Causes Of Frontotemporal Dementia
This is an important cause of dementia in younger people. It’s most often diagnosed between the ages of 45 and 65.
It’s caused by an abnormal clumping of proteins, including tau, in the frontal and temporal lobes at the front and sides of the brain.
The clumping of these proteins damages nerve cells in the frontal and temporal lobes, causing brain cells to die. This leads to shrinking of these areas of the brain.
Frontotemporal dementia is more likely to run in families than other, more common causes of dementia.
Read more about frontotemporal dementia.
Causes Of Vascular Dementia
Vascular dementia is caused by reduced blood flow to the brain, which damages and eventually kills brain cells.
This can happen as a result of:
- narrowing and blockage of the small blood vessels inside the brain
- a single stroke, where the blood supply to part of the brain is suddenly cut off
- lots of “mini strokes” that cause tiny but widespread damage to the brain
Not everyone who has a stroke will go on to develop vascular dementia.
Read more about vascular dementia.
Genetic Research For Alzheimers Disease
Researchers think there are probably many more genes that affect the risk of Alzheimerâs. Discovery of these genes will help doctors:
- Understand the disease better and learn why it affects certain people in certain ways
- Learn more about what increases your risk of getting it
- Identify people who are at higher risk so they can home in on preventive care
- Develop new treatments
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Getting An Accurate Diagnosis
â with young onset is that dementia is not something that they think about initially. If youâre a woman, the first thing they think about is menopause and depression and anxiety and panic and sleep disorders and all those kinds of things.â â Faye, from Windsor Junction, Nova Scotia. Faye lives with young onset Alzheimer’s disease.
Diagnosing dementia can be a long and complicated process. For younger people, itâs even more complicated and frustrating. Healthcare providers are often reluctant to diagnose dementia in someone so young, and itâs common for a person who has young onset dementia to be misdiagnosed with another condition, such as depression.
As a a result, the person living with young onset dementia may not get the appropriate knowledge, treatment and support to fight the disease.
Dementia With Lewy Bodies
Lewy bodies are deposits of a particular type of protein that build up in the brain and damage cells. They can sometimes be found in the brains of people with other types of dementia, such as Parkinson’s disease dementia and Alzheimer’s.
The cause of dementia with Lewy bodies is unknown, but the overlaps with Parkinson’s and Alzheimer’s suggest there could be a genetic link between different types of dementia. However, familial cases of dementia with Lewy bodies are very rare.
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What Will They Do
The team has designed an ambitious long-term study into early-onset Alzheimers which will combine brain scans with blood and spinal fluid samples to track the development of the disease over time.
During the course of the study, volunteers will also undergo a series of memory and thinking tests, including assessments of smell, eye movements and sleep quality.
Carers will also be asked for their input on the quality of life of those with the disease.
Their findings will shed more light on why early-onset Alzheimers can affect people in such different ways and how it differs from late-onset Alzheimers.
To develop ways to detect and track changes in early-onset Alzheimers, the team has also been studying spinal fluid from people with the disease.
They have been measuring levels of hallmark Alzheimers proteins in the samples.
Changes in these proteins may act as markers for early-onset Alzheimers that could help to detect the disease and track its course.
The team is also using clinical information and DNA samples from all possible cases of early-onset Alzheimers seen at the Dementia Research Centre since it opened 20 years ago.
They now have a large sample of over 600 patients and have completed detailed studies of the DNA code of these people.
The Combined Effect Of Multiple Genes
Why is the inheritance of late-onset Alzheimers so much less frequent than for early-onset? In part, the answer is that there is no single gene mutation that consistently causes late-onset Alzheimers in the autosomal dominant pattern characteristic of early-onset AD. Instead, the late-onset form seems to represent the combined effect of multiple genes, each of which increases the risk a little. The best known of these, the apolipoprotein E gene , provides information that the body needs to make a protein that plays a role in the transport of fats and cholesterol throughout the body. The Greek letter epsilon followed by a number is used to name the parts of ApoEs three versions: ApoE2, ApoE3, and ApoE4. One ApoE gene copy is inherited from each parent, so any combination of two gene copies can be present. The 4 type has been linked with an increased risk for early or late onset AD, and people who have inherited two copies are at even greater risk. It is estimated that people with the two copies of the 4 gene are at 12 to 15 times the risk for AD compared to noncarriers.4 But inheriting one or even two ApoE 4 genes does not guarantee that AD will develop, nor does the absence of any 4 genes assure that AD will not develop. In African Americans, the relationship of ApoE genotype to AD inheritance risk is weaker than in European Ancestry populations.
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People Affected By Dementia Are Often Concerned About Whether The Condition Can Be Passed Along In Families
Here we discuss the role of heredity in Alzheimers disease and other forms of dementia.
Dementia is the term used to describe the symptoms of a large group of illnesses which cause a progressive decline in a persons functioning. It is a broad term to describe a loss of memory, intellect, rationality, social skills and what would be considered normal emotional reactions. Alzheimers disease is the most common form of dementia, accounting for 50% to 70% of all cases of dementia. It occurs relatively frequently in older people, regardless of family history. For females aged 65 to 69 years dementia affects 1 person in 80 compared to 1 person in 60 for males. For both males and females aged 85 and over the rate is approximately 1 person in 4.
