by Rosalyn Carson-DeWitt, MD
Dementia is the progressive loss of memory and various other mental functions, including the ability to learn, reason, and judge. This loss of mental functioning impairs the patient's social functioning, and most people with dementia are eventually unable to care for themselves.
Areas of the Brain Affected by Dementia
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Alzheimer's disease is the most common cause of dementia. Other causes of dementia include:
- Brain damage after multiple small strokes (so-called, vascular dementia)
- Multiple sclerosis
- Huntington's disease
- Parkinson's disease
- Creutzfeldt-Jacob disease
- Lewy body disease
- Pick's disease
- Normal pressure hydrocephalus
- Untreated syphilis
- Toxic levels of aluminum (as can sometimes occur in dialysis patients)
- Vitamin B12 deficiency
A risk factor is something that increases your chance of getting a disease or condition.
Risk factors for dementia include:
- Advancing age
- Family members with dementing illness
- Down syndrome
- Apolipoprotein E status (a genetic risk)
- Elevated cholesterol
- Multiple strokes
Symptoms of dementia generally come on gradually. They often begin mildly and progress over time. Symptoms vary according to the cause of the dementia, but often include:
- Increasing trouble remembering things, such as:
- How to get to familiar locations
- The names of friends, family members
- Where common objects are usually kept
- Simple math
- How to perform usual tasks, such as cooking, dressing, bathing, etc.
- How to drive
- Bill paying
- Trouble concentrating on tasks
- Trouble completing sentences, due to lost/forgotten words (This may progress to complete inability to speak.)
- Inability to remember the date, time of day, season
- Getting lost in familiar surroundings
- Mood swings
- Withdrawal, loss of interest in usual activities
- Personality changes
- Slow, shuffling walk
- Poor coordination
- Slowness and then loss of purposeful movement
Doctors diagnose dementia by:
- Taking an extensive history from the patient and his or her family
- Closely observing the patient
- Performing a physical exam
- Performing mental status and psychological tests
There are no blood tests or imaging studies to diagnose Alzheimer's disease, which is the most common cause of dementia. Tests to rule out other causes of dementia and other medical conditions that may mimic dementia include:
- Blood tests for syphilis, vitamin B12, thyroid, liver, and kidney function
- CT or MRI scans of the head - tests that use a computer (CT scan) or magnetic waves (MRI scan) to create detailed images of structures inside the body, in this case the head
- Lumbar puncture - collecting a sample of cerebrospinal fluid by inserting a needle between two vertebrae (rarely needed)
- Electroencephalogram (EEG) - a test that records the brain's activity by measuring electrical signals from the brain
Doctors must take care not to miss the diagnosis of depression, which often presents like dementia. Unlike dementia, however, depression is highly treatable.
Currently there are no treatments to cure Alzheimer's disease or many other types of dementia. Researchers are studying various drugs to see if they can improve the symptoms of dementia or slow its course.
Medications being used or studied for possible use include:
- Cholinesterase inhibitors
- NMDA receptor antagonists
- Antioxidants ( vitamin E and others)
- Anti-inflammatory agents
- Gingko biloba (herbal supplement)
Only two types of medications have been approved by the US Food and Drug Administration (FDA) to reduce the symptoms of Alzheimer's disease: cholinesterase inhibitors and more recently, an NMDA receptor antagonist.
Cholinesterase inhibitors - approved and recommended for mild-moderate Alzheimer's disease:
- Donepezil (Aricept)
- Rivastigmine (Exelon)
- Galantamine (Reminyl)
NMDA receptor antagonist - approved for moderate to severe Alzheimer's disease:
- Memantine (Namenda)
These medications have a modest effect, at best, on the progression of the disease.
Since medications cannot be relied upon for dramatic results, behavioral and environmental support is crucial in the management of dementia. These steps include:
- Keeping the patient safe in their home or other place of residence
- Providing a calm, quiet, predictable environment
- Providing appropriate eyewear and hearing aids, easy-to-read clocks, and calendars
- Playing quiet music
- Encouraging light exercise to reduce agitation and relieve depression
- Discussing healthcare wishes with family members and doctors, and appointing a healthcare proxy
People with dementia often develop psychiatric symptoms. If these symptoms become severe, medication may be needed, such as:
- Anxiolytics - to treat anxiety
- Antipsychotics - to treat severe confusion, paranoia, and/or hallucinations
Caring for a person with dementia is extremely difficult and exhausting. Primary caregivers (usually spouses or daughters) need emotional support, as well as regular respite.
There is no known way to prevent Alzheimer's disease. A healthful diet will prevent vitamin B12 deficiency and lower cholesterol. A healthful diet and exercise can also enhance cardiovascular health, which may delay the onset of vascular dementia. Limiting alcohol intake can prevent dementia from alcoholism, and avoiding drug abuse and practicing safe sex reduces the risk of AIDS-related dementia. There is also some evidence that engaging in mentally stimulating activity over a lifetime may also reduce the risk of Alzheimer's disease.
American Academy of Neurology
American Psychiatric Association
American Academy of Neurology website. Available at www.aan.com
The American Psychiatric Association's Practice Guideline for the Treatment of Patients With Alzheimer's Disease and Other Dementias of Late Life . American Psychiatric Association; 1997.
Cecil Textbook of Medicine . 21st ed. WB Saunders Company; 2000.
Current Medical Diagnosis & Treatment . 44th ed; 2005.
Kaduszkiewicz H, Zimmermann T, Beck-Bornholdt HP, van den Bussche H. Cholinesterase inhibitors for patients with Alzheimer's disease: systematic review of randomised clinical trials. BMJ . 2005;331(7512):321-327.
Mayo Foundation for Medical Education and Research website. Available at www.mayo.edu
The Merck Manual of Geriatrics . 3rd ed. Merck & Co. Inc.; 1995-2000.