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Objective: To evaluate the electromyographic activation of cervical muscles before and after botulinum toxin injections and to investigate the distribution patterns of dystonia that may occur in other muscles during the disease in Cervical Dystonia (CD) patients with no history of previous Botulinum Toxin (BT) injections. Method: Newly diagnosed 9 idiopathic CD patients, who have not been previously injected with BT, are included. After the recruitment of the participants into the study, clinical [Toronto Western Spazmodic Torticollis Evaluation Scale (TWSTRS)] and electrophysiological evaluation [4 pairs of muscles (sternocleidomastoid (SCM), splenius capitis (SC), trapezius (TRA), levator scapulae (LS), a total of 8 EMG sessions for each patient] were carried out in pre- and post-injection period every 6 weeks. BT was performed every 12 weeks (a total of 4 sessions). Results: No permanent change in bioelectrical activity was stated in comparative evaluation of the muscles at the end of the 1-year follow-up. 88.8% of the patients showed subjective amelioration. According to TWSTRS, average 13.36% amelioration was observed. Statistically significant positive correlation was detected between subjective benefit and values of clinical scale (TWSTRS). Discussion: This study is the first in the literature to investigate the changes of muscle activation patterns in CD patients after the BT injections with serial EMG studies. One year follow-up may be thought as a short follow-up period for talking about a permanent change of the muscle activity. In addition to mathematical evaluations, clinical experience and observations are very important; a subjective benefit reported by patients is also reasonably meaninful. [ABSTRACT FROM AUTHOR]

Introduction: The aim of the study is to determine the role of upper motor neuron (UMN) or lower motor neuron (LMN) dysfunction as the primary initiator of distal-proximal and lateral-medial gradients of muscle involvement in amyotrophic lateral sclerosis (ALS)., Methods: Concentric needle electromyography recordings were performed in deltoid, abductor digiti minimi, and first dorsal interosseous (FDI) muscles in patients with ALS and controls during slight voluntary contraction needed to activate two motor units (MU). Five motor unit potential (MUP) pairs were recorded from each muscle. Motor unit potential analyses were performed offline using Multi-MUP analysis program. Quantitative MUP parameters, MU firing rate (FR), FR variability (FRV), and mean consecutive difference (MCD) were calculated. Motor-evoked potentials and the triple stimulation technique (TST) were performed to evaluate UMN involvement., Results: Twenty patients with ALS along with 20 age and sex-matched healthy volunteers were enrolled. Quantitative MUP parameters compatible with denervation and reinnervation were found in patients with ALS, who also showed higher FR, FRV, and MCD values, most prominently in FDI. First dorsal interosseous FRV was lower in patients with abnormal central motor conduction time (CMCT). Firing rate and FRV were negatively correlated with CMCT, but not with TST., Conclusion: Distal limb muscles, particularly FDI, revealed more prominent FR abnormalities in patients with ALS in parallel with the distal-proximal and lateral-medial gradients of the selective muscle involvement pattern which seems predominantly to be correlated with LMN dysfunction. Reduced FRV may be associated with the presence of UMN dysfunction in ALS., Competing Interests: Conflict of Interest: The authors declared that there is no conflict of interest., (Copyright: © 2024 Turkish Neuropsychiatric Society.)