Genes And Frontotemporal Dementia
Frontotemporal dementia , originally called Picks disease, is a rarer type of dementia mostly affecting people under the age of 65 years. The symptoms of FTD can be quite varied but include changes that mostly affect behaviour or language. There are different types of FTD, and these are likely to have different causes.
Some people with FTD have a family history of dementia and the condition may be inherited in some of these families. For behavioural variant FTD, a third to half of people could have a family history. This figure is thought to be much lower for other types of FTD.
Overall, around one in ten cases of FTD are thought to be caused by a faulty gene passed down in families. Several genes have been found that can cause these inherited types of FTD, including:
Mutations in the MAPT gene can cause the tau protein to behave abnormally, forming toxic clumps that can damage brain cells. We still need to understand more about how mutations in progranulin and C9ORF72 cause the disease.
The C9ORF72 gene can cause people to develop motor neurone disease, FTD or both conditions, and may affect members of the same family differently.
In cases of FTD that are not caused by faulty genes, the risk factors are not yet fully understood, and research is ongoing.
Is genetic testing available for frontotemporal dementia?
What Should I Do If My Parent Is Diagnosed With Alzheimers Or Dementia
First and foremost, dont panic. Its not your diagnosis. Get tested so you have factual data. After getting a test you can act accordingly. Sometimes people get diagnosed with the ApoE gene and never get diagnosed with Alzheimers. Taking preventative measures regarding diet,exercise, and mentally stimulating activities puts them in far better condition than many who dont even have the gene.
Although there is no known way to prevent Alzheimers, and while we cant change our genetic profile, we can change our lifestyle to reduce our risk.
The Role Of Genetics: Will I Get Alzheimers Disease
Scientists are still trying to determine the underlying causes of Alzheimers disease. The hope is that one day we will be able to stop the disease from progressing or perhaps even prevent it altogether. To date, researchers have identified a few genes that play an important role in Alzheimers. Some of these genes are simply risk factors for Alzheimers disease. Other genes are hereditary and will cause Alzheimers disease to develop.
There are two types of Alzheimers disease: early-onset Alzheimers disease and late-onset Alzheimers disease. Early-onset Alzheimers disease is rare, occurring in people age 60 and younger. This represents less than 5% of all people with Alzheimers. One type of early-onset Alzheimers disease is known as autosomal dominant Alzheimers disease or early-onset familial Alzheimers disease . This is even more uncommon, affecting less than 1% of all people with Alzheimers. What makes this type of early-onset Alzheimers disease so unusual is that it is caused by a hereditary genetic mutation to one of three genes PSEN1, PSEN2, or APP.
A recent study examined data from 4 large, observational studies of adults ages 60 and older. The study reported the association between various APOE genotypes and the risk of developing mild cognitive impairment or dementia due to Alzheimers by age 85 as follows:
- No family history of dementia
- Being male
Factors that may increase a persons risk of developing Alzheimers include:
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Is Dementia Hereditaryand Should You Be Tested
It is possible to request genetic testing to determine whether you have inherited some of the genes associated with AD or other dementias, but there are both advantages and disadvantages associated with undergoing this process.
Since testing for many of the genes associated with the most common forms of dementia cannot indicate definitively whether an individual will or will not develop a neurodegenerative disease, fears may be raised or eased in error.
Whats more, given the fact that there is currently no dementia cure available to halt or reverse the progression of most types of dementia, genetic testing may be unnecessarily distressing and ultimately pointless for many individuals. In the majority of cases, deciding to forgo testing and instead adopt lifestyle strategies that maximize physical and mental health may provide the best response to worries about inheriting dementia.
WHAT YOU SHOULD KNOW
WHAT IS DEMENTIA?
The AA also points out people often confuse dementia with the terms senility or senile dementia. The latter terms, the AA contends, reflect the formerly widespread but incorrect belief that serious mental decline is a normal part of aging.
Physical exercise: Regular physical exercise may help lower the risk of some types of dementia. Evidence suggests exercise may directly benefit brain cells by increasing blood and oxygen flow to the brain.
Originally published in 2016, this post is regularly updated.
The Latest In Alzheimers And Dementia Testing
There are many tests today that can help determine whether you are at risk for Alzheimers or dementia. These include:
- Cognitive assessments. Medical professionals continue to refine their ability to evaluate and assess a persons cognitive health with motor skill and mental tests.
- Brain scans. Brain imaging can also shed light on alterations in the brain that may lead to or be causing dementia.
- Blood tests. Tests can detect a protein in the blood called NfL . It has proven to be an early biological marker for Alzheimers. Other tests can evaluate the level of amyloid and tau proteins in the blood.
- DNA testing. There are many tests available today that can detect the ApoE gene which has been associated with late-onset Alzheimers. Even genealogy companies like 23andMe can test for variants of the ApoE gene.
