Frontotemporal dementia

Definition

Frontotemporal dementia (frontotemporal lobar degeneration) is an umbrella term for a diverse group of uncommon disorders that primarily affect the frontal and temporal lobes of the brain — the areas generally associated with personality, behavior and language.

In frontotemporal dementia, portions of these lobes atrophy or shrink. Signs and symptoms vary, depending upon the portion of the brain affected. Some people with frontotemporal dementia undergo dramatic changes in their personality and become socially inappropriate, impulsive or emotionally indifferent, while others lose the ability to use and understand language.

Frontotemporal dementia is often misdiagnosed as a psychiatric problem or as Alzheimer's disease. But frontotemporal dementia tends to occur at a younger age than does Alzheimer's disease, typically between the ages of 40 and 70.

Symptoms

Identifying precisely which diseases fall into the category of frontotemporal dementia presents a particular challenge to scientists. The signs and symptoms may vary greatly from one individual to the next. Researchers have identified several clusters of symptoms that tend to occur together and are dominant in subgroups of people with the disorder. More than one symptom cluster may be apparent in the same person. The signs and symptoms of frontotemporal dementia progressively worsen with time, almost always over years, eventually requiring 24-hour care.

Behavioral changes
The most common signs and symptoms of frontotemporal dementia involve extreme changes in behavior and personality. These include:

• Increasingly inappropriate actions
• Loss of empathy and other interpersonal skills
• Lack of judgment and inhibition
• Apathy
• Repetitive compulsive behavior
• A decline in personal hygiene
• Changes in eating habits, predominantly overeating
• Lack of awareness of thinking or behavioral changes

Speech and language problems
Some subtypes of frontotemporal dementia are marked by the impairment or loss of speech and language difficulties. For example, primary progressive aphasia is characterized by an increasing difficulty in using and understanding written and spoken language. People with another subtype, semantic dementia, utter grammatically correct speech that has no relevance to the conversation at hand or may have difficulty recalling the words for common objects.

Movement disorders
Rarer subtypes of frontotemporal dementia are characterized by problems with movement, similar to those associated with Parkinson's disease or amyotrophic lateral sclerosis (ALS), which is also often called Lou Gehrig's disease.

Movement-related signs and symptoms may include:

• Tremor
• Rigidity
• Muscle spasms
• Poor coordination
• Difficulty swallowing
• Muscle weakness

Causes

A variety of mutations on several different genes have been linked to specific subtypes of frontotemporal dementia. But more than half the people who develop frontotemporal dementia have no family history of dementia.

In some cases of frontotemporal dementia, the affected parts of the brain contain microscopic Pick bodies — abnormal protein-filled structures that develop within brain cells. Frontotemporal dementia was once known as Pick's disease, but now that terminology is reserved for the subtype that actually features these abnormal structures.

Risk factors

Your risk of developing frontotemporal dementia is higher if you have a family history of dementia. There are no other known risk factors.

Preparing for your appointment

People who have frontotemporal dementia often don't recognize that they have a problem. In many cases, family members are the ones who notice the symptoms and arrange for a doctor's appointment. Your family physician may refer you to a neurologist or psychologist for further evaluation.

What you can do
Because you may not be aware of all your signs and symptoms, it's a good idea to take a family member or close friend along with you to the doctor's appointment. You may also want to take a written list that includes:

• Detailed descriptions of your symptoms
• Information about medical problems you've had in the past
• Information about the medical problems of your parents or siblings
• All the medications and dietary supplements you take
• Questions you want to ask the doctor

What to expect from your doctor
In addition to a physical exam, your doctor may also check your neurological health by testing your:

• Reflexes
• Muscle strength
• Muscle tone
• Senses of touch and sight
• Coordination
• Balance

During the appointment, your doctor might also conduct a brief mental status evaluation, which may assess:

• Memory
• Problem-solving abilities
• Attention span
• Counting skills
• Language usage

Tests and diagnosis

No single test can identify frontotemporal dementia, so doctors attempt to identify certain characteristic features while excluding other possible causes.

Blood tests
To see if your symptoms are being caused by a different condition, such as liver or kidney disease, your doctor may order blood work.

Neuropsychological testing
Sometimes doctors undertake a more extensive assessment of reasoning and memory skills. This type of testing, which can take several hours to complete, is especially helpful in trying to differentiate between the different types of dementia at an early stage.

Brain scans
By looking at images of the brain, doctors may be able to pinpoint any visible abnormalities — such as clots, bleeding or tumors — that may be causing signs and symptoms.

• Magnetic resonance imaging (MRI). An MRI machine uses radio waves and a strong magnetic field to produce detailed images of your brain. You lie on a narrow table that slides into the tube-shaped MRI machine, which makes loud banging noises during scans. The entire procedure can take an hour or more. MRIs are painless, but some people feel claustrophobic in the machine.
• Computerized tomography (CT). For a brain CT scan, you lie on a narrow table that slides into a small chamber. X-rays pass through your head from various angles, and a computer uses this information to create cross-sectional images, or slices, of your brain. The test is painless and takes about 20 minutes.
• Positron emission tomography (PET). PET scans use a small amount of low-dose radioactive material that's injected into a vein to help visualize brain metabolism, which can help identify abnormalities.

MRI comparison

MRI comparison

The image on the right, particularly the area near the white arrow, shows the brain shrinkage common in frontotemporal dementia. ...

Treatments and drugs

There's no cure for frontotemporal dementia and no effective way to slow its progression. Treatment relies on managing the symptoms.

Medications

• Antidepressants. Some types of antidepressants, such as trazodone (Desyrel, Oleptro), may reduce the behavioral problems associated with frontotemporal dementia. Selective serotonin reuptake inhibitors (SSRIs) have also been effective in some cases, although study results have been mixed.
• Antipsychotics. Although antipsychotic drugs are sometimes used to combat the behavioral problems of frontotemporal dementia, side effects can include an increased risk of mortality in older people.

Therapy
People experiencing language difficulties may benefit from speech therapy, to learn alternate strategies for communication.

Lifestyle and home remedies

In some cases, caregivers can reduce behavior problems by changing the way they interact with people who have dementia. Examples include:

• Avoiding events or activities that trigger the undesirable behavior
• Anticipating needs and alleviating them promptly
• Maintaining a calm environment

Coping and support

If you've been diagnosed with frontotemporal dementia, receiving support, care and compassion from people you trust can be invaluable. Through your doctor or the Internet, find a support group for people with frontotemporal dementia. You'll find information tailored for your needs, as well as a forum that gives you the opportunity to share your experiences and feelings.

For caregivers
Caring for someone with frontotemporal dementia can be challenging and stressful because of the extreme personality changes and behavioral problems that frequently develop. Caregivers need assistance — from family members and friends, support groups, or respite care provided by adult care centers or home health care agencies.

When a person with frontotemporal dementia requires 24-hour care, most families turn to nursing homes. Plans made ahead of time will make this transition easier and may allow the person to be involved in the decision-making process.