Motor Unit Potential Duration Research Articles

Differential Diagnosis Of Multiple-System Atrophy With Parkinson's Disease By External Anal- And Urethral-Sphincter Electromyography.

BackgroundThe differential diagnosis of Parkinson’s disease (PD) with multiple-system atrophy (MSA) is difficult because of their similarity in symptoms and signs. The objective of this study was to investigate the value of external anal-sphincter electromyography (EAS-EMG) and urethral-sphincter electromyography (US-EMG) in differentiating MSA from PD.MethodsA total of 201 patients, — 101 MSA and 100 PD — were recruited in this study. Average duration and amplitude of motor unit potentials (MUPs), percentage of polyphasic MUPs, amplitude during strong contractions, and recruitment patterns during maximal voluntary contractions were recorded and analyzed to assess diagnostic efficiency of EAS-EMG and US-EMG for MSA.ResultsSignificant differences in average MUP duration and recruitment patterns during maximal voluntary contractions were found between patients with MSA and patients with PD using both EAS-EMG (P<0.001, P<0.001) and US-EMG (P<0.001, P<0.001). The percentage of polyphasic MUPs and amplitude during strong contractions showed significant differences in MSA and PD using only EAS-EMG (P<0.001, P=0.005). Cutoff points for average MUP duration in EAS-EMG and US-EMG for differential diagnosis of MSA with PD were 10.9 and 11.1 milliseconds, respectively. With average MUP duration of EAS-EMG and US-EMG being applied jointly, sensitivity and specificity in distinguishing MSA from PD were 83.2% and 71.8%, respectively.ConclusionEAS-EMG and US-EMG were sensitive and specific methods for the diagnosis and differential diagnosis of MSA, and the combination of both would improve the diagnostic rate of MSA compared to only one method being used.

Muscle velocity recovery cycles in neurogenic muscles

ObjectiveTo examine muscle membrane properties in neurogenic muscles using Muscle Velocity Recovery Cycles (MVRCs). MethodsForty-seven patients referred to Nerve Conduction Studies (NCS) and Electromyography (EMG) for peroneal nerve entrapment neuropathy were prospectively included. The patients were categorized as peroneal nerve entrapment neuropathy across knee (n = 22), L5-radiculapathy (n = 10), normal NCS/EMG (n = 9) and other disorders (n = 6) using NCS/EMG and neuroimaging results. Strength in anterior tibial muscle was measured by Medical Council Scale (MRC) and disease duration was recorded. In addition to conventional NCS/EMG, all subjects were examined with MVRCs in anterior tibial muscle. This provided parameters of muscle relative refractory period (MRRP) and early supernormality (ESN) and late supernormality (LSN). The results were compared with 29 age-matched healthy control subjects. ResultsMRRP was prolonged and ESN and LSN were reduced in neurogenic muscles. MRRP, ESN and LSN correlated to MRC and incidence of spontaneous activity but not to motor unit potential parameters or disease duration. ConclusionsMVRC changes provide in vivo evidence of depolarization in intact human muscle fibres that could underlie reduced muscle excitability and hence weakness in neurogenic muscles. SignificanceMVRCs appear to be a useful technique for revealing disease mechanism in a broad range of neuromuscular diseases.

P51-F Quantitative electromyography: Normative data in paraspinal muscles

Objectives Paraspinal muscle may be affected in neuromuscular disorders, and EMG may be crucial in the diagnosis. The aim of the study was to develop normative data at different spinal segments. Methods Sixty-five healthy subjects (49% men, 51% women) aged 21–82 years were studied. In each subject, 16–92 motor unit potentials (MUPs) were recorded bilaterally at C7, Th10 and L5 segments using concentric needle electrodes. At each segment, average MUP amplitudes, durations, incidence of polyphasic potentials, and the amplitude at maximal voluntary contraction (MVC) were measured. The incidence of spontaneous activity was examined. Results There was no relationship between the EMG parameters and age. The mean MUP duration and amplitude, and the amplitude at MVC increased caudally (ANOVA, P Conclusions In contrast to limb-muscles EMG parameters were unrelated to the age of the subject. The gradient of EMG parameters caudally from C7 suggesting larger motor units at more caudal segments. The proportion of polyphasic potentials may be due to the organization of muscle fibers. The incidence of fibrillation activity was similar to limb muscles. Significance The study describes normative data for EMG of paraspinal muscles according to the examined spinal segment. These data may be useful in quantitative EMG examination of paraspinal muscle in neuromuscular disease.

