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Other dementias

“Other dementias” resemble Alzheimer’s disease in that they also involve a progressive degeneration of brain cells that is currently irreversible. There are many different types of dementia, although some are far more common than others.

A small percentage of dementias are reversible, occurring as a secondary development in treatable conditions. Toxic reactions to prescription or over the counter medications are the most common cause of reversible dementia. Others include dietary or vitamin B12 deficiencies, infections, tumours, alcoholism, inflammatory states, hormonal dysfunction, environmental toxins, drug abuse, and depression.

Frontotemporal dementia

Frontotemporal dementia tends to occur at a younger age than Alzheimer’s disease and can affect both men and women. The average length of the disease can vary. This type of dementia resembles Alzheimer’s disease in that it also involves a progressive degeneration of brain cells that is irreversible.

With this form of dementia, a person may have symptoms such as sudden onset of memory loss, behaviour changes, or difficulties with speech and movement.

Unlike Alzheimer’s disease, which generally affects most areas of the brain, frontotemporal dementia is an umbrella term for a group of rare disorders that primarily affect the frontal and temporal lobes of the brain – the areas generally associated with personality and behaviour. In some cases, brain cells in these areas shrink or die. In other cases, the brain cells in these areas get larger, containing round, silver “Pick’s bodies”. Pick’s disease refers to a subtype of frontotemporal dementia that has these specific abnormalities. In frontotemporal dementia, the changes in the brain affect the person’s ability to function. Researchers estimate that approximately two to five per cent of all dementia cases are frontotemporal dementia.

Other names often used for frontotemporal dementia, in addition to Pick’s disease, include:

  • Semantic dementia
  • Frontal Lobe dementia
  • Primary progressive aphasia
  • Corticobasal degeneration
  • Pick’s complex
Symptoms of frontotemporal dementia

Since the frontal and temporal areas of the brain can be affected, early symptoms often affect either behaviour et/ou speech (language).

  • Changes in behaviour may include becoming either withdrawn or disinhibited (e.g., losing the ability to restrain one’s behaviour and actions). The person may lose interest in personal hygiene, become easily distracted or repeat the same action over and over again. Overeating or compulsively putting objects in the mouth may occur. Sometimes incontinence is an early symptom of the disease.

Other possible changes in behaviour include

    • Inappropriate social behaviour, e.g. they may say inappropriate things or come across as rude or tactless
    • Distractability
    • Loss of insight into the behaviours of oneself and others (making it seem as if they don’t care)
    • Changes in food preferences
    • Blunted emotions
    • Decreased energy and motivation
    • Changes in personality, e.g. more outgoing people may become quieter and quiet people may become more extroverted
  • Problems with speech (language) can range from speaking less to total loss of speech, i.e. becoming mute. They may have difficulty finding the right words and may use circumlocution, i.e., talking around the words or describing what they mean. Echoing what has been said by others and stuttering are common symptoms. The person may have difficulty sustaining a train of thought or maintaining a conversation for any length of time. Writing and reading are also affected.

In the early stage of frontotemporal dementia, behaviour changes or problems with speech (language) can appear separately. As the disease progresses, these two areas will overlap. Unlike Alzheimer’s disease, a person with frontotemporal dementia often remains oriented to time and memory is not a problem in the early stages. In the later stages of the disease, general symptoms of dementia arise, i.e. confusion and forgetfulness. Motor skills are lost and swallowing difficulties occur.

Diagnosis of frontotemporal dementia

Assessment is important to rule out other problems, for example, primary psychiatric disorder, for which it may be mistaken. No single test can diagnose frontotemporal dementia. Doctors diagnose the disease through a process of identifying characteristic features of the disease and ruling out other possible causes. Cognitive (thinking) tests may be done to assess which brain functions are affected. A history will be taken from the person, family and caregivers, to get a detailed picture of what has been happening. Brain imaging (such as with an MRI) can also be helpful in making a diagnosis of frontotemporal dementia.

Risk factors for frontotemporal dementia

Little is known about the cause of frontotemporal dementia and risk factors have yet to be identified. While most cases are not inherited, there is one extremely rare type of frontotemporal dementia which can be passed from generation to generation.

Treatment for frontotemporal dementia

At present, there is no known cure and no effective way to slow its progression. Cholinesterase inhibitors, used as treatment for Alzheimer’s disease, usually do not work for the treatment of frontotemporal dementia, as different areas of the brain are affected.

Much can be done, however, to help manage the symptoms. It is important to learn as much as possible about the disease, to help understand and respond to the person’s new behaviours. People around the individual will need to seek support to learn coping strategies to work around the individual’s behaviour, rather than trying to get the person to change. Speech pathologists may be helpful in teaching strategies to work around the communication problems.

