scholarly journals Death by Stimulation of the Left Vagus Nerve in a Case of Neck Grasping in a Healthy Young Man

2021 ◽  
2000 ◽  
Vol 89 (1) ◽  
pp. 139-142 ◽  
Author(s):  
Robert L. Coon ◽  
Patrick J. Mueller ◽  
Philip S. Clifford

The canine cervical trachea has been used for numerous studies regarding the neural control of tracheal smooth muscle. The purpose of the present study was to determine whether there is lateral dominance by either the left or right vagal innervation of the canine cervical trachea. In anesthetized dogs, pressure in the cuff of the endotracheal tube was used as an index of smooth muscle tone in the trachea. After establishment of tracheal tone, as indicated by increased cuff pressure, either the right or left vagus nerve was sectioned followed by section of the contralateral vagus. Sectioning the right vagus first resulted in total loss of tone in the cervical trachea, whereas sectioning the left vagus first produced either a partial or no decrease in tracheal tone. After bilateral section of the vagi, cuff pressure was recorded during electrical stimulation of the rostral end of the right or left vagus. At the maximum current strength used, stimulation of the left vagus produced tracheal constriction that averaged 28.5% of the response to stimulation of the right vagus (9.0 ± 1.8 and 31.6 ± 2.5 mmHg, respectively). In conclusion, the musculature of cervical trachea in the dog appears to be predominantly controlled by vagal efferents in the right vagus nerve.


1916 ◽  
Vol 24 (5) ◽  
pp. 605-619 ◽  
Author(s):  
G. Canby Robinson

The experiments that have been reported indicate that stimulation of either the right vagus or the left vagus nerve is equally effectual in blocking impulses from the auricles to the ventricles when auricular fibrillation is present. Stimulation of the left vagus nerve is as effectual in blocking impulses from the normally beating auricles as from the auricles when in a state of fibrillation, and the type of auricular activity has apparently no influence on the effect which stimulation of the left vagus has on auriculoventricular conduction.


ABSTRACT:Background:Stimulation of the left vagus nerve (VNS) has been shown to control seizures in double blinded crossover studies in man. Animal studies have reported vagal afferent induced depression of nociceptive and motor reflexes which may be caused by an effect on the descending reticular system controlling spinal cord function. Anticonvulsant drug therapy may cause postural instability. The effects of VNS are assessed not only from the perspective of seizure control but also from the view of potential harm to other bodily systems. Long term (2¼ years) effects of VNS were compared to postural stability analyses.Methods:8 subjects, 2 were females, mean age 34.5 ± 8.23 SD years, with intractable complex partial seizures, taking 3 anticonvulsant drugs were assessed for postural stability in quiet standing and while moving forwards, backwards and sideways with eyes open (EO) and eyes closed (EC). Data were collected and collated using an AMTI Biomechanics immovable forceplate, Newton M.A. U.S.A. The study design was longitudinal with pre-operative baseline data collected prior to neurostimulation and at intervals post operatively.Results:4/8 balance measures showed significant changes from pre-operative values and after 2¼ years of stimulation. Area of sway (EO) in quiet standing p = .022 and total sway (EC) in the moving state p = .019 and total sway (EC) in quiet standing showed an increase in sway p = .003. Area of sway (EC) p = .004 tended to decrease. Regression analysis for frequency of stimulation showed an increase in sway with higher frequencies T = 1.99, P = .05.Conclusion:Chronic VNS does not augment postural instability.


Author(s):  
Natalya Shova ◽  
Vladimir Mikhailov ◽  
Korovina Svetlana ◽  
Diana Alekseeva ◽  
Anton Platunov

Epilepsy affects millions of people around the world. Stimulation of the left vagus nerve (VNS) has proven to be effective in reducing the frequency of seizures for over 30 years, and some authors have noted the positive dynamics of the effect of stimulation on the emotional status of patients. In this clinical observation, we describe changes in the pathopsychological condition before and after VNS therapy in a patient with a drug-resistant form of epilepsy and suicidal intentions.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Polona Pečlin ◽  
Janez Rozman

Alternative paradigm for spatial and fibre-type selective vagus nerve stimulation (VNS) was developed using realistic structural topography and tested in an isolated segment of a porcine cervical left vagus nerve (LVN). A spiral cuff (cuff) containing a matrix of ninety-nine electrodes was developed for selective VNS. A quasitrapezoidal stimulating pulse (stimulus) was applied to the LVN via an appointed group of three electrodes (triplet). The triplet and stimulus were configured to predominantly stimulate the B-fibres, minimizing stimulation of the A-fibres and by-passing the stimulation of the C-fibres. To assess which fibres made the most probable contribution to the neural response (NR) during selective VNS, the distribution of conduction velocity (CV) within the LVN was considered. Experimental testing of the paradigm showed the existence of certain parameters and waveforms of the stimulus, for which the contribution of the A-fibres to the NR was slightly reduced and that of the B-fibres was slightly enlarged. The cuff provided satisfactory fascicle discrimination in selective VNS as well as satisfactory fascicle discrimination during NR recording. However, in the present stage of development, fibre-type VNS remained rather limited.


1912 ◽  
Vol 16 (6) ◽  
pp. 732-757 ◽  
Author(s):  
Alfred E. Cohn

It may be concluded from the results obtained in these experiments : 1. That stimulation of the right vagus nerve in the dog usually causes arrest of all the chambers of the heart. 2. That stimulation of the left vagus nerve exerts a moderate negative chronotropic effect on the auricles. 3. That stimulation of the left vagus nerve has a profound effect on the conduction of impulses over the auriculoventricular system. 4. That the degree of effect exercised on the auriculoventricular system by stimulation of the left vagus nerve varies. In some dogs conduction is depressed to an extent which causes only a delay in the conduction of impulses from auricles to ventricles (P-R time) ; in other dogs the conduction is depressed to a degree which results in incomplete heart-block; while in still other dogs conduction is so depressed that although the auricles continue to contract, no impulses pass from them to the ventricles. 5. That when stimulation of either the right or left vagus nerve causes asystole of nomotopic ventricular contractions, ectopic ventricular contractions may occur. 6. That the time which elapses before ectopic ventricular contractions occur depends upon the irritability of the ventricular muscle, and this may vary in different dogs. 7. That stimulation of the left vagus nerve may rarely cause sino-auricular block. Possibly stimulation of the right nerve may also produce this effect. 8. That there is consequently usually a great qualitative difference in the action of the two vagus nerves on the heart of the dog.


1913 ◽  
Vol 18 (6) ◽  
pp. 704-714
Author(s):  
G. Canby Robinson

The tumultuous auricular activity which follows faradization of the auricles of mammals and which has been variously described, could be distinctly seen to consist almost constantly in our experiments on dogs of true fibrillatory movements of the separate muscle fibers coëxisting with a rapid auricular tachycardia. During peripheral stimulation of the right vagus nerve the true fibrillation alone existed, the tachycardia being inhibited. A comparison of the electrocardiograms from dogs with this abnormal auricular activity with those from patients with the type of cardiac arhythmia which has been attributed to auricular fibrillation, and from patients with so called auricular flutter, indicates that the auricular activity in patients with either of these conditions differs somewhat from that usually seen in the faradized auricles of the dog in our experiments. The auricular activity of the cases of cardiac arhythmia is apparently true fibrillation, similar to that seen in the faradized auricles of the dog during right vagus stimulation. The electrocardiograms from cases of so called auricular flutter usually give no evidence of auricular fibrillation, and the auricular activity seems to consist of tachycardia alone. Fibrillation may apparently coëxist with the tachycardia in some cases, when the auricular activity seems to resemble closely that usually seen in the dog after auricular faradization. During peripheral stimulation of the left vagus nerve, the electrocardiograms obtained after auricular faradization show changes which render them more nearly similar to those obtained from patients with auricular flutter. The facts that the auricular activity of the faradized auricles of the dog may apparently pass spontaneously into that closely resembling auricular flutter in man, that it may be changed into true fibrillation by right vagus stimulation, and that the abnormal auricular activity in man passes from a state of flutter to that of fibrillation in a similar manner, may be taken as evidence for the belief that auricular fibrillation and auricular flutter in man are closely allied cardiac disorders.


