• The Korean Journal of Physiology
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• v.6 no.2
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• pp.31-37
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• 1972

The right cervical vagus nerve was electrically stimulated for 30 sec, and 30 minutes recording cardiac rate responses and electrocardiogram. The main purposes of the present experiment are to determine effect of stimulation frequency on the maintenance of cardiac rate responses and to determine recovery time of sinus rhythm after asystole period followed by idioventricular rhythm during prolonged electrical stimulation of the vagus, and the optimal stimulation parameters for vagal stimulation were studied as well. The results obtained are summarized as follows: 1. The maximum negative chrontropic responses were obtained with the following ranges of electrical parameters. Intensity: 3V-7V, Frequency: 20/sec-60/sec, and pulse duration: 5 msec-20 msec. 2. Compared with the responses from sympathetic effectors, cardiac rate responses to electrical stimulation of vagus nerve were well maintained with all stimulation frequencies. 3. At all stimulation frequencies except 20/sec, sinus node started to take over primary pacemaker activity when cardiac rates were restored to about 38-40/min. 4. It was indicated that upper limit of idioventricular rhythm does not exceed 38-40/min. 5. With the stimulation parameter set of 20/sec-5 msec-3 V, sinus rhythm did not appear during 30 minutes of stimulation period. Therefore, this electrical parameter set appears to be optimal for elicitation of prolonged and maximum cardiac rate responses by vagal stimulation.

• Journal of Korean Neurosurgical Society
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• v.42 no.1
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• pp.16-19
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• 2007

Objective : This report describes the clinical study of the surgical method of lateral third infraclavicular implantation of vagal nerve stimulation (VNS) generator through the axillary wrinkle incision. Methods : In a retrospective study, the data for 20 patients with medically intractable epilepsy treated by this approach were examined. The mean age was 31.4 years (range : 14-50), and the mean follow-up period was 12.15 months (range : 4-21 months). The male to female ratio was 2.3 : 1. The subcutaneous pocket for the generator was located in the lateral third infraclavicular area through the axillary wrinkle. Our method was a modification of the standard VNS generator implantation in the mid-infraclavicular pocket through anterior axillary incision. Results : There were the excellent or good cosmetic satisfaction in 95% of the cases and fair in 5%. The generator was located outside the lung field in 15%, periphery of the lung field in 45%, and crossed over the lung field in 40%. Discomfort from shoulder motion occurred transiently in 35% of cases. Other complications were minimal. Conclusion : These results demonstrate that the lateral third infraclavicular apporach will offers cosmetic benefits and reduction of obscuration of the lung field without serious complications. Thus, this technique provides an attractive alternative among the surgical techniques for the vagal nerve stimulation.

• Asian-Australasian Journal of Animal Sciences
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• v.2 no.3
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• pp.177-178
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• 1989

• Proceedings of the KOSOMBE Conference
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• v.1995 no.11
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• pp.205-208
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• 1995

Analysis of Heart Rate Variability has been studied to estimate autonomic nervous system. PR interval represents conduction time from atrium to ventricle. PR interval variability(PRV) is also can be used to estimate autonomic nervous system. We have acquired two-state ECGs of children who are before vagal stimulation and after vagal stimulation. We applied chaotic theory to each ECG in order to analyze PRV, and compared the results from frequency domain analysis. The correlation dimension of PRV of pre-stimulated children is higher than that of post-stimulated children.

• Korean Journal of Clinical Laboratory Science
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• v.38 no.2
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• pp.141-146
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• 2006

Vagal nerve stimulation (VNS) has been proposed as a possible way to improve the control of refractory epilepsy. We report the effects following VNS treatment in patients with refractory epilepsy. Seventeen patients with a mean age of 12.8 years, ranging from 5 to 29 years, underwent the implantation of vagal nerve stimulation (Cyberonics, Houston, TX). We reviewed the clinical findings before and after VNS in seizure frequency, number of antiepileptic drugs (AED), and quality of life (QOL). All of the patients had intractable seizures, eleven of the patients had additional medical complications, three had hippocampus atrophy, one had encephalomalacia, five had encephalitis, one had pachygyria, and one had schizencephaly. Thirteen patients had symptomatic partial epilepsies, three patients had Lennox-Gastaut syndrome and one had cryptogenic partial epilepsy. The mean follow up duration was 35 months. The mean reduction of seizure frequency compared with baseline before VNS was 26.1% after 3 months (p<0.005), 41.9% after 6 months (p<0.001), 46.9% after 1 year (p<0.001), and 53% at the latest follow-up (p<0.001). Twelve patients showed an improvement of QOL such as mood, language, alertness, expression, and motor function. The most common side effects were transient hoarseness or voice change or cough, which was detected in six patients (35%) and wound infection in one patient (5%). This study has shown a good anti-seizure effect of VNS, decrease in seizure frequency and improvements in QOL. We concluded that VNS is a beneficial therapy in refractory epilepsy with a non-resectable epileptic focus. Further studies should be focused on the prediction of unresponsiveness and the adjustment of VNS parameters for maximum efficacy in patients with various medical histories.

