Click on the green bars below for more information on:
- Alzheimer’s Disease
- Mixed Dementia
- Vascular Dementia
- Frontotemporal Dementia
- Lewy Body Dementia
- Parkinson’s Dementia
- Young Onset Dementia
What is Alzheimer’s disease?
Alzheimer’s Disease (AD) is the most common type of dementia and present in approximately 60- 80% of all dementia diagnoses. AD is a chronic neurodegenerative disease associated with progressive impairments in memory, language, thinking, and behaviour over time. The hallmark of AD is characteristic brain atrophy associated with presence of two abnormal structures called beta-amyloid plaques and tangles. Beta-amyloid plaques are deposits of a protein fragments that build up in the space between nerve cells. It is believed the accumulation of the beta-amyloid impairs electrical signals between neurons and adversely affects their metabolism, contributing to neuronal death. Neurofibrillary tangles are twisted fibers of another protein called tau that builds up inside cells. The accumulations of neurofibrillary tangles within the neuron also contribute to cell death and brain atrophy affecting the function of the brain and increasing the severity of symptoms.
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What is Mixed Dementia?
Mixed dementia is a condition in which brain changes associated with more than one cause of dementia occur simultaneously. At least one in every ten people with dementia is diagnosed as having more than one type. Mixed dementia is much more common in older age groups, such as those over 75 years.
In the most common form of mixed dementia, the abnormal protein deposits associated with Alzheimer’s disease coexist with blood vessel problems linked to vascular dementia. Brain changes disease can also coexist with Lewy bodies. In some cases, a person may have brain changes linked to all three conditions: Alzheimer’s disease, vascular dementia and Lewy body dementia.
Researchers don’t know exactly how many people currently diagnosed with a specific type of dementia actually have mixed dementia. However, autopsy studies indicate that mixed dementia may be much more common than previously realized. Some experts recommend suspecting mixed dementia whenever a person has both evidence of cardiovascular disease (e.g. diabetes) and progressing dementia symptoms.
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What is Vascular Dementia?
Vascular Dementia (VD) is a type of dementia caused by damage to the brain as a result of reduced blood flow or bleeding in the brain. A network of blood vessels called the vascular system supply the brain with oxygen and nutrients, allowing the brain to function properly. If the vessels supplying the brain are blocked, diseased or bleeding, blood is prevented from reaching the brain. With no oxygen and nutrients, the affected cells in the brain are damaged. This can lead to sudden symptoms of a stroke, such as paralysis or weakness of a limb, impairment of speech, loss of consciousness and confusion. With or without medical intervention these stroke symptoms may improve. In some instances these symptoms may be minimal or masked by sleep and so not recognized by the individual. However, over time it may become apparent that there are persisting problems with memory, speech, difficulty thinking, making decisions, planning or remembering things. If these problems with brain function are progressive and impair daily function a diagnosis of VD may be made.
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FRONTOTEMPORAL DEMENTIA (FTD)
What is Frontotemporal Dementia?
Frontotemporal Dementia (FTD) is an umbrella term for a group of disorders that primarily affect the frontal and temporal lobes of the brain – the areas generally associated with personality, behaviour, emotions, language, speech, abstract thinking and movement. FTD causes irreversible progressive degeneration of brain cells and affects a person’s ability to function. In some cases, brain cells in the frontal and temporal areas shrink or die. In other cases, the brain cells in these areas get larger, containing round, silver “Pick’s bodies”. Researchers estimate that approximately 5 to 10% of all dementia cases are FTD. However, when symptoms of dementia start before the age of 65 (known as young onset dementia), approximately 20% of cases are FTD.
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LEWY BODY DEMENTIA (LBD)
What is Lewy Body Dementia?
Lewy Body Dementia (LBD) is a type of dementia that occurs because of abnormal deposits of a protein called alpha-synuclein inside of the brain’s nerve cells. LBD shares many similarities with Parkinson’s disease. These deposits are called “Lewy bodies” that causes the loss of connections between nerve cells, which lead to dementia. Why or how Lewy bodies form is unknown. People living with LBD also have low levels of important chemicals (e.g. acetylcholine and dopamine) that carry messages between nerve cells. LBD affects the areas of the brain that involve thinking and movement and usually progresses quickly.
LBD is the second most common type of dementia, accounting for between 5 and 15% of all dementia cases. It is a progressive disease, meaning symptoms start slow and progress over time. The disease lasts an average of 5 to 8 years from the time of diagnosis to death.
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What is Parkinson’s Disease?
Parkinson’s disease is a progressive neurodegenerative disease that presents with tremors, slowness of movement, rigidity, reduced mobility and postural instability. A decline in thinking and reasoning may develop in individual living with Parkinson’s. Symptoms such as depression and dementia may also emerge over time.
Parkinson’s disease dementia (PDD) is diagnosed if dementia is present and the onset occurs a year or more after the onset of motor symptoms. If symptoms of dementia appear before or at the same time as symptoms of Parkinson’s, it is usually called dementia with Lewy bodies.
Young Onset Dementia Resources
YOUNG ONSET DEMENTIA
What is Young Onset Dementia?
People living with dementia whose symptoms started before they were 65 are often described as having Young Onset Dementia (YOD), or early onset dementia. The age of 65 is used because it is the age at which people traditionally retired. However, this is an artificial cut-off point without any biological significance. A diagnosis of YOD does not necessarily refer to different symptoms associated with age, but rather the different needs and support of those under 65 living with dementia. YOD accounts for an estimated 2 to 8% of all dementia cases. Right now, at least 16,000 Canadians under the age of 65 are living with YOD.