Pain
-
Nerve lesions and secondary hyperalgesia may both be present after surgery, and their relative contributions to chronic postsurgical neuropathic pain (CPSNP) remain unclear. This prospective study explored the roles of these factors in the development of CPSNP after iliac crest bone harvest. CPSNP was defined as pain in the area of hypoesthesia, with a positive Douleur neuropathique 4 questionnaire (DN4) score 3 months after iliac crest bone harvest. ⋯ However, neither the area nor the severity of hypoesthesia differed significantly between patients with and without CPSNP. Two independent, additive predictors of CPSNP were identified: area of secondary hyperalgesia (odds ratio 1.02; P=.004) and DN4 score (odds ratio 1.94; P=.001). These findings suggest that both nerve lesions and central sensitization are involved in CPSNP development and could be seen as early warning signs.
-
Procedural pain is associated with poorer neurodevelopment in infants born very preterm (≤ 32 weeks gestational age), however, the etiology is unclear. Animal studies have demonstrated that early environmental stress leads to slower postnatal growth; however, it is unknown whether neonatal pain-related stress affects postnatal growth in infants born very preterm. The aim of this study was to examine whether greater neonatal pain (number of skin-breaking procedures adjusted for medical confounders) is related to decreased postnatal growth (weight and head circumference [HC] percentiles) early in life and at term-equivalent age in infants born very preterm. ⋯ Greater neonatal pain predicted lower body weight (Wald χ(2)=7.36, P=0.01) and HC (Wald χ(2)=4.36, P=0.04) percentiles at 32 weeks postconceptional age, after adjusting for birth weight percentile and postnatal risk factors of illness severity, duration of mechanical ventilation, infection, and morphine and corticosteroid exposure. However, later neonatal infection predicted lower weight percentile at term (Wald χ(2)=5.09, P=0.02). Infants born very preterm undergo repetitive procedural pain during a period of physiological immaturity that appears to impact postnatal growth, and may activate a downstream cascade of stress signaling that affects later growth in the neonatal intensive care unit.
-
Most people suffer musculoskeletal pain sometime in their lives. Although the pain usually disappears with the healing, it may become chronic. Recent evidence suggests that high-level cortical representations play a role in chronic pain. ⋯ However, patients with chronic shoulder pain were specifically impaired to judge the weight from observed manual transfer movements, whereas chronic low-back pain patients were specifically impaired for trunk-rotation movements. This result gives important new insights into chronic pain. Also, this new impairment of biological motion perception is unique in that it is unrelated to visual deficits.
-
Tactile acuity measured by 2-point discrimination performance is impaired in patients with complex regional pain syndrome type I (CRPS-I). This is mirrored by pain-associated shrinkage of the cortical representation of the affected limb. We investigated whether, also, more complex tactile performance assessed by a dynamic 2D-form perception task is disturbed in CRPS-I patients. ⋯ The performance in the BT was not impaired in CRPS-I patients (compared to sex- and age-matched controls from study I) and was not correlated to the TPDT. The intact 2D-form recognition ability in CRPS-I patients might be explained by intact dynamic tactile and proprioceptive functions, which appear to be uncompromised by the impaired static tactile perception, provided that the spacing of the dot pattern is above the individual tactile acuity. These intact 2D-form perception capacities may also be related to higher sensory integration functions like the visual system and intact semantic understanding, which may be spared by the cortical reorganization phenomena in CRPS-I.