• Child Health Nursing Research
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• v.6 no.1
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• pp.32-50
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• 2000

A descriptive exploratory design was used in this study to evaluate the effects of sponge bathing on physiological(heart rate, heart period, vagal tone, oxygen saturation, respiration) and behavioral responses in newly born 40 preterm infants from intensive care unit of S University Hospital in Seoul. Data has been collected from October, 1997 to March, 1999. The infants were between 27-33 weeks gestational age at birth, and were free of congenital defects. The subjects entered the protocol when they were medically stable (determined by initiation of feeding and discontinuation of all respiratory support) but still receiving neonatal intensive care. The infants' physiologic parameters were recorded a 10 - minute before, during, and after bathing. Continuous heart rate data were recorded on a notebook computer from the infant's EKG monitor. The data were digitized off-line on software(developed by Lee and Chang in Wavelet program) which detected the peak of the R wave for each heart beat and quantified sequential R-R intervals in msec(i.e. heart periods). Heart period data were edited to remove movement artifact. Heart period data were quantified as : 1) mean heart period; 2) vagal tone. Vagal tone was quantitfied with a noninvasive measure developed by Porges(1985) in Mxedit software. To determine behavioral status, tools were developed by Scafidi et al(1990) were used. Collected data were analyzed with the SPSS program using paried t-test, ANOVA, and Pearson correlation. The result were as follow. 1. The results of the ANOVAs indicated that vagal tone were signifcantly lower during bathing than baseline and post-bathing. There were significant differences in heart period and heart rate levels across the bathing. But the mean oxygen saturations and respirations were no differences. Also, there were no significant differences on behavioral sign, motor activity, behavioral distress, weight changes, morbidity, and hospitalization period. 2. To evaluate the relation between vagal tone and subsequent parameters, the two groups (the high group had 19 subjects and low group had 21subjects) were divided by the mean baseline vagal tone. Vagal tone measured prior to bathing were significantly associated with respiration before bathing, vagal tone during bathing, and the magnitude of change in both vagal tone. But, other subsequent reactivities were no differences in two groups. 3. Correlations were also calculated between vagal tone and the subsequent physiological reactivities from baseline through after- bathing. Correlations were significant between baseline vagal tone and baseline heart rate, between baseline vagal tone and baseline heart period, between baseline vagal tone and oxygen saturation after bathing. In summary, the bathing in this study showed a stressful stimulus on premature infants through there was significance in the physiological parameters. In addition, our study represents the documentation that vagal tone reactivity in response to clearly defined external stimulation provides an index of infant's status.

• The Korean Journal of Physiology
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• v.25 no.1
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• pp.27-35
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• 1991

Generally, it has been known that cholecystokinin (CCK) release into the plasma is under cholinergic control, but secretin release is not. Thus in anesthetized dogs we studied the effect of atropine $(50\;{\mu}g/kg\;followed\;by\;50\;{\mu}g/kg/hr)$ on pancreatic secretion and plasma concentrations of bioactive CCK and immunoreactive secretin in response to intraduodenal perfusion of sodium oleate (1, 3 and 9 mmol/hr). The volume, protein output and bicarbonate output of the secretion were increased by sodium cleats and this oleate-induced secretion was decreased significantly by atropine administration. However the increased plasma CCK and secretin levels by sodium oleate were not changed by atropine. These results indicate that atropine suppressed sodium oleate-induced pancreatic secretion through inhibiting cholinergic mechanism directly rather than decreasing the release of pancreatic secretory hormones. In another set of experiments, bilateral cervical vagi were stimulated electrically to observe the changes of pancreatic secretion and the above two plasma hormone levels in the presence or absence of atropine. In the vagally stimulated dogs, the volume, protein output and bicarbonate output of the pancreatic secretion were increased significantly. Both plasma secretin and CCK were concomitantly released significantly by vagal stimulation. Atropine significantly depressed the pancreatic secretory response as well as the release of these two pancreatic secretory hormones. Therefore, we conclude that in the presence of atropine the depressed pancreatic response to vagal stimulation is at least, in part, due to decreased release of endogenous CCK and secretin. In the vagally stimulated animals, however, the involvement of direct cholinergic influence on pancreatic exocrine gland remains to be answered.

