Frontotemporal Disorders: Information for Patients, Families, and Caregivers

Frontotemporal disorders can be grouped into three types, defined by the earliest symptoms physicians identify when they examine patients.

• Progressive behavior/personality decline—characterized by changes in personality, behavior, emotions, and judgment (e.g., behavioral variant frontotemporal dementia).
• Progressive language decline—marked by early changes in language ability, including speaking, understanding, reading, and writing (e.g., primary progressive aphasia).
• Progressive motor decline—characterized by various difficulties with physical movement, including shaking, difficulty walking, frequent falls, and poor coordination.

It can be hard to know which of these disorders a person has because symptoms and the order in which they appear can vary widely from one person to the next. Also, the same symptoms can appear in different disorders. For example, language problems are most typical of primary progressive aphasia but can also appear in the course of behavioral variant frontotemporal dementia. The table below summarizes the three types of frontotemporal disorders and lists the various terms that could be used when clinicians diagnose these disorders.

Behavioral Variant Frontotemporal Dementia

The most common frontotemporal disorder, behavioral variant frontotemporal dementia (bvFTD), involves changes in personality, behavior, and judgment. People with this dementia can act strangely around other people, resulting in embarrassing social situations. Often, they don’t know or care that their behavior is unusual and don’t show any consideration for the feelings of others. Over time, language and/or movement problems may occur, and the person needs more care and supervision.

In the past, bvFTD was called Pick's disease, named after Arnold Pick, the German scientist who first described it in 1892. The term Pick’s disease is now used to describe abnormal collections in the brain of the protein tau, called "Pick bodies," which can only be seen under the microscope after death. Some patients with bvFTD have Pick’s disease, and some do not.

Primary Progressive Aphasia

Primary progressive aphasia (PPA) involves changes in the ability to communicate—to use language to speak, read, write, and understand what others are saying. Problems with memory, reasoning, and judgment are not apparent at first but can develop over time. In addition, some people with PPA may experience significant behavioral changes, similar to those seen in bvFTD, as the disease progresses. As symptoms get worse, people with PPA cannot live alone safely.

Currently, there are three types of PPA, categorized by the kind of language problems seen at first. Researchers do not fully understand the different types of PPA. But they hope one day to link specific language problems with the abnormalities in the brain that cause them.

In semantic PPA, also called semantic dementia, a person slowly loses the ability to understand single words and sometimes to recognize the faces of familiar people and common objects.

In agrammatic PPA, also called progressive nonfluent aphasia, a person has trouble saying words that link nouns and verbs together—for example, "of," "from," and "for." Eventually, the person may no longer be able to speak at all. He or she may also have difficulty swallowing and develop movement symptoms similar to those seen in corticobasal syndrome.

In logopenic PPA, a person has trouble finding the right words during conversation but can understand words and sentences. The person does not have problems with grammar.

Movement Disorders

Two rare neurological disorders associated with FTLD, corticobasal syndrome (CBS) and progressive supranuclear palsy (PSP), occur when the nerves attached to muscles malfunction and cause problems with movement. The disorders may affect thinking and language abilities, too.

CBS is caused by corticobasal degeneration—gradual atrophy and loss of nerve cells in specific parts of the brain. This degeneration causes progressive loss of movement and muscle rigidity, typically beginning around age 60. Symptoms may appear first on one side of the body, but eventually both sides are affected. Occasionally, a person with CBS first has language problems or trouble orienting objects in space and later develops movement symptoms.

PSP causes serious problems with balance and walking. People with the disorder typically move slowly, fall, and have body stiffness, especially in the neck and upper body—symptoms similar to those of Parkinson’s disease. A hallmark sign of PSP is trouble with eye movements, such as involuntary closing of the eyelids, difficulty opening and closing the eyes, trouble looking way up and way down, and limited blinking. These symptoms may give the face a fixed stare. Behavior problems can also develop.

Other movement-related frontotemporal disorders include frontotemporal dementia with parkinsonism and frontotemporal dementia with amyotrophic lateral sclerosis (FTD-ALS).

Frontotemporal dementia with parkinsonism is an inherited disease caused by a genetic mutation. Symptoms include movement problems similar to those of Parkinson’s disease, such as slowed movement, stiffness, and balance problems, and changes in behavior or language.

FTD-ALS is a combination of bvFTD and ALS, commonly called Lou Gehrig’s disease. Symptoms include the behavioral and/or language changes seen in bvFTD as well as the muscle weakness, shrinking, and jerking seen in ALS. Symptoms of either disease may appear first, with other symptoms developing over time. Mutations in certain genes have been found in some patients with FTD-ALS.