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What Kind Of Dementia Is Hereditary
Just because your family member had dementia does not mean you will also get it. Although you are at higher risk, there are also a number of things you can do to lower your risk. Dont smoke, get regular exercise, eat healthfully, manage health issues , maintain regular social connection, and do activities that challenge your brain . Dr. Wegner
Researchers have identified several genes that increase the riskof Alzheimers, such as the APOE-e4 gene. An estimated 40% to 65% of those diagnosed with Alzheimers have this gene.
Vascular dementia is less likely to be influenced by genes. It is more likely linked to risk factors for heart disease like high blood pressure, being overweight, having a sedentary lifestyle, or diabetes.
About one in three of frontotemporal disorders may be hereditary.
Causes Of Dementia With Lewy Bodies
Lewy bodies are tiny clumps of a protein called alpha-synuclein that can develop inside brain cells.
These clumps damage the way the cells work and communicate with each other, and the brain cells eventually die.
Dementia with Lewy bodies is closely related to Parkinson’s disease and often has some of the same symptoms, including difficulty with movement and a higher risk of falls.
Read more about dementia with Lewy bodies.
Young Onset Vs Early Stage
It’s important to know that term “young onset dementia” does not mean the early stage of dementia. While most people diagnosed with young onset dementia are likely experiencing mild symptoms that indicate they are in the early stage, “young onset” and “early stage” have different meanings. A 57-year-old living with young onset dementia could already be in the late stage, while a 80-year-old just diagnosed with dementia might be in the early stage.
It’s also important to note that young onset dementia encompasses all types of dementia. If a person is diagnosed with Alzheimer’s disease â the most common type of dementia âunder the age of 65, then that person can be said to have young onset Alzheimer’s disease. Likewise, if a person is diagnosed with frontotemporal dementia under 65, then that person has young onset frontotemporal dementia.
However, each person living with young onset dementia has their own preferred term to describe their dementia â ask them what they prefer!
What Is Early Onset Familial Alzheimer Disease
Definition: What Is eFAD?
Early onset familial Alzheimer disease is hereditary and marked by Alzheimer disease symptoms that appear at an unusually early age. Symptoms can start in a person’s thirties, forties, and fifties . Generally, if you are diagnosed with eFAD, then one of your parents will also have had it if he or she lived long enough, and your siblings and your children may have a 50-50 chance of having inherited it. Very rarely, eFAD can make a first-time appearance in a family through a new genetic mutation.
Genetics researchers studied eFAD families to discover the three known genes that cause familial AD: amyloid precursor protein , presenilin-1 , and presenilin-2 . Of these, PS1 mutations account for most eFAD, while APP and PS2 are more rare. Having a pathogenic mutation in one of these three genes virtually guarantees that one will develop early onset Alzheimer disease. Tests can determine which gene is at fauly . There are also cases of eFAD that cannot be linked to one of these three genes. There may be additional genes waiting to be discovered, if only researchers could connect with more eFAD families.
Prognosis: Is eFAD Different from LOAD?
How Common Is Early Onset Familial Alzheimer Disease?
For practical and research purposes, doctors and scientists need defined populations for study and the numbers change based on the definitions. The definition would seem to rest on two criteria:
|Early onset sporadic||Late-onset sporadic|
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Confusion In Actions Or Words
6Another consequence of the weakening of short-term memory, which is primarily affected by dementia, is confusion in words or actions. Trying to open an apartment with a car key, not recognizing recent acquaintances, confusing the events of the past day all this can be manifestations of incipient dementia.
Clinical Manifestations Of Eoad
In general, the clinical manifestation of AD is characterized by a predominant impairment of anterograde episodic memory. This symptom is typically accompanied by a multitude of cognitive impairments in domains, such as visuospatial, language, and executive function . The combination of the aforementioned characteristics contributes to a global cognitive decline, eventually leading to a total dependent state, and death . Although this typical clinical presentation of memory-predominant phenotypes overlaps between LOAD and EOAD cases, a subset of EOAD cases show an atypical presentation of preserved episodic memory function but focal cortical symptoms relating to language, visuospatial, or executive function . In 25% of EOAD cases, there is a distinct phenotype of non-memory symptoms, in particular apraxia, visual dysfunction, fluent or non-fluent aphasia, executive dysfunction, or dyscalculia, that is seen as the disease progresses . In addition, individuals with EOAD often present with a more aggressive disease progression and a shorter relative survival time , with the rate of progression driven at least in part by the nature of the underlying causative variant . EOAD cases have a greater pathological burden compared to LOAD .
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What Else Causes Dementia
Aside from our genes, which we cant change, our lifestyle factors and environment play potential roles in different forms of dementia.
Lifestyle factors are choices about how much alcohol we drink, if we smoke, exercise, and what we eat.
The environment we live in may cover things like pollution, social lives, education, work or exposure to vitamin D .
Its impossible, in most circumstances, to say why someone ended up with dementia due to its complex web of causes.
Even if it does, or does not, run in your family, this will not determine whether youll get a diagnosis.
Thats why taking measures to reduce your risk is always worth trying, such as eating a healthy diet and not smoking.