Electrical acustimulation relieves vection-induced motion sickness

Effect of economically friendly acustimulation approach against cybersickness in video-watching tasks using consumer virtual reality devices

BACKGROUND

Consumer virtual reality (VR) devices are becoming more prevalent in the market, but cybersickness induced by VR devices limits their potential application and promotion. Acustimulation has been found effective in reducing cybersickness symptoms. However, in previous forms, the more effective way of acustimulation is either intrusive or electrical which is hard to be applied to daily VR use.

PURPOSE

In this study, we aimed to find a both simple and more effective acustimulation approach, acupressure plus acupaste (AcP+) to reducing the adverse effects caused by cybersickness from VR applications.

METHOD

In this study, we set three conditions: acupressure plus acupaste (AcP+) (main condition of interest), acupressure with fake acupaste (AcP), and a no acustimulation condition (NoAcP). In AcP and AcP + conditions, we applied acupressure or acupressure with true acupaste on P6 point before conducting video-watching tasks using VR headsets, while in NoAcP condition, participants received no special treatment before video-watching tasks. We used questionnaires to measure symptoms of cybersickness and compared the results between these 3 conditions, especially between acupressure plus acupaste (AcP+) and acupressure (AcP) to examine the effect of AcP+, and compared AcP and AcP+ with NoAcP to confirm the effect of acustimulation.

RESULT

Participants reported significant fewer symptoms of cybersickness nausea feelings in both acustimulation methods, compared with NoAcP; and AcP+ was more effective than AcP against cybersickness on visual oculomotor aspect, and facilitated cybersickness recovery.

IMPLICATION

It would be promising to develop acupressure equipment and apply stimulation before VR application to reduce cybersickness.

Use of Transcutaneous Nerve Stimulation Wristband to Treat Methotrexate-Induced Nausea

Background:

Although methotrexate is a highly effective treatment for psoriasis, nausea and vomiting may be dose-limiting side effects. Various approaches have been used to improve the tolerability of methotrexate therapy, including changing the dose or form of administration of the methotrexate or concomitant administration of folic acid or an antiemetic.

Objective:

The objective of this case report is to present the use of a novel, nonpharmacologic approach for controlling the nausea associated with methotrexate therapy.

Results:

A 47-year-old patient with long-standing psoriasis was treated with methotrexate. She developed nausea refractory to standard antiemetic measures. She noted almost immediate relief of her nausea when using a transcutaneous nerve stimulation wristband.

Conclusions:

Nerve stimulation may be a valid alternative to other first-line antiemetic therapies.

Electrical neuromodulation at acupoint ST36 normalizes impaired colonic motility induced by rectal distension in dogs

Electroacupuncture (EA) has been shown to improve impaired gastric motility and slow waves in both humans and animals. However, its effects on colonic motility have rarely been investigated. The aim of this study was to investigate the effects and underlying mechanisms of EA on impaired colonic motility induced by rectal distension (RD)in dogs. Colon contractions and transit were measured in various sessions with and without EA in hound dogs chronically placed with a colonic cannula. Colonic contractile activity was assessed by motility index (MI). Autonomic functions were determined by the spectral analysis of the heart rate variability derived from the electrocardiogram. It was found 1) RD suppressed colonic motility by 40.5% (10.8 ± 0.9 with RD vs. 6.4 ± 0.8 at baseline, P < 0.002). EA at ST36 normalized colonic contractions suppressed by RD (12.9 ± 2.8, P < 0.002 vs. RD and P = 0.1 vs. control). 2) Administration of atropine blocked the ameliorating effect of EA on colon motility. 3) RD also delayed colonic transit (65.0 ± 2.0% with RD vs. 86.0 ± 1.9% without RD, P < 0.001) that was restored with EA (84.0 ± 1.9%, P = 0.178 vs. control). 4) EA increased vagal activity suppressed by RD (0.37 ± 0.07 with RD + EA vs. 0.09 ± 0.03 with RD without EA, P < 0.001). In conclusion, RD inhibits colonic contractions and delays colonic transit in dogs; EA at ST36 restores the RD-induced impairment in both colonic contraction and transit by enhancing vagal activity and mediated via the cholinergic pathway.

Ameliorating Effect of Transcutaneous Electroacupuncture on Impaired Gastric Accommodation in Patients with Postprandial Distress Syndrome-Predominant Functional Dyspepsia: A Pilot Study

Patients with functional dyspepsia (FD) have both reduced gastric accommodation and impaired gastric motility that are difficult to treat. The aim of this study was to investigate the therapeutic potential of transcutaneous electroacupuncture (TEA) for both of these disorders in FD patients. Acute experiments were performed in FD patients to study the effect of TEA and sham-TEA on gastric accommodation assessed by a nutrient drink test and gastric motility assessed by the measurement of the electrogastrogram (EGG). TEA or sham-TEA was performed via cutaneous electrodes at acupoints ST36 and PC6 or sham-points nonacupoints. It was found that (1) gastric accommodation (maximum tolerable volume) was reduced in FD patients compared with the controls (P < 0.03). TEA improved gastric accommodation in FD patients (P < 0.02). (2) Acute TEA significantly increased the percentage and power of normal gastric slow waves in the fed state assessed in the FD patients by the EGG in comparison with sham-TEA. (3) TEA increased vagal activity assessed by the spectral analysis of the heart rate variability in the fed state in FD patients. It was concluded that needleless method of transcutaneous electroacupuncture may have a therapeutic potential for treating both impaired gastric accommodation and impaired gastric motility in patients with FD.

An alternative to current therapies of functional dyspepsia: self-administrated transcutaneous electroacupuncture improves dyspeptic symptoms

Functional dyspepsia is of high prevalence with little treatment options. The aim of this study was to develop a new treatment method using self-management transcutaneous electroacupuncture (TEA) for functional dyspepsia (FD). Twenty-eight patients with FD were enrolled and underwent a crossover clinical trial with 2-week TEA at ST36 and PC6 and 2-week sham-TEA at nonacupuncture sham-points. Questionnaires were used to assess symptoms of dyspepsia and quality of life. Physiological testing included gastric emptying and electrogastrography. It was found that (1) TEA but not sham-TEA significantly improved dyspeptic symptoms and 4 domains in quality of life; improvement was also noted in self-rated anxiety and depression scores; (2) gastric emptying was significantly and substantially increased with 2-week TEA but not sham-TEA; and (3) gastric accommodation was also improved with TEA but not sham-TEA, reflected as increased ingested nutrient volumes at the levels of satiety and maximum tolerance. These findings suggest a therapeutic potential of self-administrated TEA method for functional dyspepsia, possibly attributed to improvement in gastric motility.

