Alzheimer’s disease is a form of dementia, but not all dementia is due to Alzheimer’s disease. So, what is the difference?
Dementia is a term physicians use to describe a patient with chronic and progressive loss of cognitive function. A patient with dementia usually has memory loss and in addition must have at least one of the following problems:
- Difficulty with verbal and/or written language
- Impaired abstract reasoning and judgement
- Impaired ability to recognize people and things for what they are
- Impaired ability to perform complex tasks that require a thought process, for example, cooking or dressing.
The cognitive losses must be severe enough to cause impaired daily function in comparison to a person’s previous level of normal daily function, whether a housewife or CEO.
Once the diagnosis of dementia has been made, the next step is to determine the cause so proper treatment can be prescribed.
- In approximately 65% of people with dementia, the cause is Alzheimer’s disease
- In about 20%, the cause is vascular disease of the brain caused by small mini-strokes
- In 10% of dementias, the cause is Lewy body disease, sometimes complicated by Parkinsonism.
- In another 5% of dementias, the cognitive impairment is caused by a pre-existing medical problem that is potentially treatable such as:
- The side effects of prescription and non-prescription medicine
- Certain medical illnesses, such as thyroid disease or pernicious anemia resulting in vitamin B12 deficiency
- Normal pressure hydrocephalus, brain tumors