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Pelvic floor electromyography in men with chronic pelvic pain syndrome: a case-control study.

AIMS: The objectives of this study were (1) to identify differences between men with chronic pelvic pain syndrome (CPPS), compared with pain-free men, in surface electromyography/biofeedback (sEMG/BFB) readings of pelvic floor muscles and (2) to determine which pelvic floor muscle sEMG readings may have differential diagnostic and treatment selection value by accurately predicting group membership, CPPS versus normal. METHODS: Twenty-one men with CPPS and 21 healthy men without pelvic pain underwent a standardized sEMG examination by a licensed physical therapist. RESULTS: On group difference measures men with CPPS showed significantly greater sEMG instability in preliminary resting baseline. Three sEMG measures reliably categorized CPPS versus normals with CPPS showing greater preliminary resting baseline hypertonicity and instability with lowered voluntary endurance contraction amplitude. CONCLUSIONS: CPPS patients manifest pelvic floor muscle instability compared to normals. Prebaseline resting hypertonicity and instability along with endurance contraction weakness reliably predicts subject membership in the CPPS vs. normal group. Pelvic floor muscle sEMG may be a valuable screening tool to identify patients with CPPS who may benefit from therapies aimed at correcting pelvic floor muscle dysfunction.

Adolescent↗

Diagnostic discordance of electromyography (EMG) versus voiding cystourethrogram (VCUG) for detrusor-external sphincter dyssynergy (DESD).

AIMS: Detrusor sphincter dyssynergia (DSD) is defined as: "a detrusor contraction concurrent with an involuntary contraction of the urethral and/or periurethral striated muscle." In neurogenic etiology, this usually refers to involuntary contraction of the external striated sphincter and has classically been termed detrusor-external sphincter dyssynergia (DESD). There is currently no consensus regarding diagnosis [specifics of electromyographic (EMG) or voiding cystourethrographic (VCUG) determination], and little data on how well these modalities correlate. We explore the diagnostic congruence for DESD between needle EMG and VCUG in the neurogenic population. METHODS: Consecutive studies performed by a single urodynamicist at a major neurologic center were reviewed. Presence of DESD was determined by increased wire needle EMG activity and/or by dilated bladder neck and proximal urethra during detrusor contraction, in the absence of valsalva or attempt to inhibit voiding. Minimal acceptable criterion for agreement between the two tests was set at 70%. RESULTS: Fourty nine patients were diagnosed with DESD, had a videourodynamic study available, and had no history of sphincterotomy or stent. Binomial testing demonstrated significant disagreement (P < 0.000) in observed proportions. There was 60% agreement (28 patients) and 40% disagreement (21 patients) between EMG and VCUG for diagnosis of DESD. CONCLUSIONS: We found significant disagreement between needle EMG and VCUG for a positive diagnosis of DESD. A combination of EMG and VCUG may identify more cases of DESD than either modality alone and underscores the need for more strict criteria when defining this entity from a urodynamic standpoint.

Adult↗

Electromyography of the human nasal muscles.

Electromyographic (EMG) activity of six nasal muscles was monitored in 17 male volunteers without nasal complaints. Surface electrodes were placed on the nasal skin in such a way that they selectively recorded the activity of these muscles. Recordings were made under different breathing conditions and during voluntary nasal movements. Inspiratory EMG activity was observed during nasal and oral breathing in one or more of the following muscles: dilator naris, nasalis muscle (alar and transverse parts) and apicis nasi. EMG activity increased markedly in response to physical exercise and was more often present in subjects with decreased nasal patency. During voluntary nasal movements a combined activity of the six nasal muscles was consistently found. We conclude that the function of the dilator naris, the nasalis muscle and the apicis nasi strongly relates to respiration. These muscles probably contribute to the prevention of collapse of the nasal valve. The role of the procerus and levator labii superioris alaeque nasi seems to be primarily concerned with facial expression.

Adult↗

[Motility disorders in the blind loop after Roux-en-y reconstruction. Electromyography studies in the animal experiment].

Disturbances of intestinal motility, bacterial overgrowth and pancreocibal asynchrony are frequent findings in patients after Roux-en-y reconstruction (RYR). In dogs (n = 6) electromyographic recording of motility after partial gastrectomy with Roux-en-y reconstruction revealed no significant differences from controls in the Roux limb. However, changes in intestinal motility were extensively in the blind loop. The electromyographic pattern was characterized by an extreme loss of activity in the fasted and postprandial state. The activity front of the migrating motility complex occurred only in 25% of the fasting studies and was not correlated in time with motility patterns of connected small intestine. Food intake led to a significant increase in the motility index in the Roux limb (60.2 +/- 10.5), but not in the blind ending loop (27.8 +/- 4.1). Pharmacological stimulation of the hypomotile blind loop with cisapride is successful: increase of the motility index to 111.2 +/- 16.5. It might be useful in the treatment of symptomatic patients after RYR.

