The word dementia means deprived of mind. It
is a catchall term that covers memory loss, confusion, changes in
personality, a decline in thinking skills, and dwindling ability to
perform everyday activities.
There are many types of dementia.
Alzheimer's disease is the most common. Half or more of people with
dementia have Alzheimer's disease. It is caused by the accumulation of
tangles and clumps of protein in and around brain cells. These tangles
and clumps make it difficult for brain cells to communicate with one
another, and can eventually kill them.
Vascular dementia, the second most common
type, develops when cholesterol-clogged arteries can't deliver enough
oxygen-rich blood to the brain. Sometimes small blockages completely
cut off the blood supply to a part of the brain, causing nearby brain
cells to die.
The terms dementia and Alzheimer's are
often used interchangeably. In part, that's because it is very hard to
tell them apart. Usually, a specific type of dementia can only be
diagnosed by an autopsy after someone has died.
Dementia affects areas of the brain
involved in learning and memory. So a common symptom is difficulty in
recalling new information. Memory loss disrupts daily life. An
individual with dementia may get lost in a once-familiar neighborhood.
He or she may have increasing trouble making decisions, solving
problems, or making good judgments. Mood and personality may change. A
person with dementia can become more irritable or hostile, or lose
interest in almost everything.
Once dementia has developed, it is usually
hard to reverse. The goal of treatment is to manage symptoms and slow
its progression. Some medications can help slow the intellectual
decline in mild to moderate dementia. Psychotherapy techniques like
reality orientation and memory retraining can also help people with
A small percentage of people with dementia develop the condition because of medical issues such as an underactive thyroid gland, an infection, not getting enough vitamin B12, medication side effects, or drinking too much alcohol. In these cases, treating the underlying cause can reverse the dementia.
The below article is taken from Harvard medical site: