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At least 19 recordsLinked to original sources
PubMed1997

Single-fiber electromyography, nerve conduction studies, and conventional electromyography in patients with critical-illness polyneuropathy: evidence for a lesion of terminal motor axons.

Nine patients at risk for critical illness polyneuropathy (CIP) were included in a prospective study. We performed nerve conduction studies, electromyography, and a stimulation single-fiber electromyography (SFEMG). Five of 9 patients were diagnosed as CIP because they developed abnormal spontaneous activity during the follow-up period. Their SFEMG revealed a significant increase in mean jitter (25%, P < 0.005). In 4 patients without abnormal spontaneous activity there was no significant increase in the mean jitter, although 1 of the latter 4 patients showed an increased jitter, indicating that abnormal SFEMG may precede abnormal spontaneous activity. Nerve conduction studies did not show any significant changes in both patient groups. Our findings suggest that CIP is a primarily axonal motor neuropathy. The increased jitter in patients with CIP indicates that CIP is a primarily axonal neuropathy with a lesion of terminal motor axons.

Adult↗
PubMed1999

[From cathodic tube to digitalized electromyography: a brief story of electromyography in France].

This article covers the stages of the development of electromyography in France, since the founding works of Lerique [4], the first publications of the "Société d'EEG et des sciences connexes de langue française" (1948), the first international meeting (Strasbourg, 1960), the French-speaking meeting on electromyography which is now being held every other year. It also deals with the difficulties of registering and interpreting the first recordings and the considerable help brought by the improvement in electronics and computer sciences.

Diagnosis, Computer-Assisted↗
PubMed1994

Single-fiber electromyography in neuromuscular disorders: correlation of muscle histochemistry, single-fiber electromyography, and clinical findings.

We performed single-fiber electromyography (SFEMG) and correlated the results with muscle-biopsy histochemistry in 56 patients with various neuromuscular diseases. Increased muscle-fiber density, delineated by SFEMG, was most prominent in diseases of ordinary denervation, namely motor neuron disorders and peripheral neuropathies, and it correlated with histochemical fiber type grouping. Both phenomena reflect denervation followed by reinnervation. In patients with central core disease and rod disease, fiber density was not increased despite massive type I fiber predominance. The normal distribution of type I fiber subtypes in those patients indicated tht their fiber predominance was not due to sprouting and reinnervation, but probably to paucity of the type II fibers. In type I fiber hypotrophy with central nuclei, fiber density was increased, perhaps attributable to the small diameter and consequent denser packing of the type I fibers. Fiber density was slightly increased in the majority of patients with acid-maltase deficiency, limb-girdle dystrophy, and polymyositis, in nearly half with mitochondrial myopathy, and in 1 older Duchenne dystrophy patient. In these myopathic disorders, myogenous deinnervation (followed by reinnervation) is one possible explanation. Normal fiber density was present in all patients with muscle phosphorylase deficiency, myotonia congenita, and in the hypokalemic periodic paralysis patients under age 40.

Adult↗
PubMed1985

Urethral sphincter electromyography with vaginal surface electrodes: a comparison with sphincter electromyography recorded via periurethral coaxial, anal sphincter needle and perianal surface electrodes.

Urethral sphincter electromyography recording via vaginal surface electrodes was compared to simultaneous sphincter electromyographic registrations obtained with a periurethral coaxial needle electrode and perianal surface or needle electrodes in 10 neurologically intact women. Qualitative similarity of the vaginal surface and periurethral needle electrode recordings was found. Based on this and our previous studies, we conclude that electromyographic recording with vaginal surface electrodes offers a simple and reliable technique to evaluate the striated urethral sphincter during routine urodynamic studies in women.

Adult↗
PubMed1994

Basic experimental studies on corpus cavernosum electromyography and smooth-muscle electromyography of the urinary bladder.

In contrast to the extensive work on in vitro experiments for elucidation of the electrical properties of smooth musculature, the acquisition of knowledge on electrical signal behaviour from smooth-muscle cells in an in vivo situation remains very limited and rare. Smooth-muscle electromyographic recording from the smooth musculature of the genitourinary tract, in particular from the penile cavernous bodies and the urinary bladder, has recently become one of the most interesting issues in both impotence research as well as neurophysiological assessment of the urinary bladder. However, the inadequate available data on corpus cavernosum and EMG recordings remains controversial due to the significant discrepancy between basic physiology of the smooth musculature, technical prerequisites and the expected clinical impact from the smooth-muscle EMG of genitourinary organs. This article is an attempt to describe the fundamentals of smooth-muscle EMG signal behaviour and the technical prerequisites for data acquisition and analysis of electrical activity from smooth-muscle cells of the cavernous bodies and urinary bladder. A description is given of the technical aspects, including methodology and interpretation of the recorded data, and also of the possible interference by artefacts (endogeneous and exogeneous) that might limit the clinical relevance of this encouraging method. The advantages, pitfalls and limitations of online analogous data registration and the possibility of computer-assisted smooth-muscle electrical activity recording and analysis are demonstrated by basic in vivo studies on cavernous bodies and also the detrusor muscle.

Animals↗
PubMed2003

Utility of laryngeal electromyography in predicting recovery after vocal fold paralysis.

OBJECTIVES: To determine the value of laryngeal electromyography in predicting recovery after vocal fold paralysis and to determine what elements of laryngeal electromyography are most predictive of outcome. DESIGN: Cohort study with retrospective data review. SETTING: University voice center. PARTICIPANTS: Consecutive sample of 31 patients with vocal fold paralysis diagnosed by indirect laryngoscopy, using either nasal insertion with a flexible nasopharyngoscope or peroral with a 70 degrees Hopkins rod. Inclusion criteria were that laryngeal electromyography had to have been performed between 21 days and 6 months from the onset of symptoms and patients must have been followed a minimum of 6 months. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURE: Vocal fold motion at 6 months from onset of symptoms. RESULTS: Nine subjects (29%) had resolved vocal fold motion, whereas 22 (71%) had persistent vocal fold paralysis. By using our laryngeal electromyography paradigm, 4 of 6 patients with a laryngeal electromyography prognosis of excellent resolved. The predictive value for a negative test was 66.7%. For patients with a fair or poor prognosis, 5 of 25 resolved. The predictive value for a positive test was 80%. Only 8 of 22 patients with persistent vocal fold paralysis had fibrillations, and spontaneous activity was not significantly related to outcome. Patients with absent or greatly decreased motor unit recruitment had a significantly higher proportion of permanent vocal fold paralysis (P<.05). Stepwise forward logistic regression determined that prognosis by laryngeal electromyography and onset time were significant predictors of outcome (P<.01). The model predicted 44.4% of resolved cases, which represents a moderate prediction. CONCLUSIONS: This study confirms the utility of laryngeal electromyography in assessing prognosis for recovery of vocal fold motion after laryngeal nerve injury. The results support our hypothesis that preset decision rules based on laryngeal electromyography data can be effectively used to determine a prognosis for recovery of vocal fold motion.

Electromyography↗
PubMed1998

Intraoperative electromyography during thoracolumbar spinal surgery.

Intraoperative electromyography can provide useful information regarding lumbosacral nerve root function during thoracolumbar spinal surgery. Free-running electromyography provides continuous feedback regarding the location and potential for surgical injury to the lumbosacral nerve roots within the operative field. Stimulus-evoked electromyography can confirm that transpedicular instrumentation has been positioned correctly within the bony cortex. However, electromyography has a number of potential limitations, which are discussed in this article along with improved methods to increase the overall efficacy of intraoperative electromyography, including: 1) Electromyography is sensitive to blunt lumbosacral nerve root irritation or injury, but may provide misleading results with "clean" nerve root transection. 2) Electromyography must be recorded from muscles belonging to myotomes appropriate for the nerve roots considered at risk from surgery. 3) Electromyography can be effective only with careful monitoring and titration of pharmacologic neuromuscular junction blockade. 4) When transpedicular instrumentation is stimulated, an exposed nerve root should be stimulated directly as a positive control whenever possible. 5) Pedicle holes and screws should be stimulated with single shocks at low-stimulus intensities when pharmacologic neuromuscular blockade is excessive. 6) Chronically compressed nerve roots that have undergone axonotmesis (wallerian degeneration) have higher thresholds for activation from electrical and mechanical stimulation. 7) Hence, whenever axonotmetic nerve root injury is suspected, the stimulus thresholds for transpedicular holes and screws must be specifically compared with those required for the direct activation of the adjacent nerve root (and not published guideline threshold values).

Electromyography↗
PubMed1996

Penile electromyography and its smooth muscle content: interpretation of 25 impotent patients.

PURPOSE: We studied the correlation of penile electromyography and the cavernous smooth muscle content in 25 impotent patients. MATERIALS AND METHODS: After a complete hormonal and diagnostic evaluation, all patients underwent corpus cavernosum penile electromyography and a penile biopsy of the corpus cavernosum with the biopsy gun device. Cavernous tissue was analyzed using immunohistochemical stain actin anti-actin and computerized image analysis. RESULTS: Of the patients 20 had normal and 5 had abnormal corpus cavernosum penile electromyography. Of the 20 patients with normal corpus cavernosum penile electromyography 12 (60%) showed a normal percentage of cavernous smooth muscle and 8 (40%) had abnormal muscle content. All patients with abnormal corpus cavernosum penile electromyography showed abnormally low cavernous smooth muscle fibers. CONCLUSIONS: Our study showed an overall low sensitivity between corpus cavernosum penile electromyography potential amplitude and cavernous smooth muscle content. However, a high specificity (100%) of corpus cavernosum penile electromyography in the diagnosis of abnormal low cavernous muscle content was observed. Further studies with a larger number of patients are needed to evaluate corpus cavernosum penile electromyography as a predictor of cavernous smooth muscle function.

Adult↗
PubMed1999

Electromyography of the external anal sphincter: comparison between needle and surface electrodes.

PURPOSE: Electromyography of the external anal sphincter is frequently used when investigating patients with defecation disorders. Investigations are often performed using an invasive technique by perineal insertion of a needle or wire electrode. The aim of the present study was to investigate whether surface electromyography, with electrodes applied to the perineal skin, is a reliable method in the diagnosis of paradoxical anal sphincter reaction. METHODS: Seventy-one patients with defecation disorders participated in the present study. They were investigated with electromyography of the external anal sphincter using surface and needle electrodes. RESULTS: In 65 of 71 (92 percent) patients the electromyography recording showed the same result during straining using surface electrodes when compared with needle electrodes. Twenty-two of these 65 patients had paradoxical anal sphincter reaction, and 43 patients had decreased electromyography activity. In 6 of 71 (8 percent) patients the electromyography recording showed a different pattern during straining using surface electrodes when compared with needle electrodes. CONCLUSION: The present study demonstrates a good correlation between surface electrodes applied to the perineal skin and concentric needle electrodes in the diagnosis of paradoxical anal sphincter reaction. Noninvasive electromyography recordings of the external anal sphincter are often preferred in the diagnosis of paradoxical anal sphincter reaction.

Anal Canal↗
PubMed2002

Clitoral electromyography.

PURPOSE: The clitoris has several histomorphological and functional similarities to the penis. In this study we evaluated spontaneous and evoked electromyography activity in the clitoris. MATERIALS AND METHODS: We evaluated 11 healthy female volunteers with clitoral electromyography using a concentric needle electrode placed intracorporeally. The hand, foot and genital sympathetic skin responses, and spontaneous electrodermal activity were simultaneously recorded with silver surface electrodes. Another concentric needle electrode was placed subdermally on the mons pubis to differentiate clitoral activity from possible artifact. After recording spontaneous electromyography and electrodermal activity the left median nerve was stimulated to record evoked clitoral activity, and the sympathetic skin response in the hand, foot and genital regions. RESULTS: There was spontaneous electromyography activity in the corpus clitoris. All dermal sites, including the hand, foot and genital regions, showed spontaneous electrodermal activity. No spontaneous activity was recorded from the subdermal needle electrode. Distraction of attention and coughing increased the amplitude and frequency of spontaneous clitoral electromyography and electrodermal activity at all sites. After stimulating the left median nerve all sites except that of the subdermal needle electrode showed evoked activity. CONCLUSIONS: The demonstrated evoked and spontaneous clitoral electromyography activity seems to indicate a sympathetic tonus of the corpus clitoris, as recorded from the corpus cavernosum of the penis in human males. Clitoral electromyography may be a useful objective assessment tool for evaluating female sexual dysfunction as well as genital autonomic innervation.

Adult↗
PubMed1996

Evoked and spontaneous electromyography to evaluate lumbosacral pedicle screw placement.

STUDY DESIGN: A prospective study was performed to evaluate the effectiveness of evoked and spontaneous electromyography in predicting pedicle wall breakthrough and subsequent lumbar radiculopathy occurring after placement of pedicle screw instrumentation of the lumbar spine. OBJECTIVES: To correlate cortical breakthrough of the pedicle wall with an electrically evoked electromyography threshold of stimulation, to assess the sensitivity of mechanically evoked electromyography for nerve root irritation, and to correlate postoperative nerve root irritation with intraoperative findings. SUMMARY OF BACKGROUND DATA: Pedicle wall breakthrough has been evaluated by radiographic means and found to be difficult to evaluate. Methods to perform both electrically evoked and mechanically evoked electromyography have been developed more sensitive tests for breakthrough. METHODS: Twenty-five patients receiving 112 pedicle screws were evaluated. RESULTS: Cortical breakthrough was associated with electrically evoked electromyography threshold of less than 11 milliAmps. Not all screws that had broken through the pedicle wall caused a postoperative radiculopathy. Electromyographic activity was sensitive to nerve root stimulation. CONCLUSIONS: Measuring the electrically evoked electromyography threshold of stimulation helps to assess pedicle screw placement. Mechanically evoked electromyography indicates intraoperative nerve root displacement. Postoperative radiculopathy correlated with pedicle wall breakthrough, but did not occur in every case.

Adolescent↗
PubMed1991

An experimental study on the laryngeal electromyography and visual observations in varying types of surgical injuries to the unilateral recurrent laryngeal nerve in the neck.

A series of varying types of surgical injuries to the recurrent laryngeal nerve, including half section, double crush, suture ligation, and complete section of the nerve, was investigated in dogs by correlating clinical and electromyographic findings. The state of recovery from palsy was evaluated by recording the electromyography from the affected laryngeal muscles as well as by observing the movements of the vocal cords. Six electromyography patterns were recorded from the affected muscles following injuries to the recurrent laryngeal nerve. There is a close relationship between the electromyography patterns and the types of nerve injuries. Within 3 months after injuries of the recurrent laryngeal nerve, the electromyography motor unit potentials in the involved intrinsic laryngeal muscles and vocal cord movements on the side of the nerve injury were back to normal in the groups of dogs in which the recurrent laryngeal nerves were partially sectioned and doubly crushed; the electromyography potentials and vocal cord motion on the affected side did not return to normal in the group of dogs in which the recurrent laryngeal nerves were permanently ligated with suture. In the group of dogs which had had a complete section of the recurrent laryngeal nerve, no recovery of both electromyography and vocal cord function on the affected side was observed 6 months after injury of the recurrent laryngeal nerve. This study showed that the frequency of the regenerated potentials recorded from the affected muscles is related to the types and degrees of injuries to the recurrent laryngeal nerve. Recovery from recurrent laryngeal nerve palsy is complete within 3 months after nerve impairment if over half of the nerve fibers of the impaired nerve are maintained intact without degeneration. Moreover, the period from onset to complete recovery from palsy was remarkably short, less than 2 months. The most appropriate time for the electromyography examination to evaluate the degrees of the nerve injury and to anticipate the prognosis of recurrent laryngeal nerve palsy was proposed.

Animals↗
PubMedDate not supplied

Electromyography of the external anal sphincter muscle during urodynamic testing in children with meningomyelocele.

In this study the correlation between the electromyographic examination of the external sphincter muscle and the urodynamic findings in patients with meningomyelocele was evaluated. Urodynamic testing, consisting of cystometry with bladder, urethral and abdominal pressure monitoring was performed with simultaneous electromyography of the external and sphincter muscle in 61 children, 29 boys and 32 girls, divided in groups according to age and to the level of lesion. Normal urodynamic studies were always correlated with normal external sphincter electromyography. In all patients with a high lesion and in 79% of all others detrusor hyperactivity was correlated with pathological sphincter electromyography. The clinical neurological level of the lesion was not correlated with the function of the detrusor-sphincter mechanism. In 29% of the patients examined with needle electromyography detrusor-sphincter dyssynergia was found, which is less than in most other published studies. And although dyssynergia is a risk factor for renal deterioration, the authors conclude that its effect on the ureter is less important than in subjects with normal perineal musculature, since 80% of the examined patients with meningomyelocele showed pathological sphincter electromyography. These findings thus show a significant correlation between electromyography of the external sphincter muscle and the urodynamic findings in meningomyelocele patients, and clearly demonstrate the importance of urodynamic testing with simultaneous external sphincter electromyography, in order to improve both diagnostic accuracy and reliability of follow-up and treatment.

Adolescent↗