Anastomosis, Roux-en-Y↗

Time course of locomotor recovery and functional regeneration in spinal-transected lamprey: kinematics and electromyography.

The time course of recovery of locomotor function was examined with kinematic analysis and muscle recordings in larval lampreys 2-32 weeks after rostral spinal cord transection at the level of the third gill (approximately 10% of body length, BL). Animals began to recover locomotor movements within 2-4 weeks of spinal cord transection, but the amplitude of locomotor movements in the tail region was less than in normal animals. At 2 weeks post-transection, locomotor activity was limited to 20% BL, and at 3 weeks after spinal transection activity could be recorded at least as far as 40% BL. At 4 weeks after spinal transection, well-coordinated locomotor muscle activity was often present as far as 60% BL. At 8 weeks of recovery and longer, well-coordinated locomotor activity was present consistently at least as far as 60% BL, and the amplitudes of locomotor movements were restored to normal values. At each recovery time examined the ranges of locomotor parameters (cycle time, burst proportion, and intersegmental phase lag) overlapped with those in normal animals. Thus, the gradual recovery of the amplitude of locomotor movements in the caudal body is associated with the gradual return of coordinated muscle activity at progressively more caudal levels along the body. The mechanisms responsible for this gradual recovery of locomotor function are discussed in relation to our recent anatomical and in vitro studies.

Animals↗

Electromyography and nerve conduction study in autosomal dominant olivopontocerebellar atrophy.

Electromyographic examination and studies of motor and sensory conduction velocities were performed in 11 patients with a presumptive diagnosis of olivopontocerebellar atrophy with autosomal dominant transmission. Peripheral nervous system involvement was shown in eight. In two patients with early onset of disease, electrophysiological alterations clearly pointed to severe axonal degeneration, whereas in six they were compatible with slight demyelination.

Action Potentials↗

Quantitative electromyography in the detection of the carriers in Duchenne type muscular dystrophy.

The quantitative EMG technique was used to detect Duchenne muscular dystrophy carriers. The tests were carried out, measuring the parameters of M.U. potentials (the duration, the phase, and the 0 index according to Van den Bosch, modified by Gardner-Medwin), and using the Willison analyzer, in a group of carriers and normal subjects. Ten M.U. potentials from the deltoid, biceps brachii and quadriceps muscles were photographed and measured in each subject, and the right and the left biceps were examined with the Willison analyzer. An high detection rate was obtained by manual EMG, measuring traditional values such as mean number of phases, A.P. duration and 0 index. The Willison analyzer was significant in 2 known carriers. The total EMG detection rate was higher than the CPK tests both in the known carriers and the possible carriers. It is concluded that the quantitative EMG technique is an useful and specific test to detect carriers of the gene of Duchenne muscular dystrophy.

Action Potentials↗

Relative efficacy of clinical examination, electromyography, plain film radiography, myelography and lumbar phlebography in the diagnosis of low back pain and sciatica.

The procedures used in the investigation of low back pain and sciatica have been subjected to a double statistical analysis to determine their diagnostic accuracy, since contradictory opinions have been expressed in the literature. It was found that only lumbar phlebography was more accurate than the most simple procedure, the clinical examination. Myelography is more accurate than clinical examination only in making a positive diagnosis. In this case, it equals the reliability of lumbar phlebography, but so does plain film radiography which however leads to a positive diagnosis less constantly. Lumbar phlebography is the most accurate procedure for making a negative diagnosis, mainly by avoiding a false negative conclusion. A comparison is made with the statements in the literature and the complementary use of the different procedures is proposed for the investigation of low back pain and sciatica.

Adolescent↗

Significance of skin temperature changes in surface electromyography.