Lewy body dementia

Lewy body dementia is a form of dementia that occurs because of abnormal deposits of a protein called alpha-synuclein inside the brain’s nerve cells. These deposits are called “Lewy bodies,” after the scientist who first described them. The deposits interrupt the brain’s messages. Lewy body dementia usually affects the areas of the brain that involve thinking and movement. Why or how Lewy bodies form is unknown.

Lewy body dementia can occur by itself, or together with Alzheimer’s disease or Parkinson’s. It accounts for 5-15% of all dementias.

Other names for Lewy body dementia include:

  • Diffuse Lewy body disease
  • Cortical Lewy body disease
  • Lewy body disease
  • Senile Dementia of Lewy Type
  • Dementia with Lewy bodies
  • Lewy body variant of Alzheimer’s disease
How does Lewy body dementia affect the person?

A person with Lewy body dementia may have symptoms much like those of both Parkinson’s disease and Alzheimer’s disease. A progressive loss of memory, language, reasoning and other higher mental functions such as calculating numbers is common. He may have difficulty with short-term memory, finding the right word and keeping a train of thought. He may also experience depression and anxiety. Obvious changes in alertness may also happen. He may be sleepy during the day, but wide awake at night, unable to sleep. Sometimes, he may seem like he does not care about anything. This is called apathy.

Lewy body dementia usually progresses quickly. Problems with memory may not be an early symptom, but can come up as Lewy body dementia progresses. Visual hallucinations (seeing things that are not real) are common and can be worse during times of increased confusion. The visual hallucinations often come back again and again, and typically are of people, children or animals. People with the disease may also make errors in perception, for example, seeing faces in a carpet pattern.

Some features of Lewy body dementia can resemble those in Parkinson’s disease. These include rigidity (stiffness of muscles), tremors (shaking), stooped posture, and slow, shuffling movements. Sensitivity to medication, especially some sedatives, may make these symptoms worse.

How is Lewy body dementia assessed?

No single test can diagnose Lewy body dementia. Doctors diagnose the disease by eliminating other diseases and conditions that can cause similar symptoms. Assessment may include a neurological exam that looks at the gait (way of walking), posture and how rigid or stiff the person’s body is.

What are the risk factors for Lewy body dementia?

Doctors do not yet know what causes Lewy body dementia. Risk factors have not been identified. But Lewy bodies have a protein that is also seen in Parkinson’s disease and they are often found in the brains of people with Parkinson’s disease or Alzheimer’s disease. This means that the three conditions may be linked in some way. If a family member has Lewy body dementia, there may be a higher risk of developing Alzheimer’s disease. Lewy body dementia is more common in men than in women.

Is there treatment?

There is no cure yet for Lewy body dementia. Sometimes doctors may prescribe medications to treat symptoms such as those associated with Parkinson’s disease, depression, and unpleasant hallucinations.

Medications used to treat Alzheimer’s disease are called cholinesterase inhibitors. They can improve alertness and cognition in some people. They may also reduce hallucinations and other distressing symptoms. Lewy body dementia has so many different features, as well as Parkinson’s disease symptoms, that medications may not be an option. One symptom may be treated, but another symptom may get worse at the same time. One way to avoid or prevent this is to treat symptoms according to how severe they are.

Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease

Creutzfeldt-Jakob disease (CJD) is a rare form of irreversible dementia that comes on fast. It is caused by infectious proteins called prions. Prions are proteins that are naturally in the brain and are normally harmless. When they are not shaped properly, however, they can have devastating effects. They can attack the brain, kill cells and create gaps or holes in brain tissue.

Prion diseases affect both humans and animals. Prion diseases were often in the news during the mid-1980s, with the bovine spongiform encephalopathy (BSE) epidemic (or, as it is more commonly called, ‘mad cow disease’). This is a prion disease of cattle. The best known prion disease in humans is Creutzfeldt-Jakob disease. It affects about one to two persons in a million worldwide each year, with about 35 new cases being diagnosed in Canada every year 1 .

There are two types of CJD: classic CJD and variant CJD (vCJD). The three types of classic CJD include:

  1. Sporadic: This type of CJD accounts for 90% of cases in Canada. It affects people between 45 and 75 years old. The cause of sporadic CJD is not known. The disease appears without warning. Most people with sporadic CJD die within one year.
  2. Familial or genetic: This type of CJD appears in families with an abnormal gene. It makes up 7 per cent of cases. Genetic testing can be done by a blood test. It can also be done after someone has died, by looking at the brain tissue. A person who has this abnormal gene has a 50 per cent chance of passing it on to his or her children. Gerstmann-Sträussler-Scheinker (GSS) and Fatal Familial Insomnia (FFI) are very rare forms of genetic CJD.
  3. Iatrogenic: Few people around the world get CJD from accidental transmission during a medical procedure such as: human pituitary hormone therapy, human dura-mater grafts, corneal grafts or instruments used in neurosurgery. Less than 1 per cent of people have this type of CJD.