Simultaneous transcutaneous electrical nerve stimulation mitigates simulator sickness symptoms in healthy adults: a crossover study

Background

Flight simulators have been used to train pilots to experience and recognize spatial disorientation, a condition in which pilots incorrectly perceive the position, location, and movement of their aircrafts. However, during or after simulator training, simulator sickness (SS) may develop. Spatial disorientation and SS share common symptoms and signs and may involve a similar mechanism of dys-synchronization of neural inputs from the vestibular, visual, and proprioceptive systems. Transcutaneous electrical nerve stimulation (TENS), a maneuver used for pain control, was found to influence autonomic cardiovascular responses and enhance visuospatial abilities, postural control, and cognitive function. The purpose of present study was to investigate the protective effects of TENS on SS.

Methods

Fifteen healthy young men (age: 28.6 ± 0.9 years, height: 172.5 ± 1.4 cm, body weight: 69.3 ± 1.3 kg, body mass index: 23.4 ± 1.8 kg/m²) participated in this within-subject crossover study. SS was induced by a flight simulator. TENS treatment involved 30 minutes simultaneous electrical stimulation of the posterior neck and the right Zusanli acupoint. Each subject completed 4 sessions (control, SS, TENS, and TENS + SS) in a randomized order. Outcome indicators included SS symptom severity and cognitive function, evaluated with the Simulator Sickness Questionnaire (SSQ) and d2 test of attention, respectively. Sleepiness was rated using the Visual Analogue Scales for Sleepiness Symptoms (VAS-SS). Autonomic and stress responses were evaluated by heart rate, heart rate variability (HRV) and salivary stress biomarkers (salivary alpha-amylase activity and salivary cortisol concentration).

Results

Simulator exposure increased SS symptoms (SSQ and VAS-SS scores) and decreased the task response speed and concentration. The heart rate, salivary stress biomarker levels, and the sympathetic parameter of HRV increased with simulator exposure, but parasympathetic parameters decreased (p < 0.05). After TENS treatment, SS symptom severity significantly decreased and the subjects were more able to concentrate and made fewer cognitive test errors (p < 0.05).

Conclusions

Sympathetic activity increased and parasympathetic activity decreased after simulator exposure. TENS was effective in reducing SS symptoms and alleviating cognitive impairment.

Trial registration number

Australia and New Zealand Clinical Trials Register: http://ACTRN12612001172897

History of acupuncture research

The acupuncture has been practiced in China for more than 3000 years and was spread to Europe and American from the sixteenth to the nineteenth century. The history of acupuncture research was initiated in the eighteenth century and developed rapidly since then. In the past, physicians tried hard to apply acupuncture into clinical practice, while scientists were focused on the possible characteristics of acupoints and meridians. In the modern time, scientists have strived hard to evaluate the real effectiveness of acupuncture and the underlying physiological and biological mechanisms of acupuncture. Reviewing research history from past to present, we are delighted to witness this wonderful development. Accumulated evidences that acupuncture is beneficial in various conditions significantly enhanced our understanding the mechanisms of acupuncture treatment. However, there is still no conclusive evidence in acupuncture clinical studies. The clinical research still needs great improving, while the basic research results need to be appropriately transformed into clinical outcomes. Based on current achievements, we believe that although the challenges and difficulties exist, a more collaborative, innovative, and integrated approach will help us to achieve further progress in future acupuncture research.

Effect and mechanism of acupuncture on gastrointestinal diseases

Acupuncture modulates various biomechanical responses, such as prokinetic, antiemetic, and antinociceptive effects. Acupuncture treatment involves the insertion of thin needles into the skin and underlying muscle and the needles are stimulated manually or electrically. Thus, acupuncture stimulates the somatic afferent nerves of the skin and muscles. The somatic sensory information from the body is carried to the cortex area of the brain. Somatic sensory fibers also project to the various nuclei, including the brain stem, periaqueductal gray (PAG), and paraventricular nucleus (PVN) of the hypothalamus. Somatosensory pathways stimulated by acupuncture activate these nuclei. Activation of the brain stem modulates the imbalance between sympathetic activity and parasympathetic activity. Opioid released from the PAG is involved in mediating antiemetic and antinociceptive effects of acupuncture. Oxytocin release from the PVN mediates antistress and antinociceptive effects of acupuncture. Acupuncture may be effective in patients with functional gastrointestinal (GI) disorders because of its effects on GI motility and visceral pain. It is expected that acupuncture is used in the treatment of patients with functional GI disorders.

Effects and possible mechanisms of acupuncture at ST36 on upper and lower abdominal symptoms induced by rectal distension in healthy volunteers

Background acupuncture (AP) has been shown to have a therapeutic potential for gastrointestinal motility disorders. The aims of this study were to investigate the effects and possible mechanisms of acupuncture on postprandial upper and lower abdominal symptoms induced by rectal distension (RD). Twenty healthy volunteers were involved in a two-session study (AP and sham-AP, AP and no-AP, or sham-AP and no-AP). In 12 of the volunteers, RD was performed for 60 min in the postprandial state, and AP at ST36 or sham-AP was performed during the second 30-min period of RD. Gastric slow waves and heart rate variability (HRV) were recorded using the electrogastrogram and electrocardiogram, respectively. Upper and lower abdominal symptoms were scored during RD with AP and sham-AP. In five of the subjects, an additional experiment with two sessions (with AP and no-AP) was performed. In the remaining eight volunteers, the same experiment was performed with sham-AP and no-AP was performed. The results were, first, RD at an average volume of 171 ml induced upper and lower abdominal symptoms (P < 0.01). AP, but not sham-AP or no-AP, reduced both upper and lower abdominal symptoms (P < 0.05). Second, RD decreased the percentage of normal gastric slow waves (P < 0.05). AP improved gastric slow waves compared with sham-AP or no-AP (P < 0.05). Third, in the larger, but not smaller, sample size experiment, the vagal activity during the RD plus AP period was significantly higher than that during the RD alone period in the same session and the corresponding period with sham-AP or no-AP in other sessions (P < 0.05). Neither sham-AP nor no-AP showed any effects on vagal activity (P > 0.05). Finally, in the experiment with eight volunteers, neither sham-AP nor no-AP showed any effects on RD-induced impairment in gastric slow waves, abdominal symptoms, or vagal activity (P > 0.05). The conclusions are RD induces upper or lower abdominal symptoms and impairs gastric slow waves in healthy volunteers. AP at ST36 is able to improve upper and lower abdominal symptoms and impaired gastric slow waves induced by RD, possibly mediated via the vagal pathway.