Differing results have been reported concerning the direction and quantity of the electromyogram (EMG) amplitude response to changes in tissue temperature. The EMG signals from the soleus muscle of six healthy human subjects were therefore recorded during dynamic exercise (concentric contractions) at ambient temperatures of 30 degrees C and 14 degrees C. The mean skin temperature (Tsk) above the muscle investigated was 32.9 degrees C and 21.7 degrees C, respectively. The core temperature, estimated by rectal temperature, was unchanged. The cooling of the superficial tissues caused approximately a doubling of the EMG amplitude. For the probability level 0.9 in the amplitude probability distribution function, the average signal level increased from 73 microV to 135 microV (P = 0.02). The average mean power frequency of the EMG signal was reduced from 142 Hz to 83 Hz (P = 0.004). The amplitude increase was not due to shivering but other possible explanations are presented. As the changes in Tsk investigated were within the range which may occur normally during the working hours, it was concluded that Tsk should be carefully controlled in vocational EMG studies.

Adult↗

Microcirculation in the upper trapezius muscle during varying levels of static contraction, fatigue and recovery in healthy women--a study using percutaneous laser-Doppler flowmetry and surface electromyography.

Microcirculation in the upper portion of the trapezius muscle was measured percutaneously by continuous laser-Doppler flowmetry (LDF) during two 10-min series of alternating 1-min periods of static contraction and rest determined electromyographically (EMG). Stepwise increased contraction was induced by keeping the arms straight and elevated at 30, 60, 90 and 135 degrees, which was repeated with a 1-kg load carried in each hand. Thereafter, fatigue and recovery were recorded while the subject kept her arms straight and elevated at 45 degrees carrying the 1-kg hand load as long as possible, followed by rest with arms hanging and no load. A group of 16 healthy women of different ages was studied. Signal processing was done on line using a 386 SX computer. The LDF- and root-mean-square (rms) EMG signals were normalized. Spectrum analyses of EMG mean power frequency (MPF) and median spectrum frequency were performed. The rms-EMG increased significantly with an increase in the calculated shoulder torque (r = 0.75). Accumulated local fatigue was indicated by a decrease in MPF with increased shoulder angle and added load (r = -0.54). Blood flow increased with increased shoulder angle (r = 0.82, with hand load r = 0.62) and with increased shoulder torque (r = 0.72), and also showed a significant increase with increased EMG activity (r = 0.74). The LDF showed a negative correlation to MPF (r = -0.67), with increased values when MPF was lowered. During the endurance test, a moderate increase of LDF occurred which reached its maximum during the 1st min of recovery.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Electromyography and fatigue during prolonged, low-level static contractions.

Findings from five separate studies of EMG changes and muscle fatigue during prolonged low-level static contractions are summarized, and the possible mechanisms behind the changes are briefly discussed. Sustained static contractions (10%, 7% and 5% MVC) of up to 1 h duration were performed by finger flexors, elbow flexors and extensors, and knee extensors. In one experiment, intermittent static arm pulling (triceps) (10 s contraction and 5 s rest, average work load 14% and 10% MVC) was performed for 7 h. The endurance time for the sustained contractions was around one hour for 10% MVC, and it was shown--all in all--that the concept of "indefinite" endurance times at contractions below 15-20% MVC cannot be maintained. After 5% MVC sustained contractions for one hour a 12% reduction in MVC was seen, and significant increases in EMG amplitude and decreases in the mean spectral frequency of the EMG-power spectrum were found. Marked differences were also seen in the EMG changes in the elbow flexors and extensors, and transcutaneous electrical stimulation of the knee extensors showed that low frequency fatigue was present after the contraction. With intermittent contractions similar changes in the EMG parameters were seen after 2-3 h of contractions at 14% MVC. On average, during contractions of 10% MVC no EMG changes were detected. Increased extracellular potassium concentration in the contracting muscles is suggested as a possible explanation of these findings.

Electromyography↗

Laryngeal electromyography with separated surface electrodes in patients with multiple system atrophy presenting with vocal cord paralysis.

When recording the activity of the posterior cricoarytenoid muscle (PCA) with surface electrodes, there is contamination from the surrounding muscles such as the cricopharyngeal muscle. We therefore devised a new oesophageal catheter electrode of the separate type, having three individual surface electrodes for the PCA, cricopharyngeal muscle and diaphragm. The records obtained with this catheter demonstrated satisfactory separation between PCA and cricopharyngeal muscle activities. We used this catheter in patients with multiple system atrophy presenting with vocal cord paralysis, who were awake or asleep. There were two interesting electromyographical findings, which were inspiratory activity of the adductor muscle (the thyroarytenoid muscle) and fade-out of the abductor muscle, that is, PCA activity during sleep. Although vocal cord paralysis is one of the most serious life-threatening complications, the precise mechanism has not been clarified. We believe that our catheter may be useful in investigating the mechanism of vocal cord paralysis which could cause sudden death in neurodegenerative disorders, including multiple system atrophy.

Aged↗