Brain function characteristics of chronic fatigue syndrome: A task fMRI study

Zack Y Shan; Kevin Finegan; Sandeep Bhuta; Timothy Ireland; Donald R Staines; Sonya M Marshall-Gradisnik; Leighton R Barnden

doi:10.1016/j.nicl.2018.04.025

Brain function characteristics of chronic fatigue syndrome: A task fMRI study

Neuroimage Clin. 2018 Apr 25:19:279-286. doi: 10.1016/j.nicl.2018.04.025. eCollection 2018.

Authors

Zack Y Shan¹, Kevin Finegan², Sandeep Bhuta², Timothy Ireland², Donald R Staines³, Sonya M Marshall-Gradisnik³, Leighton R Barnden³

Affiliations

¹ National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia. Electronic address: z.shan@griffith.edu.au.
² Medical Imaging Department, Gold Coast University Hospital, Parklands, QLD 4215, Australia.
³ National Centre for Neuroimmunology and Emerging Diseases, Menzies Health Institute Queensland, Griffith University, Southport, QLD 4222, Australia.

Abstract

The mechanism underlying neurological dysfunction in chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is yet to be established. This study investigated the temporal complexity of blood oxygenation level dependent (BOLD) changes in response to the Stroop task in CFS patients. 43 CFS patients (47.4 ± 11.8 yrs) and 26 normal controls (NCs, 43.4 ± 13.9 yrs) were included in this study. Their mental component summary (MCS) and physical component summary (PCS) from the 36-item Short Form Health Survey (SF-36) questionnaire were recorded. Their Stroop colour-word task performance was measured by accuracy and response time (RT). The BOLD changes associated with the Stroop task were evaluated using a 2-level general linear model approach. The temporal complexity of the BOLD responses, a measure of information capacity and thus adaptability to a challenging environment, in each activated region was measured by sample entropy (SampEn). The CFS patients showed significantly longer RTs than the NCs (P < 0.05) but no significant difference in accuracy. One sample t-tests for the two groups (Family wise error adjusted P_FWE < 0.05) showed more BOLD activation regions in the CFS, although a two sample group comparison did not show significant difference. BOLD SampEns in ten regions were significantly lower (FDR-q < 0.05) in CFS patients. BOLD SampEns in 15 regions were significantly associated with PCS (FDR-q < 0.05) and in 9 regions were associated with MCS (FDR-q < 0.05) across all subjects. SampEn of the BOLD signal in the medioventral occipital cortex could explain 40% and 31% of the variance in the SF-36 PCS and MCS scores, and those in the precentral gyrus could explain an additional 16% and 7% across all subjects. This is the first study to investigate BOLD signal SampEn in response to tasks in CFS. The results suggest the brain responds differently to a cognitive challenge in patients with CFS, with recruitment of wider regions to compensate for lower information capacity.

Keywords: Chronic fatigue syndrome; Event related fMRI; Sample entropy; Stroop task; fMRI.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Brain / diagnostic imaging*
Fatigue Syndrome, Chronic / diagnostic imaging*
Fatigue Syndrome, Chronic / psychology
Female
Humans
Linear Models
Magnetic Resonance Imaging
Male
Middle Aged
Neuropsychological Tests
Reaction Time / physiology
Surveys and Questionnaires