Background: We aimed to investigate the compression and ischemic effects of two different tourniquet pressures on tissues during surgery show a clinical difference., Methods: Patients aged 18-65 years who underwent foot and ankle surgery and applied a tourniquet in a single center between September 2022 and November 2023 were included in this prospective randomized study. Accordingly, tourniquet pressures were applied as limb occlusion pressure (LOP) + 50 mmHg in group 1 (12 patients) and LOP + 100 mmHg in group 2 (12 patients). The time point at which the femoral nerve motor evoked potential (MEP) decreased by 50%, the time point at which the MEP decreased by 100% for all nerves (femoral, tibial, and deep peroneal), and the time point at which all responses returned after the tourniquet was deflated were identified as the time points for analysis., Results: There were no differences in demographic data (age, body mass index, and sex) between the two groups. The mean tourniquet pressure was 191 ± 16 mmHg in Group 1 and 247 ± 21 mmHg in Group 2 (p < 0.001). A 50% decrease in the femoral nerve MEP value was observed at an average of 47 min in Group 1 and 34 min in Group 2 (p < 0.001). A complete loss of MEP responses for all nerves was observed at an average of 69 min in Group 1 and 56 min in Group 2. After the tourniquet was deflated, all MEP responses returned to baseline values at an average of 8.5 min in Group 1 and 12.6 min in Group 2 (p = 0.007). The results showed that lower limb nerve innervation was affected later and returned to normal earlier after deflation of the tourniquet in Group 1 (low tourniquet pressure group)., Conclusions: The innervations of the lower extremity nerves were affected later in the group in which low tourniquet pressure was applied (average 191 mmHg). Again, in this group (LOP + 50 mmHg), nerve conduction recovered an average of 10 min after deflation and four minutes earlier than in the high tourniquet pressure group., Level of Evidence: Level I, diagnostic study., Trial Registration: NCT05926154., (© 2024. The Author(s).)

Background and Aims: This study aimed to identify the clinical characteristics and electrodiagnostic subtypes of Guillain-Barré syndrome (GBS) in Istanbul., Methods: Patients with GBS were prospectively recruited between April 2019 and March 2022 and two electrodiagnostic examinations were performed on each patient. The criteria of Ho et al., Hadden et al., Rajabally et al., and Uncini et al. were compared for the differentiation of demyelinating and axonal subtypes, and their relations with anti-ganglioside antibodies were analyzed., Results: One hundred seventy-seven patients were included, 69 before the coronavirus disease 2019 pandemic (April 2019-February 2020) and 108 during the pandemic (March 2020-March 2022), without substantial changes in monthly frequencies. As compared with the criteria of Uncini et al., demyelinating GBS subtype diagnosis was more frequent according to the Ho et al. and Hadden et al. criteria (95/162, 58.6% vs. 110/174, 63.2% and 121/174, 69.5%, respectively), and less frequent according to Rajabally et al.'s criteria (76/174, 43.7%). Fourteen patients' diagnoses made using Rajabally et al.'s criteria were shifted to the other subtype with the second electrodiagnostic examination. Of the 106 analyzed patients, 22 had immunoglobulin G anti-ganglioside antibodies (14 with the axonal subtype). They had less frequent sensory symptoms (54.5% vs. 83.1%, p = 0.009), a more frequent history of previous gastroenteritis (54.5% vs. 22.9%, p = 0.007), and a more severe disease as compared with those without antibodies., Interpretation: Serial electrodiagnostic examinations are more helpful for accurate subtype diagnosis of GBS because of the dynamic pathophysiology of the disease. We observed no significant increase in GBS frequency during the pandemic in this metropolis., (© 2024 Peripheral Nerve Society.)

Introduction: The aim of this study is to demonstrate the conduction disturbance at the neuromuscular junction in a cranial muscle by measuring jitter with a concentric needle (CN) electrode in the diagnosis of Amyotrophic Lateral Sclerosis (ALS) and to investigate the utility of evaluating the peak number as an ongoing reinnervation marker., Method: Twelve patients diagnosed with ALS were included in this study. Single fiber electromyography (SFEMG) was performed using a CN electrode during the voluntary contraction of the right extensor digitorum communis (EDC) and left frontalis muscles., Results: In SFEMG from the right EDC muscle, the mean jitter value was high in all of them. The average jitter calculated in EDC muscles was 57.76±24.17 μs. The mean jitter value in the frontal muscles was 28.91±10.21 μs. In all patients, the number of CN electrode peaks was more than 4 in the EDC muscle and above 4 in 91.67% of the frontal muscle., Conclusion: Detection of high jitter in SFEMG examination indicates that the examined muscle undergoes a denervation-reinnervation process in the case of increased peak number values. When such a determination is made in the extremity muscles, it becomes important for the diagnosis of ALS., Competing Interests: Conflict of Interest: The authors declared that there is no conflict of interest., (Copyright: © 2023 Turkish Neuropsychiatric Society.)

