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The concept nociplastic pain has been developed for patients in whom clinical and psychophysical findings suggest a predominant central sensitization type of pain that is not fully explained as nociceptive or neuropathic. Here we tested, how well the recently published grading system differentiates between chronic primary pain or chronic secondary pain conditions. We recruited patients with Fibromyalgia (FMS, 41), Complex Regional Pain Syndrome (CRPS, 11), Osteoarthritis (OA, 21) or Peripheral Nerve Injury (PNI, 8). We used clinical history, pain drawings, Quantitative Sensory Testing (QST) and questionnaires to classify patients' pains as possibly or probably nociplastic in nature. All FMS and CRPS patients exhibited widespread or regional pain that was not explainable by nociceptive nor neuropathic mechanisms. Widespread pain in 12 OA patients was fully explained as nociceptive and regional pain in 4 PNI patients as neuropathic in all but one in each group. QST provided evidence for hypersensitivity in 9/11 CRPS patients but only 27/41 FMS patients (possible nociplastic pain). 82% of the CRPS patients but only 54% of FMS patients reported a history of hypersensitivity and mental comorbidities (probable nociplastic pain). We suggest that clinical examination of hypersensitivity should be done in more than one region and that adding a high tender point count as evidence for hypersensitivity phenomena may be useful. Further we suggest to switch the sequence of steps so that self-reported hypersensitivity and comorbidities come before clinical examination of hypersensitivity; Since the nociplastic pain concept calls for brainstem and cortical plasticity we discuss in detail potential measurement strategies.

Continuous real‐time functional magnetic resonance imaging (fMRI) neurofeedback is gaining increasing scientific attention in clinical neuroscience and may benefit from the short repetition times of modern multiband echoplanar imaging sequences. However, minimizing feedback delay can result in technical challenges. Here, we report a technical problem we experienced during continuous fMRI neurofeedback with multiband echoplanar imaging and short repetition times. We identify the possible origins of this problem, describe our current interim solution and provide openly available workflows and code to other researchers in case they wish to use a similar approach.

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Background The majority of knowledge about fibromyalgia syndrome (FMS) derives from studies of female patients. Little is known about the clinical characteristics and treatment outcomes of male FMS patients. Objective We investigated whether male FMS patients differ from female patients in terms of 1.) symptom burden, 2.) psychological characteristics, and 3.) clinical treatment response. Methods For this retrospective cohort study with a prospective posttreatment-follow-up, we identified 263 male (4%) out of 5,541 FMS patients completing a three-week multimodal pain-treatment program. Male FMS patients (51.3±9.1 years) were age- and time-matched (1:4) with female FMS patients (N = 1052, 51.3±9.0 years). Data on clinical characteristics, psychological comorbidities and treatment response were obtained from medical records and validated questionnaires. Results Levels of perceived pain, psychological comorbidity, and functional capacity were similar between genders, although male FMS patients showed a higher prevalence for alcohol abuse. Compared to female patients, male FMS patients experienced themselves less often as overly accommodating (Cohen’s d=-0.42), but more often as self-sacrificing (d = 0.26) or intrusive (d = 0.23). Regarding pain coping, male patients were less likely to utilize mental distraction, rest- and relaxation techniques, or counteractive activities (d = 0.18–0.27). Male FMS patients showed a slightly worse overall response rate than women (69% vs. 77%), although differences between individual outcome measures were small (d < 0.2). Conclusion Although male and female FMS patients in our cohort were similar in clinical presentation and treatment response, the gender-specific differences in interpersonal problems and pain coping suggest a consideration of these aspects in the treatment of male FMS patients.