Stimulation Of Nerve Trunks Research Articles

Hypoglossal nerve trunk stimulation: electromyography findings during drug-induced sleep endoscopy: a case report

BackgroundLiterature has demonstrated hypoglossal nerve stimulation to be a safe and effective treatment for patients with obstructive sleep apnea nonadherent to positive airway pressure therapy. However, the recommended criteria for patient selection are still unable to identify all the unresponsive patients, highlighting the need for improved understanding about hypoglossal nerve stimulation for obstructive sleep apnea.Case presentationA 48-year-old Caucasian male patient with obstructive sleep apnea had been successfully treated with electrical stimulation of the hypoglossal nerve trunk, documented by level 1 polysomnography data. However, due to snoring complaints, he underwent postoperation drug-induced sleep endoscopy for evaluation of electrode activation during upper airway collapse, aiming to improve electrostimulation parameters. Concurrent surface electromyography of the suprahyoid muscles and masseter was obtained. Activation of electrodes 2, 3, and 6 promoted upper airway opening most strongly at the velopharynx and tongue base during drug-induced sleep endoscopy. The same channels also significantly increased the electrical activity on suprahyoid muscles bilaterally, but predominantly on the stimulated side (right). The masseters also presented a considerable asymmetry in electrical potential on the right side (> 55%).ConclusionBeyond the genioglossus muscle, our findings demonstrate recruitment of other muscles during hypoglossal nerve stimulation, which may be attributed to the electrical stimulation of the nerve trunk. This data provides new insights on how stimulation of the hypoglossal nerve trunk may contribute to obstructive sleep apnea treatment.

Application of nerve trunk stimulation therapy in functional rehabilitation of the lower limbs in the patients with cerebral apoplexy at convalescence stage

To explore the value of nerve trunk stimulation in the rehabilitation of lower limb function in the patients with cerebral apoplexy at convalescence stage. According the random number table, the patients with the lower limb dysfunction of cerebral apoplexy at convalescence stage were divided into a control group and a treatment group, 42 cases in each group. The drug therapy and the routine rehabilitation training were provided in the two groups. Additionally, in the treatment group, the nerve trunk stimulation therapy was adopted， in which, Chize (LU5，stimulating point of radial nerve), Neiguan (PC6, stimulating point of median nerve), Xiaohai (SI8, stimulating point of ulnar nerve) were selected. In the control group, acupuncture intervention was supplemented. Before and after treatment, the peak torque (PT) of the lower flexor-extensor muscle of the knee joint, gait parameters，the score of the modified Ashworth spasm scale (MAS), the score of Fugl-Meyer motor assessment (FMA) and the score of Fugl-Meyer balance scale (FBS) were recorded. After the treatment, the PT of the lower flexor-extensor muscle of the knee joint，the scores of FMA and FBS，the step speed and frequency were all increased, the score of MAS and the difference in the stride between the left and the right were decreased as compared with those before treatment (P<0.01). After the treatment, The PT of the lower flexor-extensor muscle of the knee joint，the scores of FMA and FBS，the step speed and frequency in the treatment group were higher than those in the control group (P<0.01). The score of MAS and the difference in the stride between the left and the right in the treatment group were lower than those in the control group (P<0.01). Nerve trunk stimulation therapy quite effectively increases the muscle strength and relieves the muscle tension as well as improves the motor function, the balance and the walking pattern of the lower limbs. This therapy is significantly valuable in the rehabilitation of the lower limbs in the patients with cerebral apoplexy at convalescence stage.

Comments on the definition of "acupuncture science"

The experts in China believe that the substance of "dry needling" is in the category of acupuncture therapy for the treatment by needle inserting the human body. But, its recognition has not been implied from the definition of "acupuncture science". Since 1970 s, the different definitions of it are closely related to TCM theories, due to which, it has been limited. This flaw restricts the development of acupuncture theory, narrows the connotation of acupuncture science and goes against the communication of traditional Chinese acupuncture theory. No matter regarding the theory or technique, the acupuncture therapy nowadays changes greatly in its connotation. Rather than guided by TCM theories, acupuncture therapy mainly includes the nerve trunk stimulation theory, the cerebral function orientation therapy, biological holographic therapy, fascia stimulation therapy and trigger therapy, etc. Expect that the medical devices used in these therapies are same as the traditional acupuncture, these methods cannot be regarded in the category of acupuncture science when the current definition of it is considered. Hence, the writer is trying to define "acupuncture science" as: acupuncture science refers to the science for the methodology and mechanism of therapeutic devices, e.g. acupuncture therapy and moxibustion therapy, for the prevention and treatment of disease by stimulating the body, and its theory includes but not limits in traditional Chinese medical theory.

Zebrafish heart as a model to study the integrative autonomic control of pacemaker function

The cardiac pacemaker sets the heart's primary rate, with pacemaker discharge controlled by the autonomic nervous system through intracardiac ganglia. A fundamental issue in understanding the relationship between neural activity and cardiac chronotropy is the identification of neuronal populations that control pacemaker cells. To date, most studies of neurocardiac control have been done in mammalian species, where neurons are embedded in and distributed throughout the heart, so they are largely inaccessible for whole-organ, integrative studies. Here, we establish the isolated, innervated zebrafish heart as a novel alternative model for studies of autonomic control of heart rate. Stimulation of individual cardiac vagosympathetic nerve trunks evoked bradycardia (parasympathetic activation) and tachycardia (sympathetic activation). Simultaneous stimulation of both vagosympathetic nerve trunks evoked a summative effect. Effects of nerve stimulation were mimicked by direct application of cholinergic and adrenergic agents. Optical mapping of electrical activity confirmed the sinoatrial region as the site of origin of normal pacemaker activity and identified a secondary pacemaker in the atrioventricular region. Strong vagosympathetic nerve stimulation resulted in a shift in the origin of initial excitation from the sinoatrial pacemaker to the atrioventricular pacemaker. Putative pacemaker cells in the sinoatrial and atrioventricular regions expressed adrenergic β2 and cholinergic muscarinic type 2 receptors. Collectively, we have demonstrated that the zebrafish heart contains the accepted hallmarks of vertebrate cardiac control, establishing this preparation as a viable model for studies of integrative physiological control of cardiac function by intracardiac neurons.

Closed-Loop Neuromodulation Technology for Baroreflex Blood Pressure Control

Blood pressure is a vital element to maintain circulation and eventually cellular respiration and metabolism. Blood pressure abnormalities are one of the most common diseases worldwide and their prevalence increases with age. For decades, basic and clinical investigations have shown that autonomic dysregulation/imbalance is involved in the development and progression of cardiovascular diseases. Arterial baroreflex is a powerful regulator of blood pressure and sympathetic nervous system. Closed-loop neuromodulation technology focusing on arterial baroreflex is challenging and might be promising to tackle the pathogenesis of blood pressure-related disorders, autonomic dysregulation, and eventually cardiovascular diseases. For more than a decade, we and associates have developed “bionic” baroreflex systems. “Bionic” means that the device is designed to replicate the dynamic characteristics of the native system to fully restore the function. The bionic baroreflex system basically consists of an artificial pressure sensor, a neurostimulator for autonomic nerves and a regulator that encodes blood pressure into neurostimulation. In the process of development toward clinical applicability, researchers have faced logical problems in designing the controller and practical problems of how to approach baroreflex activation. Closed-loop baroreflex systems utilizing sympathetic nerve trunk stimulation, spinal cord stimulation and noninvasive transcutaneous stimulation were proposed. Recently, the bionic baroreceptor was reported and proposed to be a potential therapy for heart failure. In this article, we introduce the closed-loop neuromodulation technology for baroreflex blood pressure control and discuss future direction of development of this technology.

Electrical stimulation site influences the spatial distribution of motor units recruited in tibialis anterior

ObjectiveTo compare the spatial distribution of motor units recruited in tibialis anterior (TA) when electrical stimulation is applied over the TA muscle belly versus the common peroneal nerve trunk. MethodsElectromyography (EMG) was recorded from the surface and from fine wires in superficial and deep regions of TA. Separate M-wave recruitment curves were constructed for muscle belly and nerve trunk stimulation. ResultsDuring muscle belly stimulation, significantly more current was required to generate M-waves that were 5% of the maximal M-wave (Mmax; M5%max), 50% Mmax (M50%max) and 95% Mmax (M95%max) at the deep versus the superficial recording site. In contrast, during nerve trunk stimulation, there were no differences in the current required to reach M5%max, M50%max or M95%max between deep and superficial recording sites. Surface EMG reflected activity in both superficial and deep muscle regions. ConclusionsStimulation over the muscle belly recruited motor units from superficial to deep with increasing stimulation amplitude. Stimulation over the nerve trunk recruited superficial and deep motor units equally, regardless of stimulation amplitude. SignificanceThese results support the idea that where electrical stimulation is applied markedly affects how contractions are produced and have implications for the interpretation of surface EMG data.

Transmission to Interneurons Is via Slow Excitatory Synaptic Potentials Mediated by P2Y1 Receptors during Descending Inhibition in Guinea-Pig Ileum

BackgroundThe nature of synaptic transmission at functionally distinct synapses in intestinal reflex pathways has not been fully identified. In this study, we investigated whether transmission between interneurons in the descending inhibitory pathway is mediated by a purine acting at P2Y receptors to produce slow excitatory synaptic potentials (EPSPs).Methodology/Principal findingsMyenteric neurons from guinea-pig ileum in vitro were impaled with intracellular microelectrodes. Responses to distension 15 mm oral to the recording site, in a separately perfused stimulation chamber and to electrical stimulation of local nerve trunks were recorded. A subset of neurons, previously identified as nitric oxide synthase immunoreactive descending interneurons, responded to both stimuli with slow EPSPs that were reversibly abolished by a high concentration of PPADS (30 μM, P2 receptor antagonist). When added to the central chamber of a three chambered organ bath, PPADS concentration-dependently depressed transmission through that chamber of descending inhibitory reflexes, measured as inhibitory junction potentials in the circular muscle of the anal chamber. Reflexes evoked by distension in the central chamber were unaffected. A similar depression of transmission was seen when the specific P2Y1 receptor antagonist MRS 2179 (10 μM) was in the central chamber. Blocking either nicotinic receptors (hexamethonium 200 μM) or 5-HT3 receptors (granisetron 1 μM) together with P2 receptors had no greater effect than blocking P2 receptors alone.Conclusions/SignificanceSlow EPSPs mediated by P2Y1 receptors, play a primary role in transmission between descending interneurons of the inhibitory reflexes in the guinea-pig ileum. This is the first demonstration for a primary role of excitatory metabotropic receptors in physiological transmission at a functionally identified synapse.

High-Frequency Transcutaneous Peripheral Nerve Stimulation Induces a Higher Increase of Heat Pain Threshold in the Cutaneous Area of the Stimulated Nerve When Confronted to the Neighbouring Areas

Background. TENS (transcutaneous electrical nerve stimulation) is probably the most diffused physical therapy used for antalgic purposes. Although it continues to be used by trial and error, correct targeting of paresthesias evoked by the electrical stimulation on the painful area is diffusely considered very important for pain relief. Aim. To investigate if TENS antalgic effect is higher in the cutaneous area of the stimulated nerve when confronted to neighbouring areas. Methods. 10 volunteers (4 males, 6 females) underwent three different sessions: in two, heat pain thresholds (HPTs) were measured on the dorsal hand skin before, during and after electrical stimulation (100 Hz, 0.1 msec) of superficial radial nerve; in the third session HPTs, were measured without any stimulation. Results. Radial nerve stimulation induced an increase of HPT significantly higher in its cutaneous territory when confronted to the neighbouring ulnar nerve territory, and antalgic effect persisted beyond the stimulation time. Conclusions. The location of TENS electrodes is crucial for obtaining the strongest pain relief, and peripheral nerve trunk stimulation is advised whenever possible. Moreover, the present study indicates that continuous stimulation could be unnecessary, suggesting a strategy for avoiding the well-known tolerance-like effect of prolonged TENS application.

Spinal Involvement and Muscle Cramps in Electrically Elicited Muscle Contractions

Electrical stimulation of innervated muscles has been investigated for many decades with alternations of high and low clinical interest in the fields of rehabilitation medicine and sports sciences. Early work demonstrated that afferent fibers have lower thresholds and are usually activated first (therefore eliciting an H-reflex). In the case of nerve trunk stimulation, the order of recruitment is mostly conditioned by the axonal dimension and excitability threshold. In the case of muscle motor point stimulation, the spatial distribution of nerve branches plays a predominant role. Sustained stimulation produces a progressive increase of force that is often maintained in subsequent voluntary activation by stroke patients. This observation suggested a facilitation mechanism at the spinal and/or supraspinal level. Such facilitation has been observed in healthy subjects as well, and may explain the generation of cramps elicited during stimulation and sustained for dozens of seconds after the stimulation has been interrupted. The most recent interpretations of facilitation resulting from peripheral stimulation focused on presynaptic (potentiation of neurotransmitter release from afferent fibers) or postsynaptic (generation of "persistent inward currents" in spinal motor neurons or interneurons) mechanisms. The renewed attention to these phenomena is once more increasing the interest toward electrical stimulation of the neuromuscular system. This is an opportunity for a structured investigation of the field aimed to resolving elements of confusion and controversy that still plague this area of electrophysiology.

Évaluation électrophysiologique des nerfs crâniens moteurs (V, VII, IX, X, XI, XII)

In various neurosurgical operations, there is a risk of cranial nerve lesion that can be avoided or minimized with intraoperative electrophysiological monitoring. Regarding motor function of the cranial nerves, stimulodetection techniques are used, including electrical stimulation of nerve trunks and electromyographic recording of evoked motor responses. These techniques can be used for monitoring the trigeminal nerve (Vth cranial nerve), facial nerve (VIIth), glossopharyngeal nerve (IXth), pneumogastric nerve (Xth), spinal accessory nerve (XIth), and hypoglossal nerve (XIIth), in particular during surgical removal of tumors of the cerebellopontine angle or skull base. When beginning an operation, electrical stimulation is only used to identify the nerve structures. As removal of the tumor progresses, the goal is to verify that a surgical injury to the nerve is avoided by looking for the absence of any change regarding amplitude, morphology, and latency of motor responses. Intraoperative electromyographic monitoring can also be applied during the surgical treatment of primary hemifacial spasm by microvascular decompression. An effective decompression is usually associated with the disappearance of "lateral spread" motor responses to facial nerve branch stimulation. Therefore, the intraoperative disappearance of the lateral spread responses can be considered a predictive factor of good postoperative clinical outcome, even if this assertion remains a matter of debate.

Analgesic and antinociceptive effects of peripheral nerve neurostimulation in an advanced human experimental model

Electrical peripheral nerve neurostimulation (PNS) is reported to be an effective pain treatment. An objective proof of antinociceptive effect is lacking. The human experimental study addressed PNS effects on nociception and pain by electrophysiology and psychophysics. In 23 healthy volunteers, 39 sessions were conducted. Three experiments (PNS ipsilateral, PNS contralateral, Control) consisted of 13 sessions each. Conditioning PNS (100 Hz) of left (PNS ipsilateral) or right (PNS contralateral) superficial radial nerve trunk evoked non-painful, tingling sensations on the hand dorsum. Local cutaneous anesthesia at PNS site provided for preferential nerve trunk stimulation. Cortical laser-evoked potentials (LEP) after painful stimulation at left hand dorsum were recorded together with mechanical and thermal perception thresholds at the same site before ( T1), during ( T2), and after ( T3) PNS or a no stimulation period (Control). Mechanical and thermal perception decreased in the anesthetized area. Late LEP amplitude decreased independently of PNS site. Exclusively under ipsilateral PNS, N2 latency increased and laser ratings decreased. Mechanical detection threshold transiently increased during ipsilateral PNS at hand dorsum. PNS induced strong reduction of mechanical perception due to peripheral collision of orthodromic (test stimulus) and antidromic (PNS) selective Aβ fiber excitation. Delay of N2 component and reduction of laser pain were specific to ipsilateral PNS. Divergent and common effects of ipsilateral and contralateral PNS suggest a combination of peripheral and central antinociceptive mechanisms. The study in man documents inhibition of nociception and pain by PNS and provides with an experimental model for future objectives in neuromodulation.

Proximal femoral conductions in patients with lumbosacral radiculoplexus neuropathy

Objectives Lumbosacral radiculoplexus neuropathy (DLRPN) is a rare form of neuropathy observed in diabetic and rarely non-diabetic patients. Pathophysiology and lesion location are not clearly understood. Our aim was to analyze proximal and distal femoral conductions in patients with DLRPN. Methods Six patients with DLRPN, 14 patients with diabetic polyneuropathy and 25 healthy subjects were included in the study. We performed L3 monopolar root stimulation and femoral nerve trunk stimulation at the inguinal region and calculated lumbar plexus conduction time by subtracting the latency of compound muscle action potential (CMAP) of the vastus medialis evoked by femoral nerve stimulation from the latency of CMAP of vastus medialis evoked by L3 root stimulation. Additionally peak to peak amplitudes and areas of CMAPs were analyzed. Results Electrophysiological examination showed that there was an axonal involvement in all patients with DLRPN. Prolonged lumbar plexus conduction time (in five extremities), and prolonged distal latency of the femoral nerve (in five extremities) probably due to secondary demyelination were also observed. Similar abnormalities were not observed in the diabetic polyneuropathy group. Conclusions DLRPN may affect different localizations on the peripheral nerves. L3 root stimulation may have an important role in the electrodiagnosis of DLRPN.

Spastic long-lasting reflexes in the awake rat after sacral spinal cord injury.