Objectives: To investigate the long-term evaluation with electromyography of ulnar nerve function in patients with distal humerus fractures (DHFs) treated with open reduction and internal fixation., Design: Retrospective cohort study., Setting: Level 1 trauma center., Patients: Fifty-two patients (20 men and 32 women) with DHFs., Interventions: All patients underwent open reduction and internal fixation between 2002 and 2017 with a minimum five years' follow-up., Main Outcome Measurements: The nerve conduction test was done for evaluation ulnar nerve function. Secondary outcomes were modified McGowan grading system for symptoms of ulnar neuropathy., Results: The mean follow-up time was 112.7 ± 39 months after surgery. 28.8% (15) of the patients scored in Grade I, 30 (57.6%) in Grade II, and 7 (13.6%) in Grade III on the affected side according to McGowan grading scale. According to EMG results, 40.1% (21/52) of patients had abnormal results. There was significant difference between fracture and unaffected side regarding ulnar nerve motor wrist CMAP amplitude, motor below elbow CMAP amplitude, above elbow CMAP amplitude, above elbow MNCV, and sensory wrist amplitude. Ulnar nerve motor wrist-ADM latency (p = 0.01; r = 0.446) and ulnar nerve sensory conduction velocity (p < 0.001, r = -0.504) were significant correlation with McGowan grading scale., Conclusion: There were significant difference ulnar nerve motor amplitude and sensory wrist amplitude between fracture and unaffected side. A mean decrease in sensory amplitude of fracture elbow was found 25% compared to the unaffected side in our result., Level of Evidence: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Conflict of Interest: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

In this study, we aimed to determine the genetic basis of a Turkish family related to hereditary spastic paraplegia (HSP) by exome sequencing. HSP is a progressive neurodegenerative disorder and displays genetic and clinical heterogeneity. The major symptoms are muscle weakness and spasticity, especially in the lower extremities. We studied seven affected and seven unaffected family members, as well as a clinically undetermined member, to identify the disease-causing gene. Exome sequencing was performed for four affected and two unaffected individuals. The variants were firstly filtered for HSP-associated genes, and we found a common variant in the ZFYVE27 gene, which has been previously implied for association with HSP. Due to the incompletely penetrant segregation pattern of the ZFYVE27 variant, revealed by Sanger sequencing, with the disease in this family, filtering was re-performed according to the mode of inheritance and allelic frequencies. The resulting 14 rare variants were further evaluated in terms of their cellular functions, and three candidate variants in ATAD3C, VPS16, and MYO1H genes were selected as possible causative variants, which were analyzed for their familial segregation. ATAD3C and VPS16 variants were eliminated due to incomplete penetrance. Eventually, the MYO1H variant NM&#95;001101421.3:c.2972&#95;2974del (p.Glu992del, rs372231088) was found as the possible disease-causing deletion for HSP in this family. This is the first study reporting the possible role of a MYO1H variant in HSP pathogenesis. Further studies on the cellular roles of Myo1h protein are needed to validate the causality of MYO1H gene at the onset of HSP., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction/aims: Motor unit number estimation by F waves (F-MUNE) is an uncommonly used MUNE technique. Our aim in this study was to assess the sensitivity of F-MUNE values elicited with newly developed software in motor neuron diseases., Methods: F waves were recorded by 300 submaximal stimuli from abductor digiti minimi and abductor pollicis brevis muscles of 35 patients with amyotrophic lateral sclerosis, 18 with previous poliomyelitis, and 20 controls. The software determined the surface motor unit action potentials (sMUAPs) and calculated the F-MUNE values. Compound muscle action potential scans were also recorded to obtain MScanFit., Results: The sMUAP amplitudes were higher and F-MUNE values were lower in both muscles of the patients when compared with controls. F-MUNE values could distinguish patients from controls. Significant correlations were found between F-MUNE and MScanFit in the patient groups., Discussion: The new F-MUNE software offered promising results in revealing motor unit loss caused by motor neuron diseases., (© 2022 Wiley Periodicals LLC.)

