Research explores the impact of fatigue on prospective memory (PM) in persons with multiple sclerosis (PwMS), revealing a significant association between high fatigue levels and subjective PM impairment.

Fatigue is a common symptom in MS that often affects cognitive functioning. The relationship between self-reported fatigue and performance-based cognition in MS remains uncertain due to conflicting evidence. Despite the importance of PM in functional independence, its relationship to fatigue in MS has not been studied. The objective of this study is to compare subjective and objective PM scores in PwMS with high versus low levels of fatigue.

A memory test (Memory for Intentions Test; MIST) and questionnaire (Perceived Deficits Questionnaire–PM subscale; PDQ-PM) were given to 112 PwMS to assess prospective memory. Participants were divided into high-fatigue and low-fatigue groups based on their scores on a fatigue impact scale. Differences in prospective memory between the 2 fatigue groups were analyzed using linear regression, controlling for various demographic and disease-related factors, as well as depressive symptoms. Additional tests were conducted to compare specific complaints about prospective memory between the groups using the questionnaire.

There was no significant difference in MIST scores between participants with high and low fatigue levels, but those with high fatigue had significantly higher PDQ-PM scores. High fatigue remained associated with PDQ-PM scores even after controlling for covariates. Participants with high fatigue reported more problems with their memory compared to those with low fatigue.

“Fatigue level was not associated with scores on an objective measure of PM,” said researchers. “However, PwMS with high fatigue had higher subjective PM, particularly with forgetting the date and missing appointments. These findings highlight how varying levels of fatigue influence perceived PM impairment in PwMS.” 

Reference 
Jackson D, Turner A P, Raskin S A, et al. Forgotten intentions: The impact of fatigue on prospective memory in multiple sclerosis; CMSC 2024; May 29-June 1, 2024; Nashville, TN; Abstract PSY02.