• The Journal of Internal Korean Medicine
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• v.29 no.3
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• pp.621-628
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• 2008

Objectives : The aim of this study was to investigate changes of gastric vagal nerve activity and pyloric valve function after execution of combination treatments of both electroacupuncture at Zusanli(ST36) and manual acupuncture at other acupoints in patient with functional dyspepsia. Methods : Bowel sounds of 49 patients (18 male, 31 female) were recorded and their % of bowel sound (%BS) and ratio of dominant frequency (DF) were analyzed. Postprandial %BS was used to indicate the gastric vagal activity after eating. Ratio of postprandial/fasting dominant frequency was used to present the degree of pyloric valve function. According to values of %BS and DF ratio, each patient was classified into normal or abnormal (<6 %BS, hypoactivity: <1 DF ratio, dysfunction) group. For 2 weeks, patients received a treatment consisting of both electroacupuncture stimulation at Zusanli (ST36) and acupuncture at other meridian points. Variation of parameters shifting normal to abnormal or abnormal to normal was observed, and total cure rate was calculated. Results : Total cure rate of %BS was 16%, and that of DF was 37%. Patients who improved to normal value from abnormal or aggravated to abnormal level showed both significant difference in both vagal nerve hypoactivity and pyloric valve dysfunction, respectively. Conclusions : Analysis of bowel sound might be useful to evaluate both gastric vagal nerve activity and pyloric valve function. Combination effects of Zusanli (ST36) electroacupuncture and manual acupuncture of other acupoints showed a bidirectional effect in which their activity and function were in general improved. sometimes from aggravated to abnormal level.

• Korean Journal of Clinical Laboratory Science
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• v.39 no.1
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• pp.56-62
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• 2007

Lennox-Gastaut syndrome(LGS) is a severe age-specific epilepsy syndrome that causes medication-resistant seizures in childhood. Vagal nerve stimulation (VNS) has been proposed as a possible way to improve the treatment of refractory epilepsy. We treated 9 patients with Lennox-Gastaut syndrome between the ages of 2 and 11 years (mean 5.8 years), by using the vagus nerve stimulation. The mean follow-up duration was 35 months. The mean reduction of seizure frequency compared with baseline before VNS was 52% after 6 months (range, 0% to 89%; P<0.011), and 58% after 1 year (range 0% to 89%; P<0.012). Seven patients showed improvements of quality of life (QOL) such as alertness, mood, and language skills. The most common side effects were transient hoarseness (6 patients) and drooling (1 patient). Our results suggest that the vagus nerve stimulation could be an effective and safe adjunct therapy for the treatment of Lennox-Gastaut syndrome.

• Journal of Korean Academy of Nursing
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• v.35 no.8
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• pp.1451-1460
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• 2005

Purpose. The purpose of this study was to evaluate the premature infants' responses to infant massage (tactile and kinesthetic stimulation). These responses measured by weight, physiological (vagal tone, heart rate, oxygen saturation) and behavioral responses (behavioral states, motor activities, and behavioral distress). Methods. This study was conducted using an equivalent control pretest-posttest design. The sample was divided into two groups of 13 infants with gestational age less than 36 weeks at birth, birth weight less than 2000g, and no congenital anomalies. The experimental group received the massage intervention twice daily for 10 days. The data were collected for 10 minutes prior to and 10 minutes after the massage. Results. The vagal tone was significantly higher after massage than before massage in the experimental group, while no change in the control group. The experimental group had significantly higher scores for awake state and motor activity than the control group. Significantly greater awake state, more fidgeting or crying, and increased motor activity were reported after massage than before massage. Conclusions. The results of this study showed that massage therapy might enhance optimal physiological responses and behavioral organization of premature infants. Nursing staff in the NICU can use massage to promote the infant's capability to respond positively to his environment and to provide developmental support for healthy premature infants.