We investigated how properties of single-fiber action potentials (SFAP) and jitter changed in different recording sites in patients with myopathy and controls. SFAP and jitter were recorded using a disposable single-fiber electrode in the biceps brachii muscle of three patients and controls in two sites: i) near the end-plate zone (EPZ), ii) near the tendon. SFAP and spike duration were longer in patients than in controls. Moving the needle away from the EPZ did not change the electrophysiologic parameters. Longer SFAP duration may reflect slow velocity in muscle fibers and serve as an indicator for small fiber size in myopathy., Competing Interests: Declaration of Competing Interest None of the authors has any conflict of interest to disclose., (Copyright © 2022 Elsevier Masson SAS. All rights reserved.)

Background and Objective: The aim of this study was to evaluate the contribution of extraocular muscle function testing with video-oculography (VOG), which is a noninvasive and easily applicable method of recording eye movement with digital cameras, to the diagnosis of myasthenia gravis (MG) in patients without any clinical eye movement abnormalities., Methods and Materials: The study included 18 patients prediagnosed with ocular MG: MG Group (N = 7) with abnormal, and non-MG Group (N = 11) with normal single-fiber electromyography. Control group included 50 healthy volunteers. Ocular movements were recorded with the EyeSeeCam VOG device., Results: The inward latency of the 10° horizontal saccade and the downward latency of the 10° vertical saccade were significantly delayed; and the downward amplitude of the 10° vertical saccade was significantly lower in the MG group. Receiver operating characteristic curve analyses showed high specificity values for the discrimination of MG patients., Conclusions: This study supports the usefulness of the VOG device in revealing subclinical extraocular muscle involvement in MG., Competing Interests: None

Purpose: To examine upper motor neuron functions comparatively in patients with amyotrophic lateral sclerosis (ALS) and poliomyelitis survivors using transcranial magnetic stimulation (TMS) methods., Methods: Single- and paired-pulse TMS with conventional methods and the triple-stimulation technique were performed by recording from the abductor digiti minimi and abductor pollicis brevis muscles in 31 patients with ALS, 18 patients with poliomyelitis survivors, and 21 controls. Nine patients were diagnosed as having postpoliomyelitis syndrome after a 6-month follow-up., Results: Triple-stimulation technique and some of conventional TMS studies were able to distinguish ALS from both poliomyelitis survivors and controls. A reduced ipsilateral silent period in abductor pollicis brevis muscles was the only parameter to show a significant difference when comparing thenar and hypothenar muscles in ALS. No significant difference was present in any TMS parameters between the postpoliomyelitis syndrome and non-postpoliomyelitis syndrome groups., Conclusions: Conventional TMS and particularly triple-stimulation technique studies are helpful in disclosing upper motor neuron dysfunction in ALS. The results of this study might favor the cortical hypothesis for split hand in ALS, but they revealed no significant indication for upper motor neuron dysfunction in postpoliomyelitis syndrome., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

n-Hexane gives cause to one of the most common toxic polyneuropathies seen in poorly ventilated factories. It is a sensory-motor polyneuropathy ending up with axonal degeneration. Nerve biopsy reveals paranodal axonal swelling and secondary myelin retraction in early stages. Myelin retraction imitates demyelination causing focal conduction block and failure before axonal degeneration emerges. This brings to mind the new category of nodo-paranodopathy described first for anti-ganglioside antibody-mediated neuropathies, which can be proved by electrophysiological re-evaluations. We, herein, discuss the clinical and electrophysiological follow-up of three patients with n-hexane neuropathy and remark overlaps with new concept nodo-paranodopathy.

