Effortful Swallowing Training Coupled with Electrical Stimulation Leads to an Increase in Hyoid Elevation During Swallowing

We tested the effects of surface electrical stimulation on hyoid elevation during swallowing in healthy volunteers. Sixteen people were recruited and randomly divided into two groups. Electrical stimulation was applied to the skin above the infrahyoid muscle in the experimental group. The stimulation current was adjusted until muscle contraction occurred and the hyoid bone became depressed. Participants were asked to swallow forcefully so as to elevate the hyolaryngeal complex when the stimulation began. The same experiment was performed in the control group except the intensity of stimulation was adjusted to just above the sensory threshold. The two groups received ten 20-min treatments over 2 weeks. We recorded the myoelectrical activity of the submental muscles and the amount of hyoid bone movement at three time points (pretreatment, immediately post-treatment, and 2 weeks after treatment). In the experimental group, the amount of y-axis hyoid bone excursion was increased immediately post-treatment, but this effect faded within 2 weeks following the treatment. Myoelectrical activity was not affected by either treatment regimen. We concluded that effortful swallowing coupled with electrical stimulation increases the degree of hyoid elevation in healthy volunteers. It needs to be evaluated for its long-term effectiveness in increasing the elevation of hyolaryngeal complex.

胃电刺激对胃电节律紊乱的作用

背景:胃电刺激已成为一种潜在的治疗胃动力障碍性疾病的方法。目的:观察、比较单导联和两导联长脉冲胃电刺激对胃电节律紊乱和呕吐相关样症状的作用。方法:以静脉滴注垂体后叶素(一种血管加压素)建立犬胃动力紊乱模型,将多导电刺激器与胃浆膜电极相连,输入最佳刺激参数以控制胃慢波,评估盐水组、垂体后叶素组和单导联、两导联胃电刺激组在静脉滴注生理盐水或垂体后叶素的30min里的症状评分并全程记录四导联胃肌电活动。结果:垂体后叶素能诱导胃电节律紊乱和呕吐相关样症状(P<0.05)。单导联和两导联长脉冲胃电刺激均能纠正胃电节律紊乱(P<0.01),但对呕吐相关样症状无明显缓解作用(P>0.05)。两导联胃电刺激纠正胃电节律紊乱的最佳刺激能量(320ms×mA±43ms×mA)显著低于单导联胃电刺激(2 750ms×mA±186ms×mA)(P<0.01)。结论:单导联和两导联长脉冲胃电刺激能纠正垂体后叶素诱导的胃电节律紊乱,但不能缓解呕吐相关样症状。两导联胃电刺激控制胃慢波所需的刺激能量较单导联胃电刺激低。     

Physiological Variability in the Deglutition Literature: Hyoid and Laryngeal Kinematics

A literature review was conducted on hyoid and/or laryngeal displacement during swallowing in healthy populations according to several inclusion criteria. Anterior and superior displacement measures of both structures from previously published studies were compiled for meta-analysis. Results showed a large degree of variability across studies for each structure and plane of movement. Potential sources of variation were identified, including statistical, methodological, stimulus-related, and participant-related sources.     

Effects of Neuromuscular Electrical Stimulation on Submental Muscle Activity

Neuromuscular electrical stimulation (NMES) therapy has been proposed as a treatment option for pharyngeal dysphagia. However, little is known about the effects, if any, that NMES has on specific biomechanical aspects of the pharyngeal swallow. The purpose of this study was to determine if two weeks of NMES applied to the submental muscles increased myoelectric activity. Ten age- and gender-matched subjects participated, and eight completed the protocol. Treatment was delivered using an AB or BA design. No treatment was given during the A condition. Subjects received ten 1-h NMES treatments during the B condition. Results indicated that seven of eight subjects exhibited no significant gains in myoelectric activity of the submental muscles following NMES. Therefore, the benefit of NMES to the submental muscles with the goal of improving the pharyngeal swallow is not supported. Additional research investigating duration of treatment as well as frequency and amplitude modulation of NMES is needed to determine if, how, and why NMES applied to the submental muscles affects the biomechanical aspects of both the normal and disordered pharyngeal swallow.Work was performed at The University of Memphis.     

