Cognitive Inhibition Correlates with Exercise-Induced Hypoalgesia After Aerobic Bicycling in Pain-Free Participants.

PURPOSE: Exercise-induced hypoalgesia (EIH) is the short-term reduction of pain sensitivity after a single bout of exercise. Descending pain inhibition has been proposed to at least partly underlie EIH. Cognitive inhibition is the ability to inhibit a pre-potent response and has in turn been associated with descending pain inhibition, as indexed by conditioned pain modulation. Therefore, we hypothesized that cognitive inhibition is associated with higher EIH. METHODS: In this cross-sectional study, 37 pain-free participants (16 male, age 27.75 ± 9.91) completed a stop-signal task assessing cognitive inhibition ability and a control condition in the first session. In the second session, pre-post-test design EIH was assessed by means of aerobic bicycling (15 min., 75% VO2max) and isometric knee extension (90 sec, 30% MVC). EIH was assessed with pressure pain thresholds (PPT) and temporal summation of pain (TSP), each at the hand and at the leg. Correlational analyses quantified the associations between cognitive inhibition and EIH change scores. RESULTS: Better cognitive inhibition correlated with EIH change scores in PPTs after aerobic bicycling at the hand (r = -0.35, 95% CI: -0.57; -0.08, p =0.021), but not at the leg (rho = -0.10, 95% CI: -0.36; 0.18, p = 0.277). No correlations between cognitive inhibition and change in PPTs after isometric knee extension at the hand (rho = -0.03, 95% CI: -0.30; 0.25, p = 0.857) nor at the leg (rho = -0.03, 95% CI: -0.25; 0.30, p = 0.857) were observed. There were no EIH effects after isometric exercise and, generally, no effects of exercise on TSP. CONCLUSION: This study provides preliminary evidence for the notion that cognitive inhibition might play a supportive role in EIH. Although these results are clearly in need of replication, they accord well with previously reported associations between cognitive inhibition, experimental pain and descending pain inhibition.

[Physical activity and musculoskeletal pain : A focus review within the MiSpEx research group]. / Körperliche Aktivität und muskuloskeletale Schmerzen : Ein Fokus-Review aus dem MiSpEx-Forschungsverbund.

Chronic pain diseases are often accompanied by a subjectively perceived impairment in physical activity. Moreover, to date it has not been possible to formulate general recommendations on a therapeutic quantity of physical activity and how activities of daily life and movement exercises should be designed for specific patient populations. This article gives an overview about the effects of physical activity in chronic pain patients and healthy subjects with respect to the different contexts of activities of daily living. Empirical evidence suggests that physical activity might have health-promoting or even pain-provoking effects, depending on the amount and intensity. In particular, a temporary exacerbation of symptoms after an exercise intervention could pose a serious problem concerning patient adherence to treatment. Studies investigating the influence of psychosocial risk factors on pain and disability indicate the need for more individualized pain management techniques.

[Obstructive sleep apnea syndrome caused by occupational exposure to solvents]. / Obstruktives Schlafapnoesyndrom durch eine berufliche Lösungsmittelexposition.

HISTORY AND ADMISSION FINDINGS: A 52-year-old man working in a chemical laboratory was referred with the possible diagnosis of toxic encephalopathy. For 17 years he had been exposed to high concentrations of perchlorethylene and n-butanol vapours which every day had caused acute symptoms of organic solvent intoxication. Current complaints were autonomic nervous system symptoms, loss of concentration and memory, and fatigue in the second half of the day. The patient was obese but in good general condition. INVESTIGATIONS: Neuropsychiatric examination confirmed the reported loss of concentration and planning ability at work. The polysomnogram indicated an increased number of largely obstructive apnoea attacks. DIAGNOSIS, TREATMENT AND COURSE: As the patients had an obstructive type of sleep apnoea treatment consisted of positive pressure ventilation at night and weight reduction. The occupational exposure to organic solvents was the likely cause. CONCLUSIONS: As the symptoms of encephalopathy and sleep apnoea syndrome overlap, the latter should be considered before an encephalopathy is diagnosed. Because a rare cause of the sleep apnoea syndrome is prolonged and marked occupational exposure to organic solvents this should be asked about in taking the history. If indeed there has been occupational exposure, it should cease at once and be reported.