Variant CJD affects younger people at an average age of 28 years. This form of CJD can develop from eating beef that was infected with BSE. Also, variant CJD has been reported to be transmitted by a blood transfusion from a person with variant CJD in the United Kingdom 2 .

There may be several years between the time a person is exposed to the disease and the first prions become misshapen, but once the symptoms do begin, the disease moves quickly.

There may be several years between the time a person is exposed to the disease and the first prions become misshapen, but once the symptoms do begin, the disease moves quickly.

How does Creutzfeldt-Jakob disease affect the person?

Classic CJD can look like many other dementias. It comes on quickly and the decline in thinking ability also moves quickly once symptoms appear.

The person may have:

  • Mood swings
  • Memory problems
  • A lack of interest and not act like himself
  • Rapidly progressing dementia with a loss of memory and thinking abilities
  • Difficulty with balance when walking
  • Clumsiness
  • Vision problems, including blindness
  • Stiff limbs
  • Muscle jerks or twitching
  • Difficulty speaking
  • Difficulty swallowing
  • “Akinetic mutism” (the person can move her eyes and seem alert, but cannot speak or voluntarily move)

Discomfort

People who are in the later stages of CJD lose awareness of their disease as it develops. This is seen in neurological (nerve) examinations. In the early stages of the disease, though, people with CJD can be quite scared, which can be very distressing. It is probably associated with visual hallucinations (seeing things that are not there). They may feel uncomfortable. Some of the symptoms of the disease, such as myoclonus (sudden jerking of the limbs) are also distressing for caregivers to see. There are medications and care strategies that can ease these symptoms and make the person more comfortable. For more information on the care of a person with CJD, visit the CJD Foundation website at www.CJDfoundation.org.

Coma and death

People with sporadic CJD generally live less than 12 months after the signs and symptoms appear, although some people may live as long as two years. Most people fall into coma before death. Death is usually a result of complications such as heart failure, respiratory (breathing) failure or pneumonia.

Symptoms of variant CJD are:

  • Depression, withdrawal and behaviour changes
  • Pain and odd sensations in the face or limbs
  • Difficulty walking
  • Progressive dementia
  • Inability to move or speak

People with variant CJD tend to live slightly longer — about 12 to 14 months after signs and symptoms appear.

How is Creutzfeldt-Jakob disease assessed?

Creutzfeldt-Jakob disease is very hard to diagnose, especially in the beginning of the disease. There is no test to diagnose CJD in a living person. The only way to tell if a person has CJD is to examine the brain tissue after death, during an autopsy. However, doctors will do a detailed exam and many tests to help diagnose this disease. The following steps may be taken:

  • Detailed medical history: This will help the doctor learn when the person’s signs and symptoms started, because CJD develops so quickly.
  • CT scan (computerized tomography) takes a picture of the brain. It can be used to diagnose other diseases, as well.
  • MRI (magnetic resonance imaging) also takes a picture of the brain. It helps to tell the difference between sporadic CJD and variant CJD. It can also be used to find other diseases.
  • EEG (electroencephalogram) measures the electrical activity of the brain. Sometimes, but not always, there is a specific pattern on the EEG that helps to diagnose CJD.
  • Lumbar puncture: Using a needle and syringe, a doctor can take fluid from the person’s spine. This is examined to rule out other infections of the brain. One of the tests is called the 14-3-3 protein. If the 14-3-3 is positive, it means that there has been some brain cell death, though this is not always because of CJD.
  • Blood tests: Blood tests are sometimes done to rule out other diseases and to see if there is a possibility of the genetic form of CJD. For a list of genetic counsellors in Canada visit the Canadian Association of Genetic Counsellors website: www.cagc-accg.ca.
  • Brain autopsy: The only way to confirm CJD is by looking at brain tissue with a microscope, after death. Brain autopsies are performed only in certain large hospitals in Canada. The CJD Surveillance System (see contact information at end) can help make arrangements for a brain autopsy if CJD is suspected and if the next of kin gives consent.
What are the risk factors for Creutzfeldt-Jakob disease?

Doctors do not know the true risk of developing either form of CJD. Right now, there is no specific way to protect someone from getting sporadic or familial CJD. However, certain factors may increase one’s risk:

Pituitary hormone treatment: If pituitary hormone treatment taken from human tissue was used before the genetically engineered form of the hormone was available in the 1980s, there is an increased risk. Since 1985, human growth hormones have been man-made. This means the disease can no longer be transmitted this way.

