Saturday, 10 May 2014

Alzheimer's Disease & Choosing to Die


One of the main reasons I first considered studying neuroscience was due to a personal link I had to the prevalent neurodegenerative disease, Alzheimer’s. My granddad was diagnosed in 2008 and unfortunately passed away in 2010. Whilst it was of course extremely upsetting to see him go through the motions of the disease, it was also compelling to see first-hand the progression of Alzheimer’s. I observed as the brain, which usually works to help us, began to fail him. 

This experience opened my eyes to the vulnerability of the brain, and spurred me to want to learn as much about it as possible. It sounds cliché, but my 16-year-old self naively wanted to study neuroscience to fulfil my dream of one day finding the cure for Alzheimer’s.

"Journey into Alzheimer's" by Ruth Blackford

Of course that hasn’t happened yet, but studying neuroscience at university has opened my eyes to just how complex our brains are.  Some of the mechanisms for what causes this awful disease are understood, but the possibility of a cure is far off, unlikely to happen overnight.  However, as always with neuroscience, techniques and technology are continuously improving and moving fast, providing new opportunities for research that may one day find the cure.

 
Alzheimer’s Disease (AD) is a form of dementia, and accounts for 75% of diagnoses. Dementia is a kind-of umbrella term for diseases of the brain that lead to a loss of cognitive function (the ability to think/reason clearly), and results in an impairment of a person’s daily functioning. I recently read that 80% of those over the age of 80 will suffer from some form of dementia, a sobering thought for us all.

Like many diseases, AD is multifactorial. This means that there is not one cause that results in a person suffering from the disease. In the case of AD, there is a combination of factors including genetics and age that can contribute to the onset. There is also a multitude of hypotheses that attempt to explain why people contract the disease.

Generally, however, it is understood that those with AD have an abnormal amount of protein (specifically, amyloid plaques), fibres (tau tangles) and chemicals (acetylcholine) in the brain. The combination of these reduces the effectiveness of healthier neurons and gradually destroys them (hence why AD is called a neurodegenerative disease – it worsens over time). Over progression of the disease, the damage can spread to areas of the brain such as the hippocampus and grey matter, which are responsible for memory and processing thoughts respectively.

Source: http://www.macrobioticshop.co.uk/articles/alzheimer%E2%80%99s-can-be-prevented-david-mccarthy

Currently, there is no cure for the disease. However, through the identification of some mechanisms of the disease, scientists are able to refine their research to cater to this. There are also some FDA approved drugs in order to help relieve symptoms. These drugs are either classed as cholinesterase inhibitors or NMDA receptor antagonists.

A cholinesterase inhibitor works by slowing down the breakdown of acetylcholine (ACh). ACh is a key neurotransmitter (brain chemical) that the breakdown of can result in memory loss and lack of thinking skills. These inhibitors can help those suffering from AD’s brain cells to work better. Although these drugs do not stop the disease entirely, they can help to slow down the degenerative process.

An NMDA receptor antagonist is an anaesthetic that works to inhibit the action of the NMDA receptor (it antagonises its action), which normally release glutamate. In the case of AD, glutamate is a chemical released when brain cells are damaged, and causes them to be damaged further. Therfore by reducing the amount of glutamate released, less damage to neurons will occur. Again, this drug cannot cure AD, but it can help to slow down the process.

Shown through the short list of drugs approved to treat AD it appears that most of the care provided for those with Alzheimer’s is palliative. Charities like Alzheimer's Society work to improve the quality of life for those suffering from AD. 

A comparison of a healthy brain and one of a person suffering from Alzheimer's Disease. 
Source: Wikipedia

Sadly, due to the fact there is no exact cause of AD known, there is no specific way to prevent the disease. However, there are some preventative measures that can help to slow the onset. These include reducing your risk of cardiovascular disease (stopping smoking, exercising, drinking less alcohol etc) and staying “mentally active” (reading, learning language, playing an instrument etc).

This is not to say that researchers are not working around the clock to try find a cure for this terrible disease. Charities like Alzheimer's Research UK conduct pioneering research in the race to find a cure, and there are continually new developments.


The prevalence of AD is such that it is likely to affect all of us, either directly or indirectly.   It is an important exciting time to be part of research into this debilitating disease – I hope to be part of it.

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http://www.sub-titles.net/terry-pratchett-
choosing-to-die-2011-legendas-p1248134
An extremely interesting documentary I watched recently was “Terry Pratchett: Choosing to Die”, exploring the controversial subject of assisted suicide. This is different from euthanasia, as the latter is the killing of another in order to end suffering. Pratchett had recently been diagnosed with Alzheimer’s, and his documentary followed him as he met others choosing to commit assisted suicide after being diagnosed with the same disease. The paradox of this practice is that you must be able to prove you are “of sound mind” in order to be provided with the lethal dose of medication – Pratchett pondered the fact that he did not want to die now, and that when his Alzheimer’s progressed he may feel differently. However, at that point he may not longer be considered of sound mind and so would not be able to die “dignifiedly” as he said. His documentary, although upsetting, is extremely thought provoking. I highly recommend it.

Click Here for a link to Terry Pratchett’s documentary. I must warn you that there is a scene where you see the full process of assisted suicide carried out, and therefore this documentary may not be suitable for all viewers.

If you’d like to learn more about this disease, click here for a link to the Alzheimer’s Society website, and click here for a link to the Alzheimer's Research UK website. 

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