Hyoid Bone and Laryngeal Movement Dependent Upon Presence of a Tracheotomy Tube

The aim of this prospective, consecutive study was to investigate the biomechanical effects, if any, of the presence of a tracheotomy tube and tube cuff status, tube capping status, and aspiration status on movement of the hyoid bone and larynx during normal swallowing. Seven adult patients (5 male, 2 female) with an age range of 46–82 years (mean = 63 years) participated. Criteria for inclusion were no history of cancer of or surgery to the head and neck (except tracheotomy), normal cognition, normal swallowing, and ability to tolerate decannulation. Digital videofluoroscopic swallowing studies were performed at 30 frames/s and with each patient seated upright in the lateral plane. Variables evaluated included maximum hyoid bone displacement and larynx-to-hyoid bone approximation under three randomized conditions: tracheotomy tube in and open with a 5-cc air-inflated cuff; tracheotomy tube in and capped with deflated cuff; and tracheotomy tube out (decannulated). Differences between maximum hyoid bone displacement and larynx-to-hyoid approximation (cm) based on presence/absence of a tracheotomy tube, tube cuff status, and tube capping status were analyzed with the Student’s t test. Reliability testing with a Pearson product moment correlation was performed on 21% of the data. No significant differences (p > 0.05) were found for both maximum hyoid bone displacement and larynx-to-hyoid bone approximation during normal swallowing based on tracheotomy tube presence, tube cuff status, or tube capping status. Intraobserver reliability for combined measurements of maximum hyoid displacement and larynx-to-hyoid approximation was r = 0.97 and interobserver reliability for the absence of aspiration was 100%. For the first time with objective data it was shown that the presence of a tracheotomy tube did not significantly alter two important components of normal pharyngeal swallow biomechanics, i.e., hyoid bone movement and laryngeal excursion. The hypothesis that a tracheotomy tube tethers the larynx thereby preventing hyoid bone and laryngeal movement during normal swallowing is not supported.     

Effects of Intestinal Electrical Stimulation on Intestinal Dysrhythmia and Symptoms in Dogs

The aim of this study was to investigate the effect of intestinal electrical stimulation on small intestinal dysrhythmia and motion sickness-like symptoms induced by vasopressin. Female dogs chronically implanted with two pairs of electrodes on jejunum serosa were used in a four-session study. Saline and vasopressin were infused in sessions 1 and 2, respectively. Sessions 3 and 4 were the same as session 2, except a long- or short-pulse intestinal electrical stimulation was applied on the proximal pair of electrodes. Intestinal slow waves and motion sickness-like symptoms were recorded in each session. Results were as follows. (1) Vasopressin induced intestinal dysrhythmia, uncoupling of slow waves, and vomiting and motion sickness-like symptoms (P < 0.05, ANOVA). (2) Intestinal electrical stimulation with long pulses, but not short pulses, was capable of preventing vasopressin-induced intestinal dysrhythmia. (3) Intestinal electrical stimulation with short pulses, but not long pulses, prevented vomiting and the motion sickness-like symptoms. It is concluded that vasopressin induces intestinal dysrhythmia. Long-pulse intestinal stimulation normalizes vasopressin-induced intestinal slow-wave abnormalities with no improvement in symptoms. Short-pulse stimulation prevents emetic symptoms induced by vasopressin but has no effect on slow waves. These data suggest different mechanisms involved with different methods of intestinal stimulation.     

Effects of Cerebral Electrical Stimulation on Alcoholism: A Pilot Study

Cerebral electrical stimulation (CES), born from research on electroanesthesia in the seventies, consists of the application of a pulsating current of small intensity (usually less than 1 mA, and below the threshold of perception) through the skull, e.g., in daily 30-min sessions.
Claims of biological effectiveness (neurochemical, hormonal and EEG changes, naloxone-reversible analgesia in rats, etc.) and of clinical effectiveness (anxiety, depression, cognitive functions in alcoholics) have often relied on poorly controlled data. A recent controlled study in the treatment of opiate withdrawal has been positive. The present double-blind controlled study compares active CES with sham stimulation in 64 alcohol-dependent males. Over 4 weeks, both treatment groups improved significantly in most aspects. In the active treatment group additional significant improvement was observed in week-end alcohol consumption, and in two psychological measures: depression and stress symptoms index, but not in general drinking behavior.     