Stimulation of gastric slow waves with manual acupuncture at acupuncture points ST36 and PC6--a randomized single blind controlled trial

BACKGROUND

To investigate the effects of stimulated and non-stimulated manual acupuncture at ST36 and PC6 on gastric myoelectrical activity and autonomic function.

METHODS

A total of 65 healthy volunteers were randomly assigned to a 1: 1: 2 ratio to receive either 15 min of verum acupuncture (VA) with stimulation followed by 15 min of VA without stimulation (nsVA), or 15 min of nsVA followed by 15 min of VA with stimulation (sVA), or 30 min of sham acupuncture (SA). Measures of autonomic function included electrogastrogram, electrocardiogram, impedance cardiography and assessment of blood pressure, breathing frequency, and electrodermal activity. Outcome parameters were compared between VA and SA, and between sVA and nsVA. The percentage of regular gastric slow waves (normogastria) was defined as the primary outcome.

KEY RESULTS

The percentage of normogastria was not significantly different between VA and SA. Differences in secondary outcomes such as power spectrum of gastric slow waves and heart rate variability parameters were pronounced in the comparison of sVA and nsVA. During sVA, the percentage of normogastria was lower (P = 0.005), the percentage of bradygastria was higher (P = 0.003) and power ratio was higher (P < 0.001), systolic blood pressure was lower (P = 0.039) and RMSSD was higher (P < 0.001) as compared with nsVA.

CONCLUSIONS & INFERENCES

Our study suggests that manual stimulation of acupuncture needles at ST36 and PC6 affects gastric myoelectrical as well as cardiac activities in healthy volunteers. The effect of stimulation in acupuncture deserves further investigation.

Effects of transcutaneous electrical nerve stimulation on motion sickness induced by rotary chair: a crossover study

OBJECTIVES

Motion sickness (MS) is evoked by the conflict among somatosensory, visual, and vestibular input. Some of the MS symptoms and signs are mediated by activation of the autonomic nervous system (ANS). Transcutaneous electrical nerve stimulation (TENS), a maneuver used for pain control, was found to influence cardiovascular responses through ANS reflex, and to enhance motor function, visuospatial abilities, postural control, and cognitive function. The purpose of the present study is to investigate the effects of TENS on MS.

SUBJECTS AND DESIGN

Fifteen (15) healthy young men participated in a within-subjects crossover study. Each completed four test sessions (control, rotation, TENS, TENS+rotation) in randomized order. Rotary chair (120°/s) combined with pitch movement of the subject's head was used as a model to provoke MS. Whole rotation protocol consisted of 5 1-minute rotations, each separated by a 1-minute rest period. TENS protocol involved simultaneous electrical stimulation of posterior neck and Zusanli acupoint.

OUTCOME MEASURES

Motion sickness susceptibility was rated on a standardized questionnaire (Motion Sickness Susceptibility Questionnaire). Motion sickness symptoms, blood pressure (BP), skin temperature, heart rate (HR), and heart rate variability (HRV) were measured. Saliva samples were collected to analyze the level of stress markers. Cognitive function was evaluated with d2 test prior to and after MS provocation.

RESULTS

Spinning by itself significantly decreased task response speed and contraction. MS symptom scores, BP, as well as the sympathetic parameter of HRV increased progressively with MS provocation (p<0.05), but skin temperature decreased (p=0.023). Severity of MS symptoms significantly decreased with TENS intervention (p<0.05). After TENS treatment, subjects were able to concentrate better and showed fewer errors in a cognitive test. Salivary cortisol concentration significant decreased after TENS treatment.

CONCLUSIONS

Sympathetic activity increased but parasympathetic activity decreased during MS. TENS was effective in reducing MS symptoms as well as alleviating cognitive impairment.

Effects and mechanisms of electroacupuncture on glucagon-induced small intestinal hypomotility in dogs

BACKGROUND

Little is known on the effect of electroacupuncture (EA) (Br Med J, 2, 1976, 1225) on intestinal motility. The aim of this study was to investigate effects and mechanisms of EA on small intestinal contractions, transit, and slow waves in dogs.

METHODS

Six dogs were equipped with two intestinal cannulas for the measurement of small intestinal contractions and transit. Glucagon was used to induce postprandial intestinal hypomotility. Each dog was studied in five randomized sessions: Control, glucagon, glucagon + EA, glucagon + EA + naloxone, and glucagon + EA + atropine.

KEY RESULTS

1 In the fasting state, EA induced intestinal contractions during motor quiescence (contractile index or CI: 4.4 ± 0.8 VS 8.3 ± 0.7, P < 0.05). 2 In the fed state, EA improved glucagon-induced intestinal hypomotility (CI: 3.8 ± 0.4 VS 6.1 ± 0.6, P < 0.05). 3 Electroacupuncture accelerated intestinal transit delayed by glucagon (67.9 ± 4.3 VS 40.2 ± 5.0 min, P < 0.05). 4 There was a negative correlation between the CI and the total transit time (R(2) = 0.59, P < 0.05). 5 The excitatory effect of EA was blocked by naloxone and partially blocked by atropine. 6 The percentage of normal slow waves was reduced with glucagon (70 ± 2%VS 98 ± 1% at baseline, P = 0.0015). Electroacupuncture normalized impaired slow waves and the effect was blocked by naloxone.

CONCLUSIONS & INFERENCES

Electroacupuncture enhances intestinal contractions during Phase I of the migrating motor complex and glucagon-induced hypomotility in the fed state, and accelerates intestinal transit via the opioid and cholinergic pathways in dogs. Electroacupuncture may have a therapeutic potential for intestinal hypomotility.

