Increased H-Reflex Response Induced by Intramuscular Electrical Stimulation of Latent Myofascial Trigger Points

2009 ◽  
Vol 27 (4) ◽  
pp. 150-154 ◽  
Author(s):  
Hong-You Ge ◽  
Mariano Serrao ◽  
Ole K Andersen ◽  
Thomas Graven-Nielsen ◽  
Lars Arendt-Nielsen

Background Myofascial trigger points (MTrPs) present with mechanical hyperalgesia and allodynia. No electrophysiological evidence exists as to the excitability of muscle spindle afferents at myofascial trigger points MTrPs. The purpose of this current study was to explore whether an H-reflex response could be elicited from intramuscular electrical stimulation. If so, to assess the possibility of increased reflex response at MTrPs. Methods The H-reflex latency and the conduction velocity were first determined from electrical stimulation of the tibial nerve in 13 healthy subjects. Then an intramuscular monopolar needle electrode was inserted randomly into a latent MTrP or a non-MTrP in the gastrocnemius muscle. Electrical stimuli at different intensities were delivered via the intramuscular recording electrode to the MTrP or non-MTrP. Results The average conduction velocity (44.3 ± 1.5 m/s) of the electrical stimulation of tibial nerve was similar (p>0.05) with the conduction velocity (43.9 ± 1.4 m/s) of intramuscular electrical stimulation. The intramuscular H-reflex at MTrPs was higher in amplitude than non-MTrPs (p<0.001). The reflex threshold was lower for MTrPs than non-MTrPs (p<0.001). Conclusion The current study provides first electrophysiological evidence that intramuscular electrical stimulation can evoke H-reflex, and that higher H-reflex amplitude and lower H-reflex threshold exist at MTrPs than non-MTrPs respectively, suggesting that muscle spindle afferents may be involved in the pathophysiology of MTrPs.

2019 ◽  
Vol 12 (2) ◽  
pp. 50-64
Author(s):  
George Elesnitsalis ◽  
Ioannis Amiridis ◽  
Dimitrios Patikas ◽  
Ioanna Vekili ◽  
Maria Vourvou

Introduction: Polyneuromyopathy constitutes a common complication in critically ill patients of the Intensive Care Unit (ICU) and in the last few years it appears to be identified as a syndrome detectable in the limbs and respiratory muscles. It is associated with the difficulties during weaning from mechanical ventilation. Aim: The present study investigates the reflective reaction of the soleus muscle following an electrical stimulation of the tibial nerve in intubated critically ill patients hospitalized in ICU with no medical history prior to their admission. Methods: Thirteen (13) patients who had been hospitalized for more than five (5) days and had a high APACHE II score (>15) and 13 age-matched control subjects were asked to participate in the present study on a volunteer basis. During the study, as reflective response parameters the range of the H-reflex and M-wave of the soleus muscle, as well as the conduction velocity of the tibial nerve, after electro-stimulation of the tibial nerve at the popliteal-fossa level, were assessed Results: Statistical analysis revealed significantly lower values in the ICU patients compared to healthy controls in both H-reflex range (p<0,049) and the M-wave range (p<0,041), as well as conduction velocity (p<0,001) of the tibial nerve. Conclusions: It is concluded that the reflective response of the soleus muscle as well as the tibial nerve’s conduction velocity are affected in critically ill patients hospitalized in ICU. The study of the above neurological parameters can provide further insights into the establishment and progress of polyneuromyopathy of critically ill patients in ICUs.


1984 ◽  
Vol 52 (3) ◽  
pp. 435-448 ◽  
Author(s):  
D. Burke ◽  
S. C. Gandevia ◽  
B. McKeon

