Neuromuscular Transmission Studies in the Healthy Dog: EMG and Muscle Force Measurement after Repetitive Nerve Stimulation

1992 ◽  
Vol 39 (1-10) ◽  
pp. 372-381 ◽  
Author(s):  
M.K. Waxenberger ◽  
R. Heckmann ◽  
Th. Wiestner ◽  
H.P. Hogg
2016 ◽  
pp. 328-346
Author(s):  
Kathleen D. Kennelly

Repetitive stimulation is a technique that evaluates the function of the neuromuscular junction. It is important not only in the detection, clarification, and follow-up of neuromuscular junction diseases, but also in excluding these disorders in patients with symptoms of fatigue, vague weakness, diplopia, ptosis, and malaise, or with objective weakness of uncertain origin. The technique requires knowledge of the physiology and pathophysiology of neuromuscular transmission and the basic techniques of nerve conduction studies. This chapter includes a brief review of the anatomy and physiology of the neuromuscular junction as it applies to repetitive stimulation, a detailed discussion of the technique, the pitfalls that can occur if not carried out correctly, criteria used to classify the results as normal or abnormal, the patterns of abnormalities that can be seen, and the clinical correlation of those abnormalities with the various different disorders of neuromuscular transmission.


2017 ◽  
Vol 33 (08) ◽  
pp. 533-543 ◽  
Author(s):  
Jingming Chen ◽  
Themba Nyirenda ◽  
Liancai Mu ◽  
Stanislaw Sobotka

Background Increasing evidence suggests that 1-hour electrical nerve stimulation during surgery improves nerve regeneration and functional recovery. However, it remains unknown if this approach has beneficial effects on the outcomes of our recently developed nerve–muscle-endplate band grafting-native motor zone (NMEG-NMZ) technique for muscle reinnervation. Methods In this study, NMEG-NMZ transplantation was performed in a rat model. The right sternomastoid muscle was experimentally denervated and immediately reinnervated by implanting a NMEG harvested from the ipsilateral sternohyoid (SH) muscle into the NMZ of the target muscle. Before implantation of the NMEG, the SH nerve branch innervating the NMEG was subjected to intraoperative 1-hour continuous electrical stimulation (20 Hz). Three months after surgery, the degree of functional recovery was evaluated with muscle force measurement and the extent of nerve regeneration and endplate reinnervation was examined using histological and immunohistochemical methods. Results A combination of NMEG-NMZ with electrical nerve stimulation resulted in a greater degree of functional recovery than the NMEG-NMZ alone. The mean muscle force of the treated muscles was 90% of the contralateral control. The muscle mass was recovered up to 90% of the control. The mean number and percentage of area of the regenerated axons in the treated muscles was computed to be 81 and 84% of the control muscles, respectively. On average, 83% of the denervated endplates in the treated muscles were reinnervated by regenerated axons. Conclusion Intraoperative brief nerve stimulation promotes nerve regeneration, endplate reinnervation, and functional recovery of the muscles reinnervated with NMEG-NMZ technique.


1989 ◽  
Vol 47 (3) ◽  
pp. 279-282 ◽  
Author(s):  
Marcela Garcia Erro ◽  
O. Genovese ◽  
J. Correale ◽  
R. E. P. Sica

An electrophysiological investigation of the state of the neuromuscular transmission (nmt) was carried out in 58 patients with the diagnosis of chronic Chagas' disease. On repetitive supramaximal nerve stimulation it was found that some patients did not show abnormalities, others had decremental muscle responses, others developed enhancement of the muscle evoked potential amplitudes, while some other patients combined both types of pathological responses. The findings suggest that some patients with chronic Chagas' disease develop impairement of nmt, though data obtained in this study do not give information about neither the type of impairement nor the localization (pre or postsynaptic, or both) of the damage.


Author(s):  
Bashar Katirji

Myasthenia gravis is a relatively common neuromuscular junction disorder. The diagnosis of myasthenia gravis may be challenging particularly in seronegative patients. This case starts by discussing the diagnostic modalities available to confirm the diagnosis of myasthenia gravis including serum antibodies, the Tensilon test, and the ice pack test. After a detailed discussion of the physiology of neuromuscular transmission, the case emphasizes the role of electrodiagnostic studies in the diagnosis of myasthenic gravis. This includes detailed findings on repetitive nerve stimulation recording distal and proximal muscles as well as single-fiber electromyography jitter studies. Finally, the diagnostic sensitivity of the available tests in myasthenia gravis is compared and a suggested electrodiagnostic strategy for patients with suspected myasthenic gravis is outlined.


2001 ◽  
Vol 59 (3B) ◽  
pp. 681-685 ◽  
Author(s):  
Maria da Penha A. Morita ◽  
Alberto A. Gabbai ◽  
Acary S.B. Oliveira ◽  
Audrey S. Penn

Myasthenia gravis (MG) in childhood is rare comprising 10 to 20 % of all myasthenic patients. We studied 18 patients with MG whose first symptoms started from 1 to 12 years of age, followed at the Department of Neurology of the UNIFESP-EPM, from January 1983 to August 1997. There were 10 girls and 8 boys (1.2:1). Eleven patients (61%) presented moderate or severe generalized disease and 4 (22%) had at least one myasthenic crisis. EMG with supramaximal repetitive nerve stimulation was diagnostic in 8 (47%) out of 17 patients, and chest CT was normal in 14 patients. Seropositivity to acetylcholine receptor antibodies was found in 81.6% (9 out of 11 tested) and the levels had no relation to clinical severity. Nine out of 16 patients (56%) worsened with pyridostigmine alone and were treated with prednisone. Four out of those nine continued worsening despite steroids and were subjected to thymectomy (all showed thymic lymphoid follicular hyperplasia). Three patients (75%) improved markedly after thymectomy and one (25%) worsened, eventually getting better with intravenous immunoglobulin and oral azathioprine. MG treatment, using all resources available, has to be individualized for each child.


2013 ◽  
Vol 9 (1) ◽  
pp. 32 ◽  
Author(s):  
Jee Young Kim ◽  
Kee Duk Park ◽  
Seung-Min Kim ◽  
Il Nam Sunwoo

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