The severity of motor dysfunctions and urinary dysfunction is not correlated in multiple system atrophy

ObjectiveAlthough it is well known that patients with multiple system atrophy (MSA) cerebellar dominant type (MSA-C) show severe autonomic dysfunction, the relationship between autonomic and motor dysfunction remains uncertain. Previously we reported that severe urinary voiding dysfunction is useful in differential diagnosis of MSA and other diseases. Herein, we aimed to clarify the relationship between the severity of motor dysfunctions and urinary dysfunction. MethodThis study is a retrospective review of 46 patients with MSA-C diagnosed according to Gilman's second consensus criteria. The severity of motor dysfunctions was evaluated using International Cooperative Ataxia Rating Scale (ICARS). Urinary voiding dysfunction was evaluated by measuring post-void residual (PVR). The mean duration of motor unit potentials in external anal sphincter muscles on electromyography, which represents the severity of neurodegeneration in Onuf's nucleus, was also examined. ResultsThe mean age of patients was 63.8 ± 8.2 years and mean disease duration was 3.0 ± 1.9 years. The mean ICARS score was 40.1 ± 14.7. The mean PVR was 119.1 ± 102 ml and the mean duration of motor unit potentials (MUPs) in anal sphincter electromyography was 9.2 ± 2.2 ms. The correlation coefficient between ICARS and PVR was 0.093 (p = .539), and between ICARS and mean duration of MUPs was 0.105 (p = .811). A significant positive correlation (r = 0.296, p = .005) was noted between PVR and the mean duration of MUP. ConclusionMotor and urinary dysfunctions were not correlated in MSA-C.

Chapter 18 - Normal and abnormal voluntary activity

An important component of needle EMG entails recording and interpreting the electrical signals generated from motor units during voluntary contraction. The recorded motor unit potentials (MUPs) reflect the number of motor units within a muscle and the distribution and density of muscle fibers within a motor unit within a portion of a muscle. Various MUP parameters are assessed to determine the integrity of the motor units, including recruitment, stability, phases and turns, duration, and amplitude. Each of these parameters is altered in a different way in various neuromuscular diseases. In neurogenic disorders, the earliest changes occur in the recruitment pattern of motor units followed by MUP morphologic changes (increased MUP phases and duration) as reinnervation occurs. MUP instability, indicating impaired neuromuscular transmission, also occurs in reinnervating neurogenic disorders as well as in neuromuscular junction disorders. In myopathies, a reduction in the size of the motor unit is manifested by MUPs of low amplitude and short duration. Interpreting the voluntary MUP changes along with spontaneous activity helps to determine the type, severity, and temporal course of neuromuscular diseases.

Clinical analysis of arytenoid cartilage reposition with snake mouth forceps for the arytenoid cartilage dislocation

To investigate the clinical effect of the arytenoid cartilage reposition using snake mouth reduction forceps under general anesthesia. Data of twenty-six cases accepted arytenoid cartilage reposition under intravenous general anesthesia were analyzed, nineteen cases accepted laryngeal CT scan and cricoarytenoid joint reconstruction, all patients underwent endolaryngeal muscle electromyography examination. According to the position of cartilage dislocation prompted by laryngoscope and CT, the arytenoid cartilage was repositoned under the visual laryngoscope using special snake mouth reduction forceps. If bilateral arytenoid cartilage were still asymmetrically at the end of the surgery, patients needed repeated reposition 1 to 2 times 1 week after operation. The efficacy was evaluated 4 weeks later. All patients had a hoarse and breathing voice preoperative. Under laryngoscope, there were different degrees of vocal cord movement disorders accompanied by incomplete glottis closure, 22 cases happened in left side and 4 in right side. The arytenoid cartilage was dislocated anteromedially in 25 cases and posterolaterally in 1 case. CT showed that 15 cases of arytenoid cartilage were tilted anteromedially; the interval of the cricoarytenoid joint was widened. In axial CT images, there were no direct signs of the arytenoid cartilage dislocation in the 4 cases, but the abnormal position was seen in the reconstruction images. The laryngeal electromyography indicated that 7 cases were abnormal, duration of motor unit potential were visible and the raising potential were mixed. There were 4 patients with normal voice in the first day after surgery, and 19 cases underwent twice and 3 cases underwent three times surgery. Vioce became normal in 4 weeks. Swallowing pain and bucking were all disappeared. Vocal cords movement were recovered to normal level in 25 cases. In 1 case with neck strangulation, the vocal cord movement was slightly worse than health side, but significantly better than that before operation. The arytenoid cartilage reposition using snake mouth reduction forceps under general anesthesia was an effective method for the treatment of the cricoary-tenoid joint dislocation.