Studies were undertaken in normal subjects to determine whether it is possible for oligosynaptic reflex pathways to affect motoneuron discharge in the ankle jerk and H-reflex of the soleus. It is argued that if the rising phase of the increase in excitability of the soleus motoneuron pool produced by tendon percussion or by electrical stimulation of the peripheral nerve lasts more than a few milliseconds and if the increase in excitability takes several milliseconds to reach the threshold for motoneuron discharge, these reflexes are unlikely to be exclusively monosynaptic. In relaxed subjects, changes in excitability of the soleus motoneuron pool produced by tendon percussion and by electrical stimulation of the tibial nerve were examined using conditioning stimuli just below threshold and a test H-reflex just above threshold for a reflex response. The increase in excitability due to tendon percussion had an average rise time of 10.8 ms and a total duration of approximately 25 ms. With electrical stimulation the rising phase appeared shorter, but it could not be measured accurately due to afferent refractoriness. In single motor units, the rise times of the composite excitatory postsynaptic potentials (EPSPs) set up by subthreshold tendon percussion and by subthreshold electrical stimulation of the tibial nerve were estimated from changes in the probability of discharge of voluntarily activated single motor units. Rise times were significantly longer with tendon percussion (mean +/- SD, 7.1 +/- 2.3 ms; n = 34) than with electrical stimulation (2.4 +/- 1.4 ms; n = 32). In four experiments in which a number of motor units were studied using identical mechanical and identical electrical stimuli, the poststimulus time histograms (PSTHs) for each stimulus were pooled to provide an estimate of the rise time of the excitability change in the motoneuron pool. The mean rise times of these four samples were 10.5 ms with mechanical stimulation and 4.5 ms with electrical stimulation. The spontaneous variability in latency of reflexly activated single motor units was 0.8-3.1 ms (average SD, 0.34 ms) in the tendon jerk, and 0.6-1.4 ms (average SD, 0.19 ms) in the H-reflex. Comparison of these figures with the measurements of rise time given above suggests that the composite EPSPs are larger than the background synaptic noise. With six motor units, the timing of reflex discharge in the tendon jerk when the subject was relaxed was compared with the timing of the change in probability of discharge due to apparently identical percussion when the units were activated voluntarily.(ABSTRACT TRUNCATED AT 400 WORDS)


2014 ◽  
Vol 116 (12) ◽  
pp. 1623-1631 ◽  
Author(s):  
Steffen Vangsgaard ◽  
Janet L. Taylor ◽  
Ernst A. Hansen ◽  
Pascal Madeleine

Trapezius muscle Hoffman (H) reflexes were obtained to investigate the neural adaptations induced by a 5-wk strength training regimen, based solely on eccentric contractions of the shoulder muscles. Twenty-nine healthy subjects were randomized into an eccentric training group ( n = 15) and a reference group ( n = 14). The eccentric training program consisted of nine training sessions of eccentric exercise performed over a 5-wk period. H-reflex recruitment curves, the maximal M wave (Mmax), maximal voluntary contraction (MVC) force, rate of force development (RFD), and electromyographic (EMG) voluntary activity were recorded before and after training. H reflexes were recorded from the middle part of the trapezius muscle by electrical stimulation of the C3/4 cervical nerves; Mmax was measured by electrical stimulation of the accessory nerve. Eccentric strength training resulted in significant increases in the maximal trapezius muscle H reflex (Hmax) (21.4% [5.5–37.3]; P = 0.01), MVC force (26.4% [15.0–37.7]; P < 0.01), and RFD (24.6% [3.2–46.0]; P = 0.025), while no significant changes were observed in the reference group. Mmax remained unchanged in both groups. A significant positive correlation was found between the change in MVC force and the change in EMG voluntary activity in the training group ( r = 0.57; P = 0.03). These results indicate that the net excitability of the trapezius muscle H-reflex pathway increased after 5 wk of eccentric training. This is the first study to investigate and document changes in the trapezius muscle H reflex following eccentric strength training.


2008 ◽  
Vol 187 (4) ◽  
pp. 623-629 ◽  
Author(s):  
Hong-You Ge ◽  
Yang Zhang ◽  
Shellie Boudreau ◽  
Shou-Wei Yue ◽  
Lars Arendt-Nielsen

1988 ◽  
Vol 118 (3) ◽  
pp. 471-483 ◽  
Author(s):  
L. M. Voloschin ◽  
E. Décima ◽  
J. H. Tramezzani