Mechanism of acupuncture on neuromodulation in the gut--a review

INTRODUCTION

Acupuncture has been used for treating various gastrointestinal (GI) diseases. However, the mechanism of acupuncture remains unclear.

METHODS

The aim of this article is to review the published literature on the mechanism of acupuncture on neuromodulation in the gut.

RESULTS

Acupuncture treatment involves the insertion of thin needles into the skin and underlying muscle and the subsequent stimulation of the needles manually or electrically. Thus, acupuncture stimulates the somatic afferent nerves of the skin and muscles. The somatic sensory information from the body is carried to the cortex area of the brain. Somatic sensory fibers also project to the various nuclei at the brain stem and hypothalamus. Via somato-autonomic reflex, acupuncture modulates various biomechanical responses, such as prokinetic, antiemetic, and anti-nociceptive effects.

CONCLUSION

According to traditional Chinese medicine, "Acupuncture is believed to restore the balance of Yin and Yang." This can be translated into the Western medicine terminology that "Acupuncture modulates the imbalance between the parasympathetic and sympathetic activity." Acupuncture may be effective in patients with functional GI disorders because of its effects on GI motility and visceral pain.

Correlations among electrogastrogram, gastric dysmotility, and duodenal dysmotility in patients with functional dyspepsia

AIM

The aim of this study was to assess gastric slow waves, antral and duodenal motility simultaneously, and determine the correlation among all these measures in patients with functional dyspepsia.

METHODS

Thirty-one patients with functional dyspepsia were assessed for severity of upper gastrointestinal symptoms with the electrogastrography (EGG) and antroduodenal manometry. The EGG and manometry were recorded for 3 to 4 hours in the fasting state and for 2 hours after a solid meal. Computerized spectral analysis methods were used to compute various EGG parameters.

RESULTS

The EGG was abnormal in 71.0% of patients. The abnormalities included normal slow waves lower than 70% in the fasting state (51.6% of patients) and in the fed state (48.4% of patients), a decrease in dominant power in 28.9% of patients. Antral motility was abnormal in 80.6% of patients and duodenal motility was abnormal in 74.2% of patients. For the EGG and antral motility, 19 of 31 patients had both abnormal EGG and abnormal antral motility; 2 of 31 patients had both normal EGG and normal antral motility. For the EGG and duodenal motility, these values were 16/31 and 2/31, respectively. By both EGG and antroduodenal manometry, abnormal gastric motor function was found in 93.5% of patients. However, quantitative one-to-one correlation between any of the EGG parameters and the antroduodenal dysmotility was not noted. The patients showed high symptom scores particularly to upper abdominal pain, nausea, and belch. No one-to-one correlation was noted between the symptom scores and any of the EGG or motility parameters.

CONCLUSIONS

More than two-thirds of patients with functional dyspepsia have abnormalities in the EGG and antral/duodenal motility. The sensitivity of these 2 different methods is essentially the same. EGG and antroduodenal manometry can complement each other in demonstrating gastric motor dysfunction in patients with functional dyspepsia.

Rhythmic and spatial abnormalities of gastric slow waves in patients with functional dyspepsia

OBJECTIVE

The objectives of this study were to assess differences in gastric slow waves measured by a newly approved multichannel electrogastrogram (EGG) device between patients with functional dyspepsia (FD) and healthy controls.

MATERIALS AND METHODS

Gastric myoelectrical activity was measured by multichannel EGG for 1 hour preprandially and for 2 hours postprandially in 72 FD patients and 16 healthy volunteers. Computerized spectral analysis methods were used to compute various EGG parameters.

RESULTS

(1) Multichannel EGG was abnormal in 83.3% of patients. (2) The regularity of the gastric slow wave was significantly lower in the FD patients in both fasting and fed states; the lowest regularity was seen in channel 3. (3) There was a significantly higher incidence of arrhythmia and tachygastria in FD patients. The highest percentage of arrhythmia and tachygastria were both seen in channel 3. (4) The FD patients showed a significantly lower percentage of slow wave coupling among the 4-channel EGGs in the fed state. (5) The postprandial-preprandial power ratio was significantly less in FD patients. (6) These patients had high symptom scores particularly to nausea, upper abdominal pain, and bloating. However, no significant correlation was noted between the EGG parameters and the symptoms.

CONCLUSIONS

Gastric myoelectrical activity is impaired in most patients with FD. The impairment is reflected as a decreased percentage of normal slow waves and an excessive amount of arrhythmia as well as an abnormal spatial distribution of EGG parameters among the 4 channels, suggesting an impaired coordination of gastric slow waves.

Transcutaneous electroacupuncture improves dyspeptic symptoms and increases high frequency heart rate variability in patients with functional dyspepsia

The aim of the study was to evaluate the therapeutic value and possible mechanisms of transcutaneous electroacupuncture (TEA) in a double-blind and cross-over study in patients with functional dyspepsia (FD). Twenty-seven patients with FD were enrolled and the study consisted of two parts: (i) acute effects of TEA at PC6 and ST36 on gastric slow waves and heart rate variability and (ii) chronic (2 weeks) effects of TEA at PC6 and ST36 on dyspepsia symptoms, gastric slow waves, heart rate variability and neuropeptide Y (NPY) and motilin. The results of this study are: (i) The dyspepsia symptom score was decreased by 55% at the end of chronic TEA and the improvement was significant (P < 0.01); (ii) the high frequency (HF) assessed from the spectral analysis of heart rate variability was markedly increased with both acute TEA (76% increase, P = 0.01) and chronic TEA (75% increase, P = 0.025); (iii) gastric slow waves were not altered by either acute or chronic TEA; and (iv) the plasma level of NPY but not motilin was increased after chronic TEA. Non-invasive and needleless transcutaenous electroacupuncture at ST36 and PC6 markedly improves dyspepsia symptoms and the improvement may be associated with the increase in HF heart rate variability and the modulation of NPY.

The effects of manipulating expectations through placebo and nocebo administration on gastric tachyarrhythmia and motion-induced nausea

BACKGROUND

Interest in the role of expectation in the development of nausea and other adverse conditions has existed for decades. The purpose of this study was to examine the effects of manipulating expectations through the administration of placebos and nocebos on nausea and gastric tachyarrhythmia provoked by a rotating optokinetic drum.