The utility of motor unit number estimation methods versus quantitative motor unit potential analysis in diagnosis of ALS

ObjectiveTo compare the diagnostic utility of motor unit number estimation (MUNE) methods to motor unit potential (MUP) analysis in amyotrophic lateral sclerosis (ALS). MethodsTwenty-five patients (1 definite, 11 probable, 9 possible ALS and 4 progressive muscular atrophy) and 22 healthy controls were prospectively included. Quantitative MUP analysis and three MUNE methods; Multiple Point Stimulation MUNE (MPS), Motor Unit Number Index (MUNIX) and MScanFit MUNE (MScan) were done in abductor pollicis brevis muscle. The sensitivities were compared by McNemar chi-square test. MUNE, MUP and revised ALS Functional Rating Scale (ALSFRS-R) parameters were correlated by regression analysis. ResultsThe sensitivities of MPS (76%) and MScan (68%) were higher than MUP duration (36%) and amplitude (40%) in detecting motor unit loss (p < 0.05). MUNE methods increased the categorical probability from possible to probable ALS in 4 patients (16%). There was only significant correlation between ALSFRS-R and MScan (r = 0.443, p = 0.027) among the electrophysiological tests. MUNE methods did not correlate to MUP parameters. ConclusionsMUNE methods are more sensitive in showing abnormality than MUP analysis. SignificanceMUNE methods, in particular MScan, may have the potential to be implemented in the clinical practice for diagnosis and follow-up of neuromuscular disorders particularly ALS.

Quantitative facial electromyography monitoring after hypoglossal-facial jump nerve suture.

Objectives/HypothesisThe time course of the reinnervation of the paralyzed face after hypoglossal‐facial jump nerve suture using electromyography (EMG) was assessed. The relation to the clinical outcome was analyzed.Study DesignRetrospective single‐center cohort studyMethodsReestablishment of motor units was studied by quantitative EMG and motor unit potential (MUP) analysis in 11 patients after hypoglossal‐facial jump nerve suture. Functional recovery was evaluated using the Stennert index (0 = normal; 10 = maximal palsy).ResultsClinically, first movements were seen between 6 and >10 months after surgery in individual patients. Maximal improvement was achieved at 18 months. The Stennert index decreased from 7.9 ± 2.0 preoperatively to a final postoperative score of 5.8 ± 2.4. EMG monitoring performed for 2.8 to 60 months after surgery revealed that pathological spontaneous activity disappeared within 2 weeks. MUPs were first recorded after the 2nd month and present in all 11 patients 8–10 months post‐surgery. Polyphasic regeneration potentials first appeared at 4–10 months post‐surgery. The MUP amplitudes increased between the 3rd and 15th months after surgery to values of control muscles. The MUP duration was significantly increased above normal values between the 3rd and 24th months after surgery.ConclusionReinnervation can be detected at least 2 months earlier by EMG than by clinical evaluation. Changes should be followed for at least 18 months to assess outcome. EMG changes reflected the remodeling of motor units due to axonal regeneration and collateral sprouting by hypoglossal nerve fibers into the reinnervated facial muscle fibers.Level of Evidence3b.

