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Dementia subtypes defined

Recently at one of my community education sessions, a person was telling me why she decided to attend the talk on dementia.
10936311_web1_Genesh

Recently at one of my community education sessions, a person was telling me why she decided to attend the talk on dementia.

“My mother has been diagnosed with Alzheimer’s disease, and I want to know more about this disease before she progresses to dementia”. She is one among the many Albertans who are confused between Alzheimer’s disease and dementia.

Dementia

Dementia is a degenerative condition affecting the brain that leads to progressive loss of recent memory, difficulties with decision-making, communication difficulties, and changes in personality, mood and behaviour. With more than 50 different causes of dementia, people have a number of misconceptions about what dementia is, and what is not.

Alzheimer’s disease

Alzheimer’s disease is the most common cause of dementia. It is characterized by abnormal collections of beta amyloid protein and twisted fibres of tau protein constituting the hallmark features of plaques and tangles. These changes affect the normal communication between the brain cells leading to their destruction. 95% of Alzheimer’s disease occurs in older adults over the age of 65 years.

Vascular dementia

Vascular dementia is another common type of dementia that occurs when the blood flow to a particular part of the brain is blocked. This can either be the result of a single stroke that has affected a large part of the brain, or a series of mini-strokes affecting smaller areas of the brain.

Mixed dementia

When two or more forms of dementia are present at the same time, this is referred to as mixed dementia. Although the most common combination is vascular dementia and Alzheimer’s disease, this term refers to any combination of dementia types.

Mild Cognitive Impairment

Difficulty in thinking and reasoning, and changes in alertness that varies from day to day or at different times of the day, are some of the main hallmarks of Lewy Body Dementias (LBD).

This type of dementia is caused by abnormal deposits of alpha synuclein protein in different parts of the brain, which were first identified by Dr. Frederich Lewy and were called Lewy Bodies.

Besides the marked fluctuation in cognition, other symptoms of LBD are visual hallucinations — seeing things that are not there, and features of Parkinson’s Disease which includes slow, sluggish movements or difficulty walking. Dementia with Lewy Body and Parkinson’s Disease dementia are different presentations of LBD.

Frontotemporal lobe dementia

(FTLD) results from progressive damage to the frontal and temporal lobes of the brain, which are located in the front and sides of the brain respectively. The main symptoms of FTLD include personality changes, lack of initiative, decision-making difficulty, loss of inhibitions leading to inappropriate behaviour, and language difficulties. FTLD is commonly seen in people between the ages of 40-70 years.

Young-onset dementia

Young-onset dementia (YOD) refers to dementia occurring in people under the age of 65. According to Alzheimer Society of Canada approximately 16,000 Canadians are currently living with YOD. There are a variety of causes for YOD, including the inherited form of Alzheimer’s disease, stroke, FTLD, or damage due to alcohol or a traumatic brain injury.

Mild Cognitive Impairment

Mild Cognitive Impairment (MCI) includes a mild yet noticeable and measurable decline in a person’s memory and thinking skills. The person could be forgetting important things that they were initially able to recall easily, or they might have difficulty making decisions or completing the steps of a complex task. About 15% of individuals diagnosed with MCI progress to Alzheimer’s disease in a year, the others may remain stable or recover their original level of cognition.

As we age, we are likely to experience minor lapses in memory, confusion, mood changes and so on. Most of the time, these changes are not serious enough to interfere with daily life. But if these lapses become more frequent, it is a good idea to discuss with your physician and take the necessary action promptly.

Padmaja Genesh, who holds a bachelor degree in medicine and surgery as well as a bachelor degree in Gerontology, has spent several years teaching and working with health care agencies. Please send your comments to padmajaganeshy@yahoo.ca