Frontotemporal degeneration, also called Pick’s disease, from which American actor Bruce Willis suffers, is a much less common form of dementia than Alzheimer’s disease, which primarily affects language functions.
While nearly 70% of all cases of dementia are caused by Alzheimer’s disease, only about 5% are attributable to frontotemporal degeneration. Lewy body dementia, which actor Robin Williams suffered from, is thought to be responsible for 15% of cases and an equal or slightly higher number of people suffer from vascular dementia.
Frontotemporal dementia (FTD) is also different from Alzheimer’s disease in that it affects younger people. While the frequency of Alzheimer’s disease increases after the age of 65, FTD mainly strikes people between the ages of 45 and 65.
This neurodegenerative disease is characterized by a very marked atrophy of the frontal and temporal lobes of the brain, from which it takes its name. There are three types of DFTs. The most classic and well-known form first affects the behavior of the person, who experiences a change in personality. “The interests of the person change. She may become more religious, more emotionally detached, more uninhibited and say inappropriate things. His social filters are deteriorating, ”says the Dr Étienne De Villers-Sidani, neurologist at The Neuro (Montreal Neurological Institute-Hospital).
There is also a language form and a semantic form of DFT. People with the semantic form come to forget the usefulness of everyday objects. “They don’t necessarily have difficulty speaking, but they don’t know what to do with a hammer, for example. Their knowledge of usefulness, meaning [de la sémantique] things disappear,” he said.
Bruce Willis is likely to have the language form of DFT, believes Dr.r From Villers-Sidani. In this particular form, the frontotemporal degeneration occurs primarily in the hemisphere—most often the left—which is responsible for language. This cerebral degradation is “first reflected in difficulties of articulation and pronunciation. The language becomes jerky, it loses its fluidity. So many symptoms that must have been visible quite early in an actor like Bruce Willis, ”notes the neurologist.
“The person comes to have difficulty properly ordering the relative position of words in a sentence, respecting the agreement of verbs. She makes grammatical errors. These difficulties affect both spoken and written language. While coordination of multiple muscles in the vocal cords, tongue and mouth normally happens automatically and unconsciously when we speak, the person with FTD has to think about how to articulate words, what comes out of their mouth is so often disorganized. The person has progressive aphasia and has difficulty understanding certain complex instructions transmitted orally or in writing. We understand that it is really the center of the language that is affected”, he explains.
By the way, Bruce Willis had already been diagnosed with aphasia in the spring of 2022.
“As FTD is uncommon, these symptoms are often mistakenly attributed to a cerebrovascular accident (CVA)”, underlines the neurologist who admits that FTD is more difficult to diagnose.
It is the neural networks involved in language that are targeted in this disease, but the degeneration continues to spread beyond this region and eventually affects the entire brain. This is why other difficulties gradually appear, such as motor losses in the upper limbs, memory problems.
In Alzheimer’s disease, it is rather the interior of the temporal lobes which are first affected, more precisely the hippocampi, structures which play a central role in memory, hence the loss of short-term memory which occurs manifest early in the disease. However, there is “a form of Alzheimer’s which mainly affects language and which is called logopenic aphasia. The latter does not affect phonetic articulation as FTD does, but causes difficulty in finding the right words to describe things,” explains the dementia specialist.
Genetic abnormalities may be the cause of the language form of FTD, which Bruce Willis suffers from. “An abnormality on chromosome 7 is sometimes present in affected individuals. If a child inherits the mutation carried by one of its two parents, it is almost certain that it will develop the disease”, warns the Dr De Villers-Sidani.
At the moment, there is no treatment for this disease. The life expectancy of patients is 7 to 13 years. As the language form of DFT attacks the various muscles in the mouth involved in language, there comes a time when the person has difficulty swallowing, and may then suck in food and become unable to eat.