Postvoid residual predicts the diagnosis of multiple system atrophy in Parkinsonian syndrome

ObjectiveIt is difficult to differentiate multiple system atrophy (MSA) from Parkinson's disease (PD) at least in the early stage. Urodynamic study (UDS) is useful in differentiating MSA from PD. We aimed to clarify which UDS parameter was useful in differentiating MSA from PD. MethodsWe retrospectively reviewed 273 cases and performed UDS and external anal sphincter electromyography (EAS-EMG) in patients with MSA (n=182) and PD (n=91). We analyzed the utility of UDS parameters, including postvoid residuals (PVR), detrusor overactivity (DO), degree of bladder contraction, and mean duration of motor unit potentials (MUPs) in EAS-EMG, for differentiating MSA from PD. ResultsPVR>150ml during free-flow study strongly indicated MSA rather than PD (OR 8.723, 95% CI 2.612–29.130, p<0.001). ‘Weak detrusor’ also suggested MSA, but it was not a statistically significant indicator (OR 10.598, 95% CI 0.359–312.473, p=0.172). DO and neurogenic changes in EAS-EMG (mean duration of MUPs>10ms) did not significantly contribute to the differentiation of MSA from PD. ConclusionsPVR>150ml during free-flow study might be more useful than other UDS parameters in clinically differentiating MSA from PD.

O25 Motor unit number estimation methods compared to quantitative motor unit potential analysis in amyotrophic lateral sclerosis

Objectives To compare the sensitivity of MUNE methods to quantitative motor unit potential (MUP) analysis in amyotrophic lateral sclerosis (ALS). Methods Twenty-four patients (1 definite, 11 probable and 8 possible ALS according to awaji criteria as reference standard, and 4 progressive muscular atrophy) were included. Patients were evaluated by revised ALS functional rating scale (ALSFRS-R). In all patients, quantitative MUP analysis and three MUNE methods; MScanFit MUNA (MScan), multiple point stimulation MUNE (MPS), and Motor Unit Number Index (MUNIX) were done in abductor pollicis brevis (APB). MUNE results were compared to 20 age-matched healthy controls and EMG to laboratory controls. The sensitivity of each methods was compared using McNemar chi-square test. MUNE values and MUP parameters were correlated to ALSFRS-R by regression analysis. Results MScan (70%) and MPS (61%) more frequently showed abnormality than MUP duration (35%) whereas only MScan was more often abnormal than MUP amplitude (39%) ( p r = 0.42, p = 0.03) but not MPS ( r = 31), MUNIX ( r = 35), MUP duration ( r = 0.19) or amplitude ( r = 0.09). Discussion MUP analysis gives information about reinnervation, but not about loss of motor units. Therefore MUNE methods may be preferable in ALS electrodiagnosis. Conclusions MUNE methods, particularly MScan, had higher sensitivities than MUP analysis in detection of abnormality in APB and were correlated better to ALSFRS-R. Significance MScan is a promising novel method which should be considered in diagnosis and monitoring disease progression in ALS.

O21 Peak ratio and motor unit potential analyses in detection of chronic neurogenic changes in amyotrophic lateral sclerosis

Objectives Peak ratio analysis is a quantitative way of analyzing interference pattern by turns-amplitude analysis. We aimed in this study to compare the sensitivities of peak ratio analysis and quantitative motor unit potential (MUP) analysis in detecting chronic neurogenic changes in amyotrophic lateral sclerosis (ALS). Methods Twenty-two patients (1 definite, 7 probable, and 9 possible ALS according to Awaji criteria as reference standard, and 5 progressive muscular atrophy) were prospectively included. Quantitative MUP and peak ratio analyses were done in 22 biceps brachialis (BB), 22 tibialis anterior (TA) and 18 abductor pollicis brevis (APB) muscles on the least affected side. Results were compared to laboratory controls. The sensitivity of MUP duration and peak ratio was compared using the McNemar chi-square test. Results Peak ratio analysis was more frequently abnormal than MUP analysis in BB (59% vs. 23%), and TA (59% vs. 18%) muscles ( p Discussion Peak ratio analysis sampled at stronger effort detected more frequently chronic neurogenic changes than MUP analysis recruited at weak effort. Conclusions Peak ratio analysis may provide earlier detection of chronic neurogenic changes, thereby facilitating earlier diagnosis of ALS. Significance Peak ratio analysis which is available in commercial EMG machines should be considered in the electrodiagnostic investigation of ALS.

Motor unit potentials of the erector spinae muscle by concentric needle electromyography.

