Changes in Fatigue Following a Behavioral Memory Intervention in Multiple Sclerosis

Background: Fatigue is one of the most common and debilitating symptoms of Multiple Sclerosis (MS), negatively impacting an individual’s cognitive functioning and overall quality of life.  The current study evaluated the impact of a behavioral memory intervention, the modified Story Memory Technique (mSMT), on self-reported fatigue.

Objectives: Evaluate the effects of a 10-session, behavioral, highly-manualized memory retraining protocol, the modified Story Memory Technique (mSMT), on self-reported fatigue in MS patients.

Methods: 72 participants with MS were  randomly assigned to either a treatment group (N=37) or a placebo-control group (N=35).   All participants received comprehensive baseline neuropsychological (NP) assessment. Global assessment of functioning included a self-report measure of fatigue (Modified Fatigue Impact Scale; MFIS).  Participants were then randomly assigned to the two groups. The treatment group underwent a10-session memory retraining protocol (modified Story Memory Technique; mSMT). The control group engaged in similar exercises during the 10 sessions, but did not receive training in visualization and context, the key ingredients of the mSMT . Following treatment, all participants completed a repeat NP evaluation which included most of the baseline NP and functional measures, including the MFIS.  

Results: There were no significant differences between the groups on any demographic variables.  When examining differences in self-reported fatigue from pre-treatment to post-treatment, there were no significant differences between the treatment and placebo-control groups.  However, there was a significant difference  in the change in self reported fatigue post treatment when comparing “responders” to treatment  versus the control group.  Specifically, contrary to our expectations, responders to treatment reported greater self-reported fatigue at follow-up as compared to  baseline (t (2, 13) = -1.95, p = .073, trend), while participants in the placebo-control group reported no changes in self-reported fatigue (t (2, 34) = 1.458, p = .154). Treatment responders showed significantly higher levels of self-reported fatigue at follow-up as compared to placebo-control particpants (F (1, 49) = 12.133, p =.001). No such differences were found at baseline (F (1, 59) = .524, p=.472).

Conclusions: Increase in fatigue following treatment was specific to those participants in the treatment group that showed a positive response to treament. in terms of their memory ability.  The increase in fatigue was significant as compared with control participants.  This finding likely reflects the fact that the application of the newly learned techniques is effortful.  We hypothesize that as these participants continue to utilize these techniques, the application of the techniques will become more automatic, require less cognitive effort and  result in less self-reported fatigue over time.