Following chronic sacral spinal cord transection in rats the affected tail muscles exhibit marked spasticity, with characteristic long-lasting tail spasms evoked by mild stimulation. The purpose of the present paper was to characterize the long-lasting reflex seen in tail muscles in response to electrical stimulation of the tail nerves in the awake spastic rat, including its development with time and relation to spasticity. Before and after sacral spinal transection, surface electrodes were placed on the tail for electrical stimulation of the caudal nerve trunk (mixed nerve) and for recording EMG from segmental tail muscles. In normal and acute spinal rats caudal nerve trunk stimulation evoked little or no EMG reflex. By 2 wk after injury, the same stimulation evoked long-lasting reflexes that were 1) very low threshold, 2) evoked from rest without prior EMG activity, 3) of polysynaptic latency with >6 ms central delay, 4) about 2 s long, and 5) enhanced by repeated stimulation (windup). These reflexes produced powerful whole tail contractions (spasms) and developed gradually over the weeks after the injury (< or =52 wk tested), in close parallel to the development of spasticity. Pure low-threshold cutaneous stimulation, from electrical stimulation of the tip of the tail, also evoked long-lasting spastic reflexes, not seen in acute spinal or normal rats. In acute spinal rats a strong C-fiber stimulation of the tip of the tail (20 x T) could evoke a weak EMG response lasting about 1 s. Interestingly, when this C-fiber stimulation was used as a conditioning stimulation to depolarize the motoneuron pool in acute spinal rats, a subsequent low-threshold stimulation of the caudal nerve trunk evoked a 300-500 ms long reflex, similar to the onset of the long-lasting reflex in chronic spinal rats. A similar conditioned reflex was not seen in normal rats. Thus there is an unusually long low-threshold polysynaptic input to the motoneurons (pEPSP) that is normally inhibited by descending control. This pEPSP is released from inhibition immediately after injury but does not produce a long-lasting reflex because of a lack of motoneuron excitability. With chronic injury the motoneuron excitability is increased markedly, and the pEPSP then triggers sustained motoneuron discharges associated with long-lasting reflexes and muscle spasms.

Cervical Nerve Root Stimulation: Demonstration of an Extra-Foraminal Technique

Since the description of electrical stimulation of nerve trunks as a means of providing pain relief, innovative peripheral nerve and nerve root stimulations have been developed. An extra-foraminal technique of electrical stimulation of cervical nerve roots resulting in reduction of upper extremity radicular pain is demonstrated here. Electrical stimulation of the C6 and C7 nerve roots was accomplished using a four-electrode spinal cord stimulator lead that was placed percutaneously within the exit zone of the neuroforamina using an extra-foraminal approach. Subsequent C6 and C7 nerve root stimulation provided a reduction in arm pain within the distribution of the stimulation.

The spatial organization of central sensitization of hind limb flexor reflexes in the decerebrated, spinalized rabbit

This study was designed to investigate the relationship between the location of a noxious stimulus and the magnitude and duration of the plastic effects induced by that stimulus in withdrawal reflexes acting about the knee and the ankle, in rabbits. Reflexes were evoked in the nerves to the anterior tibial and semitendinosus flexor muscles by electrical stimulation at the toes. Repetitive, high intensity electrical stimulation of nerve trunks (sural, medial gastrocnemius, superficial peroneal, tibial, 100 pulses, 20 V, 1 ms at 0.5 Hz) was generally found to be a poor method for inducing central sensitization in these flexor reflexes. ‘Natural’ noxious stimulation induced more reliable enhancement of both reflexes. Mechanical (clamp) or chemical (mustard oil) stimulation of the heel induced prolonged (median duration >30 min) increases in reflexes to both muscles. Mechanical (clamp and superficial pinch) or chemical (mustard oil) stimulation of the toes, and injection of bradykinin into the gastrocnemius muscles or into the soft tissues of the sole of the foot, also led to enhancement of both reflexes, with the median duration of potentiation between 7 and 30 min. The effects obtained from deep tissue stimulation were generally weaker than those obtained after stimulation of superficial structures. These data show that there were no major differences in the effects obtained from the heel vs the toes, or between the two reflexes. It appears that the spatial organization of the spinal mechanisms underlying central sensitization of flexor withdrawal reflexes is rather more crudely drawn than that pertaining to the reflexes themselves. Furthermore, the data indicate that in the present preparation, afferents from deep tissues are no more effective in generating central sensitization than those from superficial structures.

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome

An Institutional Experience with Cervical Vagus Nerve Trunk Stimulation for Medically Refractory Epilepsy: Rationale, Technique, and Outcome