Week 4: Among the causes of dementia, which is the most common and how does it present?

Alzheimer's disease is the most common cause of dementia, accounting for 60 to 80 percent of dementia cases. The majority of people with Alzheimer's are aged 65 and older. Up to 5 percent of people with this disease have early onset Alzheimer's (also known as younger-onset), which often appears when someone is in their 40s or 50s.

Alzheimer's worsens over time. Dementia symptoms gradually worsen over years. The most common early symptom of Alzheimer's is difficulty remembering newly learned information, because Alzheimer's changes typically begin in the part of the brain that affects learning. As Alzheimer's advances through the brain and leads to increasingly severe symptoms, including disorientation, mood, and behavior changes; deepening confusion about events, time, and place; unfounded suspicions about family, friends, and professional caregivers; more serious memory loss and behavior changes; and difficulty speaking. Eventually even walking and swallowing problems can develop.

People with memory loss or Alzheimer’s may find it hard to recognize that they have a problem. Signs of dementia may be more obvious to family members or friends. Patients with Alzheimer's live an average of eight years after their symptoms become noticeable to others, but survival can range from four to 20 years, depending on age and other health conditions.

Alzheimer's and the Brain:

Microscopic changes in the brain begin long before the first signs of memory loss.

The brain has 100 billion nerve cells (neurons). Each nerve cell connects with many others to form communication networks. Groups of nerve cells have special jobs. Some are involved in thinking, learning, and remembering. Others help us see, hear, and smell.

To do their work, brain cells operate like tiny factories. They receive supplies, generate energy, construct equipment, and get rid of waste. Cells also process and store information, and communicate with other cells. Keeping everything running requires coordination, as well as large amounts of fuel and oxygen.

Scientists believe Alzheimer's disease prevents parts of a cell's factory from running well. They are not sure where the trouble starts. But just like a real factory, backups and breakdowns in one system cause problems in other areas. As damage spreads, cells lose their ability to do their jobs and eventually die, causing irreversible changes in the brain.

The characteristic pathology of Alzheimer’s disease, “plaques and tangles” are the prime suspects in damaging nerve cells, and tend to spread through the cortex as the disease progresses.

Plaques are deposits of a protein fragment called beta-amyloid (BAY-tuh AM-uh-loyd) that builds up in the spaces between nerve cells.

Tangles are twisted fibers of another protein called tau (rhymes with “wow”) that builds up inside cells.

Although most people develop some plaques and tangles as they age, those with Alzheimer's tend to develop far more. They also tend to develop them in a predictable pattern, beginning in areas important for memory before spreading to other regions.

Scientists do not know exactly what role plaques and tangles play in Alzheimer's disease. Most experts believe they somehow play a critical role in blocking communication among nerve cells and disrupting processes that cells need to survive. It is the destruction and death of nerve cells that causes memory failure, personality changes, problems carrying out daily activities, and other symptoms of Alzheimer's disease.

Alzheimer's has no current cure at the moment, but treatments for symptoms are available and research continues. Although current treatments cannot stop Alzheimer's from progressing, they can temporarily slow the worsening of dementia symptoms and improve quality of life for those with Alzheimer's and their caregivers. Today, there is a worldwide effort under way to find better ways to treat the disease, delay its onset, and prevent it from developing.  

For more details, please refer to the Alzheimer’s Association:

www.alz.org/alzheimers_disease_what_is_alzheimers.asp

Week 3: What are the causes of dementia?

Many diseases can cause dementia, including Alzheimer's disease, vascular dementia, Lewy Body disease, head trauma, frontotemporal dementia, Creutzfeldt-Jakob disease, Parkinson’s disease, and Huntington’s disease. These conditions can have similar and overlapping symptoms. In spite of these similarities, the cause of the dementia may have effects on the treatment and outcome of the illness. It is therefore always important to ensure your physician has investigated the possible causes of the dementia. 

Alzheimer's Disease

A slowly progressive brain disease that begins well before symptoms emerge, due to deposits of the protein fragment beta-amyloid (plaques) and twisted strands of the protein tau (tangles), as well as evidence of nerve cell damage and death in the brain. 

Vascular Dementia

Vascular dementia was previously known as multi-infarct or post-stroke dementia. It occurs from cerebrovascular disease which can include blood vessel blockage or damage leading to infarcts (strokes) or bleeding in the brain. The location, number, and size of the brain injury determine how the individual's thinking and physical functioning are affected.  

Dementia with Lewy Bodies

Lewy bodies are abnormal aggregations or clumps of the protein alpha-synuclein. When they develop in a part of the brain called the cortex, dementia can result. Alpha-synuclein also aggregates in the brains of people with Parkinson's disease, but these aggregates may appear in a pattern that is different from dementia with Lewy bodies. 

Mixed Dementia

In mixed dementia, abnormalities linked to more than one cause of dementia occur simultaneously in the brain. The most common type of mixed dementia is Alzheimer’s disease and cerebrovascular disease.  

Parkinson's Disease Dementia

Best known for the movement problems it causes, Parkinson’s disease can also be associated with a specific type of dementia. Alpha-synuclein clumps are likely to begin in an area deep in the brain called the substantia nigra. These clumps are thought to cause degeneration of the nerve cells that produce dopamine. 

Frontotemporal Dementia

Frontotemporal dementia includes a variety of different dementia syndromes such as behavioral variant, primary progressive aphasia, Pick's disease, corticobasal degeneration and progressive supranuclear palsy. Many different microscopic abnormalities are linked to the various cases. 

