A particular effect of sleep, but not pain or depression, on the blood-oxygen-level dependent response during working memory tasks in patients with chronic pain

Nicolas A Elvemo,1 Nils I Landrø,2,3 Petter C Borchgrevink,3,4 Asta K Håberg1,5 1Department of Neuroscience, Medical Faculty, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 2Clinical Neuroscience Research Group, Department of Psychology, University of Oslo, Oslo, Norway; 3Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; 4National Norwegian Advisory Unit for Complex Disorders, St Olav University Hospital, Trondheim, Norway; 5Department of Medical Imaging, St Olav University Hospital, Trondheim, Norway Background: Patients with chronic pain (CP) are often reported to have deficits in working memory. Pain impairs working memory, but so do depression and sleep problems, which are also common in CP. Depression has been linked to changes in brain activity in CP during working memory tasks, but the effect of sleep problems on working memory performance and brain activity remains to be investigated. Methods: Fifteen CP patients and 17 age-, sex-, and education-matched controls underwent blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging at 3T while performing block design 0-back, 2-back, and paced visual serial addition test paradigms. Subjects also reported their level of pain (Brief Pain Inventory), depression (Beck Depression Inventory II), and sleep problems (Pittsburgh Sleep Quality Index) and were tested outside the scanner with neuropsychological tests of working memory. Results: The CP group reported significantly higher levels of pain, depression, and sleep problems. No significant performance difference was found on the neuropsychological tests in or outside the scanner between the two groups. There were no correlations between level of pain, depression, and sleep problems or between these and the neuropsychological test scores. CP patients exhibited significantly less brain activation and deactivation than controls in parietal and frontal lobes, which are the brain areas that normally show activation and deactivation during working memory tasks. Sleep problems independently and significantly modulated the BOLD response to the complex working memory tasks and were associated with decreased brain activation in task-positive regions and decreased deactivation in the default mode network in the CP group compared to the control group. The pain and depression scores covaried with working memory activation. Discussion: Sleep problems in CP patients had a significant impact on the BOLD response during working memory tasks, independent of pain level and depression, even when performance was shown not to be significantly affected. Keywords: magnetic resonance imaging, 2-back, serial addition test, deactivation, activatio

Patients with chronic pain lack somatic markers during decision-making

Nicolas-Andreas Elvemo,1 Kristian Bernhard Nilsen,1,2 Nils Inge Landrø,3,4 Petter Christian Borchgrevink,4,5 Asta Kristine Håberg1,6 1Department of Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Neurology, Section for Clinical Neurophysiology, Oslo University Hospital, Oslo, Norway; 3Clinical Neuroscience Research Group, Department of Psychology, University of Oslo, Oslo, Norway; 4Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway; 5Department of Anesthesiology, St Olav University Hospital, Trondheim, Norway; 6Department of Medical Imaging, St Olav University Hospital, Trondheim, Norway Abstract: Patients with chronic pain have impaired cognitive functions, including decision making, as shown with the Iowa gambling task (IGT). The main aim of this study was to elucidate whether patients' decision making is associated with a lack of the anticipatory skin conductance response (SCR). An increase in anticipatory SCR before making unfavorable choices is known to guide decisions in healthy controls during the IGT. Since several brain regions involved in decision making are reported to have altered morphology in patients with chronic pain, the second aim was to explore the associations between IGT performance and brain structure volumes. Eighteen patients with chronic pain of mixed etiology and 19 healthy controls matched in terms of age, sex, and education were investigated with a computerized IGT during the recording of SCR, heart rate, and blood pressure. The participants also underwent neuropsychological testing, and three-dimensional T1-weighted cerebral magnetic resonance images were obtained. Contrary to controls, patients did not generate anticipatory SCRs before making unfavorable choices, and they switched between decks of cards during the late phase of the IGT significantly more often, and this was still observed after adjusting for depression scores. None of the other autonomic measures differed during IGT performance in either group or between groups. In patients, IGT scores correlated positively with total cortical grey matter volume. In controls, there was no such association, but their IGT scores correlated with the anticipatory SCR. It may be speculated that the reduction in anticipatory SCRs makes the chronic pain patients rely more on cortical resources during decision making. Keywords: Iowa gambling task, skin conductance response, autonomic measures, magnetic resonance imaging, corte

Gross and fine motor function in fibromyalgia and chronic fatigue syndrome

Omid Rasouli,1,2 Egil A Fors,3 Petter Chr Borchgrevink,4,5 Fredrik Öhberg,6 Ann-Katrin Stensdotter1 1Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 2Department of Public Health and Nursing, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 3Department of Public Health and Nursing, General Practice Research Unit, Norwegian University of Science and Technology, Trondheim, Norway; 4Department of Circulation and Medical Imaging, Pain and Palliation Research Group, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway; 5National Competence Centre for Complex Symptom Disorders, St. Olav’s University Hospital, Trondheim, Norway; 6Department of Radiation Sciences, Biomedical Engineering, Umeå University, Umeå, Sweden Purpose: This paper aimed to investigate motor proficiency in fine and gross motor function, with a focus on reaction time (RT) and movement skill, in patients with fibromyalgia (FM) and chronic fatigue syndrome (CFS) compared to healthy controls (HC).Methods: A total of 60 individuals (20 CFS, 20 FM, and 20 HC), age 19–49 years, participated in this study. Gross motor function in the lower extremity was assessed using a RT task during gait initiation in response to an auditory trigger. Fine motor function in the upper extremity was measured during a precision task (the Purdue Pegboard test) where the number of pins inserted within 30 s was counted.Results: No significant differences were found between FM and CFS in any parameters. FM and CFS groups had significantly longer RT than HC in the gait initiation (p=0.001, and p=0.004 respectively). In the Purdue Pegboard test, 20% in the FM group, 15% in the CFS groups, and 0% of HC group, scored below the threshold of the accepted performance. However, there were no significant differences between FM, CFS, and HC in this task (p=0.12).Conclusion: Compared to controls, both CFS and FM groups displayed significantly longer RT in the gait initiation task. Generally, FM patients showed the worst results in both tests, although no group differences were found in fine motor control, according to the Purdue Pegboard test. Keywords: fatigue syndrome, chronic, musculoskeletal diseases, gait initiation, Purdue ­Pegboard, reaction time&nbsp