Comparing the Effects of Rehabilitation Swallowing Therapy vs. Functional Neuromuscular Electrical Stimulation Therapy in an Encephalitis Patient: A Case Study

A 49-year-old man with pharyngeal dysphagia after encephalitis is presented in this case study. Sixteen months earlier the patient experienced a sudden severe fever which resulted in encephalitis, leading to liquid dysphagia. Despite receiving an initial treatment of swallowing therapy, the patient’s liquid dysphagia did not improve. Functional neuromuscular electrical stimulation, which is a new treatment method, was then applied to the patient. The patient showed improvement in the pharyngeal phase of swallowing. Clinical and treatment observations are reported.     

电刺激对心血管系统影响

心血管疾病已成为威胁人类健康的主要疾病。药物、介入和外科手术等是治疗心血管疾病的重要手段和方法,但临床上有很大一部分病例疗效尚不理想且治疗费用高,研究表明,适宜的电刺激对支配心脏的神经、心脏传导系统、心肌细胞、血管内皮细胞和血管均有积极作用,为心血管疾病尤其是那些不适合于经皮冠状动脉介入治疗、冠状动脉旁路移植术及内科药物等治疗或效果极差的病人开辟了新的治疗途径。现就以上几个方面进行综述。     

Effects and Mechanisms of Anal Electrical Stimulation on Anorectal Compliance and Tone in Dogs

Purpose This study was designed to investigate the changes in rectal compliance and tone during anal electric stimulation and the involvement of the α-adrenergic pathway in conscious dogs. Methods Eight healthy dogs were studied in five randomized sessions. Anal sphincter pressure was quantified by using the area under the contractile curve. Rectal compliance and tone were measured in a pressure-controlled phasic and isobaric distention by using an electronic barostat. Anal electric stimulation was performed via a pair of ring electrodes attached to the catheter. Results The electric stimulation-induced increase in sphincter pressure was lowered by the presence of an α₁-adrenergic receptor antagonist, prazosin (18.6 ± 7.4 vs. 45.4 ± 9.7, P < 0.05), or α₂-adrenergic receptor antagonist, yohimbine (10.2 ± 8.2 vs. 38.3 ± 7.6, P < 0.05), compared with the control. The threshold volume in rectoanal inhibitory reflex during electric stimulation was significantly higher than during baseline (27.5 ± 0.9 vs. 22.5 ± 1.9 ml, P < 0.05). There were no significant differences between the percentage drops in sphincter pressure with and without stimulation at a rectal distention level of 45 ml of air. Anal electric stimulation significantly increased rectal compliance reflected as reduced P_1/2 (11.1 ± 1.5 vs. 16.7 ± 1.1, P = 0.027) and reduced κ (11.6 ± 2.5 vs. 20.5 ± 2.6, P = 0.0095), compared with the control session, but did not significantly alter rectal tone. Conclusions Anal electric stimulation increases anal sphincter pressure, mediated at least partially by the α-adrenergic pathway. It also increases rectal compliance but does not alter rectal anal inhibitory reflexes.     

Effects and Mechanisms of Vaginal Electrical Stimulation on Rectal Tone and Anal Sphincter Pressure

Purpose This study was designed to evaluate the effect of vaginal electrical stimulation on rectal tone and compliance and anal sphincter pressure and to explore possible mechanisms involved in the effects of vaginal electrical stimulation on rectal tone in conscious dogs. Methods Seven dogs inserted with a probe with two ring electrodes were studied. The study included two experiments. The first experiment was composed of two series of sessions rectal tone and compliance; and anal sphincter pressure. Each series included three sessions: vaginal electrical stimulation with long pulses, vaginal electrical stimulation with trains of long pulses, and vaginal electrical stimulation with trains of short pulses. The second experiment was performed in two sessions: vaginal electrical stimulation with long pulses plus guanethidine, and vaginal electrical stimulation with trains of long pulses plus guanethidine. In each session, rectal tone was recorded. Results 1) Vaginal electrical stimulation with long pulses or trains of long pulses but not trains of short pulses significantly decreased rectal tone and increased anal sphincter pressure. 2) None of the vaginal electrical stimulation methods altered rectal compliance. 3) The inhibitory effect of vaginal electrical stimulation on rectal tone was abolished by guanethidine. Conclusions Vaginal electrical stimulation with long pulses or trains of long pulses but not trains of short pulses reduces rectal tone and increases anal sphincter pressure. The inhibitory effect of vaginal electrical stimulation on rectal tone is mediated by the sympathetic pathway. These findings suggest that vaginal electrical stimulation may be a potential therapy for fecal incontinence. Presented at Digestive Disease Week, Los Angeles, California, May 21 to 26, 2006.     

