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At least 19 recordsLinked to original sources

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↗

PubMed1989

[An effect of the clenching speed on the method of calculating the biting force of patients by using electromyography].

The recovery of the masticatory function in patients with dentures was assessed by several indices such as masticatory efficiency, maximal biting force and electromyographic analysis. We have attempted to develop a new method of calculating the biting force of edentulous patients by using electromyography. The method has almost been established, but, depending on the clenching speed, there is a certain difference between the estimates obtained from this method and the biting force obtained from a force transducer. The purpose of this study is to clarify the effect of the clenching speed on the method of calculating the biting force by using electromyography. In 9 healthy subjects with normal dentitions, biting force and electromyograms were recorded simultaneously under 3 different clenching speed conditions. After the recording, the relation between the biting force and integrated electromyography was compared thoroughly. The effect of the clenching speed on the method of calculating the biting force by using electromyography was also investigated. The following results and conclusions were obtained: 1. At a slow clenching speed, a linear relation between the biting force and integrated electromyography was found. 2. At a medium clenching speed, the relation showed a slightly upward curvature as the biting force was increased and a slightly downward curvature as it was decreased. 3. At a fast clenching speed, the relation between the biting force and integrated electromyography showed an upward curvature as the biting force was increased, and a downward curvature as it was decreased. 4. At the slow and medium clenching speeds the estimates obtained from this method approximated the biting forces obtained from a force transducer. 5. At the fast clenching speed, the tendency was found that the estimates obtained from this method were higher than the biting force obtained from a force transducer. 6. When realizing this tendency, the method of calculating the biting force by using electromyography can be said to be clinically effective.

Bite Force↗

PubMed1990

Evaluation of flow electromyography in patients with benign prostatic hyperplasia.

Combined uroflowmetry and external sphincter electromyography studies were done both preoperatively and postoperatively in patients with benign prostatic hyperplasia. In 56 patients preoperative electromyography during voiding showed silent or markedly suppressed activity in 41 patients (73.2%), while the remaining 15 patients (27.8%) revealed active electromyography. In the postoperative studies, 12 patients revealed active electromyography even after the release of obstruction. The urine flow rate following operation was not drastically improved in the active electromyography group compared to the silent electromyography group. We suppose that long-term urethral obstruction with prostatic adenoma could influence the function of relaxation of the external sphincter muscle in some patients with benign prostatic hyperplasia.

Aged↗

PubMed1992

Predictive value of electromyography in diagnosis and prognosis of the hypotonic infant.

To investigate the diagnostic validity of electromyography in the hypotonic infant, 79 children aged 0 to 12 months, seen over a 20-year period, were studied retrospectively. The diagnoses using clinical, muscle biopsy, and laboratory characteristics were: 25 central hypotonia, 20 spinal muscular atrophy, 20 myopathy, four myotonic dystrophy, four benign congenital hypotonia, two congenital muscular dystrophy, two myasthenia gravis, one infantile inflammatory myopathy, and one arthrogryposis multiplex congenita. Using strict criteria, electromyography accurately predicted the final diagnosis in 65% of infants with spinal muscular atrophy and was consistent with the diagnosis in another 25%. In contrast, electromyography accurately predicted the final diagnosis in only 10% of infants with myopathy and was normal in 88% of infants with central hypotonia. In infants with spinal muscular atrophy, there was no difference in the predictive value of electromyography when performed in the newborn compared to older infants. Normal distal nerve conduction velocities in infants with spinal muscular atrophy may predict prognosis, since these infants had a longer survival. Electromyography thus has a high predictive value for infantile spinal muscular atrophy but not for myopathy.

Biopsy↗

PubMed1976

Needle electromyography: its effect on serum creatine phosphokinase activity.

The effect of needle electromyography on serum creatine phosphokinase (CPK) levels has remained unclear despite the diagnostic implications. Serum CPK was serially assayed for changes before and after electromyography (EMG) in two healthy persons and ten persons having low back pain, while they remained at total bed rest. Mean curves showed a peak at 6 hours post-EMG and a return to baseline 48 hours post-EMG. The mean peak value was 1.5 times the baseline. Only one sample exceeded the normal range and it was from a patient with frank positive waves and fibrillation potentials. Correcting for dilution of CPK released, by body weight and for total trauma, by number of needle insertions did not modify the results. The time course and magnitude of elevation of CPK parallel those reported for post exercise changes but are much less than those reported to follow myocardial infarction. In the differential diagnosis of myopathies, care must be taken to ensure that the combination of needle electromyography, exercise, diurnal variation and active denervation does not lead to a "false-positive" elevation of CPK above the normal range. Needle electromyography by itself should not induce a false-positive CPK level in a normal person and no significant changes in CPK levels are likely to occur within two hours after the study.

Adolescent↗

PubMed1989

Evaluation of the use of surface electromyography in the diagnosis, documentation, and treatment of dental patients.

The use of electromyography as an aid in the differential diagnosis and treatment of dental patients is carefully examined in this literature review. Electromyography has been advocated for the establishment of rest and occlusal positions, and for the detection of muscle hyperactivity and hypoactivity, spasm, fatigue, and muscle imbalance. However, these claims were often based on studies that failed to include a control group when comparing various clinical parameters and EMG activity of the muscles of mastication. When a control group was incorporated, the authors usually failed to match the patients by such variables as age, sex, facial morphology, and history of bruxism. These variables have a significant influence on the level of EMG activity and may account for the high degree of variability observed between groups. Controlled trials evaluating the efficacy of biofeedback using electromyography found significant reductions of diurnal parafunctional activity during treatment, but the low symptom levels were not maintained after cessation of biofeedback. Based upon this extensive literature review, there is no convincing evidence to support the use of electromyography in the diagnosis or treatment of dental patients except in the treatment of parafunction.

Biofeedback, Psychology↗

PubMed1990

A comparison of thermography and electromyography in the diagnosis of cervical radiculopathy.

We studied 20 asymptomatic control subjects and 14 patients with clinically unequivocal cervical radiculopathy to compare the diagnostic value of thermography with that of electromyography. We measured the average skin temperature of designated regions over the neck, shoulder, and upper extremities. We then compared the temperature between corresponding regions of the two limbs, and between fingers innervated by different roots in the same hand. Thermography was abnormal in 6 patients (43%), whereas electromyography was abnormal in 10 (71%). Thermographic abnormalities were seen only in the hands and fingers, and the pattern did not follow the dermatome of the clinically involved cervical root. When compared to electromyography, thermography provided no additional diagnostic information. Thus, thermography does not have an established role in the evaluation of patients with cervical radiculopathy.

Arm↗

PubMed1989

Laryngeal electromyography.

Over the last 40 years sporadic reports have appeared in the otolaryngological and neurological literature describing techniques and applications of laryngeal electromyography. Despite considerable refinements in methodology and instrumentation over that time laryngeal electromyography has not been widely adopted in routine clinical practice. This paper describes a simple, reliable and reproducible technique which has been employed by the author over a 15-year period. The indications for laryngeal electromyography are reviewed and the technique currently used is briefly described with reference to alternative techniques. The usefulness of the information obtained by this examination is discussed.

Electromyography↗

PubMed1991

Is paradoxical sphincter reaction provoked by needle electrode electromyography?

In 10 patients with emptying disturbances, the anal sphincter reaction was investigated clinically and by electromyography with needle and wire electrodes to elucidate whether pain during the investigation could provoke the paradoxical sphincter reaction. In eight of the patients, the paradoxical reaction was easily felt at digital examination. Two patients complained of pain during the needle electrode recording; none complained during the wire electrode investigation. Nevertheless, all 10 patients had paradoxical sphincter reaction independent of the electrode used at electromyography. With careful clinical investigation, most cases of paradoxical sphincter reaction can be diagnosed. When this is inconclusive, the diagnosis should be confirmed by electromyography, preferably by the wire technique.

Adult↗

PubMed1978

Rest vertical dimension determined by electromyography with biofeedback as compared to conventional methods.

This study was undertaken to determine if electromyography with biofeedback can be utilized to produce a more reliable determination of rest vertical dimension than conventional methods such as phonetics and swallowing. It was found that: 1. Electromyography with biofeedback appeared to produce a more consistently reliable determination of rest vertical dimension than conventional methods when used with edentulous subjects. 2. Determinations of rest vertical dimension by individual dentists using phonetics and swallowing had wide variations in two of the five patients in a range of up to 6 mm. An error of this magnitude could easily cause an intrusion upon the interocclusal distance and resultant failure of treatment. Since this study was limited to five patients, a more expanded study is necessary to determine the validity of electromyography vs. conventional methods for determining rest vertical dimension. Both methods have questionable aspects in relation to the time of day, patient's understanding of each technique, and past dental history. However, the most critical problem of the electromyographic technique is the feasibility of its use in a private practice in light of the excessive cost of the required equipment.

Biofeedback, Psychology↗

PubMed1992

The role of manometry, electromyography and radiology in the assessment of intractable constipation.

An analysis is made of functional studies performed in 96 constipated patients to see how these studies influenced the choice of surgical treatment. All patients underwent anal manometry, and other investigations included colonic transit studies (56), anal sphincter electromyography (42) and defaecatory proctography (34). Additionally nine patients underwent full thickness rectal biopsy. The resting anal canal pressures of the patients studied were lower than controls, and fibre density studies on electromyography were abnormal in half the patients studied suggesting a degree of denervation of the sphincter muscles, which possibly related to chronic straining on the toilet. There was evidence of reduced rectal sensation as shown by an increase in the least perceived volume on balloon distension of the rectum, and in those with megarectum and/or megacolon an increase in maximum tolerated volume. The recto-anal inhibitory reflex was used to screen for adult Hirschsprung's disease, but in one patient the reflex was present despite absence of ganglia on full thickness rectal biopsy indicating the need for biopsy as the definitive diagnostic procedure. Delayed colonic transit using radio opaque markers was a necessary requirement before recommending colectomy, and delayed transit was demonstrated in 34% of the patients studied. Anismus on electromyography was found in 20% of the patients but there was poor correlation with failure of the anorectal angle to widen when bearing down on proctography. The investigations helped in the choice of treatment, but were difficult to interpret. They should be used in severe constipation when surgery is being contemplated.

Adolescent↗

PubMedDate not supplied

Diagnosis of cauda equina abnormalities by using electromyography, discography, and epidurography in dogs.

Electromyography (EMG), L7-S1 discography and epidurography were investigated in 15 dogs with clinical signs of cauda equina dysfunction and in 7 control dogs without such clinical signs. Electromyography of paraspinal and pelvic limb muscles was done in 13 of 15 affected dogs. An L7-S1 discogram followed by an epidurogram was performed in all 22 dogs using 20% iopamidol. Results of discograms, epidurograms, and gross necropsy examinations were normal in six of seven control dogs. The one dog in which these studies were abnormal had a mild L7-S1 disc protrusion that did not result in nerve root compression at necropsy. Electromyographic analysis was 100% accurate in predicting the presence or absence of cauda equina disease. None of the results of discograms were falsely negative. Twelve of 15 discograms in clinically affected dogs indicated dorsal disc protrusion, but 2 of these protrusions were found to be noncompressive at surgery (13% error). Abnormal epidurograms occurred in 9 of 15 clinically affected dogs. There was one false positive and two false negatives (20% error). Electromyography was a sensitive screening technique for the presence of cauda equina disease. Discography may be more sensitive for detection of L7-S1 disc protrusion than epidurography. An abnormal radiographic contrast study of the cauda equina may only be useful when combined with an abnormal EMG.

Animals↗

PubMed1977

Chemonucleolysis: evaluation of effectiveness by electromyography.

Findings in 97 consecutive patients who had undergone chemonucleolysis were analyzed. The purpose of this prospective clinical study was two-fold: (1) to provide a comparison of preoperative findings of electromyography, myelography and discography and (2) to evaluate postoperative electromyography as an objective test of recovery. All the patients had complete history and physical examination, five-view roentgenographic study of the lumbosacral spine, electromyography preoperatively and again at three months postoperatively, myelography and discography. Computer analysis of the results was done for the multiple cross-correlations in the study. All patients had had at least three months preoperative conservative care without relief of symptoms. The study shows that electromyographic study three months postchemonucleolysis is of value for corroboration of clinical improvement only if the EMG becomes completely normal. A greater percentage of patients recovered clinically after chemonucleolysis when the preoperative EMG was normal as compared to those for whom the preoperative EMG was abnormal. We were surprised to find no significant correlation between end result and the existence of pending litigation.

