Alzheimer’s disease is a neurodegenerative disease which is characterised by loss of neurons and synapses in the brain, called cerebral atrophy. It affects around 6% of people over the age of 65 and is the leading cause of dementia.
What is the difference between Alzheimer’s and dementia?
Dementia is a general term for age related cognitive decline, whereas Alzheimer’s is a specific neurological condition. Alzheimer’s accounts for 40-60% of all instances of dementia, and is often referred to as Alzheimer’s dementia. Other types of dementia include:
How does Alzheimer’s Disease work?
It isn’t very well understood how Alzheimer’s disease originates, and there are multiple competing theories, but we do know how it affects the brain. There are two main biological markers:
People with Alzheimer’s develop plaques of misfolded proteins in their cortex, as well as some subcortical regions of the brain. These plaques are made of a protein called amyloid beta (Aβ), formed from the breakdown of a larger protein, called amyloid precursor protein. In the Alzheimer’s brain, abnormal levels of this naturally occurring protein clump together to form plaques that collect between neurons and disrupt cell function. Research is ongoing to better understand how, and at what stage of the disease, the various forms of beta-amyloid influence Alzheimer’s.
Neurofibrillary tangles are misfolded “tau” proteins that collect inside neurons. Healthy neurons have support systems called microtubules, which help guide nutrients and molecules from the cell body to outer parts of the neuron, such as the axon and dendrites. In healthy neurons, tau normally binds to and stabilizes microtubules. In Alzheimer’s disease, abnormal chemical changes cause tau to detach from microtubules and stick to other tau molecules, forming tangles inside neurons. These tangles block the microtubules from transporting molecules along the neuron, which harms the communication between neurons.
What’s the result?
Both the Aβ plaques and the neurofibrillary tangles disrupt communication between neurons. If neurons can’t communicate between each other, programmed cell death takes place, in which the neuron’s will deem themselves not useful and die off. This causes cerebral atrophy which means reduction of brain matter.
A second issue that arises from these abnormalities includes constriction of cerebral blood flow (CBF). This can be caused by Aβ plaques blocking arteries, atherosclerosis (hardening of arteries) and increased risk of stroke. People with Alzheimer’s typically have around 20% lower volumes of blood in the brain than those with healthy brains. Restriction of blood flow around the brain means that vital molecules like oxygen and various nutrients are not as effectively distributed.
Finally, people with Alzheimer’s often experience chronic inflammation of the brain. This is likely due to the buildup of glial cells which are trying to repair the damage done by the Aβ plaques and neurofibrillary tangles. Among other roles, glial cells support brain health by destroying pathogens and removing dead neurons. The sudden increase in dead neurons (from the programmed cell death) mean that glial cells intended to remove them build up and cause inflammation in the brain, a side effect which can cause further damage.
What can be done to stop this?
There is currently no cure for Alzheimer’s, but there are treatments available in the UK .to ease symptoms and either slow, pause, or temporarily improve cognitive decline.
Available medicines include acetylcholinesterase inhibitors, which reduce breakdown of acetylcholine in the brain. Acetylcholine helps neurons communicate with each other. Another medicine called memantine is often used to block excessive amounts of an excitatory neurotransmitter called glutamate.
Therapies including cognitive stimulation and rehabilitation are used to stimulate the brain through giving the patient problem solving tasks, recalling memories, and other tasks which involve using areas of their brain that may be damaged by Alzheimer’s. Studies suggest that regular cognitive stimulation has a beneficial effect on the memory and thinking test scores of people with Alzheimer’s, though it doesn’t affect their mood or ability to function independently.
TPS can be used in conjunction with all three of the previously mentioned treatments, and will not jeopardise their effectiveness. Current research suggests TPS may have a positive effect on some symptoms of Alzheimer’s. Alzheimer’s Clinics is currently the only clinic in the UK which provides TPS®. You can find out more about how it works, whether you or someone else may meet the eligibility requirements, or contact one of our TPS® experts through the details below to book a consultation.