Background: The purpose of this study was to assess the effectiveness of transcutaneous electrical nerve stimulation (TENS) in chronic low back pain and neuropathic pain., Methods: Seventy-four patients aged 18-65 with chronic low back pain were included in the study. Baseline measurements were performed, and patients were randomized into three groups. The first group received burst TENS (bTENS), the second group conventional TENS (cTENS), and the third group placebo TENS (pTENS), all over 15 sessions. Patients' visual analogue scale (VAS) scores were evaluated before treatment (preT), immediately after treatment (postT), and in the third month after treatment (postT3). Douleur Neuropathique 4 Questions (DN4), the Modified Oswestry Low Back Pain Disability Questionnaire (MOS), the Beck Depression Inventory (BDI), and sympathetic skin response (SSR) values were also evaluated preT and postT3., Results: A statistically significant improvement was observed in mean VAS scores postT compared to preT in all three groups. Intergroup comparison revealed a significant difference between preT and postT values, that difference being assessed in favor of bTENS at multiple comparison analysis. Although significant improvement was determined in neuropathic pain DN4 scores measured at postT3 compared to preT in all groups, there was no significant difference between the groups. No statistically significant difference was also observed between the groups in terms of MOS, BDI, or SSR values at postT3 ( P > 0.05)., Conclusions: bTENS therapy in patients with low back pain is an effective and safe method that can be employed in short-term pain control.

Background: Compound muscle action potential (CMAP) scan and MScanFit have been used to understand the consequences of denervation and reinnervation. This study aimed to monitor these parameters during Wallerian degeneration (WD) after acute nerve transections (ANT)., Methods: Beginning after urgent surgery, CMAP scans were recorded at 1-2 day intervals in 12 patients with ANT of the ulnar or median nerves, by stimulating the distal stump (DS). Stimulus intensities (SI), steps, returners, and MScanFit were calculated. Studies were grouped according to the examination time after ANT. Results were compared with those of 27 controls., Results: CMAP amplitudes and MScanFit progressively declined, revealing a positive correlation with one another. SIs were higher in WD groups than controls. Steps appeared or disappeared in follow-up scans. The late WD group had higher returner% than the early WD and control groups., Conclusions: MScanFit can monitor neuromuscular dysfunction during WD. SIs revealed excitability changes in DS., (© 2020 Wiley Periodicals, Inc.)

Introduction: The objective of this study was to compare the properties of bioelectrical signals of motor units recorded at different sites in the muscles of controls, patients with myopathy and patients with motor neuron disease (MND)., Methods: Five controls, 10 patients with myopathy and 11 patients with MND were included. Electrophysiologic tests were performed in the biceps brachii (BB) muscle from two recording sites. Site 1 was near the belly of the muscle and Site 2 was 5cm distal from Site 1, near the tendon. Multi-motor unit potential (MUP) analysis, jitter analysis, and peak number count were calculated from the signals recorded using a concentric needle electrode (CN)., Results: At Site 2, duration was longer, number of phases was higher and amplitudes were smaller in MUPs compared with those recorded at Site 1. This significant difference between recording site and patient groups was related to neurogenic muscles. Jitter analysis showed no significant difference except an intergroup difference between the patient groups and controls. The peak number calculated using the CN was greater when recorded from Site 1 in concordance with MUP analysis., Conclusion: Duration of MUP was longer and amplitude was smaller when the recording electrode was placed distally along the muscle near the tendon in neurogenic muscles, probably related to increased temporal dispersion. However, changing the position of the needle did not provide further information in distinguishing myogenic muscles., (Copyright © 2020 Elsevier Masson SAS. All rights reserved.)

