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About Alzheimer's & Dementia

Types of dementia Alzheimer's Disease

What is Alzheimer’s disease?

“Dementia” refers to progressive general decline in mental abilities that is sufficiently severe to interfere with daily living and could be caused by numerous conditions or diseases. Alzheimer ’s disease is the most common cause of dementia. Alzheimer’s disease is a physical, progressive and degenerative disease of the brain characterized by memory loss, communication difficulties, disorientation regarding time and place, visuo-spatial challenges, and changes in personality and behaviour. Each of these symptoms affects a person’s ability to function independently.

It is caused by the development of plaques and tangles in the brain. While the plaques affects the ability of the nerve cells to communicate with each other, the tangles lead to collapse of a vital transport system inside the cell, which ultimately causes the nerve cells to die. In addition to the loss of connections between cells, there is a decrease in the level of neurotransmitters that help transmit messages from one cell to the other. The affected parts of the brain may shrink as a result.
 
·         Plaques – abnormal collection of Beta amyloid protein in the spaces between the neurons (nerve cells )
·         Tangles - twisted strands of Tau protein that collect inside the nerve cells.
 
The hippocampus is the first region in the brain to be affected in Alzheimer’s disease. It is  primarily involved with learning and memory, which is often why a person’s frequent loss of memory about recent events is the first noticeable symptom.
 
Symptoms of Alzheimer’s disease and the course of its progression can vary greatly from one person to another, depending on the parts of the brain affected and the rate of progression. The anticipated life expectancy also varies considerably and can range anywhere from 8 to 12 years.

Is it genetic? Can it be passed on to family members?

There are two types of Alzheimer’s disease we know of:
  • Sporadic: This is the most common type of Alzheimer’s disease and constitutes 95% of all diagnosed occurrences. It typically affects people over 65 years of age and is known to progress more slowly. The only proven risk factor for sporadic type Alzheimer’s is advancing age. A genetic component has also been identified and involves the gene for a lipoprotein APOE E4 on chromosome 19. Having one copy of APOEE4 increases the risk of developing late onset Alzheimer’s disease by 2 times, whereas having 2 copies of APOE4 increases the risk by 3-5 times. About 25% of individuals in the community have one copy of APOEE4 and about 2% have 2 copies of this gene.
  •  Familial: This refers to Alzheimer’s disease that is passed down through generations by family members and makes up only 5% of all cases of Alzheimer’s disease. In these cases, the age of onset can occur before 65 years, is considered “young onset” and generally known to progress more rapidly. The familial Alzheimer’s disease is attributed to mutations in 3 chromosomes, namely Chromosome 21 (coding for Amyloid Precursor Protein). Chromosome 14 (coding for Presenilin 1), and Chromosome 1 (coding for Presenilin 2). Of these the Presenilin 1 gene on Chromosome 14 has been implicated in 80% of cases of familial Alzheimer’s Disease.

What changes can I expect?

Unfortunately, symptoms and changes associated with Alzheimer’s disease will progress and grow more noticeable over time. These changes could take place rapidly or slowly, depending on the individual case. The person may need assistance with activities such as preparing meals, banking, transportation, managing a household and taking care of finances. In later stages, assistance may be needed for daily living including feeding, personal hygiene, grooming, dressing and bathing.
 
You may also notice behaviour changes. These can include anxiety, depression, or frustration in the early stages to hallucinations, delusions, hoarding, suspicions about family or professional care partners, apathy and sometimes aggression. In the later stages, the person may experience difficulty with walking, swallowing or recognizing family members. These can prove very challenging for caregivers.

How is it diagnosed?

There is no single test for Alzheimer's disease or any other type of dementia. A diagnosis is usually made by excluding other causes which may present with similar symptoms. The diagnosis is made based on history, physical assessment, blood tests, imaging and cognitive assessment. The physician will first rule out conditions such as infections, vitamin deficiency, thyroid problems and the side-effects of medication.
 
Physicians often conduct initial blood tests and make a referral to a specialist such as a neurologist, a specialist in geriatric medicine or a general psychiatrist or geriatric psychiatrist. The person's memory and thinking skills may be assessed in detail. A brain scan could be scheduled to gather information about the changes taking place in the person's brain. Various scans, including Computerized Tomography (CT), Magnetic Resonance Imaging (MRI) and Positron Emission Tomography (PET) scans may be used.

What kind of treatment is available?

Currently there is no known cure for Alzheimer’s disease but medications are available to help manage or minimize the symptoms of dementia. The medications currently available are Aricept, Exelon, Reminyl, and Ebixa.

 

Unfortunately, these medications do not stop or slow the progression of the disease itself. Aricept, Exelon, and Reminyl  help restore the level of neurotransmitters (acetylcholine) in the brain which enables the cells to function more efficiently. Ebixa helps in reducing the toxicity of glutamate which is produced in the brain when neurons die, by blocking the NMDA receptors through which it acts. 

The first 3 medications are intended for early to moderate disease.  Ebixa is intended for the later stages of the disease and is not covered by Alberta Blue Cross.