No abstract

BackgroundSomatic afferent nerve stimuli are used for treating an overactive bladder (OAB), a major cause of nocturia in the elderly. Clinical evidence for this treatment is insufficient because of the lack of appropriate control stimuli. Recent studies on anesthetized animals show that gentle stimuli applied to perineal skin with a roller could inhibit micturition contractions depending on the roller’s surface material. We examined the efficacy of gentle skin stimuli for treating nocturia.MethodsThe study was a cross-over, placebo-controlled, double-blind randomized clinical study using two rollers with different effects on micturition contractions. Participants were elderly women (79–89 years) with nocturia. Active (soft elastomer roller) or placebo (hard polystyrene roller) stimuli were applied to perineal skin by participants for 1 min at bedtime. A 3-day baseline assessment period was followed by 3-day stimulation and 4-day resting periods, after which the participants were subjected to other stimuli for another 3 days. The primary outcome was change in the frequency of nighttime urination, for which charts were maintained during each 3-day period.ResultsTwenty-four participants were randomized, of which 22 completed all study protocols. One participant discontinued treatment because of an adverse event (abdominal discomfort). In participants with OAB (n = 9), change from baseline in the mean frequency of urination per night during the active stimuli period (mean ± standard deviation, −0.74 ± 0.7 times) was significantly greater than that during placebo stimuli periods (−0.15 ± 0.8 times [p < 0.05]). In contrast, this difference was not observed in participants without OAB (n = 13).ConclusionsThese results suggest that gentle perineal stimulation with an elastomer roller is effective for treating OAB-associated nocturia in elderly women. Here the limitation was a study period too short to assess changes in the quality of sleep and life.Trial RegistrationUMIN Clinical Trial Registry (CTR) UMIN000015809

This study aimed to clarify whether the reflex excitation of muscle sympathetic nerves induced by contractions of the skeletal muscles modulates their contractility. In anesthetized rats, isometric tetanic contractions of the triceps surae muscles were induced by electrical stimulation of the intact tibial nerve before and after transection of the lumbar sympathetic trunk (LST), spinal cord, or dorsal roots. The amplitude of the tetanic force (TF) was reduced by approximately 10% at 20 min after transection of the LST, spinal cord, or dorsal roots. The recorded postganglionic sympathetic nerve activity from the lumbar gray ramus revealed that both spinal and supraspinal reflexes were induced in response to the contractions. Repetitive electrical stimulation of the cut peripheral end of the LST increased the TF amplitude. Our results indicated that the spinal and supraspinal somato-sympathetic nerve reflexes induced by contractions of the skeletal muscles contribute to the maintenance of their own contractile force.

Electrical stimulation of myelinated afferent fibers of the superior laryngeal nerve (SLN) facilitates calcitonin secretion from the thyroid gland in anesthetized rats. In this study, we aimed to quantify the electrical SLN stimulation-induced systemic calcitonin release in conscious rats and to then clarify effects of chronic SLN stimulation on bone mineral density (BMD) in a rat ovariectomized disease model of osteoporosis. Cuff electrodes were implanted bilaterally on SLNs and after two weeks recovery were stimulated (0.5 ms, 90 microampere) repetitively at 40 Hz for 8 min. Immunoreactive calcitonin release was initially measured and quantified in systemic venous blood plasma samples from conscious healthy rats. For chronic SLN stimulation, stimuli were applied intermittently for 3–4 weeks, starting at five weeks after ovariectomy (OVX). After the end of the stimulation period, BMD of the femur and tibia was measured. SLN stimulation increased plasma immunoreactive calcitonin concentration by 13.3 ± 17.3 pg/mL (mean ± SD). BMD in proximal metaphysis of tibia (p = 0.0324) and in distal metaphysis of femur (p = 0.0510) in chronically SLN-stimulated rats was 4–5% higher than that in sham rats. Our findings demonstrate chronic electrical stimulation of the SLNs produced enhanced calcitonin release from the thyroid gland and partially improved bone loss in OVX rats.