Monday, June 01, 2015

Alzheimer's Disease: A Death of 1000 Subtractions

Every 4 seconds someone is diagnosed with Alzheimer's Disease; a slow fatal disease of the brain affecting 1 in 10 people over the age of 65. It's the most common cause of dementia affecting over 40 million people worldwide, and yet finding a cure is something that still eludes its researchers today.
Doctor Aloysius Alzheimer, a German psychiatrist first described the symptoms in 1901, when he noticed that a particular hospital patient (Auguste Deter) had some peculiar problems; including difficulty sleeping, disturbed memory, drastic mood changes, and increasing confusion. When the patient passed away, Dr Alzheimer was able to do an autopsy and test his idea that perhaps the symptoms were caused by irregularities in the brain's structure. What he found beneath the microscope were visible differences in brain tissue; in the form of mis-folded proteins called plaques; and neurofibrillary tangles. Those plaques and tangles worked together to break down the brain's structure.
Plaques arise when another protein in the fatty membrane's surrounding nerve cells get sliced up by a particular enzyme, resulting in beta-amyloid proteins, which are 'sticky', and have a tendency to clump together. That clumping is what forms the things we know as plaques. These clumps block signalling and therefore communication between cells; and also seem to trigger immune reactions that cause the destruction of disabled nerve cells.
In Alzheimer's Disease (AD), neurofibrillary tangles are built from a protein known as tau. The brain's nerve cells contain a network of tubes that act like a highway for food molecules - among other substances. Usually, the tau-protein ensures that these tubes are straight, allowing molecules to pass through freely. But in AD, the protein collapses into twisted strands or tangles, making the tubes disintegrate - obstructing nutrients from reaching the nerve cell, and leading to cell death.
The destructive pairing of plaques and tangles starts in a region called the hippocampus - which is responsible for forming memories. This is why short-term memory loss is usually the first symptoms of Alzheimer's Disease. The proteins then progressively invade other parts of the brain, creating unique changes that signal various changes of the disease.

Pronounced neural atrophy in the AD brain
At the front of the brain, the proteins destroy the ability to process logical thoughts. Next, they shift to the region that controls emotions - resulting in erratic mood changes. At the top of the brain, they cause paranoia and hallucinations; and once they reach the brain's rear, the plaques and tangles work together to erase the mind's deepest memories. Eventually, the control centres governing heart rate and breathing are overpowered aswell, resulting in death.
The immensely destructive nature of this disease has inspired many researchers to look for a cure, but currently they're focused on slowing its progression. One temporary treatment helps reduce the breakdown of acetylcholine (ACh) - an important chemical messenger in the brain; which is decreased in Alzheimer's patients due to the death of the nerve cells that make it. Another possible solution is a vaccine that trains the bodies immune system to attack beta-amyloid plaques before they can form clumps.
My own personal interest around Alzheimer's Disease is a mixture of both fascination and abhorrence. It can afflict anyone, and does indeed become the most unwelcome of visitors to many. Alzheimer's disease has been termed ''a demographic time bomb'' (Shenk). Over 35 million people worldwide struggle with Alzheimer’s or some other form of dementia, according to the World Health Organization. Alzheimer's Disease was discovered more than a century ago, and yet it is still not well understood.

The progression from mild forgetting to death is slow and steady, and takes place over an average of 8 to 10 years. No one is immune. It is relentless, devastating for the sufferers and carers; and, for now, incurable.
Jun, I. S. Y. (April, 2014)

Suffering is always hard to quantify - especially when the pain is caused by as cruel a disease as Alzheimer's. Most illnesses attack the body; Alzheimer's destroys the mind - and in the process, annihilates the very self  ~ Jeffrey Kluger