What is Alzheimer’s Disease?
Alzheimer’s disease is the most common form of dementia in the United States. It usually starts with recent memory loss – then progresses to forgetting where you are, familiar faces and names. Eventually, the disease continues to progress and patients develop impaired mobility, difficulty swallowing, and inability to care for themselves. Alzheimer’s disease is a major cause of disability and death in the United States.
What Causes Alzheimer’s Disease?
Alzheimer’s disease is neurodegenerative disorder characterized by a decrease in acetylcholine levels in the brain. This is caused by the build of amyloid plaques and neurofibrillary tangles in the neurons certain brain regions. These likely develop as a result of genetic and environmental factors. Genes such as apolipoprotein E-e4 (APOE-e4) have been identified as a risk factor. Abnormalities in genes coding the following proteins are also associated with increased risk:
- Amyloid precursor protein (APP)
- Presenilin-1 (PS-1)
- Presenilin-2 (PS-2)
The most common risk factors for Alzheimer’s disease include:
- Family history
- Certain genetic mutations
- Advanced age
- Traumatic brain injury
How Common is Alzheimer’s Disease?
Alzheimer’s disease is the most common cause of dementia. It is frequently evaluated and managed in primary care clinic. This disease frequently requires referral to a specialist in geriatrics or neurology.
After age 65, the risk of developing Alzheimer’s disease doubles every 5 years. This is noteworthy as the American population continues to age - especially with the “baby boomer” generation. There are estimates that Americans age 65 and older will grow from 13% of the population today to approximately 20% in 2030. Individuals older than age 85 are the quickest growing age group and have a tremendously high prevalence of disease.
Signs and Symptoms
The most common symptom of include:
- Memory loss
- Loss of time and space perception
- Impaired language
- Impaired cognition
- Changes in behavior
- Intellectual dysfunction – inability to plan or judge appropriately
- Impaired mobility
Patients usually become dependent on others due to inability to feed, prepare food, bathe, dress, or brush one’s teeth. Patients eventually develop issues with swallowing and often die of pneumonia – lung infection.
Your doctor will often evaluate for certain findings on your physical examination. They will usually test your memory with a mini-mental status examination or Montreal Cognitive Assessment (MoCA).
Alzheimer’s disease is diagnosed based on symptoms, physical examination findings, and laboratory tests to exclude other conditions.
Alzheimer’s disease is a form of dementia. When you have symptoms such as memory loss - your doctor will first screen you with a memory test called the mini-mental status examination (MMSE) or Montreal Cognitive Assessment (MoCA). This typically involves recalling the time and where you are, drawing objects, recognizing objects, repeating words, and remembering words. If your score does not meet a certain cut-off value, this is highly suggestive of dementia.
Individuals who screen positive for dementia are typically referred for formal neuropsychological testing. They also typically receive a brain MRI to rule out other causes of memory loss such as stroke and brain tumor.
Dementia generally falls into 2 categories: reversible dementia and irreversible dementia. Common types of reversible dementia include:
- Thyroid disease
- Vitamin B12 deficiency
- Alcohol abuse
- Infectious (HIV, syphilis)
- Wilson disease
- Medication side effect
Your doctor will typically perform a detailed medication review and order blood tests to rule out these forms of dementia. Your doctor will also likely order blood tests such as a CMP (comprehensive metabolic panel), CBC (complete blood cell count), and check your cholesterol levels and screen for diabetes.
Alzheimer’s Disease Medication and Treatment
The treatment of Alzheimer’s disease is first to address whether there is a reversible cause of dementia. If there are any of the aforementioned diseases present - vitamin B12 deficiency, abnormal thyroid function, syphilis or HIV, Wilson disease – these should be treated. Your doctor will also typically discontinue any medications that can worsen or exacerbate symptoms of dementia such as anticholinergics (e.g., tricyclic antidepressants), antihistamines (e.g., Benadryl), and benzodiazepines, (e.g., Ativan, Valium).
Besides treating reversible types of dementia and discontinuing certain medications, studies have shown that exercise increases the production of nerve cells in the temporal lobe – this in turn leads to improved memory.
There are certain medications that have shown to have a modest benefit in improving memory and quality of life in individuals with mild to moderate Alzheimer’s disease. The most commonly prescribed drugs include:
These medications generally work by increasing acetylcholine levels in the brain. Remember that Alzheimer’s disease is associated with low levels of acetylcholine in certain brain regions, which contributes to symptoms such as memory loss.
- Lawler E, Avila A. Alzheimer’s Disease: Monotherapy vs. Combination Therapy. Am Fam Physician. 2017 Apr 1;95(7):452. - https://www.aafp.org/afp/2017/0401/p452.html
- Pierce AL, Bullain SS, Kawas CH. Late-Onset Alzheimer’s Disease. Neurol Clin. 2017 May;35(2):283-293. - https://www.ncbi.nlm.nih.gov/pubmed/28410660
The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.