“Thank goodness it’s just dementia” says a recently-diagnosed women. “I was afraid it was Alzheimer’s.”
“Why are these people from Alzheimers visiting me when I have frontotemporal dementia?” complains the ex-boxer.
These are a couple of examples of the confusion the public suffers when thinking about dementia and Alzheimer’s disease. What are these conditions?
“Dementia” is an umbrella term for all people who have progressive cognitive decline, that is, for those whose memory and other thinking skills are gradually deteriorating. Actually, even the term “dementia” is out of date: the American Psychological Association (APA) now calls dementia “Neurocognitive Impairment” (major and minor) to more accurately reflect conditions where a person’s thinking ability is affected – to a greater or lesser extent. However, it seems unlikely that the heavy, medical term, Neurocognitive Impairment, will readily catch on with the public!
Dementia, is a term, like “heart failure” or “arthritis” that describes damage to the affected organ for a variety of reasons. Just as your heart can be damaged by blood vessel blockage, alcohol or a virus and your joints could be a problem because of (among other things) osteoarthritis, gout or infection, your brain can deteriorate because of many different diseases and degenerative processes.
The most common cause of progressive brain damage, aka “dementia”, is Alzheimer’s disease; about 60% of all dementia is caused by Alzheimer’s disease. (The frequency is an approximation because we cannot always be sure of the exact reason that dementia develops.)The next most common cause is Vascular Dementia, the result of poor blood supply to the brain. This is due to atherosclerosis, the hardening and narrowing of blood vessels to the brain, or blood clots from outside the brain lodging in blood vessels. Either way, the supply of oxygen and nutrients is cut off to parts of the brain and the cells die. Not uncommonly, Vascular Dementia and Alzheimer’s are both present giving “Mixed Dementia”. Then there is Lewy Body Dementia (around 15% of all cases), a condition that produces Parkinson’s-like symptoms as well as cognitive difficulties and frontotemporal dementia (about 10%) that affects the frontal and temporal lobes of the brain and often occurs in younger people.
In total there are about seventy different forms of dementia. It is useful to know what form of dementia is affecting you (though differentiating them is still an imperfect art). Knowing the type of dementia may help to anticipate the progression of the disorder or where to focus treatment.
For example, Alzheimer’s disease has a fairly predictable course where the person loses skills gradually in the reverse order that they gained them as a child and young adult. People with Alzheimer’s disease usually lose insight early on, that is, they soon fail to recognise that they have a problem and this can helpfully reduce anxiety. As well, they tend to keep their social skills, so they can remain involved for a long time in their usual activities. An artist I met continued to fit in easily with her eccentric, creative friends well into the later stages of Alzheimer’s disease.
On the other hand, the progression of Vascular Dementia is erratic, depending on which areas of the brain are starved of blood. In this condition, people are often painfully aware that things are not right and this can lead, unsurprisingly, to depression and anxiety. However, there are things to be done to prevent further vascular damage, so it is worth making the diagnosis.
In Lewy Body Dementia, some treatments can help and some are dangerous. Knowing someone has frontotemporal dementia helps to understand their behaviour. So it is worth making a diagnosis in both situations.
The lady relieved to not have Alzheimer’s is reacting to the stigma of that name. In fact, her own condition could have a worse outlook than Alzheimer’s disease. The man with frontotemporal dementia might associate the word “Alzheimers” with little old ladies and cannot apply it to himself. It is less confusing and probably less stigmatising to call dementia by its overarching name and recognise that Alzheimer’s disease is but one of many conditions that cause cognitive decline.
Originally published in Mind Matters, the newsletter of Dementia Auckland.
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