Chymopapain↗

PubMed1988

The human cervical myotomes: an anatomical correlation between electromyography and CT/myelography.

To correlate the accuracy of electromyography in diagnosing the correct root involved in cervical radiculopathy, 20 patients with cervical radiculopathy, diagnosed by electromyography using strict inclusion and exclusion criteria, were studied. Metrizamide myelography/computerized tomography were evaluated in all 20 patients independently, and the involved root was defined. The root involved, using the EMG examination and the myotome chart of the Medical Research Council, was C5 in 3 patients, C6 in 6, C7 in 9 patients, and C8 in 2 patients. The overall correlation with myelography/CT was 65% (33.3, 66.6, 77.7, and 50% for C5, C6, C7, and C8, respectively). EMG done properly has a good correlation of myelography/CT. This correlation is higher (73.3%) for the commonly occurring cervical radiculopathies (C6 and C7).

Action Potentials↗

PubMed1989

Electromyography in congenital nemaline myopathy.

To clarify the discrepancies between earlier reports of electromyography (EMG) in congenital nemaline myopathy (CNM), conventional electromyography was done on 13 patients with CNM, and results were compared with those of 18 earlier EMG examinations of the same patients. Fiber density was measured in 10 patients with a computerized method and neuromuscular jitter in 3 with single-fiber EMG. With age, the EMG abnormality progressed, and "neuropathic" EMG features developed in distal muscles. In 9 of 10 patients fiber density was higher than normal. In two of three patients jitter was abnormal. Motor (13 of 13 patients) and sensory (3 of 3 patients) nerve conduction velocities were normal. Our results seem to explain the conflicting reports of EMG in CNM. We conclude that active degeneration and regeneration of muscle fibers takes place in CNM and suggest that the "neuropathic" motor unit potentials seen in our patients may be secondary to myopathic disease activity.

Adolescent↗

PubMed1992

[Electromyography and functional analytic findings in obstructive disorders of defecation. A contribution to the differentiation of neurogenic and myogenic sphincter damage].

The aim of this study was to get further information about functional results in patients with outlet obstruction. We investigated 27 patients (age between 42 and 74 years) by electromyography (EMG), manometry and radiology with contrast-solution. The electromyography, a dynamic investigation method, allows the differentiation between neuronal and muscular malfunctions of the voluntary controlled pelvis muscles. Patients with outlet obstruction should be divided into three groups by EMG diagnosis: One group with neuronal alterations, another group with muscular alterations and one group with neuro-muscular alterations. We obtained marked statistical differences between patients with neuronal or muscular malfunctions in the mean amplitude, the turns per second and the integration of the mean amplitude compared to the control group (14 patients). Patients with only neuronal alterations showed furthermore statistically significant distinctions of the action potential duration from control, whereas the data of patients with muscular malfunctions were significantly different from control in the peak amplitude of the action potentials. 77% of all investigated patients were not able to relax the pelvis muscles during defecation.

Adult↗

PubMed1992

Electromyography of the pubococcygeus muscles in patients with obstructed defaecation.

The function of the pubococcygeus muscles during defaecation straining was compared in 10 women with obstructed defaecation and 12 age-matched control subjects. Video-proctography in each patient showed failure to evacuate the rectum and sagging of the pelvic floor during attempted defaecation. Trans-perineal concentric needle electromyography in the puborectalis muscle and transvaginal electromyography in the pubococcygeus muscle was carried out during defaecation straining and during attempted rectal balloon expulsion. Contraction of the pubococcygeus muscle was observed in 10 of the 12 control subjects and in 2 of the 10 patients with obstructed defaecation (P < 0.005). Virtually equal proportions of subjects in each group showed relaxation or contraction of the puborectalis muscle during straining. There was significant perineal descent on straining in the patient group (P = 0.005). This group of patients with obstructed defaecation showed failure of the pubococcygeus muscles to contract, perhaps due to neuropathic weakness of the muscles. The puborectalis muscle did not cause obstructed defaecation in these patients, and the concept of "paradoxical" contraction of this muscle is questioned.

Adult↗