IntroductionThe needle electromyography (EMG) serves to supply additional information in patients with suspected neuromuscular disorders. We aimed to provide motor unit potential (MUP) data by concentric needle EMG in the erector spinae (ES) in comparison with biceps brachii (BB) and lateral vastus (LV).MethodsElectromyography MUP data (n) were obtained in ES (517), BB (539), and LV (627) in 32 healthy volunteers (16f).ResultsMotor unit potential data: amplitude (μV) 393 ± 174 (ES), 375 ± 162 (BB), and 577 ± 304 (LV); duration (ms) 10.4 ± 2.4 (ES), 10.1 ± 2.1 (BB), and 11.1 ± 2.3 (LV), area (μV × ms) 585 ± 327 (ES), 538 ± 267 (BB), and 881 ± 492 (LV); phase number 3.23 ± 0.94 (ES), 2.98 ± 0.76 (BB), and 3.19 ± 0.81 (LV); size index 0.60 ± 0.56 (ES), 0.51 ± 0.53 (BB), and 0.96 ± 0.55 (LV). LV displayed higher values (p at least <.001) for MUP amplitude, duration, area, and size index as compared to both, BB and ES.ConclusionConcentric needle EMG investigations in healthy adult human subjects revealed similar MUP parameters in the ES and BB muscles, while in the LV muscle MUP amplitude, duration, area, and size index were significantly larger. Different neuromuscular disorders display a predominant involvement of proximally located muscles such as truncal muscles. The present results given here may facilitate the diagnosis of neuromuscular disorders.

Needle electromyography features and values of paraspinal muscle parameters in assessment of respiratory function of patients with amyotrophic lateral sclerosis

Objective: To analyze the features of needle electromyography (EMG) in patients with amyotrophic lateral sclerosis (ALS), and explore the correlation between EMG parameters of the tenth thoracic paraspinal muscle and disease duration, rate of disease progression, forced vital capacity (FVC) and revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R). Methods: Standard EMG was recorded from unilateral sternocleidomastoid muscle and/or tongue muscles, upper and lower limbs muscles and the tenth thoracic paraspinal muscle in 112 patients with definite ALS between March 2012 and June 2013 in the Department of Neurology at Chinese PLA General Hospital. Parameters studies included spontaneous potentials, duration and amplitude of motor unit potentials (MUP), pattern of recruitment. Results: EMG revealed diffuse neurogenic changes in each case. Fibrillation potential or positive sharp waves were found in some muscles in all of patients, and both of them were found in most of the cases. Fasciculation potentials (FPs) were found in 8 patients and accompanied with fibrillation potential and positive sharp waves in 5 of them. Complex repetitive discharges (CRDs) were found in only 1 patient. Duration and amplitude of MUP was prolonged and increased in ALS patients, and the rate of high amplitude and decreased recruitment pattern were 35.71% and 72.32%, respectively. Logistic regression analysis revealed an association of the FVC loss with the drop of ALSFRS-R and peak amplitude of the tenth thoracic paraspinal muscle. Conclusions: The abnormal spontaneous activity with high frequency are fibrillation potentials and/or positive sharp waves. However, FPs is observed in a small number of patients and CRDs is rarely seen in ALS. The ALSFRS-R and peak amplitude of thetenth thoracic paraspinal muscle may be of certain clinical value in estimating the severity of disease especially the respiratory dysfunction in ALS patients.

ID 311 – Do the motor unite potentials properties change with recording from near tendon?

Objectives Purpose is to compare the properties of motor unit potentials (MUP) voluntarily recorded from neuromuscular junction (NMJ) and 5 cm distally from NMJ (near tendon) of the biceps muscle. Methods We recorded MUPs in voluntarily activated biceps muscle from 5 healthy controls and 6 patients with motor neuron disease (MND), 7 patients with myopathy. We evaluated amplitudes and durations from neuromuscular junction and near tendon with concentric needle electrodes. Results The mean duration from NMJ and tendon were 6.37 and 7.4 ms in healthy controls; 4.94 and 4.35 ms in patients with myopathy; 8.52 and 11.2 ms in patients with MND respectively. The mean amplitudes from NMJ and tendon were 456 and 474 μV in healthy controls, 508 and 421 μV in patients with myopathy; 1169 and 1032 μV in patients with MND respectively. Conclusions Amplitudes of MUPs decrease with recording from near tendon in myopathy and neuropathy. Duration of MUPs do not change significantly in myopathy and healthy controls, but increase in neuropathy.

Pelvic floor electrophysiology in spinal cord injury.

