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, people require 24-hour care.
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
- Repetitive compulsive behavior
- A decline in personal hygiene
- Changes in eating habits, predominantly overeating
- Oral exploration and consumption of inedible objects
- 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.
Two types of primary progressive aphasia are considered frontotemporal dementia. Primary progressive aphasia is characterized by an increasing difficulty in using and understanding written and spoken language. For example, people may have trouble finding the right word to use in speech or naming objects.
Semantic dementia is one type of primary progressive aphasia. It's also known as semantic variant primary progressive aphasia. Individuals with semantic dementia have prominent difficulty naming (anomia) and may replace a specific word with a more general word such as "it" for pen. They may also lose knowledge of word meaning.
Progressive agrammatic (nonfluent) aphasia is another type of primary progressive aphasia characterized by nonfluent and hesitant speech. Speech may sound telegraphic with misuse of pronouns and errors in sentence construction.
Rarer subtypes of frontotemporal dementia are characterized by problems with movement, similar to those associated with Parkinson's disease or amyotrophic lateral sclerosis.
Movement-related signs and symptoms may include:
- Muscle spasms
- Poor coordination
- Difficulty swallowing
- Muscle weakness