ABSTRACT Electrical stimulation of the XIII thoracic nerve (the 'mammary nerve') causes milk ejection and the release of prolactin and other hormones. We have analysed the route of the suckling stimulus at the level of different subgroups of fibres of the teat branch of the XIII thoracic nerve (TBTN), which innervates the nipple and surrounding skin, and assessed the micromorphology of the TBTN in relation to lactation. There were 844 ± 63 and 868 ± 141 (s.e.m.) nerve fibres in the TBTN (85% non-myelinated) in virgin and lactating rats respectively. Non-myelinated fibres were enlarged in lactating rats; the modal value being 0·3–0·4 μm2 for virgin and 0·4–0·5 μm2 for lactating rats (P > 0·001; Kolmogorov–Smirnov test). The modal value for myelinated fibres was 3–6 μm2 in both groups. The compound action potential of the TBTN in response to electrical stimulation showed two early volleys produced by the Aα- and Aδ-subgroups of myelinated fibres (conduction velocity rate of 60 and 14 m/s respectively), and a late third volley originated in non-myelinated fibres ('C') group; conduction velocity rate 1·4 m/s). Before milk ejection the suckling pups caused 'double bursts' of fibre activity in the Aδ fibres of the TBTN. Each 'double burst' consisted of low amplitude action potentials and comprised two multiple discharges (33–37 ms each) separated by a silent period of around 35 ms. The 'double bursts' occurred at a frequency of 3–4/s, were triggered by the stimulation of the nipple and were related to fast cheek movements visible only by watching the pups closely. In contrast, the Aα fibres of the TBTN showed brief bursts of high amplitude potentials before milk ejection. These were triggered by the stimulation of cutaneous receptors during gross slow sucking motions of the pup (jaw movements). Immediately before the triggering of milk ejection the mother was always asleep and a low nerve activity was recorded in the TBTN at this time. When reflex milk ejection occurred, the mother woke and a brisk increase in nerve activity was detected; this decreased when milk ejection was accomplished. In conscious rats the double-burst type of discharges in Aδ fibres was not observed, possibly because this activity cannot be detected by the recording methods currently employed in conscious animals. During milk ejection, action potentials of high amplitude were conveyed in the Aα fibres of the TBTN. During the treading time of the stretch reaction (SR), a brisk increase in activity occurred in larger fibres; during the stretching periods of the SR a burst-type discharge was again observed in slow-conducting afferents; when the pups changed nipple an abrupt increase in activity occurred in larger fibres. In summary, the non-myelinated fibres of the TBTN are increased in diameter during lactation, and the pattern of suckling-evoked nerve activity in myelinated fibres showed that (a) the double burst of Aδ fibres, produced by individual sucks before milk ejection, could be one of the conditions required for the triggering of the reflex, and (b) the nerve activity displayed during milk-ejection action may result, at least in part, from 'non-specific' stimulation of cutaneous receptors. J. Endocr. (1988) 118, 471–483


Author(s):  
O. Kolosova

The purpose of our work was to investigate in detail the influence of pair stimulation of tibial nerve (n.tibialis) on human soleus H-reflex amplitude at rest and after long-lasting voluntary contraction of calf muscle (m.m. gastrocnemius-soleus), which caused the fatigue of soleus muscle. The method of H-reflex of soleus muscle was used. Test and conditioned responses (by pair stimulation of n. tibialis) were registered. Homosynaptic postactivation depression led to inhibition of H-reflex at rest. After fatiguing voluntary static contraction the amplitudes of test and conditioned soleus H-reflex were significantly reduced. Then both H-reflex amplitudes subsequently recovered. Soleus H-reflex inhibition might be due to the activation of the groups III and IV afferent nerves under the influence of mechanical and metabolic changes in the muscle.


1956 ◽  
Vol 185 (1) ◽  
pp. 142-144 ◽  
Author(s):  
Bernard Metz

Small doses of the potent anticholinesterase, TEPP, introduced via a cisternal puncture produce a marked potentiation of the respiratory reflex response induced by electrical stimulation of Hering's nerve in the dog. Larger doses of TEPP cause an inhibition of this reflex followed by respiratory failure. These experiments lend suggestive evidence that a neurohumoral mediator (e.g. acetylcholine) may be a component of respiratory control.


2017 ◽  
Vol Volume 10 ◽  
pp. 2717-2723 ◽  
Author(s):  
Ron Dabby ◽  
Menachem Sadeh ◽  
Ilan Goldberg ◽  
Vitaly Finkelshtein

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