Working memory performance is correlated with local brain morphology in the medial frontal and anterior cingulate cortex in fibromyalgia patients: structural correlates of pain–cognition interaction

Abstract

Fibromyalgia (FM) is a disorder of unknown aetiology, characterized by chronic widespread pain, stiffness and sleep disturbances. In addition, patients frequently complain of memory and attention deficits. Accumulating evidence suggests that FM is associated with CNS dysfunction and with an altered brain morphology. However, few studies have specifically investigated neuropsychological issues in patients suffering from FM. We therefore sought to determine whether neuropsychological deficits found in FM patients may be correlated with changes in local brain morphology specifically in the frontal, temporal or cingulate cortices. Twenty FM patients underwent extensive testing for potential neuropsychological deficits, which demonstrated significantly reduced working memory and impaired non-verbal long-term memory (limited to free recall condition) in comparison with normative data from age- and education-matched control groups. Voxel-based morphometry (VBM) was used to evaluate for potential correlations between test results and local brain morphology. Performance on non-verbal working memory was positively correlated with grey matter values in the left dorsolateral prefrontal cortex, whereas performance on verbal working memory (digit backward) was positively correlated with grey matter values in the supplementary motor cortex. On the other hand, pain scores were negatively correlated with grey matter values in the medial frontal gyrus. White matter analyses revealed comparable correlations for verbal working memory and pain scores in the medial frontal and prefrontal cortex and in the anterior cingulate cortex. Our data suggest that, in addition to chronic pain, FM patients suffer from neurocognitive deficits that correlate with local brain morphology in the frontal lobe and anterior cingulate gyrus, which may be interpreted to indicate structural correlates of pain-cognition interaction.

Associations between cognitive performance and pain in chronic fatigue syndrome: comorbidity with fibromyalgia does matter

“…Some previous studies indicated that, in patients with FM, cognitive performance is inversely related to self-reported pain (21,22), while other authors demonstrated an absence of this relationship in FM patients (15,23) and in female CFS patients (24). However, to the best of our knowledge the association between cognitive performance and experimental pain measurements and established measures of CS has never been examined in CFS patients.…”

“…Indeed, an overlap exists in components of the pain neuromatrix and brain regions involved in cognitive processing (e.g., anterior cingulate cortex, insular cortex, periaqueductal gray) (14). Together with the demonstrated changes in neuroplasticity [e.g., gray matter volume reduction (15)(16)(17)] and dysregultated neurochemistry [e.g., decreased levels of brain-derived neurotrophic factor (18), increased levels of gamma-aminobutric acid (19), increased levels of pro-inflammatory cytokines (20)], these pain-induced changes in resource utilization may (in part) explain (pain-related) cognitive impairment in chronic pain patients.…”

Are Fibromyalgia Patients Cognitively Impaired? Objective and Subjective Neuropsychological Evidence

“…In fact, in some of the studies reviewed by Glass (44), the groups of FM patients and HCs were not balanced in sample size (45) or education level (46). Concerning the shifting function, other studies failed to show impairment in FM when comparing performances with the normative data (47,48).…”

Anatomy and Pathophysiology of Chronic Pain and the Impact of Hypnotherapy

“…Moreover, it is suggested that the experience of ongoing pain further reduces gray matter density (Bushnell et al, 2015). Reduced gray matter in the cingulate and frontal cortices have shown varying degrees of cognitive dysfunction amongst chronic pain patients (Luerding et al, 2008).…”