Electrical Stimulation of the Auricular Branch Vagus Nerve Using Random and Alternating Frequencies Triggers a Rapid Onset and Pronounced Antihyperalgesia via Peripheral Annexin A1-Formyl Peptide Receptor 2/ALX Pathway in a Mouse Model of Persistent Inflammatory Pain.

This study evaluated the antihyperalgesic and anti-inflammatory effects of percutaneous vagus nerve electrical stimulation (pVNS) by comparing the effects of alternating and random frequencies in an animal model of persistent inflammatory hyperalgesia. The model was induced by Freund's complete adjuvant (CFA) intraplantar (i.pl.) injection. Mice were treated with different protocols of time (10, 20, or 30 min), ear laterality (right, left or both), and frequency (alternating or random). Mechanical hyperalgesia was evaluated, and some groups received i.pl. WRW4 (FPR2/ALX antagonist) to determine the involvement. Edema, paw surface temperature, and spontaneous locomotor activity were evaluated. Interleukin-1ß, IL-6, IL-10, and IL4 levels were verified by enzyme-linked immunosorbent assay. AnxA1, FPR2/ALX, neutrophil, M1 and M2 phenotype macrophage, and apoptotic cells markers were identified using western blotting. The antihyperalgesic effect pVNS with alternating and random frequency effect is depending on the type of frequency, time, and ear treated. The pVNS random frequency in the left ear for 10 min had a longer lasting antihyperalgesic effect, superior to classical stimulation using alternating frequency and the FPR2/ALX receptor was involved in this effect. There was a reduction in the levels of pro-inflammatory cytokines and an increase in the immunocontent of AnxA1 and CD86 in mice paw. pVNS with a random frequency in the left ear for 10 min showed to be optimal for inducing an antihyperalgesic effect. Thus, the random frequency was more effective than the alternating frequency. Therefore, pVNS may be an important adjunctive treatment for persistent inflammatory pain.

Stabilometric analysis as a cognitive function predictor in adults over the age of 50: A cross-sectional study conducted in a Memory Clinic.

BACKGROUND: The aging process reduces adaptive balance responses. Two-thirds of older adults with cognitive problems suffer at least one fall every year, a rate three times higher than that observed in older adults without dementia. This cross-sectional study aims to analyze the relationship between balance and cognitive status in adults older than 50 years. METHODS: Individuals over the age of 50, who attended a Memory Clinic, were evaluated for balance changes using stabilometry, with analysis of the center of pressure (CoP). The following CoP parameters were assessed using an S-Plate pressure platform: 1) sway length, 2) sway area, and 3) anteroposterior and laterolateral sway (width, mean deviation, and speed). The individuals were evaluated with eyes open and closed for 30 s in each test. The Montreal Cognitive Assessment (MoCA) was used to assess cognitive status. RESULTS: Eighty-seven subjects participated in the study. The average age was 67.8 years, 81.4% were female, and the average MoCA score was 19.8 points. Greater CoP oscillation was observed in the eyes closed condition, demonstrating greater postural imbalance. We found a significant and direct effect of MoCA score on the CoP area in the eyes open condition. CONCLUSION: The results suggest that stabilometric analysis may be a predictor of cognitive function.