside of the neurons. These tangles block the ability of neurons to communicate or transport nutrients which overall cause the death of cells. Almost everyone develops plaques and tangles as they age, but those with Alzheimer's disease develop many, many more much more rapidly. These plaques and tangles first cause damage to the areas of the brain that hold memories such as the hippocampus and other related structures in the temporal lobe, however, throughout time it spreads and affects other areas of the brain.

Familial Alzheimer’s disease is very rare and is caused by a Genetic predisposition. A total of less than one percent of all cases are familial, but sixty percent of all of the early-onset cases of Alzheimer’s Disease are familial. For early onset, the early stages impact declarative memory and are viewed as similar to amnesia with the symptoms that are shown. The later stages however impact all parts of the memory. Late-onset Alzheimer’s disease is the most common type and is typically prevalent in those ages sixty-five and older. We see a slower decline in this type of Alzheimer’s and it can be caused by different things such as way of life and routine, genetic risk factors, and many other factors.

Alzheimer’s disease impacts structures beyond the Hippocampus including the Amygdala and the Prefrontal Cortex. Atrophy (the decrease in size or wasting away of a body part or tissue) in these regions not only disrupts the memory, but also disrupts the memory strategy use and semantic memory (part of the long-term memory that involves the recognition of different concepts, recalling words and meanings, counting and spelling, and basic essential aspects of everyday life). Emotional Salience is also an effect, making it hard for the Alzheimer’s patient to live and function alone. Their primary focuses are disrupted and everyday tasks may not be second nature anymore.

With Alzheimer’s Disease comes many different stages of declination. It can range from difficulty completing tasks, problems with words, misplacing items, spatial unawareness, and visual perception. Every person will eventually age and require help in many new areas. Self-sufficiency will decline and they may even lose some basic skills they once had, however, the ability of you basic person who is aging at a normal pace is severely different than a person who has dementia and is rapidly facing all of these struggles and beyond. Once very familiar tasks quickly become foreign concepts to these patients. If they’ve made the same commute to work for the past fifty years or seen the same people at the grocery store each week they can turn to strangers in a short period. Aside from the normal day to day forgetfulness of a common person, people with dementia may have trouble even engaging in conversation. They could be sitting at a table telling a story, finish the story, go to the bathroom, and upon return ask if you want to hear a story which is the same one they had just finished except they had no clue they had already told it. Additionally, the person may stop in the middle of a conversation get sidetracked, and be unable to pick up where they left off. A person with dementia may forget about a past death and talk of a loved one as if they are still alive. This can be due to memory loss or confusion. An elderly person whose parents have been gone for a long time may be in such a state of confusion that they ask when they will be home, and the best thing to do is to play along to not put them in a state of frustration. If you go along with them you are not being a bad person, yet helping them in the long run because they most likely will not remember either way but they are left in a bad mood especially because irritability and agitation in Alzheimer’s patients is another very common symptom.

Sources:

https://www.hopkinsmedicine.org/health/conditions-and-diseases/alzheimers-disease/earlyonsetalzheimer-

disease

https://www.cdc.gov/aging/dementia/index.html#:~:text=Dementia%20is%20not%20a%20specif

ic,a%20part%20of%20normal%20aging.

https://www.alz.org/alzheimers-dementia/10_signs