Frontotemporal Dementia

Frontotemporal dementia (FTD) is a type of dementia that has often been called Pick’s disease. The frontal and temporal lobes of the brain are affected and shrink in size (atrophy) as a result of damage to neurons.

FTD encompasses a group of disorders that affect behavior, emotions, communication, and cognition. Other names used for FTD include:

• Frontotemporal degeneration
• Frontal temporal dementia
• Pick's complex
• Frontotemporal lobar degeneration
• Frontal dementia

FTD typically strikes relatively young persons (45 to 64), but it has also been identified in people as young as 21 and as old as the late 80s. About 60% of cases of FTD are people between the ages of 45 and 64.

Arnold Pick first identified the abnormal tau protein collections in the brain (called Pick’s bodies) in 1892. Pick’s bodies are present in some types of FTD and can only be seen under a microscope during an autopsy.

Types of Frontotemporal Dementia

Four disorders that fall into the FTD category include:

• Behavioral Variant Frontotemporal Dementia: As the name alludes to, behavioral variant FTD significantly impacts behavior, causing socially inappropriate interactions and emotions.
• Primary Progressive Aphasia: The primary component of this type of FTD is aphasia, which refers to an impairment in language ability. This can affect both the ability to communicate and understand.
• Progressive Supranuclear Palsy: Supranuclear palsy affects balance and movement, as well as cognitive abilities. A distinct symptom is impaired eye movement.
• Corticobasal Degeneration: Symptoms for corticobasal degeneration often appear as muscle weakness and tremors, and usually begin on only one side of the body. Problems with memory and behavior also develop as this disorder progresses.

Frontotemporal Dementia Symptoms

Symptoms typically first occur between the ages of 40 and 65 and can include changes in personality and behavior, progressive loss of speech and language skills, and sometimes physical symptoms such as tremors or spasms.

Behavior Changes: People with FTD often demonstrate socially inappropriate behavior, such as tactless comments, lack of insight or empathy, distractibility, increased interest in sex, or significant changes in food preferences. Others display poor hygiene, repetitive comments or behaviors, low energy, and poor motivation. They may also have a flat or blunted affect, meaning that their faces display little or no expression of emotion, including sadness, joy, or anger.

Communication Changes: FTD often affects the ability to communicate in both expressive speech (the ability to use words to express yourself) and receptive speech (the ability to understand speech). Individuals may have trouble finding the right word to say, speak very hesitantly and slowly, have a hard time reading and writing accurately, and not be able to form sentences in a way that makes sense.

Movement Changes: FTD often affects the ability to control movement and other motor actions. Those with FTD may fall frequently or have unwanted arm and leg movements or shakiness.

Interestingly, a person's memory and understanding of the space around them often remain relatively intact, especially in the earlier stages.

How FTD and Alzheimer's Differ

In Alzheimer’s, the typical initial symptoms are short-term memory impairment and difficulty learning something new. In FTD, the memory usually remains intact initially; early symptoms include difficulty with appropriate social interactions and emotions, as well as some language challenges.

FTD and Alzheimer’s also differ in how the brain is physically affected. FTD mainly affects the brain's frontal and temporal lobes, whereas Alzheimer’s affects the temporal lobes in early stages, but progression impacts most areas of the brain.

FTD also targets younger individuals. The average age of onset for FTD is about 60 years old. While some people have early-onset Alzheimer’s, the majority develop it after age 65 and many of those are well into their 70s or 80s.

Frontotemporal Dementia Causes

The cause of FTD is not known.  It is estimated that 30% to 50% of cases have a family history of FTD or related disease and the remaining cases of FTD appear to develop by chance. Approximately 10% of cases can be traced back to a change in a single gene. This gene mutation is directly inherited, meaning that if your mother or father has that specific gene for FTD, you have a 50% chance of developing FTD.

Diagnosing Frontotemporal Dementia

Similar to diagnosing Alzheimer’s disease, there is no single test that can diagnose FTD. People with possible FTD typically undergo tests such as:

• An MRI or a PET scan
• Cognitive testing to measure memory and language abilities
• Physical movement testing
• A spinal tap (possibly)
• Blood tests

Diagnosis is made by gathering all of the results from these tests, ruling out other causes such as vitamin B12 deficiency or infections, and comparing your symptoms to other cases of FTD. A neurologist familiar with FTD and other types of dementia should be involved in this evaluation since certain aspects of FTD mimic other disorders.

Treatment for Frontotemporal Dementia

There is no medication that targets this type of dementia, so the treatment goal is to control symptoms as much as possible. Physicians may prescribe medications that are often used for the movement problems in Parkinson's disease, including Carbidopa/levodopa (Sinemet). Sometimes the behaviors of FTD are addressed with antipsychotic medications if non-drug approaches are ineffective.

Antidepressant medications, specifically selective serotonin reuptake inhibitors (SSRIs), have shown some benefit in treating some of the obsessive or compulsive behaviors of FTD. Some physicians will also prescribe medications usually given for Alzheimer’s, including cholinesterase inhibitors. Research, however, has not clearly shown these medications to be effective for FTD yet.

Occupational and physical therapy can also help maintain or slow the deterioration of motor and movement abilities, while speech therapy can sometimes assist with communication deficits.

Prevalence

About 10% to 20% of all dementias are FTD, which translates to an estimated 50,000 to 60,000 Americans. FTD is one of the more common types of dementia in adults younger than age 65, and it is more common in men than women.

Prognosis

The prognosis of FTD is poor. Life expectancy is typically six to eight years, sometimes longer and sometimes shorter. FTD does not cause death, but it makes fighting other illnesses and infections more difficult.

Summary

Frontotemporal dementia is a type of dementia that includes a group of disorders that affect behavior, emotions, communication, and cognition. The cause of FTD is not known. Genetics plays a role in some cases of FTD, but most cases appear to develop by chance. A variety of tests are done to diagnose FTD and treatment focuses on controlling symptoms as best as possible.