The study aimed to investigate sacral peripheral nerve function and continuity of pudendal nerve in patients with chronic spinal cord injury (SCI) using pelvic floor electrophysiological tests. Twelve patients with low cervical or thoracic SCI were prospectively included. Quantitative external anal sphincter (EAS) muscle electromyography (EMG), pudendal nerve terminal motor latency (PNTML) testing, bulbocavernosus reflex (BCR) testing and pudendal short-latency somatosensory-evoked potential (SEP) measurement were performed. In EAS muscle EMG, two patients had abnormal increased spontaneous activity and seven prolonged motor unit potential duration. PNTML was normal in 10 patients. BCR was present with normal latency in 11 patients and with prolonged latency in one. The second component of BCR could be recorded in four patients. SEPs showed absent cortical responses in 11 patients and normal latency in one. Pudendal nerve and sacral lower motor neuron involvement are significantly associated with chronic SCI, most prominently in EAS muscle EMG. The frequent finding of normal PNTML latencies supports earlier concerns on the utility of this test; however, BCR and pudendal SEPs may have clinical relevance. As intact peripheral nerves including pudendal nerve are essential for efficient supportive therapies, pelvic floor electrophysiological testing prior to these interventions is highly recommended.

Intestinal ischemia–reperfusion induced diaphragm contractility dysfunction: Electrophysiological and ultrastructural study in a neonatal rat model

AimTo evaluate the remote effect of intestinal ischemia reperfusion (IR) injury mediated by tumor necrosis factor alpha (TNF-α) on diaphragm contractility functions and whether administration of NAC may counteract the possible detrimental effects in an experimental neonatal rat model. Methods40 Wistar rat pups were randomized into four groups; ten animals in each. Intestinal ischemia was conducted by obstructing mesentery of intestines by a silk loop. In the control group; only laparotomy was performed. After 1h ischemia, reperfusion was conducted for 1h in 1h group, 24h for 24h group and 24h for 24h+NAC group but administration of NAC (150mg/kg/day) intraperitoneally twice a day was performed. Inflammatory response was evaluated by tissue TNF-α level and contractility functions by mechanic activity studies of the diaphragm. Electrophysiology of the diaphragm and the phrenic nerve was conducted to determine neuropathy or myopathy and transmission electron microscopy was performed to evaluate ultrastructural changes in the phrenic nerve. ResultsDiaphragm tissue TNF-α level significantly increased in 1h and 24h groups (P=0.004, P=0.0001; respectively). Diaphragm mechanic activation force and duration significantly decreased at 1h and 24h (P=0.004, P=0.02 and P=0.0001, P=0.0001; respectively). NAC administration significantly prevented decrease in the maximal contraction and the duration (P<0.001). Phrenic nerve compound action potential (CMAP) amplitude significantly decreased in 1h group (P<0.0001) and NAC administration significantly prevented this decrease when compared with 24h group (P<0.001). In diaphragmatic needle electromyography, the duration of motor unit potentials (MUP) was prolonged significantly when compared with control group. Contractility and electrophysiological studies were indicating primarily neuropathy in diaphragm dysfunction. Histopathology revealed axonal and myelin degeneration in the 1h and 24h group, but less injury in the NAC administered group. ConclusionsIntestinal IR induced elevation of TNF-α level in the diaphragm. Impairment in the diaphragm contractility and neuropathic changes in the phrenic nerve occurred even in the first hour of reperfusion. NAC administration prevented these detrimental effects.

Increased motor unit potential shape variability across consecutive motor unit discharges in the tibialis anterior and vastus medialis muscles of healthy older subjects

ObjectiveTo study the potential utility of using near fiber (NF) jiggle as an assessment of neuromuscular transmission stability in healthy older subjects using decomposition-based quantitative electromyography (DQEMG). MethodsThe tibialis anterior (TA) and vastus medialis (VM) muscles were tested in 9 older men (77±5years) and 9 young male control subjects (23±0.3years). Simultaneous surface and needle-detected electromyographic (EMG) signals were collected during voluntary contractions, and then analyzed using DQEMG. Motor unit potential (MUP) and NF MUP parameters were analyzed. ResultsNF jiggle was significantly increased for both the TA and VM in the old age group relative to the younger controls (P<0.05). NF jiggle was significantly higher in the TA compared to VM (P<0.05). For TA, NF jiggle was negatively correlated with MUNE, and positively correlated with S-MUP amplitude, NF count, MUP duration, MUP peak-to-peak voltage, and MUP area (P<0.05). For VM, NF jiggle was positively correlated with NF count and MUP area (P<0.05), and no significant correlations were found between NF jiggle and S-MUP amplitude, MUP duration, or MUP peak-to-peak voltage (MUNE was not calculated for VM, so no correlation could be made). ConclusionsHealthy aging is associated with neuromuscular transmission instability (increased NF jiggle) and MU remodeling, which can be measured using DQEMG. SignificanceNF jiggle derived from DQEMG can be a useful method of identifying neuromuscular dysfunction at various stages of MU remodeling and aging.

