Progressive MS Patients Have Difficulties Perceiving Thoughts, Intentions of Others, Study Reveals

Patients with progressive multiple sclerosis (MS) have difficulties perceiving the thoughts and intentions, but not the emotions, of other individuals, Kessler Foundation researchers have found.

Those findings were reported in a study, “Cognitive but Not Affective Theory of Mind Deficits in Progressive MS,” that was published in the Journal of the International Neuropsychological Society.

MS is a neurodegenerative and autoimmune disease that commonly manifests during adulthood with a broad range of symptoms, which can include difficulties with movement (motor impairment), and cognitive and emotional changes.

“While cognitive impairments are a commonly examined component of disability in MS, there is recently heightened scientific interest in examining social cognitive impairments, such as emotion perception and theory of mind,” researchers wrote.

The theory of mind (ToM) is the individual’s ability to attribute mental states — such as beliefs, emotions, desires — to himself and others, and to understand that others may have perspectives different from his. It is extremely important for daily social interactions because it is used unconsciously by all individuals to judge and understand the actions and behaviors of their peers.

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Although social cognitive deficits are found in all disease subtypes, and are evident even in the early stages of MS, these deficits appear to be more pronounced in those with progressive MS. “Unfortunately, to date, the majority of research on social cognition in MS has focused on relapsing-remitting MS, thus limiting our ability to understand these deficits in more progressive subtypes,” researchers stated.

To fill this knowledge gap, Kessler researchers evaluated the impact of progressive MS on patients’ ability to infer the thoughts and intentions (cognitive ToM), as well as the emotions (affective ToM) of others.

The study enrolled 15 patients with progressive MS and 15 healthy volunteers. All completed the Virtual Assessment of Mentalising Ability (VAMA), a test composed of a series of video clips depicting social situations in which individuals are asked to describe what the actors are thinking and feeling at specific intervals.

Results showed that patients with progressive MS had difficulties inferring the thoughts and intentions of individuals acting in the video clips, when compared to healthy participants used as controls in the study. However, the ability to perceive the emotions of actors in the scenes was similar in both groups.

In addition, researchers found that the patients’ inability to perceive the thoughts and intentions of others was due to overall impairments in their cognitive abilities caused by MS. This was confirmed by their poor performance on both memory and processing speed tests.

“This study is an important first step toward a better understanding of cognitive dysfunction in individuals with progressive MS,” Helen Genova, PhD, said in a press release. Genova is the Kessler foundation’s assistant director of the Center for Neuropsychology and Neuroscience Research, and one of the study authors.

“By examining both the cognitive and affective components of Theory of Mind, we found evidence for differential effects of progressive MS, similar to the effects reported for relapsing remitting MS, including the apparent sparing of affective ability. Our findings indicate that VAMA will be an important tool for developing interventions that help individuals maintain the skills needed to function in everyday life,” she said.

“[This study should be interpreted cautiously in light of its small sample size and heterogeneous population of progressive MS (inclusive of all progressive subtypes and differing in medication status),” researchers noted. “Our failure to detect impairments in affective ToM could be a result of low power rather than the absence of impairment.”

Despite the study’s limitations, these findings “represent an important first step toward understanding ToM deficits in MS,” they said. The study showed that the different components of ToM “are differentially affected by MS,” which means they may represent “an ecologically valid measure” for assessing cognitive deficits in this population, they added.