Background & Aims

Cognitive symptoms, such as difficulties in concentration and attention, commonly known as ‘fibro-fog,’ are often reported by people with Fibromyalgia (FM). Patients report problems with sustained attention and concentration as particular issues (Kratz 2015; Moore 2019). However, the cause of these symptoms is unknown, as is how the self-reported severity of these cognitive symptoms relate to performance on cognitive assessments. Sleep disturbance may be a potential mechanism through which FM is associated with these cognitive symptoms (Kratz 2020).
We performed a cross-sectional study of FM patients from Oxford University Hospitals and 177 healthy controls (HC) recruited from the Prolific online participant recruitment platform. This study aims to compare performance on a visual sustained attention task in FM patients with healthy adults, and to examine the role of self-reported sleep quality and cognitive symptom severity on task performance in FM.

Methods

In this cross-sectional study, 37 FM patients (mean age 47.6 years, 91.8% female) and 177 HCs completed a web-based visual sustained attention task over 9 minutes. The task involved pressing the spacebar when ‘0’ appeared amidst other digits (1-9), masked by a semi-transparent grey checkerboard. Each minute, they rated pain, fatigue and motivation on a visual analogue scale (Zhao 2022; Zhao 2024 [in press]).
We measured accuracy through the hit (true positive) and false alarm (false positive) rates, and estimated reaction times from hit responses. FM patients reported subjective cognition (British Columbia Cognitive Complaints Inventory) and sleep quality (Pittsburgh Sleep Quality Index). Group comparisons between overall performance and group were made using linear regression. We used linear mixed effects models to evaluate the impact of FM on hit rate over time, including interactions with motivation and fatigue. For FM patients, a separate model assessed the interaction with pain.

Results

Both groups showed a decline in task performance and motivation, and an increase in fatigue, over time. Compared to HCs, FM patients showed lower age-standardised hit rate [-1.16 (95%CI -1.58 to -0.75) standard deviations; P<0.001] but no difference in reaction time or false alarm rate. The interaction between group and time on hit rate was significant [F(1,1911.04)=17.28; P<0.001), indicating a differential change in accuracy over time compared to HCs. There were significant interactions of FM with time and motivation [F(1,1865.15)=8.05; P=0.005] and fatigue [F(1,1907.73)=8.05; P<0.001], suggesting that the influence of motivation and fatigue on accuracy varies over time in FM compared to HCs. In FM, higher levels of pain during the task were associated with higher hit rate [F(1,325.86)=6.97; P=0.009]. Worse self-reported sleep quality (Rho=-0.32; P=0.062) and cognitive abilities (Rho=-0.46; P=0.006) were associated with lower hit rates.

Conclusions

We demonstrate a lower hit rate on a sustained visual attention task in patients with FM compared to HCs. We find that FM patients display a more rapid decline in accuracy over time, with a greater sensitivity to the deleterious effects of fatigue and motivation. Of note, in FM higher pain levels were not associated with worse performance, suggesting that the observed effect is not due to an interruptive effect of pain on attention. This dynamic nature of impairment in FM is a novel insight, suggesting that cognitive symptoms in FM may be more pronounced during prolonged cognitive engagement and influenced by fluctuating motivational and fatigue levels. We also find that performance correlates with self-reported cognition, suggesting that our observation aligns with patient-reported severity of cognitive symptoms. Lower levels of self-reported sleep quality are also associated with worse cognitive performance, suggesting that disturbed sleep may play a role in the cognitive symptoms.

References

Kratz AL, Schilling SG, Goesling J, Williams DA. Development and initial validation of a brief self-report measure of cognitive dysfunction in fibromyalgia. The Journal of Pain. 2015 Jun 1;16(6):527-36.

Kratz AL, Whibley D, Kim S, Sliwinski M, Clauw D, Williams DA. Fibrofog in Daily Life: An Examination of Ambulatory Subjective and Objective Cognitive Function in Fibromyalgia. Arthritis Care Res (Hoboken). 2020 Dec;72(12):1669-1677. doi: 10.1002/acr.24089. Epub 2020 Nov 9. PMID: 31609548; PMCID: PMC7153985.

Moore DJ, Meints SM, Lazaridou A, Johnson D, Franceschelli O, Cornelius M, Schreiber K, Edwards RR. The effect of induced and chronic pain on attention. The Journal of Pain. 2019 Nov 1;20(11):1353-61.

Tang NKY. Is cognitive-behaviour therapy for insomnia (CBT-I) the new best pain killer? Sleep Med Rev. 2021 Dec;60:101536. doi: 10.1016/j.smrv.2021.101536. Epub 2021 Aug 2. PMID: 34416427.

Presenting Author

Eoin Kelleher

Poster Authors

Eoin Kelleher, MB BCh MSc FCAI

MB BCh MSc FCAI

University of Oxford

Lead Author

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Sijia Zhao BSc MSc DPhil

University of Oxford

Lead Author

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Amanda Wall

University of Oxford

Lead Author

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Sanjay Manohar MRCP PhD MBPsS

University of Oxford

Lead Author

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Irene Tracey

MA (Oxon)

Wellcome Centre for Integrative Neuroimaging, FMRIB Centre, Nuffield Department of Clinical Neurosci

Lead Author

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Anushka Irani (nee Soni)

Mayo Clinic Florida

Lead Author

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Topics

  • Specific Pain Conditions/Pain in Specific Populations: Fibromyalgia