Inhibitory Effects of Gastrointestinal Electrical Stimulation on Rectal Tone are both Organ-Specific and Distance-Related in Dogs

Purpose A phenomenon of cross-talk has been noted that electrical stimulation of one part of the gut affects another part of the gut. This study was designed to investigate whether the effect of electrical stimulation of one part of the gut on another part of the gut was related to the organ or the distance between the stimulation site and the affected organ, and the mechanism of ileum electrical stimulation on rectal tone. Methods This study was performed in 13 healthy dogs (16–28 kg) in the fasting state. Experiments were performed to study 1) effects of gastric electrical stimulation, duodenal electrical stimulation, ileum electrical stimulation, and colonic electrical stimulation on rectal tone, and 2) the sympathetic and nitrergic pathways involved in the effects of ileum electrical stimulation on rectal tone. A computerized barostat was used to assess rectal tone. Results All methods of stimulations significantly inhibited rectal tone. Duodenal electrical stimulation was least effective in reducing rectal tone. The percentage of increase in rectal volume was distance-related with duodenal electrical stimulation, ileum electrical stimulation, and colonic electrical stimulation but organ-specific with gastric electrical stimulation. The inhibitory effect of ileum electrical stimulation on rectal tone was abolished by N _ω -nitro-L-arginine but not guanethidine. Conclusions Electrical stimulation of the stomach, intestine, or colon with long pulses has an inhibitory effect on rectal tone. This inhibitory effect is organ-specific as well as associated with the distance between stimulation site and affected organs. The inhibitory effect of ileum electrical stimulation on rectal tone is mediated by the nitrergic but not sympathetic pathway. Presented at Neurogastroenterology and Motility Joint International Meeting, Boston, Massachusetts, September 14 to 17, 2006.     

Measurement of Hyoid and Laryngeal Displacement in Video Fluoroscopic Swallowing Studies: Variability, Reliability, and Measurement Error

Video fluoroscopy is commonly used in the study of swallowing kinematics. However, various procedures used in linear measurements obtained from video fluoroscopy may contribute to increased variability or measurement error. This study evaluated the influence of calibration referent and image rotation on measurement variability for hyoid and laryngeal displacement during swallowing. Inter- and intrarater reliabilities were also estimated for hyoid and laryngeal displacement measurements across conditions. The use of different calibration referents did not contribute significantly to variability in measures of hyoid and laryngeal displacement but image rotation affected horizontal measures for both structures. Inter- and intrarater reliabilities were high. Using the 95% confidence interval as the error index, measurement error was estimated to range from 2.48 to 3.06?mm. These results address procedural decisions for measuring hyoid and laryngeal displacement in video fluoroscopic swallowing studies.     

Anti-Stress Effects of Transcutaneous Electrical Nerve Stimulation (TENS) on Colonic Motility in Rats

Background  

Disorders of colonic motility may contribute to symptoms in patients with irritable bowel syndrome (IBS), and stress is widely believed to play a major role in developing IBS. Stress increases corticotropin releasing factor (CRF) of the hypothalamus, resulting in acceleration of colonic transit in rodents. In contrast, hypothalamic oxytocin (OXT) has an anti-stress effect via inhibiting CRF expression and hypothalamic–pituitary–adrenal axis activity. Although transcutaneous electrical nerve stimulation (TENS) and acupuncture have been shown to have anti-stress effects, the mechanism of the beneficial effects remains unknown.