Symptoms of frontotemporal disorders vary from person to person and from one stage of the disease to the next as different parts of the frontal and temporal lobes  are affected. In general, changes in the frontal lobe are associated with behavioral symptoms, while changes in the temporal lobe lead to language and emotional disorders.
Symptoms are often misunderstood. Family members and friends may think that a person is misbehaving, leading to anger and conflict. For example, a person with bvFTD may neglect personal hygiene or start shoplifting. It is important to understand that people with these disorders cannot control their behaviors and other symptoms. Moreover, they lack any awareness of their illness, making it difficult to get help.
- Problems with executive functioning—Problems with planning and sequencing (thinking through which steps come first, second, third, and so on), prioritizing (doing more important activities first and less important activities last), multitasking (shifting from one activity to another as needed), and self-monitoring and correcting behavior.
- Perseveration—A tendency to repeat the same activity or to say the same word over and over, even when it no longer makes sense.
- Social disinhibition—Acting impulsively without considering how others perceive the behavior. For example, a person might hum at a business meeting or laugh at a funeral.
- Compulsive eating—Gorging on food, especially starchy foods like bread and cookies, or taking food from other people’s plates.
- Utilization behavior—Difficulty resisting impulses to use or touch objects that one can see and reach. For example, a person picks up the telephone receiver while walking past it when the phone is not ringing and the person does not intend to place a call.
- Aphasia —A language disorder in which the ability to use or understand words is impaired but the physical ability to speak properly is normal.
- Dysarthria—A language disorder in which the physical ability to speak properly is impaired (e.g., slurring) but the message is normal.
People with PPA may have only problems using and understanding words or also problems with the physical ability to speak. People with both kinds of problems have trouble speaking and writing. They may become mute, or unable to speak. Language problems usually get worse, while other thinking and social skills may remain normal longer before deteriorating.
David and his wife ran a successful store until he began to act strangely. He intruded on his teenaged daughters’ gatherings with friends, standing and staring at them but not realizing how embarrassed they were. He took food from other people’s plates. A year later, David, 47, and his wife lost their business. After a misdiagnosis of depression and no improvement, David’s wife took him to a neurologist, who diagnosed bvFTD.
- Apathy—A lack of interest, drive, or initiative. Apathy is often confused with depression, but people with apathy may not be sad. They often have trouble starting activities but can participate if others do the planning.
- Emotional changes—Emotions are flat, exaggerated, or improper. Emotions may seem completely disconnected from a situation or are expressed at the wrong times or in the wrong circumstances. For example, a person may laugh at sad news.
- Social-interpersonal changes—Difficulty “reading” social signals, such as facial expressions, and understanding personal relationships. People may lack empathy—the ability to understand how others are feeling—making them seem indifferent, uncaring, or selfish. For example, the person may show no emotional reaction to illnesses or accidents that occur to family members.
Not acting like himself
Previously a devoted husband, Gary began an extramarital affair at age 55—and didn’t care that everyone knew about it. His wife was devastated and angry. His friends agreed that this was not like him. All attempts to reason with him were unsuccessful, as Gary could not understand how his actions hurt others. His wife insisted on a visit to the doctor. Initially, Gary was misdiagnosed with bipolar disorder. After further evaluation, he was told he had bvFTD.
- Dystonia —Abnormal postures of body parts such as the hands or feet. A limb may be bent stiffly or not used when performing activities that are normally done with two hands.
- Gait disorder—Abnormalities in walking, such as walking with a shuffle, sometimes with frequent falls.
- Tremor —Shakiness, usually of the hands.
- Clumsiness—Dropping of small objects or difficulty manipulating small items like buttons or screws.
- Apraxia —Loss of ability to make common motions, such as combing one's hair or using a knife and fork, despite normal strength.
- Neuromuscular weakness—Severe weakness, cramps, and rippling movements in the muscles.