METHOD

Seventy-five participants were assigned to one of three groups. Positive-expectancy group participants were given placebo pills that would allegedly protect them against the development of nausea and motion sickness. Negative-expectancy group participants were given the same pills as nocebos; they were led to believe there was a tendency for them to make nausea somewhat worse. Placebo-control group participants were told the pills were indeed placebos that would have no effect whatsoever.

RESULTS

Subjective symptoms of motion sickness were significantly lower among negative-expectancy group participants than positive-expectancy and placebo-control group participants (p<0.05). Gastric tachyarrhythmia, the abnormal stomach activity that frequently accompanies nausea, was also significantly lower among negative-expectancy group participants than positive-expectancy and Placebo-Control Group participants during drum rotation (p<.05) [corrected]

CONCLUSIONS

Inducing negative expectations through nocebo administration reduced nausea and gastric dysrhythmia during exposure to provocative motion, whereas positive placebos were ineffective for preventing symptom development. That manipulation of expectation affected gastric physiological responses as well as reports of symptoms, suggests an unspecified psychophysiological mechanism was responsible for the observed group differences. These results also suggest that patients preparing for difficult medical procedures may benefit most from being provided with detailed information about how unpleasant their condition may become.

Acupuncture for functional gastrointestinal disorders

Functional gastrointestinal (GI) symptoms are common in the general population. Especially, motor dysfunction of the GI tract and visceral hypersensitivity are important. Acupuncture has been used to treat GI symptoms in China for thousands of years. It is conceivable that acupuncture may be effective in patients with functional GI disorders because it has been shown to alter acid secretion, GI motility, and visceral pain. Acupuncture at the lower limbs (ST-36) causes muscle contractions via the somatoparasympathetic pathway, while at the upper abdomen (CV-12) it causes muscle relaxation via the somatosympathetic pathway. In some patients with gastroesophageal reflux disease (GERD) and functional dyspepsia (FD), peristalsis and gastric motility are impaired. The stimulatory effects of acupuncture at ST-36 on GI motility may be beneficial to patients with GERD or FD, as well as to those with constipation-predominant irritable bowel syndrome (IBS), who show delayed colonic transit. In contrast, the inhibitory effects of acupuncture at CV-12 on GI motility may be beneficial to patients with diarrhea-predominant IBS, because enhanced colonic motility and accelerated colonic transit are reported in such patients. Acupuncture at CV-12 may inhibit gastric acid secretion via the somatosympathetic pathway. Thus, acupuncture may be beneficial to GERD patients. The antiemetic effects of acupuncture at PC-6 (wrist) may be beneficial to patients with FD, whereas the antinociceptive effects of acupuncture at PC-6 and ST-36 may be beneficial to patients with visceral hypersensitivity. In the future, it is expected that acupuncture will be used in the treatment of patients with functional GI disorders.

Systematic review: pathophysiology and management of gastrointestinal dysmotility in systemic sclerosis (scleroderma)

Gastrointestinal dysmotility in systemic sclerosis (scleroderma) is prevalent in 90% of patients, increasing morbidity and in some cases mortality. The resultant gastrointestinal complications are usually extensive, involving many regions of the gut from the oesophagus to the anus. Collagen replacement of vascular and enteric smooth muscle results in hypomotility, lumen dilatation, tensile rigidity and eventual loss of organ functions. The aim of this paper is to provide an overview of systemic sclerosis-related gastrointestinal dysmotility and available/potential therapeutic options. We evaluated published data on the pathophysiology and management of gastrointestinal dysmotility in systemic sclerosis patients using the MEDLINE database for English and non-English articles from 1966 to July 2005. Based on this systematic review, lifestyle and medical therapy approaches are preferred as they often improve and/or ameliorate symptoms. Surgery is only recommended with serious, rare complications such as bowel perforation or ischaemia. Alternative therapies such as acupuncture-based therapies are well tolerated, with clinical improvement and may be of potential therapeutic benefit for systemic sclerosis gastrointestinal dysmotility. Further elucidation of initiating and persistent mechanisms of systemic sclerosis-related gastrointestinal dysmotility will optimize the development of a multidisciplinary and more directed treatment regimen.

Sickness and satiety: physiological mechanisms underlying perceptions of nausea and stomach fullness

The pathophysiology of nausea and the physiological mechanisms underlying perceptions of stomach emptiness and fullness are not clearly understood, but several potentially important factors have been identified. Gastric dysrhythmias are believed to contribute to the subjective experience of nausea and may also be involved with perceptions of stomach emptiness, hunger, and even dyspepsia symptoms like bloating and early satiety. Normal gastric neuromuscular function is more evident in the absence of nausea and is also thought to be related to feelings of satiety or comfortable stomach fullness. Autonomic and endocrine influences may also play a critical role in the pathophysiology of nausea and abnormal perceptions of stomach emptiness or fullness. Achieving a better understanding of the gastric neuromuscular and neurohormonal influences on perceptions arising from the viscera may prove invaluable in the development of novel treatments for such conditions as unexplained nausea, functional dyspepsia, and obesity.

Inhibition of transient lower esophageal sphincter relaxations by electrical acupoint stimulation

Acupuncture has been shown to modulate visceral sensation and function. Traditionally, stimulation at the Neiguan (pericardial meridian) has been used to treat upper gastrointestinal symptoms. Some of the effects of acupuncture may be mediated through release of endogenous opioids and are reversed by naloxone. Gastric distension is the major trigger for transient lower esophageal sphincter (LES) relaxations (TLESRs). The aim of this study was to investigate the effect of electric stimulation at the Neiguan and naloxone on the TLESRs. In 14 healthy volunteers, electrical acupoint stimulation was applied at the Neiguan and a sham point on the hip in randomized order on the same day. In 12 healthy volunteers, the effects of naloxone (80 microg/kg iv bolus injection) and saline on electrical acupoint stimulation were compared on separate days at least 1 wk apart. Esophageal motility was measured during distension of the proximal stomach with 500 ml of air using a barostat balloon. Electric acupoint stimulation at the Neiguan decreased the rate of TLESRs by approximately 40% from a median of 6/h to 3.5/h (P < 0.02). Acupoint stimulation had no effect on basal LES pressure, the residual LES pressure during TLESRs, the duration of TLESRs, or gastrointestinal symptoms of fullness, bloating, discomfort, or nausea. The effect of acupoint stimulation was not inhibited by naloxone. Electric acupoint stimulation at the Neiguan significantly inhibits the frequency of TLESRs in response to gastric distention in healthy subjects. This effect does not appear to be mediated through mu-opioid receptors.

