One of the most frequently asked questions on OurAlzheimer’s is, do I have Alzheimer’s or is my memory loss just a sign that I am getting old? It is true that historically we used to associate memory loss and changes in thinking as a natural part of aging. Now we know better and we know Alzheimer’s disease is not a normal part of aging, if it were, then every person over 65 years of age would have Alzheimer’s
Differences Between the Normal Brain and the Alzheimer’s Brain
To understand how normal aging differs from Alzheimer’s we have to take a quick look at what a normal brain is like and compare that to a brain affected by Alzheimer’s disease.
The brain is a very complex structure basically made up of white and gray matter. It weighs between 1500 and 2000 grams in adults. The white matter consists of fibers that connect neurones (nerve cells) in different parts of the brain to one another and allows rapid communication between distant structures. Gray matter is composed of neurones that communicate with each other by releasing a number of different chemical transmitters onto and between other neurons. Neurotransmitters (including acetylcholine, glutamate, dopamine, serotonin and noradrenaline) are involved in the regulation of memory, mood, appetite, sleep and behavior. As Alzheimer’s disease destroys brain cells and the neurotransmitters are disrupted it becomes easy to see how their regulation is affected.
Differences between Normal and Alzheimer’s Brain Tissue
The brain in Alzheimer’s disease looks different, as we can see in this image Visually the cerebral cortex can be seen to have become atrophied (shrunken) and there is huge loss of grey matter. The cerebral cortex is the outer surface of the brain and is responsible for all intellectual functioning. Fluid filled areas of the brain called the ventricles become dilated.
Microscopic Changes Between Normal and Alzheimer’s Brain
Microscopically there are two major findings in the brain. In the Alzheimer’s brain are amyloid plaques and neurofibrillary tangles. Amyloid plaques are found outside the neurons, neurofibrillary plaques are found inside them. Although plaques and tangles are found in the brains of people without Alzheimer’s, it is the quantity of them that is significant in Alzheimer’s disease.
Other Differences Between Alzheimer’s and Normal Age-Related Memory Loss
Unlike normal age related memory loss people with Alzheimer’s find themselves unable to carry out the ordinary events of daily functioning and become unable to live independently. Here are the main differences between normal age-related memory loss and Alzheimer’s disease:
- In normal age-related memory loss, a person can usually follow verbal and written instructions without difficulty. As Alzheimer’s disease progresses people are increasingly unable to do so.
- In normal age-related memory loss, people can manage their own personal care. They are able to plan what they want to do then carry out their care (called executive functioning). However in people with Alzheimer’s disease they lose this ability.
- In normal age-related memory loss, someone might forget a word or part of an event. However given time they eventually do remember. People with mid late stage Alzheimer’s disease do not.
- In normal age-related memory loss using reminders is often helpful, but people with Alzheimer’s gradually become increasingly less able to benefit from memory aids. This is because the brain damage caused by Alzheimer’s is progressive and the damage just gets worse and worse