Sensory, Motor, and Psychosocial Characteristics of Individuals With Chronic Neck Pain: A Case-Control Study.

OBJECTIVE: Given the complex and unclear etiology of neck pain, it is important to understand the differences in central sensitization as well as psychosocial factors in individuals with chronic neck pain and healthy controls. The purpose of this study was to benchmark differences in central sensitization, psychosocial factors, and range of motion between people with nonspecific chronic neck pain and healthy controls and to analyze the correlation between pain intensity, neck disability, and psychosocial factors in people with chronic neck pain. METHODS: Thirty individuals with chronic neck pain and 30 healthy controls were included in this case-control study. Outcome measures were as follows: central sensitization (pressure pain threshold, temporal summation, and conditioned pain modulation), psychosocial factors (depressive symptoms, pain catastrophizing, and quality of life), and active cervical range of motion. RESULTS: People with neck pain had lower local pressure pain threshold, a decrease in conditioned pain modulation, more depressive symptoms, greater pain catastrophizing, lower quality of life, and reduced range of motion for neck rotation when compared with healthy controls. In people with neck pain, moderate correlations were observed between pain intensity and quality of life (ρ = -0.479), disability and pain catastrophizing (ρ = 0.379), and disability and quality of life (ρ = -0.456). CONCLUSIONS: People with neck pain have local hyperalgesia, impaired conditioning pain modulation, depressive symptoms, pain catastrophizing, low quality of life, and reduced active range of motion during neck rotation, which should be taken into account during assessment and treatment. IMPACT: This study shows that important outcomes, such as central sensitization and psychosocial factors, should be considered during assessment and treatment of individuals with nonspecific chronic neck pain. In addition, pain intensity and neck disability are correlated with psychosocial factors.

Preemptive treatment with photobiomodulation therapy in skin flap viability.

Skin Flap is used in reconstructive plastic surgery. However, complications such as ischemia followed by local necrosis may occur, requiring a new surgical procedure. It is well known that photobiomodulation therapy (PBMT) is an effective technique for improving microcirculation and neoangiogenesis, which contributes positively to the blood supply in the pre and post surgical period. Thus, the objective of the present study was to investigate the effects of preemptive treatment with laser PBMT with different energies on the viability in skin flaps in rats. Sixty-three Wistar rats, male, were randomized into five groups: Control Group (CG) (n = 15): PBMT simulation; Preemptive group 1.1 J laser (GP1) (n = 15): preemptive laser PBMT with 1.1 J of energy per point; Preemptive group 4 J laser (GP4) (n = 15): preemptive PBMT with 4 J of energy per point; Laser group 11 J (G1) (n = 9): PBMT immediately after surgery with 1.1 J of energy per point; Laser group 4 J (G4) (n = 9): TFMB immediately after surgery with 4 J of energy per point. The CG, GP1 and GP4 groups started treatment 72 h prior to surgery and were subdivided into two experimental periods, one of them on the day of the flap and the other along with the other groups on the seventh postoperative day. Three days after the randomization, the animals underwent random skin flap surgery. PBMT was performed with a 660 nm laser at three points. In the first experimental period, a greater number of vessels were found, as well as mast cells in GP1 compared to the CG and greater expression of fibroblast growth factor and vascular endothelial growth factor in the GP1 and GP4 groups compared to the CG. In the second experimental period, GP1 presented a lower percentage of necrotic tissue, a higher number of vessels and a percentage of cells labeled with both VEGF and hypoxia indicible factor alpha (HIF-1α) compared to the CG, FGF in GP1, GP4 and G4 when compared to the CG. Thus, it was concluded that preemptive treatment with PBMT with the application of 1.1 J of energy per point is effective in improving the viability of the skin flap.

Effect of photobiomodulation (670 nm) associated with vitamin A on the inflammatory phase of wound healing.

Wound healing is a complex biological process with specific phases. Photobiomodulation (PBM) decreases the inflammatory infiltrate, stimulating fibroblast proliferation and angiogenesis, and therefore, is indicated for wound healing. Vitamin A is used to reverse the inhibitory effects on wound healing and accelerate the healthy granulation tissue. The study aimed to evaluate the effect of topical vitamin A and PBM (GaAlAs) in inflammatory phase of cutaneous wounds. Forty Wistar male rats were separated into four groups: (1) control (CG); (2) laser group (LG) GaAlAs, 670 nm, 30 mW, energy per point of 0.9 J, radiating by 1 point in 30 s; (3) vitamin A group (VitAG); and (4) laser group plus vitamin A (LG + VitAG). Wounds were surgically made by a punch biopsy with 10 mm of diameter on the back of the animals and all treatments were started according to the experiment. The treatments were administered for four consecutive days and biopsy was performed on day 4. We performed both H&E and immunohistochemistry analysis. The results were compared between groups by one-way analysis of variance ANOVA test with post hoc Tukey (p < 0.05). Inflammatory infiltrate increased significantly in LG compared to CG and VitAG (p < 0.05). Regarding angiogenesis, VEGF expression was increased significantly in LG and LG + VitAG groups, p < 0.01. The results indicate that proposed treatments were effective on the healing process improved by LG and LG + VitAG. We show that laser plus vitamin A enhances healing by reducing the wound area and may have potential application for clinical management of cutaneous wounds.

Administration of the 5-HT2C receptor antagonist SB-242084 into the nucleus accumbens blocks the expression of ethanol-induced behavioral sensitization in Albino Swiss mice.

Behavioral sensitization to the stimulating effect of ethanol (EtOH) or other drugs, which can be observed in mice as an increase in locomotor activity after repeated administration, has been associated with neuroadaptations within the dopaminergic mesolimbic pathway. In the nucleus accumbens (NAc), an afferent region of the mesolimbic pathway, dopamine (DA) release can be modulated by serotonergic 2C receptors (5-HT2CR). The aim of the present study was to evaluate the function of 5-HT2CR in the expression of EtOH-induced behavioral sensitization in Albino Swiss mice with various levels of sensitization to EtOH. In the four experiments that we performed, the mice were given saline or 2.2 g/kg EtOH daily for 21 days. Based on their locomotion on day 21, the EtOH-pretreated mice were assigned to one of two groups, highly sensitized or weakly sensitized to the stimulating effect of EtOH. In each experiment, 2 weeks after the 21-day treatment (withdrawal period), the mice were submitted to four pharmacological challenges of two drug treatments each. The mice in experiments 1 and 2 received two i.p. injections, whereas the mice in experiments 3 and 4 received an intra-NAc administration followed by an i.p. injection. The challenges were: saline+saline; saline+EtOH; SB-242084 (a 5-HT2CR antagonist; 0.5, 1.0 or 2.0 mg/kg i.p. or 1.0 or 2.0 µg/side intra-NAc)+EtOH; and SB-242084 (0.5, 1.0 or 2.0 mg/kg i.p. or 1.0 or 2.0 µg/side intra-NAc)+saline. At all tested doses, i.p. administration of SB-242084 did not affect the stimulating effect of EtOH in the highly sensitized mice. However, when delivered by intra-NAc administration, SB-242084 reduced (at 1.0 µg/side) or completely blocked (at 2.0 µg/side) the expression of EtOH-induced behavioral sensitization in the highly sensitized mice. These findings suggest that the expression of behavioral sensitization to the stimulating effect of EtOH depends on accumbal 5-HT2CR activity.