Modified ligation of the intersphincteric fistula tract in the treatment of simple transsphincteric perianal fistula

To assess the efficacy and safety of modified ligation of the intersphincteric fistula tract for simple transsphincteric perianal fistula. Seventy patients with simple transsphincteric perianal fistula between October 2012 and January 2014 in our department were prospectively enrolled. According to the random number table, patients were divided into two groups: modified-LIFT group (37 cases, from the external opening close to the fistula, dissect the external sphincter fistula to the intersphincteric groove by tunneling technique, resect the lateral free fistula) and LIFT group (33 cases). Clinical parametres before and after operation were compared, and results of pelvic electromyogram (EMG) and anorectal manometry three months after operation were analyzed to evaluated anal function. The operative time, pain score, hospital stay, and healing time were not significantly different between the two groups (all P>0.05). During the median follow-up of 12 months (3-20 months), the healing rate in modified-LIFT group was 83.8% (31/37), which was significantly higher than 60% (20/33) in LIFT group (P=0.029). After operation, 4 patients had persistent unhealed wound, 2 recurred in modified-LIFT group, while 8 patients had persistent unhealed wound, and 5 recurred in LIFT group. No patients developed anal incontinence. By the pelvic EMG and anorectal manometry 3 months after operation, the duration of motor unit potential, occurrence of simple phase, mean resting pressure and maximun squeeze pressure were not significantly different. Modified-LIFT procedure for the management of simple transsphincteric perianal fistulas is a simple and effective operation with higher healing rate and similar anal function as LIFT.

AB0986 Electromyography and Biochemistry Characterization of Patients with Pain and Muscle Weakness - Extended Cohort

BackgroundMuscle damage, often manifested as muscle weakness and, rarely as muscle pain is common in rheumatic diseases. These include idiopathic inflammatory myopathies (IIM), and myopathy seen in other rheumatic diseases,...

Effects of PTH(1–84) therapy on muscle function and quality of life in hypoparathyroidism: results from a randomized controlled trial

The effects of treatment with 100 μg parathyroid hormone (PTH) (1-84) or an identical placebo on muscle function and quality of life (QoL) was studied in hypoparathyroid patients. At baseline, we found reduced QoL but no myopathy in the patients. Six months of treatment did not improve QoL, and muscle strength decreased slightly. A reduced quality of life (QoL) and myopathy that may be due to the absence of PTH have been reported in patients with hypoparathyroidism (hypoPT). Sixty-two patients with chronic hypoPT were randomized to 6 months of treatment with either PTH(1-84) 100 μg/d s.c. or placebo, given as add-on therapy to conventional treatment. Muscle function and postural stability were investigated using a dynamometer chair, a stadiometer platform, the repeated chair stands test, the timed up and go test, and electromyography. QoL was assessed using the 36-item Short Form Health Survey and the WHO-5 Well-Being Index. The mean age of the patients was 52 ± 11 years, and 85 % were females. At baseline, QoL was significantly reduced in comparison with norm-based scores. Compared with placebo, PTH did not improve QoL or muscle function. Rather, max force production decreased significantly by 30 % at elbow flexion in the PTH group compared with the placebo group. Moreover, there was a nonsignificant trend for muscle strength to decrease in the upper extremities and on knee extension in response to PTH. Treatment did not affect postural stability. Electromyography showed a slight decrease in the duration of motor unit potentials in the PTH group, indicating a tendency toward myopathy, which, however was not symptomatic. Overall, our data do not support an immediate beneficial effect of PTH replacement therapy on muscle function or QoL. A high frequency of hypercalcemia among our patients may have compromised the potential beneficial effects of reversing the state of PTH insufficiency.