Patients with frontotemporal dementia more likely to exhibit apathy, functional decline

People with behavioral variant frontotemporal dementia were more likely to exhibit apathy and functional decline, even in the mildest stage of dementia, compared with patients with Alzheimer’s disease, researchers recently reported.

“The condition is not as common as Alzheimer’s type dementia and it occurs in a somewhat younger cohort, when patients may have better cognition than those with AD, especially in the early stages,” Healio/Neurology Peer Perspective Board member and study author Mary Sano, PhD, told Healio.

Sano, director of the Alzheimer’s Disease Research Center and associate dean for clinical research at Mount Sinai School of Medicine, and colleagues conducted a cohort study to assess the link between apathy and function in adults with a range of dementia severity, including behavioral variant frontotemporal dementia (bvFDT) and AD. Researchers used data from patients enrolled in National Institute of Aging-funded Alzheimer’s Disease Research Centers.

“Apathy, which may appear as loss of initiative, is among the most common behavior in bvFTD and families as well as trained practitioners — primary care, general neurologists, nurse practitioners — may misconstrue the symptoms as depression or withdrawal or intentional lack of motivation,” Sano said. “In fact, these signs of apathy can be very serious because they are associated with problems in activities of daily living, such as handling finances and making decisions in a timely manner.”

The cohort included 866 individuals with a clinical diagnosis of bvFTD at baseline who were enrolled in the National Alzheimer's Coordinating Center Uniform Data Set (NACC-USD) between 2005 and 2019 and had one or more annual follow-ups.

Researchers measured function using the Functional Assessment Questionnaire (FAQ) and assessed apathy via clinical judgment within the NACC-USD protocol. Participants were categorized into four mutually exclusive apathy groups — never, intermittent, persistent and always. Dementia severity was categorized at baseline using the Clinical Dementia Rating (CDR) scale of 0.5+ (n = 359), 1 (n = 340) and 2 or greater (n = 167).

According to results, participants with more severe dementia had worse baseline FAQ scores: Compared with patients with a CDR of 0.5+, FAQ scores were 8.3 points higher in those with CDR of 1 and 19.9 points higher in those with a CDR of 2 or greater.

In addition, FAQ scores significantly worsened by 4.4 points per year for the entire sample, although rate of functional decline was slower in those with a baseline CDR of 1 (b = –0.125) and a baseline CDR of 2 or greater (b = –1.659), compared with participants with a baseline CDR of 0.5+.

Further, FAQ scores were 3.5 points higher at baseline in the intermittently and persistently apathetic groups compared with the never apathetic group and 5.1 points in the always apathetic group. Rate of functional decline was faster in the always apathetic group (b = 0.507) and intermittently and persistently apathic groups (b = 0.482) compared with the never apathetic group.

“This work reminds us that symptoms of apathy should be evaluated particularly in those who may have a neurologic condition, because apathy can put a person at risk to make poor judgments, to be likely to have a more precipitous decline in daily function,” Sano said. “It suggests that supervision even at the earliest stages may be needed to protect the person from rash decisions that could affect their safety as well as their financial and medical health.”