title: Pain hypersensitivity and spinal nociceptive hypersensitivity in chronic pain: prevalence and associated factors.
abstract: Hypersensitivity of pain pathways is considered a relevant determinant of symptoms in chronic pain patients, but data on its prevalence are very limited. To our knowledge, no data on the prevalence of spinal nociceptive hypersensitivity are available. We studied the prevalence of pain hypersensitivity and spinal nociceptive hypersensitivity in 961 consecutive patients with various chronic pain conditions. Pain threshold and nociceptive withdrawal reflex threshold to electrical stimulation were used to assess pain hypersensitivity and spinal nociceptive hypersensitivity, respectively. Using 10th percentile cutoff of previously determined reference values, the prevalence of pain hypersensitivity and spinal nociceptive hypersensitivity (95% confidence interval) was 71.2 (68.3-74.0) and 80.0 (77.0-82.6), respectively. As a secondary aim, we analyzed demographic, psychosocial, and clinical characteristics as factors potentially associated with pain hypersensitivity and spinal nociceptive hypersensitivity using logistic regression models. Both hypersensitivity parameters were unaffected by most factors analyzed. Depression, catastrophizing, pain-related sleep interference, and average pain intensity were significantly associated with hypersensitivity. However, none of them was significant for both unadjusted and adjusted analyses. Furthermore, the odds ratios were very low, indicating modest quantitative impact. To our knowledge, this is the largest prevalence study on central hypersensitivity and the first one on the prevalence of spinal nociceptive hypersensitivity in chronic pain patients. The results revealed an impressively high prevalence, supporting a high clinical relevance of this phenomenon. Electrical pain thresholds and nociceptive withdrawal reflex explore aspects of pain processing that are mostly independent of sociodemographic, psychological, and clinical pain-related characteristics.
authors.affiliation: Department of Anesthesiology and Pain Medicine, University of Washington, Seattle, WA, USA Department of Anesthesiology and Pain Therapy, University Hospital of Bern, Inselspital, Bern, Switzerland Center for Sensory-Motor Interaction, Institute of Social and Preventive Medicine, University of Bern, Bern, Switzerland Department of Obstetrics and Gynecology, Cantonal Hospital of Winterthur, Winterthur, Switzerland Center for Sensory-Motor Interaction, Department of Health Science and Technology, University of Aalborg, Aalborg, Denmark.
authors.forename: Michele
authors.initials: M
authors.lastname: Curatolo
authors.forename: Monika
authors.initials: M
authors.lastname: Müller
authors.forename: Aroosiah
authors.initials: A
authors.lastname: Ashraf
authors.forename: Alban Y
authors.initials: AY
authors.lastname: Neziri
authors.forename: Konrad
authors.initials: K
authors.lastname: Streitberger
authors.forename: Ole K
authors.initials: OK
authors.lastname: Andersen
authors.forename: Lars
authors.initials: L
authors.lastname: Arendt-Nielsen
mesh_terms: D000328:Adult; D000368:Aged; D058443:Catastrophization; D059350:Chronic Pain / Q000150:complications* / Q000453:epidemiology* / Q000523:psychology; D004558:Electric Stimulation / Q000009:adverse effects; D005260:Female; D006801:Humans; D006967:Hypersensitivity / Q000453:epidemiology* / Q000209:etiology*; D016015:Logistic Models; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D059225:Nociception / Q000502:physiology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology*; D015995:Prevalence; D012018:Reflex / Q000502:physiology; D012189:Retrospective Studies; D013116:Spinal Cord / Q000503:physiopathology*