Frontotemporal dementia

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at July 24, 2016
StartDiseasesFrontotemporal dementia

Frontotemporal dementia is a term that describes a group of disorders that affect the frontal lobe and temporal lobe of the brain. Language, behavior, and personality are affected by the frontal and temporal lobes. As the disease progresses, the symptoms that an individual experiences will worsen. Most individuals diagnosed with frontotemporal dementia will eventually need around-the-clock care.

Contents

Definition & Facts

Frontotemporal dementia is a diverse group of disorders that involve the loss of neurons (nerve cells) in the frontal lobe (which is located behind the forehead) or the temporal lobe (which is located behind the ears) of the brain.

The condition is sometimes misdiagnosed as Alzheimer's disease. However, with frontotemporal dementia, individuals at a younger age are usually impacted by the condition, which usually ranges between the ages of 40 and 75. Subtypes of frontotemporal dementia include: 

  • Behavioral variant. This affects behavior and personality.
  • Semantic dementia. This type affects a person's capacity to understand and use language
  • Progressive non-fluent aphasia. This inhibits a person's capacity to speak.

Frontotemporal dementia causes a variety of problems for a person's capacity to function in their relationships and at work. It inhibits a person's capacity to plan ahead and organize their behavior. Frontotemporal dementia is a debilitating, chronic, and progressive condition. It requires long-term care and management.

Symptoms & Complaints

Based on the individual, symptoms of the condition can vary. However, medical experts have identified a group of symptoms that characterize frontotemporal dementia.

An individual with the condition will experience changes in his or her behavior, difficulty speaking, and problems moving. If an individual has frontotemporal dementia, he or she will show typical changes in his or her behavior that include: 

An individual with frontotemporal dementia can also develop movement disorders that include muscle weakness and spasms; dysphagia (difficulty swallowing); and tremors.

Causes

Although the cause of frontotemporal dementia is not known, it is believed the condition is influenced by a variety of genetic factors and environmental factors. There have been autopsies performed on individuals who had frontotemporal dementia, which illustrate the death of nerve cells in the temporal and frontal lobes that is connected to clusters of abnormal proteins inside the nerve cells. The accumulation of abnormal proteins cause the frontal and temporal lobes to shrink over time.

Frontotemporal dementia tends to run in families more than other forms of dementia. An estimated 10% to 15% of individuals with the condition will have a family history of frontotemporal dementia. In most cases, an individual will inherit the condition from a parent who has a specific genetic mutation, which include defects of the genes: MAPT (tau protein), C9ORF72, and GRN.

Diagnosis & Tests

Doctors can have a difficult time diagnosing frontotemporal dementia. At first, the condition does not cause any recognizable problems, and it is hard to identify in middle-aged individuals. Doctors can misdiagnose frontotemporal dementia as atypical Alzheimer's. Doctors can also diagnose the condition as depression or another mental disorder because of behavioral changes that can be seen among patients with frontotemporal dementia.

A doctor will examine an individual's medical history and symptoms to gather information. Individuals are given neuropsychological tests such as cognitive tests to determine the severity of cognitive impairment and memory loss. Individuals may undergo tests to analyze intelligence, motor function, and and abstract thinking.

An individual will also undergo a magnetic resonance imaging (MRI) and a computed tomography (CT) scan, so a doctor can evaluate any signs of brain damage. These tests are also ways to be sure the symptoms are not caused by other factors such as a brain tumor or traumatic brain injury. A positron emission tomography (PET) scan is another imaging scan that may be conducted. This scan uses contrast dye and shows how different parts of the brain are using energy (its metabolic activity).

Another test that can aid in the diagnosis of frontotemporal dementia is an electroencephalogram (EEG) which is used to measure electric activity in the brain. It is a non-invasive test.

Other tests can include a lumbar puncture (spinal tap) and genetic testing. A lumbar puncture is a test that collects fluid from the spine for analysis. Genetic testing can also help diagnose the condition, and it will give family members an opportunity to be tested to see if they carry the defective gene that causes the condition. 

Treatment & Therapy

If an individual is diagnosed with frontotemporal dementia, then it is imperative he or she seek treatment immediately. Those with the condition should exercise on a regular basis and get enough sleep, which will aid in maintaining cognitive function.

There are also medications that can help treat behavioral symptoms that accompany frontotemporal dementia. A doctor may recommended antidepressants, which have been effective in treating symptoms that arise from the condition. Common antidepressants used to treat symptoms of frontotemporal dementia include:

Antipsychotics can also help because they block dopamine, which can cause hallucinations and irrational behavior. It is important that those with frontotemporal dementia stay away from typical antipsychotics, which can cause muscle problems. Atypical antipsychotics can help stop the effects of dopamine without some of the negative side effects of typical antipsychotics. Common atypical antipsychotics used to treat the symptoms of frontotemporal dementia include: 

If an individual with frontotemporal dementia is having problems with language, then speech therapy can be helpful. Speech therapy is an effective way to teach individuals with the condition how to deal with language problems. Occupational therapy is also beneficial because it can teach individuals different ways to function in their everyday life.

Prevention & Prophylaxis

There is no way to prevent frontotemporal dementia because its causes remain mysterous. Although an individual can take measures to prevent other forms of dementia, frontotemporal dementia may result from a defective mutation. For those with a family history of frontotemporal dementia, early testing can help individuals be prepared and seek early treatment.

End-of-life planning is recommended following diagnosis so that a patient and his or her family can be as prepared as possible for coping with the progress of the disease at all stages.