1912 ◽  
Vol 15 (1) ◽  
pp. 14-48 ◽  
Author(s):  
Canby Robinson ◽  
George Draper

The electrocardiographic records taken during vagus stimulation by pressure from children suffering with chronic heart disease have shown that the stimulation of the vagi in these cases is strikingly effectual. In some of the cases, a definite difference was demonstrated between the action of the right and left vagi. The control of the rate of the heart-beat seemed to predominate usually in the right vagus nerve, while the control of stimulus conduction from auricles to ventricles apparently predominated usually in the left vagus. This difference in the two nerves probably exists on account of the difference in their anatomical distribution, the right vagus going especially to that part of the heart which controls the rate of contraction, the sinus node above the right auricle, and the left vagus going especially to that part in which the conducting mechanism is found. Each nerve, however, has to a lesser degree the function which predominates in the other. The whole heart seems to respond, as a rule, more promptly to right than to left vagus pressure, and fairly constant differences have been seen in the effects which stimulation of each nerve has on the various waves of the electrocardiograms. The stimulation of each vagus may influence directly the contractions of the ventricles, causing great diminution in their force. Right vagus stimulation was followed at times by a complete dissociation of auricles and ventricles. The auricular rhythm was slowed sufficiently at this time to allow the ventricles, whose inherent rhythmicity is apparently unaffected by right vagus stimulation, to take up their own independent rhythm. The heightened ventricular rhythmicity in these cases allowed this to take place after only moderate slowing of the auricles. The independent ventricular rhythm was sometimes established in the region of the node of Tawara, for no disturbance of the ventricular portion of the electrocardiogram occurred. At another time, some other point in the ventricles inaugurated the stimuli of the independent ventricular contractions and an abnormal electrocardiogram resulted. The resemblance of our curves, showing dissociation, to those obtained during right vagus and left accelerator stimulation in dogs is definite. That analogy, the clinical picture, and the form of the electrocardiograms of these cases have led us to the belief that an important feature in the pathological physiology of these cases is hypertonus of the cardiac accelerator nerves. This factor, as a cause of symptoms and as a hindrance to the establishment of cardiac rest, may prove of great importance, against which a new form of cardiac therapeutics must be directed.


ABSTRACT:Background:Early studies of cognitive motor control have shown deficits in complex reaction time tests of epileptic subjects. The purpose of this efficacy study was to determine whether chronic (28 months) stimulation of the left vagus nerve (VNS) to control seizures increased these deficits in 6 epileptic subjects with intractable complex partial seizures.Methods:Subjects were assessed for simple reaction time, Test A, and subsequent Tests B and C which involved more complex cognitive strategies. Tests were done pre-operatively (S1) and at intervals, 6-8 weeks (S2-S3), and at 6 month intervals (S4-S6) over a 28 month period. Data were collected and collated on an Apple II E computer (Apple, Cupertino CA. U.S.A.) and on electronic switch pad. Data were analyzed using a repeated measures analysis of covariance technique with 2 within subject factors, day, and time of day.Results:2/11 cognitive measures showed a statistically significant difference. Error rate associated with Test A (simple reaction time) significantly decreased for the factor of day (repeated visits) p = .01. For Test C, error rates decreased in the afternoon (p = .03). This test involved the subjects ability to respond quickly to one signal while simultaneously ignoring a second signal. Data analysis of the covariate showed that the effects of VNS are weak in comparison to baseline differences and the frequency of nerve stimulation negatively predicts the number of wrong errors. High frequency stimulation results showed fewer errors than low frequency stimulation T = -2.31, p = .03.Conclusion:Chronic stimulation of the left vagus nerve to control seizure activity does not impair cognitive motor control.


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