Researchers have found how frontotemporal dementia (FTD) fundamentally alters a person’s capacity for empathy, revealing new insights into a condition that can strike people as young as 40.
The new Swedish study, published Dec. 3 in JAMA Network Open, suggests that patients with FTD, a progressive brain disorder affecting the frontal and temporal lobes of the brain, which are areas crucial for personality, behavior, and language, display distinct brain activity patterns when observing the pain of others. This differentiation sets them apart from healthy individuals.
“What is particularly interesting is that we have been able to relate this measure of brain activity in patients to how carers rate their lack of empathy,” Olof Lindberg, a brain researcher and co-author of the study, said in a press statement. “There turned out to be a strong correlation, and that’s important. It shows that what happens in the brain is connected to the people’s behavior.”
A Dementia Affecting Younger People
While FTD represents an estimated up to 20 percent of all dementia cases, unlike other types of progressive brain diseases, it is most common in people under 60.
Symptoms typically start between the ages of 40 and 65. However, it can also occur in younger and older adults, and men and women are equally at risk.
One form of FTD, known as behavioral variant frontotemporal dementia (bvFTD), is characterized by a severe loss of empathy as an early and core symptom. bvFTD is a common cause of dementia in people younger than 65 and is responsible for about half of all FTD cases.
Patients with bvFTD often exhibit a diminished response to the emotions of others, a lack of social interest, and a flat facial expression. It can also lead to insensitive comments or self-centered behavior.
Patients Displayed Lack of Empathy for Others’ Pain
The new research focused on developing a further understanding of bvFTD.
Researchers Lindberg from Karolinska Institutet and Alexander Santillo from Lund University analyzed the brain activity of 28 diagnosed FTD patients using functional magnetic resonance imaging (fMRI), a common, noninvasive type of brain imaging used to measure brain activity by detecting changes associated with blood flow, and 28 healthy controls.
Their examination focused on patient reactions to images of hands being pierced by needles, a stimulus expected to activate brain regions associated with processing pain and suffering. Patients with bvFTD had reduced responses in the brain areas involved in processing empathy.
Although dementia is often linked with memory impairment, the loss of empathy associated with FTD can lead to misdiagnosis as other psychiatric conditions, such as psychopathy, a personality disorder where people show a lack of empathy and remorse and have little to no regard for social norms.
Lindberg emphasized that the new insights into brain activity could enhance understanding of this complex disease.
“This captures a key symptom in patients, and with a lack of empathy, it naturally becomes more difficult to act socially. So, it can affect the judgement [sic] of whether to be cared for at home, for example,” he noted in the press release.