Gastric electrical stimulation significantly increases canine lower esophageal sphincter pressure

This study determined the effect of low-frequency and high-frequency gastric electrical stimulation (GES) on canine lower esophageal sphincter (LES) pressure and also evaluated the effect of such stimulation on neurohumoral factors that modulate LES pressure. Eight dogs were fitted with stimulation wires along the greater curvature of the stomach. A sleeve device measured LES pressure before, during, and after GES, and regulatory peptides were measured during fasting and after a meal. A consistent and significant rise in LES pressure was observed during GES, and it was sustained after GES was discontinued. Plasma concentration and area under the curve of pancreatic polypeptide, motilin, gastrin and neurotensin were not affected by GES. We conclude that acute low- and high-frequency GES significantly increases LES pressure. This effect may not be modulated by efferent vagal activity or release of regulatory peptides.

Inhibitory effects of stress on postprandial gastric myoelectrical activity and vagal tone in healthy subjects

The aim was to investigate gastric myoelectrical activity (GMA) and vagal activity in response to stress. The study was performed in 10 healthy subjects in three sessions (control, relaxation and stress). The control session was composed of 30-min recordings before and 30-min recordings after a test meal. The protocol of two other sessions was similar except that the fasting recording was extended to 60 min and the subjects were continuously watching a horror movie (stress) or guided meditation tape (relaxation) after the 30-min baseline. GMA was recorded using electrogastrography and heart rate variability (HRV) was derived from the electrocardiogram. Meal resulted in a postprandial increase in the dominant frequency (2.91 cpm vs 3.17 cpm, P < 0.007), dominant power (30.0 dB vs 32.5 dB, P < 0.05), and percentage of normal slow waves (79.8%vs 87.4%, P = 0.09). Similar responses were found in the relaxation session. Stress inhibited all these normal postprandial response and reduced the regularity of gastric slow waves (82.0%vs 66.0%, P < 0.01). In addition, spectral analysis of the HRV demonstrated an inhibition of postprandial vagal activity and an increase of postprandial sympathetic activity with stress. Stress has an inhibitory effect on postprandial GMA and this may involve both vagal and sympathetic pathway.

Review article: therapeutic roles of acupuncture in functional gastrointestinal disorders

Acupuncture has been practiced empirically in China for several millennia, and is being increasingly accepted by practitioners and patients worldwide. Functional gastrointestinal disorders are common in clinical gastroenterology. The prevalence of one or more functional gastrointestinal disorders is estimated to be as high as 70% in general population using Rome diagnostic criteria. Since functional gastrointestinal disorders are diagnosed based on symptoms and the exact aetiologies for most of functional gastrointestinal disorders are not completely known, it is not unusual that the treatment for these disorders is unsatisfactory and alternative therapies are attractive to both patients and practitioners. During the latest decades, a considerable number of studies have been performed on acupuncture for the treatment of functional gastrointestinal disorders and underlying mechanisms. In this article, we reviewed available data in the literature on the applications and mechanisms of acupuncture for the treatment of functional gastrointestinal disorders, including functional oesophageal disorders, nausea and vomiting, functional dyspepsia, irritable bowel syndrome, constipation, etc. A summary is provided based on the quality and quantity of published studies regarding the efficacy of acupuncture in treating these various disorders. In addition, the methodology of acupuncture is also introduced.

Effects of acupuncture on vasopressin-induced emesis in conscious dogs

Although acupuncture has a significant clinical benefit, the mechanism of acupuncture remains unclear. Vasopressin, a posterior pituitary hormone, is involved in nausea and vomiting in humans and dogs. To investigate the antiemetic effects of acupuncture on vasopressin-induced emesis, gastroduodenal motor activity and the frequency of retching and vomiting were simultaneously recorded in conscious dogs. In seven dogs, four force transducers were implanted on the serosal surfaces of the gastric body, antrum, pylorus, and duodenum. Gastroduodenal motility was continuously monitored throughout the experiment. Vasopressin was intravenously infused at a dose of 0.1 U x kg(-1) x min(-1) for 20 min. Electroacupuncture (EA, 1-30 Hz) at pericardium-6 (PC6), bladder-21 (BL21), or stomach-36 (ST36) was performed before, during, and after the vasopressin infusion. To investigate whether the opioid pathway is involved in EA-induced antiemetic effects, naloxone (a central and peripheral opioid receptor antagonist) or naloxone methiodide (a peripheral opioid receptor antagonist) was administered before, during, and after EA and vasopressin infusion. Intravenous infusion of vasopressin induced retching and vomiting in all dogs tested. Retrograde peristaltic contractions occurred before the onset of retching and vomiting. EA (10 Hz) at PC6 significantly reduced the number of episodes of retching and vomiting. EA at PC6 also suppressed retrograde peristaltic contractions. In contrast, EA at BL21 or ST36 had no antiemetic effects. The antiemetic effect of EA was abolished by pretreatment with naloxone but not naloxone methiodide. It is suggested that the antiemetic effect of acupuncture is mediated via the central opioid pathway.

Effects of electroacupuncture on gastric myoelectrical activity in healthy humans

The acupuncture point of the wrists (PC6) and the lower legs (ST36) are common points for the treatment of gastric symptoms. However, it remains unclear whether these two acupoints have different effects on gastric myoelectrical activity. We compared the effect of electroacupuncture (EAP) between PC6 and ST36 on gastric myoelectrical activity using surface electrogastrography (EGG). EAP (1 Hz, for 30 min) was applied at either ST36, or PC6, or both acupoints in eight healthy volunteers. EAP at both PC6 and ST36 did not change the percentage of normal slow waves and tachygastria. While EAP at either PC6 or ST36 did not change period dominant frequency (PDF), EAP at both PC6 and ST36 significantly decreased PDF to 78.1 +/- 8.4% of baselines. EAP at PC6 reduced period dominant power (PDP) to 47.2 +/- 5.3% of baselines, while EAP at ST36 increased PDP to 153.6 +/- 28.3% of baselines. EAP at shoulders (sham acupuncture) did not affect the gastric myoelectrical activity. EAP at either PC6 or ST36 shows an opposite effect on PDP, whereas EAP at both PC6 and ST36 has a synergistic effect on PDF. Understanding site-specific effects of acupuncture may contribute to the selection of appropriate acupoints for treating functional GI disorders.

