What exactly is frontotemporal dementia (FTD)?
Frontotemporal dementia, also called FTLD (for frontotemporal lobar degeneration), refers to a syndrome of related diseases. There are 3 main forms of frontotemporal dementia:
- Behavioral variant frontotemporal dementia (bvFTD), sometimes called frontal variant frontotemporal dementia (fvFTD) or Pick's disease, negatively impacts social skills, emotions, personal conduct, and self-awareness. People with bvFTD might act in inappropriate ways, show a lack of judgment or inhibition, neglect to maintain personal hygiene, do something compulsively or repetitively, or feel euphoric or apathetic. bvFTD is the most common form of frontotemporal dementia.
- Semantic dementia (SD), also called temporal variant frontotemporal dementia, is another form of frontotemporal dementia. Some people with SD have difficulty remembering what words signify because the disease damages the left temporal lobe, the region of the brain that pairs words with meanings. In other cases, SD starts in the right temporal lobe, and patients have trouble remembering the faces of friends and family and are unable to understand others’ emotions. Whether it begins in the left or right temporal lobe, the disease eventually spreads to both, so late-stage patients exhibit changes in both language and social skills.
- People with progressive nonfluent aphasia (PNFA) also have language difficulties, but unlike SD patients, they can remember the meaning of words. Instead, they are unable to communicate fluently. They make speak slowly, have trouble pronouncing words, or get confused when processing complex sentence structure, using the phone, or talking with a group of people. Eventually they go mute as a result of changes to the left temporal lobe. As PNFA progresses, patients experience weakness and rigidity in muscles including the arms, legs, eyes, and throat.
Some people with frontotemporal dementia also develop motor neuron disease (FTD-MND), which causes slurred speech, trouble swallowing, choking, limb weakness, and muscle wasting. These symptoms appear because MND affects motor nerve cells in the spinal cord, the brain stem, and the cerebral cortex. Recent research suggests a link between frontotemporal dementia and amyotrophic lateral sclerosis (ALS), also called Lou Gehrig's disease. Scientists believe that ALS and certain types of frontotemporal dementia are part of the same disease spectrum, in which some people have ALS only, some have frontotemporal dementia only, and some have both. Patients with these symptoms often have a family history of the disease, with mutations in the gene C9ORF72 a common cause.
How common is frontotemporal dementia?
Approximately 3000-5000 Americans are diagnosed with frontotemporal dementia each year. It is the 2nd most common dementia in individuals under age 60.
Where can I find support for patients and caregivers living with frontotemporal dementia?
Your doctor can provide you with local resources. Please see our web links for online resources.