Role of selective attention in fatigue in neurological disorders

Background:Chronic fatigue is a significant symptom in several diseases including traumatic and degenerative neurological disorders. While several studies have investigated the correlates of chronic fatigue, there is as yet no unifying framework to explain chronic fatigue. Methods:In this narrative review, I investigate the role of selective attention in the development of chronic fatigue and discuss results within the framework of the sensory attenuation model of fatigue, which posits that fatigue is the phenomenological output of altered attention to sensory input. Following a short introduction of this framework, I present results from investigations that address attentional mechanisms in fatigue in multiple sclerosis, stroke, traumatic brain injury and Parkinson's disease. Results:Attention was quantified in all four disease models using a variety of outcome measures, including behavioural, neurophysiological, structural and functional brain connectivity. The range of measures precluded direct comparison of results across disease conditions; however, in all four disease models there was evidence of poor selective attention that explained levels of chronic fatigue, supporting the sensory attenuation model of fatigue as a disease-independent mechanism of fatigue. Evidence was lacking to draw any conclusions about the direction of causality. Conclusion:The role of selective attention in development of fatigue is indicated. Future studies must focus on establishing causality and exploring attentional circuitry as a potential therapeutic target.

Automated summary

Chronic fatigue is a significant symptom in various diseases, but there is no unified framework to explain it. This narrative review investigates the role of selective attention in the development of chronic fatigue and discusses results within the sensory attenuation model of fatigue. The findings suggest that poor selective attention is associated with increased levels of chronic fatigue in multiple sclerosis, stroke, traumatic brain injury, and Parkinson's disease. However, there is currently insufficient evidence to determine the direction of causality. Future research should focus on establishing causality and exploring attentional circuitry as a potential therapeutic target.