Gastric myoelectrical activity post-chemoradiotherapy and esophagectomy: a prospective study using subscapular surface recording

The aims of this study were to prospectively evaluate gastric function in esophageal cancer patients after chemoradiotherapy and following surgery, using cutaneous electrogastrography (EGG). Twenty-three patients with esophageal adenocarcinoma were recruited to the study. A subset of patients (n = 11) underwent neoadjuvant chemoradiotherapy and were also studied at 14 days after treatment. All patients underwent EGG studies prior to and following surgery, at 3 months postoperatively. Ten of these patients were also studied at medians of 6 months and 12 months after surgery. Twenty normal volunteers were used as controls. Post-operative EGG studies were monitored with a modified technique; the electrodes being placed in the subscapular region in the area of the transposed stomach. Following neoadjuvant treatment there was a significant increase in abnormal gastric myoelectrical activity involving changes in tachygastrias and decreased motility as measured by power ratio. Post-operatively there was a significant increase in bradygastria which persisted at 6 months but not at 12 months. There was a corresponding decrease in normogastria which persisted at 6 months and to a lesser extent at 12 months. Dominant frequency remained significantly depressed at 3, 6 and 12 months. Gastric myoelectrical activity is normal in untreated esophageal cancer. Neoadjuvant chemoradiotherapy causes a disruption to normal myoelectrical activity involving reduced motility and tachygastrias. Surgery causes a depression in dominant frequency with a reduced incidence of normogastria at 3 months and 6 months but with a tendency towards normality at 12 months.

Transcutaneous acupoint electrical stimulation in preventing and treating nausea and vomiting in patients receiving electroconvulsive therapy

A significant number of patients complain of nausea after general anesthesia and electroconvulsive therapy (ECT). Nausea is second only to headache as the most frequent and troublesome systemic side effect of ECT. The most common treatment of this is antiemetic drugs. Transcutaneous acupoint electrical stimulation (TAES) is a nonpharmacologic method for preventing and treating nausea and vomiting. TAES can alleviate motion sickness, reduce the incidence of vomiting caused by chemotherapy, and treat pregnancy-induced nausea and vomiting. TAES has been shown to reduce the incidence of postoperative nausea after general anesthesia. This is the first report to review the effectiveness of TAES in preventing and treating nausea and vomiting in 11 patients receiving ECT. Nine of these patients had a good response to TAES. One patient had a mixed response, and 1 did not respond to TAES.

The efficacy of acupressure and acustimulation wrist bands for the relief of chemotherapy-induced nausea and vomiting. A University of Rochester Cancer Center Community Clinical Oncology Program multicenter study

As an adjunct to standard antiemetics for the relief of chemotherapy-induced nausea and vomiting (NV), 739 patients were randomly assigned to either: 1) acupressure bands, 2) an acustimulation band, or 3) a no band control condition. Patients in the acupressure condition experienced less nausea on the day of treatment compared to controls (P<0.05). There were no significant differences in delayed nausea or vomiting among the three treatment conditions. Additional analyses revealed pronounced gender differences. Men in the acustimulation condition, but not the acupressure condition, had less NV compared to controls (P<0.05). No significant differences among the three treatment conditions were observed in women, although the reduction in nausea on the day of treatment in the acupressure, compared to the no band condition, closely approached statistical significance (P=0.052). Expected efficacy of the bands was related to outcomes for the acupressure but not the acustimulation conditions.

Diagnosis and treatment of neuromuscular disorders of the stomach

Gastric neuromuscular disorders encompass a spectrum of dysfunction in nerve and smooth muscle that includes gastric visceral hypersensitivity, gastric dysrhythmias, fundic dysfunction, antral hypomotility, and gastroparesis. Patients with each disorder may present with such vague dyspepsia symptoms as early satiety, upper abdominal discomfort, bloating, or nausea with or without vomiting. A careful history and physical examination may suggest a gastric neuromuscular disorder, but symptoms are nonspecific. Gastroparesis is the most severe form of neuromuscular dysfunction. Such reversible causes of gastroparesis as mechanical obstruction of the stomach and chronic mesenteric ischemia must be excluded. Gastroparesis, gastric dysrhythmias, and hypersensitivity may follow viral infection or be due to degenerative processes that affect the gastric enteric neurons, smooth muscle, or interstitial cells of Cajal. Commonly, the cause of these gastric neuromuscular disorders is unknown. An approach to the diagnosis and treatment of gastric neuromuscular disorders is reviewed, including dietary counseling, drugs, and medical devices.

Effect of the acupoints ST-36 (Zusanli) and SP-6 (Sanyinjiao) on intestinal myoelectric activity of Wistar rats

Despite its ancient use as a therapeutic tool to treat several ailments, acupuncture still faces the challenge of scrutiny by Western science both in terms of its efficacy and in terms of the characterization of its effects and mechanisms of actions underlying these effects. We investigated under well-controlled and carefully characterized conditions the influence of electrical stimulation of acupuncture points ST-36 (Zusanli) and SP-6 (Sanyinjiao) on the myoelectric activity of the small intestine of 38 adult male Wistar rats. Electrical recordings obtained by means of four electrodes chronically implanted in the small intestine were used to assess the effects of acupuncture (electroacupuncture stimulation set at 2 Hz, intermittent stimulation, 1 V, for 30 min). Immobilization of the animals was associated with a consistent decrease (-8 +/- 7%) in the myoelectric activity of the small intestine as measured by means of the root mean square. Conversely, acupuncture was able to significantly increase (overshoot) this activity compared to baseline (+44 +/- 7%). In contrast, immobilized animals subjected to sham acupuncture had only modest (nonsignificant) increases in myoelectric activity (+9 +/- 6%). Using carefully controlled conditions we confirmed previous noncontrolled studies on the ability of acupuncture to alter intestinal motility. The characterization of the topographic and temporal profiles of the effects observed here represents a basis for future dissection of the physiological and pharmacological systems underlying these effects.