Creutzfeldt-Jakob disease (CJD)

CJD is the most common human form of a group of rare, fatal brain disorders affecting people and other mammals. Variant CJD (“mad cow disease”) occurs in cattle, and has been transmitted to people under certain circumstances. The disease which can arise spontaneously, be inherited, or result for infection is caused by misfolded proteins called prions. 

Normal Pressure Hydrocephalus

Caused by the abnormal buildup of fluid in the brain. It causes the characteristic features of dementia, gait disturbance and urinary incontinence. It is potentially treatable with surgery.

Huntington's Disease

A progressive brain disorder caused by a single defective gene on chromosome 4. The gene defect causes abnormalities in a brain protein that, over time, leads to a movement disorder and dementia. 

Wernicke-Korsakoff Syndrome

Korsakoff syndrome is a chronic memory disorder caused by severe deficiency of thiamine (vitamin B-1). The most common cause is alcohol abuse. Thiamine helps brain cells produce energy from sugar. When thiamine levels fall too low, brain cells cannot generate enough energy to function properly.  

Others

Other cases of dementia may be related to:

·     Drugs (including certain prescription drugs, over the counter drugs, and illicit drugs)

·     Brain tumors

·     Thyroid disease

·     Depression

Week 2: How common is dementia in Canada and around the world?

How common is dementia in general?

 

• 8 - 10% of people over 65 years of age
• 20 - 30% of people over 80
• 50 - 60% of people in long-term care institutions

 

Globally

 

According to the World Health Organization, 47.5 million people have dementia worldwide, with 58% living in low- and middle-income countries. Every year, there are 7.7 million new cases. The estimated proportion of the general population aged 60 and over with dementia at any given time is around 5 to 8 per 100 people. The total number of people with dementia is projected to increase to 75.6 million in 2030 and almost triple to 135.5 million by 2050 if no effective treatments are discovered. Much of this increase is attributable to the rising numbers of people with dementia living in low- and middle-income countries.

 

Canada

 

• 5% of the Canadian Institutes of Health Research’s budget invested in dementia research

 


• 16,000 Canadians under the age of 65 live with dementia


• 25,000 new cases of dementia are diagnosed every year
• 56,000 Canadians with dementia are being cared for in hospitals
• 564,000 Canadians are currently living with dementia


• 937,000 Canadians will be living with the disease in 15 years 


• 1.1 million Canadians are affected directly or indirectly by the disease


• $10.4 billion as the annual cost to Canadians to care for those living with dementia

 

For more information, please refer to the following: 


The Alzheimer Society of Canada report The Rising Tide 

Full report - Prevalence and Monetary Costs of Dementia in Canada, Alzheimer Society of Canada (2016) 

Executive summary - Prevalence and Monetary Costs of Dementia in Canada: A Report by the Alzheimer Society of Canada (2016)


Sources - Reference for Dementia numbers in Canada

United Kingdom

 

According to the UK Alzheimer's Society, there are around 800,000 people in the UK with dementia. One in three people over 65 will develop dementia. The number of people with dementia is increasing because people are living longer. It is estimated that by 2021, the number of people with dementia in the UK will have increased to around 1 million.

 

United States of America

 

The number of Americans living with Alzheimer's disease is growing fast. In 2016, an estimated 5.4 million Americans of all ages have Alzheimer's disease

• Of the 5.4 million Americans with Alzheimer's, an estimated 5.2 million people are age 65 and older, and approximately 200,000 individuals are under age 65 (early-onset Alzheimer's disease)
• One in nine people aged 65 and older have Alzheimer's disease
• By mid-century, someone in the United States will develop the disease every 33 seconds

These numbers will escalate rapidly in the coming years, as the baby boomer generation has begun to reach age 65 and beyond - the age range at greatest risk of Alzheimer's disease. By 2050, the number of people aged 65 and older with Alzheimer's disease may nearly triple, from 5.2 million to a projected 13.8 million.

Week 1: What is Dementia?

Dementia is characterized by the loss of cognitive function that is persistent and progressive. Symptoms of cognitive dysfunction may include memory loss and difficulties with thinking, problem-solving or language. Patients with dementia may also experience changes in mood or behaviour. Its deficits impair daily functioning.



How is normal aging different from dementia? 

Seniors with normal aging may occasionally not be able to remember details of a conversation or event that took place a while ago. They may not remember the name of an acquaintance. They may forget things and events, and have difficulty finding the correct words occasionally. They may be worried about their memory but their relatives are not concerned.

On the other hand, patients with dementia frequently do not recall details of recent events or conversations. They may not recognize or know the names of familiar people or even family members. They may have frequent pauses in their speech, and substitutions when finding words. Their relatives are worried about their memory, but the patients are often not aware of any problems (they lack insight).

What is the natural course of dementia?

In the first stages of dementia, the signs and symptoms of the disorder may be subtle with mild cognitive impairment. These problems do not affect the person’s daily function. They may have some memory trouble and trouble finding words, but they solve everyday problems well. As dementia progresses, the symptoms first experienced in the early stages of the dementia generally worsen. The rate of decline is different for each person and can depend on the cause of the dementia. People with dementia may be severely impaired in solving problems, and their social judgment is usually also impaired. They cannot usually function outside their own home, and generally should not be left alone. They begin to require assistance for personal care and hygiene. People with late-stage dementia typically turn increasingly inward, will eventually have severe communication problems, and need assistance with most or all of their personal care. They usually need 24-hour supervision to ensure personal safety, as well as to ensure that basic needs are being met. They no longer recognize familiar people. In the terminal stages of the illness, they may become bed-bound, can no longer communicate at all, and may develop swallowing problems.

For more information, please refer to the Alzheimer’s Society of Canada: http://www.alzheimer.ca/en/About-dementia/What-is-dementia/Normal-aging-vs-dementia