title: The MenFAS Study: Understanding Mental Fatigue after Stroke
Creators: name: Dillon, Avril
Publisher: name: Oxford Brookes University
Year: 2023

description: Mental fatigue is a highly distressing symptom after stroke, and motor factors alone cannot explain the persistence of severe fatigue even many months after the stroke. Evolving theories suggest that mental fatigue is associated with cognitive impairment in general, and perhaps dysfunction in the cognitive domain of attention in particular. However, the relationship between attention and mental fatigue after stroke has rarely been examined and given the negative impact of mental fatigue on participation, an understanding of underlying mechanisms mediating mental fatigue is clinically significant. Furthermore, there is insufficient evidence of the efficacy of any intervention strategy to treat or prevent post-stroke fatigue (PSF) that considers real world context and environment, such as attention or contextual factors and their potential effect on PSF. A systematic review to describe the full extent of the evidence, was extended across the post Acquired Brain Injury (ABI) fatigue literature, which included stroke populations. Analysis found sustained attentional performance had stronger associations with fatigue after ABI, though inconsistencies in measurement were shown. A synthesis of the theory base underlined the complexities involved in the domain of attention, and the need for focused measurement strategy to understand the mechanisms of fatigue. Taken together insights gained supported the development of a novel measurement strategy designed to capture the momentary lived experience of fatigue and traits of fatigue (mental and physical fatigue) within the context of the task, in the home environment. A cross sectional observation study pre-trialling the use of a novel measurement strategy involving 32 patients at the early phase (>2 months) post-stroke experiencing PSF, confirmed a relationship between sustained attention and mental and physical fatigue within a very short time-frame, in the home environment. Linear regressions (R2) revealed a statistically significant relationship between sustaining attention on the MCCPT and trait fatigue: Accuracy & FSMC sum score (R2=.141, p = .034), Accuracy & FSMC cognitive score (R2=.153, p = .027), Accuracy & FSMC motor score (R2=.152, p = .027). The pre/post study design provided insights into the mutli-dimensional facets of fatigue, with further burdens on executive attentional involved in motor control indicated. Participants experienced higher levels of fatigue in the moments following completion of the attentional task (R2=.107, p = .068), rather than before. A novel occupation-focused intervention support system to manage PSF was developed to investigate, in a sample of 29 stroke survivors at the early phase of stroke (> 2months), the extent of the impact of altering attentional focus on both fatigue levels and subsequent task performance. This feasibility trial demonstrated how investigating the impact of altering attentional focus (with noise-cancelling earphones) is feasible, acceptable, and safe within the community. Study findings supported the use of this trial design within the community. Preliminary findings offer potential further insights into how attentional mechanisms and contexts interact at the sub-acute phase of recovery. In a short time-frame (>12 minutes), increased focus appears to place greater demands on attentional processes involved in motor functioning processes, i.e. Inhibition. Over the longer term (such as a standard therapy session, <45 minutes) altering contextual noise (with noise-cancelling earphones) led to better performance (-12.6, 95% CI [-7.1, -4.7], t (28) = - 4.7, p = <.001) but at a higher cost in terms of fatigue. Conclusion: This thesis provides novel insights into the role played by sustained attention in the development of mental fatigue at the early phase post-stroke. The initial findings are promising for both research and clinical practice with potential implications for furthering knowledge of who is at risk of developing symptoms of mental fatigue. A larger definitive trial replicated with this trial design, would add to the generalisability of the findings. Furthermore, it may shed a light on possible prevention strategies, and provide suitable guidance on self-management strategies for those affected by mental fatigue that is grounded in empirical evidence.