Electroacupuncture accelerates gastric emptying in association with changes in vagal activity

Gastroparesis is a disorder with a lack of treatment options and this study investigated the effect of electroacupuncture on gastric emptying and involved mechanisms. Dogs implanted with a duodenal cannula and serosal electrodes were fed with Ensure mixed with phenol red, and the gastric effluent was collected. Electroacupuncture was performed from 30 min before until 45 min after the meal. Gastric myoelectrical activity and electrocardiogram were recorded. Gastric emptying was significantly improved with electroacupuncture. Vagal activity assessed from the spectral analysis of heart rate variability was markedly increased with electroacupuncture. Electroacupuncture increased the regularity of gastric slow waves in both the proximal and distal stomach. It also increased the number of spike bursts in the distal but not proximal stomach. Electroacupuncture accelerates gastric emptying of liquid in dogs and its potential for treating gastroparesis may be explored. The effect may be attributed to improvement in gastric slow-wave rhythmicity and antral contractile (spike) activity and may possibly involve the vagal pathway.

Electrogastrography: a non-invasive measurement of gastric function

BACKGROUND

Electrogastrography (EGG) is the non-invasive measurement of gastric electrical activity. With the development of modern technology, improved recording and automated analysis, it is a reliable and accurate technique for the measurement of gastric myoelectrical activity providing information about the frequency and regularity of the gastric slow wave.

AIM

The aim of this report is to evaluate its role in clinical practice.

METHODS

The literature is reviewed and its role investigated.

RESULTS

EGG has been successfully used in the investigation of gastroparesis, non-ulcer dyspepsia (NUD), gastric emptying (GE) disorders and diabetes mellitus (DM). EGG also provides an insight into the effect of medications on gastric function, e.g. edrophonium, cisapride, erythromycin and proton-pump inhibitors (PPI).

CONCLUSIONS

EGG has a developing role in the assessment of gastric dysfunction and on the effect of medical treatment. The effect of surgery and anaesthesia on gastric myoelectric activity is less clear.

New OTC drugs and devices 1999: a selective review

OBJECTIVES

To educate pharmacists about newly introduced nonprescription products/devices/diagnostic products, and to create a heightened awareness of the dilemma of dietary supplements and the problems their use poses for consumers and pharmacists.

DATA SOURCES

Recent clinical and pharmaceutical industry literature.

DATA SYNTHESIS

It is critical for the pharmacist to be knowledgeable about dietary supplements to be able to appropriately counsel patients on benefits and risks associated with their use. In addition, numerous other nonprescription products, including home diagnostic products and accessories, will continue to become available on the U.S. market. It is important that the pharmacist become as knowledgeable as possible about these and be capable of educating the consuming public about their appropriate use.

CONCLUSION

Dietary supplements will continue to flood the self-care market. Pharmacists need a balanced understanding of these products to assist the consumer. The new nonprescription medications cited in this review represent valuable additions to the growing array of self-care products for consumer use.

Acupuncture for gastrointestinal and hepatobiliary disorders

Acupuncture has been used for various gastrointestinal (GI) conditions. Voluminous data support the effect of acupuncture on the physiology of the GI tract, including acid secretion, motility, neurohormonal changes, and changes in sensory thresholds. Much of the neuroanatomic pathway of these effects has been identified in animal models. A large body of clinical evidence supports the effectiveness of acupuncture for suppressing nausea associated with chemotherapy, postoperative state, and pregnancy. Prospective randomized controlled trials have also shown the efficacy of acupuncture for analgesia for endoscopic procedures, including colonoscopy and upper endoscopy. Acupuncture has also been used for a variety of other conditions including postoperative ileus, achalasia, peptic ulcer disease, functional bowel diseases (including irritable bowel syndrome and nonulcer dyspepsia), diarrhea, constipation, inflammatory bowel disease, expulsion of gallstones and biliary ascariasis, and pain associated with pancreatitis. Although there are few prospective randomized clinical studies, the well-documented physiological basis of acupuncture effects on the GI tract, and the extensive history of successful clinical use of acupuncture, makes this a promising modality that warrants further investigation.

Physiological basis and pharmacology of motion sickness: an update

Motion sickness can occur when sensory inputs regarding body position in space are contradictory or are different from those predicted from experience. Signals from the vestibular system are essential for triggering motion sickness. The evolutionary significance of this malady is unclear, although it may simply represent the aberrant activation of vestibuloautonomic pathways that typically subserve homeostasis. The neural pathways that produce nausea and vomiting during motion sickness are presumed to be similar to those that generate illness after ingestion of toxins. The neural substrate of nausea is unknown but may include neurons in the hypothalamus and inferior frontal gyrus of the cerebral cortex. The principal motor act of vomiting is accomplished through the simultaneous contractions of inspiratory and expiratory respiratory muscles and is mediated by neurons in the lateral medullary reticular formation and perhaps by cells near the medullary midline. Cocontraction of the diaphragm and abdominal muscles increases pressure on the stomach, which causes gastric contents to be ejected through the mouth. Effective drugs for combating motion sickness include antihistamines, antimuscarinics, 5-HT1A (serotonergic) receptor agonists and neurokinin type 1 receptor antagonists. However, considerable information concerning the physiological basis and pharmacology of motion sickness is unknown; future research using animal models will be required to understand this condition.

Perspectives of electrogastrography and motion sickness

Electrogastrography (EGG) is a noninvasive measurement of stomach activity using surface electrodes positioned over the abdominal surface. For over 10 years, EGG has been used as an objective measure of epigastric symptoms and nausea experienced in visually induced sickness provoked by circularvection. It was reported that during sickness, there is a shift in the dominant basal electrical activity. The 3 cycles per minute activity decrease and the 4-9 cycles per minute activity increase. This technique has also been used to evaluate the efficacy of antimotion sickness drugs and to monitor sickness induced by other provocative stimuli such as Coriolis cross-coupling, parabolic flight manoeuvres and microgravity. It has been further postulated that peripheral changes in gastric myoelectrical activity in response to visually induced sickness are detected centrally and lead to the generation of motion sickness. However, other studies using either identical or equally effective motion stimuli failed to support the positive correlation of changes in gastric activity with the incidence and severity of motion sickness. The interpretation of spectral analysis on EGG during motion sickness must be taken with great caution. The inherent variability of the EGG and intersubject variability makes it difficult to consider EGG a reliable and robust indicator of motion sickness. Its relation to motion sickness and the underlying mechanism remains unclear. The true diagnostic value of EGG in motion sickness has yet to be determined.