Family history of CJD: A few people have a genetic mutation that increases their chances of developing the disease. A blood test or brain tissue examination after death can be done to find out if a person has the mutation.

Contaminated surgical instruments: A few people have been infected from contaminated instruments used during brain surgery. Today, instruments are destroyed if they were used on the brain of someone with possible CJD.

CJD precautions: These are infection control precautions that are needed only for certain medical procedures involving specific tissue. When embalming the remains of a person who has died of a possible prion disease, the World Health Organization and the Public Health Agency of Canada recommend that funeral workers use CJD precautions.

You cannot catch CJD by touching, feeding or taking care of a person with CJD at home. CJD is not a contagious disease transmitted by social or sexual contact, or by air. Since other infections can be spread that way, it is recommended that the following basic precautions be followed:

  • Wash your hands before eating or drinking.
  • Protect your hands and face from exposure to the affected person’s blood or body fluids.
  • Cover cuts or wounds with waterproof bandages.
  • Blood transfusions: The Canadian Blood Services and Héma-Québec do not allow people who have CJD to give blood.

For variant CJD only: Eating beef from countries with a relatively high rate of transmissible spongiform encephalopathy (TSE) may increase risk. To help reduce the risk of getting CJD from infected beef, think about the following options:

  • Be selective when eating beef in parts of the world where they are not as strict about quality.
  • Do not eat the highest risk parts of cattle, such as eyes, brain, spinal cord and intestines.
Is there treatment?

There is no known cure for CJD yet. There is no effective way to slow its progression. It is important to relieve pain, discomfort and other symptoms such as jerking movements and unsteadiness. Supportive nursing care is focused on keeping the person as comfortable as possible.

For more information

Contact your regional Alzheimer Society.
More information can be obtained from the following:

  1. The Public Health Agency of Canada’s (PHAC) Creutzfeldt-Jakob Disease Surveillance System (CJDSS) study team. The CJDSS conducts active monitoring of CJD in Canada. Its main purpose is to study human prion diseases in Canada and to protect public health by reducing the risk of transmitting prions. The CJDSS has a 24-hour service to make arrangement for brain autopsies of persons suspected of having CJD. More information about the CJDSS can be found at www.phac-aspc.gc.ca/hcai-iamss/cjd-mcj/cjdss-eng.php or call toll free: 1-888-489-2999.
    You can also read the spring 2013 issue of the newsletter CJD in Canada: Family Edition.
  2. Canadian Food Inspection Agency, BSE Fact Sheet or website.
  3. Prionet Canada
  4. CJD Foundation (US) or toll free: 1-800-659-1991.
  5. CJD Support Network (UK)
  6. CJD Support Network (Australia)
  7. European Collaborative Study Group of CJD (EuroCJD)
  8. University of California, San Francisco
  9. Health Ontario (Ministry of Health and Long Term Care, Ontario)
  10. Canadian Association of Genetic Counsellors
  11. World Health Organization (WHO): WHO infection control guidelines for transmissible spongiform encephalopathies. Report of a WHO consultation, Geneva, Switzerland, 23–26 March 1999. Geneva, World Health Organization, 2000.

Down syndrome

Down syndrome is a genetic disorder that affects about one in every 800 live births in Canada. It is the most common genetic cause of severe learning disabilities in children and can cause developmental delays, learning difficulties, health issues and some physical abnormalities.

People with Down syndrome have an extra copy of the 21 st chromosome. Because of recent medical advances, people with Down syndrome are living longer, usually into their 50’s. jusque dans la cinquantaine.

The incidence of Alzheimer’s disease in people with Down syndrome is about three to five times greater than the general population. As with Alzheimer’s disease, the risk increases with age.

The link between Alzheimer’s disease and Down syndrome lies in the 21st chromosome. The protein that leads to the development of plaques in the brain, a hallmark characteristic of Alzheimer’s disease, is located on that chromosome. Since people with Down syndrome have an additional copy of the 21 st chromosome, they are prone to an over-production of the protein. Not everyone with Down syndrome, however, develops Alzheimer’s disease.

For more information about Down syndrome and its relation to Alzheimer’s disease, as well as screening and treatment, read our information sheet on the topic.

Footnotes:

1Public Health Agency of Canada (2007). CJD and human prion diseases.
2Brown, P. (2007). Creutzfeldt-Jakob disease: reflections on the risk of blood product therapy. Haemophilia, 13, 5. p. 33–40.
[The contents of this document are provided for information purposes only, and do not represent advice, an endorsement or a recommendation, with respect to any product, service or enterprise, and/or the claims and properties thereof, by the Quebec Federation of Alzheimer Societies.]