<p>Cortical Thickness Mediates the Association Between Self-Reported Pain and Sleep Quality in Community-Dwelling Older Adults</p>

Abstract

Introduction: Musculoskeletal pain is prevalent in older adults representing the leading cause of disability in this population. Similarly, nearly half of older adults complain of difficulty sleeping. We aimed to explore the relationship between sleep quality with selfreported musculoskeletal pain, somatosensory and pain thresholds in community-dwelling older adults and further explore brain regions that may contribute to this association. Methods: Older adults (>60 years old, n=69) from the NEPAL study completed demographic, pain and sleep assessments followed by a quantitative sensory testing battery. A subset (n=49) also underwent a 3T high-resolution, T1-weighted anatomical scan. Results: Poorer sleep quality using the Pittsburgh Sleep Quality Index was positively associated with self-reported pain measures (all p's >0.05), but not somatosensory and pain thresholds (all p's >0.05). Using a non-parametric threshold-free cluster enhancement (TFCE) approach, worse sleep quality was significantly associated with lower cortical thickness in the precentral, postcentral, precuneus, superior parietal, and lateral occipital regions (TFCE-FWE-corrected at p < 0.05). Further, only postcentral cortical thickness significantly mediated the association between sleep quality and self-reported pain intensity using bootstrapped mediation methods. Conclusion: Our findings in older adults are similar to previous studies in younger individuals where sleep is significantly associated with self-reported pain. Specifically, our study implicates brain structure as a significant mediator of this association in aging. Future larger studies are needed to replicate our findings and to further understand if the brain can be a therapeutic target for both improved sleep and pain relief in older individuals.

The Function and Structure of Precuneus Is Associated With Subjective Sleep Quality in Major Depression

“…For example, reduced degree centrality and GMV were found in insomnia patients ( 38 , 39 ). Functional connectivity and cortical thickness in precuneus were correlated with sleep quality ( 40 , 41 ). In the current research, PSQI score was negatively correlated with the fALFF and GMV value of the precuneus bilaterally in MDs.…”

Chronic Pain is Associated With Reduced Sympathetic Nervous System Reactivity During Simple and Complex Walking Tasks: Potential Cerebral Mechanisms

“…Detailed information about the NEPAL participants have been previously reported. [24][25][26][27] Table 1 summarizes demographic characteristics of the study participants (n ¼ 31). Chronic pain participants experienced musculoskeletal pain of at least 3 months duration that significantly impacted their life on most days; pain was most commonly reported on the back and the knee/leg region.…”

Protocol for a pilot and feasibility randomized-controlled trial of four weeks of oral γ-aminobutyric acid (GABA) intake and its effect on pain and sleep in middle-to-older aged adults

“…Punctate Mechanical Pain: will be assessed at the left thenar eminence and the left foot 2nd metatarsal head using a nylon monofilament (Touchtest Sensory Evaluator 6.65) calibrated to bend at 300g of pressure. As in our previous studies [ 18 , 52 , 53 ], participants will provide a pain rating following a single contact, after which they will provide another pain rating following a series of ten contacts at a rate of one contact per second. The difference between the pain rating for the single versus multiple contacts reflects temporal summation of mechanical pain.…”

“…These lower levels of prefrontal GABA were significantly associated with self-reported and experimental pain measures [ 17 ]. A separate study in the same older cohort further showed that older individuals with the highest chronic pain reports had the worst self-reported sleep quality [ 18 ]. Although it has been suggested that GABA does not cross the blood–brain barrier (BBB) [ 19 , 20 ], or only crosses in small amounts [ 21 , 22 ], more recent work suggests that abundant amounts of GABA may cross the BBB [ [23] , [24] , [25] ].…”