The Not-So-Obvious Facts About Alzheimer's Disease

Alzheimer's is a very sad and devastating disease for both the patient and their loved ones. There have been many advances made in the research of the disease and many similarities discovered in the appearance of the brain of Alzheimer's patients. Unfortunately, there is no one known cause of Alzheimer's, but researchers know that nerve cells in the brain become inhibited and eventually die out along with the surrounding tissue causing the brain to shrink significantly in size.

Normally, nerve cells fire impulses that release neurotransmitters that carry the impulses to other nerve cells. Alzheimer's inhibits the impulses from being carried through the nerves and being shared with other nerve cells. Researchers believe that the presence of plaques (abnormal clusters of protein fragments) and tangles (twisted strands of the protein tau), which build up over time normally, but significantly more in Alzheimer's patients, are the main culprit in preventing the normal activity of nerve cells and neurotransmitters. It has been shown that plaques and tangles usually begin in the hippocampus area of the brain, which affects new memory formation, evident by the significant shrinkage of this area.

Stages

Alzheimer's can develop in the patient up to 20 years before the initial signs are shown, but by the time a patient is diagnosed, the decline before death usually progresses within four to six years.

According to the Alzheimer's Association, there are seven stages of the disease:

Stage 1: The patient functions normally.
Stage 2: There begins to be some memory loss, but it is not evident to family or friends.
Stage 3: Family and friends begin to notice a change in their loved one.
Stage 4: Patient has declined enough to warrant medical observation, which clearly shows deficiencies.
Stage 5: There is a severe cognitive decline, which begins to affect memory of important things such as address or the day of the week.
Stage 6: More declining effects include incontinence, forgetting the name of spouse, delusions, hallucinations, and wandering.
Stage 7: The final stage shows a decline to where the patient cannot walk, sit, or eat on their own, or speak, or swallow.

Death occurs usually during stage 7, but not directly from Alzheimer's. At this stage, because of decreased physical activity and the inability to swallow, patients will usually develop various types of infections including pneumonia.

Risk Factors

Increasing age is the single greatest risk factor of Alzheimer's. After age 65, the likelihood that someone will develop the disease doubles every five years and after age 85, the likelihood is at 50 percent. But, after age 95, the probability of the disease developing significantly decreases.

Family history and genetics play a role in the risk of developing Alzheimer's. Having a family member who suffered from the disease can indicate that your risk is greater than most, especially if there is more than one relative with the disease. One reason for this is a gene called apolipoprotein-E-e4 (APOE-e4). Everyone receives a copy of the gene apolipoprotein from each parent. If a person receives APOE in the -e4 form from only one parent, they will have an increased risk and an even greater risk if they receive an -e4 form from each parent, but this does not ensure that the person will develop Alzheimer's.

There is also a deterministic gene called "familial Alzheimer's disease", which affects only a handful of families worldwide and is a direct cause of Alzheimer's.

There is no real way to prevent or determine if someone will get Alzheimer's, but researchers believe that by maintaining good health; eating right, exercising, and staying physically and mentally active, there is a possibility that it may decrease the chance of developing the disease or at least, delaying it.

Sources:

Alzheimer's Association (2009). Interactive Brain Tour, Retrieved from http://www.alz.org/brain/09.asp, http://www.alz.org/alzheimers_disease_stages_of_alzheimers.asp

MedicineNet.com (2009). Alzheimer's Disease Causes, Symptoms, Diagnosis, and Treatment, Retrieved from http://www.medicinenet.com/alzheimers_disease/page7.htm