Animal experiments and studies in humans clearly show that the relation between pain (acute and chronic) and sleep quality is two-way: sleep disorders can increase pain, which in turn may cause sleep disorders. Sleep disorders and chronic low back pain are frequent health problems and it is unsurprising that the two can co-exist. This study was conducted to evaluate if sleep disorders and chronic pain associated are more frequently than one would expect. The objective of the study was to compare sleep quality in a population of patients with chronic low back pain and a control population. Sleep quality was assessed in 101 patients with chronic low back pain (CLBP) and in 97 sex- and age-matched healthy control subjects using the Pittsburgh Sleep Quality Index [PSQI; score from 0 (no disorder) to 21]. The French version of the Dallas Pain Questionnaire (DPQ) was used to assess the impact of low back pain on patients' quality of life. This impact was taken as nil in the healthy controls. The patients with CLBP and the controls were comparable in age, sex, and height, but mean bodyweight was higher in the CLBP group (70.3 +/- 14.5 vs. 61.8 +/- 11.4 kg; P < 0.05). The patients with CLBP were also more frequently on sick leave than the controls (32.3%; n = 31 vs. 0.0% n = 0; P < 0.001). Coffee, tea, and cola intakes were comparable in the two groups. Patients with CLBP had statistically higher scores in all items of the PSQI than the healthy controls. The mean PSQI was 4.7 +/- 3.2 for the healthy controls and 10.9 +/- 7.9 for the patients with CLBP (P < 0.0001). Sleep disorders were greater when the impact of CLBP on daily life (the four aspects of the DPQ) was greater [P < 0.0001]). The sleep of the patients with CLBP was significantly altered compared with that of the healthy controls, in proportion to the impact of low back pain on daily life. Our findings do not indicate whether sleep disorders are a cause or a consequence of CLBP.

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Objective: To compare spatial pain modulation capabilities between adolescents with and without migraine. Background: Conditioned pain modulation (CPM) responses at the leg are similar in adolescents with versus without migraine. However, the anatomical region of testing may affect spatial pain modulation capabilities as differences in nociceptive processing between patients with migraine and healthy controls are found in local areas that are near the site of clinical pain but not in nonlocal areas. This study aimed to examine spatial pain modulation capabilities tested by the CPM paradigm using test stimulus applied to a local body area. Methods: Nineteen adolescents with migraine (age 14.9 ± 2.3, mean ± SD; 16 female) and 20 healthy adolescents (age 13.8 ± 2.5, mean ± SD; 16 female) completed this case-control study at Cincinnati Children's Hospital Medical Center. Pressure pain thresholds (PPT) were assessed at the trapezius before and during immersion of the foot in a cold water bath (8°C). Results: In the migraine group (146.0 ± 79.1, mean ± SD), compared to healthy controls (248.0 ± 145.5, mean ± SD), significantly lower PPT (kilopascal) values were found (estimate = 124.28, 95% CI: 58.98, 189.59, p < 0.001; effect size: d = 1.40). No differences between the groups were found for pain intensity and unpleasantness ratings of cold-water immersion nor the CPM response. Conclusions: This study found altered ascending nociceptive processing of mechanical stimuli at the neck in adolescents with migraine. However, endogenous pain modulatory mechanisms were functional and not altered. In light of other studies, impairments in inhibitory control may not be involved in migraine pathophysiology in pediatric patients regardless of stimulus location.