Understanding dementia
Dementia is a shorthand word that is used to describe the changes that happen when someone has cognitive decline. It’s only called dementia if it continues over a long period of time and never gets better.
Mild Cognitive Impairment is the expression that describes a temporary change, or a reduction in cognition that does not continue, but stays stable at the new slightly reduced level. If the mild impairment continues to get worse and doesn’t get better, that’s described as dementia.
“Alzheimers has become a shorthand expression or alternative word for dementia. That’s not always helpful.”
People often ask me about the difference between what’s called Alzheimers and “dementia”. Alzheimers disease is one of many diseases of the brain that can cause dementia symptoms. In lay terms, for example in a newspaper or in family communications, it might often be said that someone “has Alzheimers” although no one knows if that is the specific disease. So Alzheimers has become a shorthand expression or alternative word for dementia. That’s not always helpful.
Technically, “Alzheimers disease” has a very specific meaning, related to the way in which the pathological changes in the brain are taking place. Physical changes include the presence of proteins that clump together between the nerve cells of the brain and form sticky pieces called amyloid plaques, and there is an immune reaction that causes inflammation. But even within the diagnosis of Alzheimer’s disease that there are variations, such as early onset (where the person may be of working age) or familial (where it is a genetic variation and it is passed on) and late onset (where the person is very old) that can be subdivided into different gene variants.
All these variants have led neurologists to start to use the term “progressive cognitive neurodegeneration” as the expression of these diseases, rather than the more general term dementia. This degeneration is a breakdown of neural pathways related to thinking, and it continues to get worse. They are interested to know which specific part of the brain is most affected, and to know which sort of pathology is causing it. From the point of view of someone affected, they want to know if there is a cure, or if there is anything they can do to slow it or make life easier in the meantime. Others may want to know how it can be avoided. The picture is complex, and understanding as much as possible is the key to making the best of a tragic situation.