Objective: To extract insight about the mechanism of repeater F-waves (Frep) by exploring their correlation with electrophysiologic markers of upper and lower motor neuron dysfunction in amyotrophic lateral sclerosis (ALS)., Methods: The correlations of Frep parameters with clinical scores and the results of neurophysiological index (NI), MScanfit MUNE, F/M amplitude ratio (F/M%), single and paired-pulse transcranial magnetic stimulation (TMS), and triple stimulation technique (TST) studies, recorded from abductor digiti minimi (ADM) and abductor pollicis brevis (APB) muscles of 35 patients with ALS were investigated., Results: Frep parameters were correlated with NI and MScanfit MUNE in ADM muscle and F/M% in both muscles. None of the Frep parameters were correlated with clinical scores or TST and TMS measures. While the CMAP amplitudes were similar in the two recording muscles, there was a more pronounced decrease of F-wave persistence in APB, probably heralding the subsequent split hand phenomenon., Conclusion: Our findings suggest that the presence and density of Freps are primarily related to the degree of lower motor neuron loss and show no correlation with any of the relatively extensive set of parameters for upper motor neuron dysfunction., Significance: Freps are primarily related to lower motor neuron loss in ALS., (Copyright © 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Introduction: The objective of this study was to determine compound muscle action potential (CMAP) scan parameters and MScanFit motor unit number estimation (MUNE) in patients with amyotrophic lateral sclerosis (ALS) and to compare the results in the abductor pollicis brevis (APB) to those in the abductor digiti minimi (ADM)., Methods: CMAP scans were recorded from the APB and ADM in 35 patients with ALS and 21 controls. MScanFit MUNE, neurophysiological index (NI), step%, returner%, and D50 were calculated., Results: CMAP scan parameters including the returner%, MScanFit MUNE, and NI can distinguish ALS with high sensitivity and specificity. The electrophysiological parameters, with the exception of D50 (the number of largest consecutive differences of recorded responses generating 50% of maximum CMAP), showed more pronounced changes in the APB than in the ADM, even though most of the patients had normal APB/ADM amplitude ratios., Discussion: CMAP scan parameters and MScanFit MUNE can be used in the evaluation of denervation and reinnervation and may herald the "split hand" in ALS., (© 2019 Wiley Periodicals, Inc.)

Introduction: The present study is an examination of possible subclinical involvement of lower motor neuron (LMN) in patients with primary lateral sclerosis (PLS) and hereditary spastic paraparesis (HSP) electrophysiologically., Methods: Nine PLS patients and 5 HSP patients were prospectively analyzed. Jitter measurement with concentric needle electrode (25 mm, 30 G) (CN-jitter) recorded from right extensor digitorum muscle during voluntary contraction with 1 kHz high-pass frequency filter set. European Myelopathy Score (EMS) was used to evaluate disability. The relationship between disability score and jitter values was investigated., Results: HSP patients had suffered from the disease for longer period of time (p<0.001). Mean jitter values of patients with PLS and HSP were 26.5±12.1 µs and 30.8±34.8 µs, and the number of individual high jitters (>43 microseconds) observed in the PLS and HSP groups was 16/180 and 9/100, respectively without a significant intergroup difference. The ratio of patients with an abnormal jitter study were higher in HSP group (60%) compared to PLS (22%) (p<0.05). Potential pairs with blocking were present in HSP group (7 of 100 potential pairs) but not seen in PLS patients. EMS values were significantly lower in patients having potential pairs with high jitter and blocking compared to those without high jitter and blocking., Conclusion: The present study has demonstrated that early signs of LMN dysfunction can be detected electrophysiologically by CN-jitter in patients with UMN involvement. These electrophysiological findings in these patients with longer disease duration and lower clinical scores may be explained by spreading of the disease to LMNs or transsynaptic degeneration and its contribution in disease progression., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors., (Copyright: © 2020 Turkish Neuropsychiatric Society.)

Introduction: The aim of this study was to define the diagnostic accuracy of concentric needle (CN)-jitter in newly diagnosed myasthenia gravis (MG) patients and to compare CN-jitter with repetitive nerve stimulation., Methods: In 30 MG patients, repetitive nerve stimulation in 4 muscles (orbicularis oculi, nasalis, trapezius and abductor digiti minimi) and CN-jitter of extensor digitorum (ED) and frontalis muscles were evaluated., Results: Twenty-eight of 30 patients (93%) had high jitter in at least one muscle. Repetitive nerve stimulation was abnormal in 23 of the patients (77%). Eighty-six percent of the patients in whom repetitive nerve stimulation test was negative could be diagnosed with CN-jitter. The most frequent muscle showing abnormal decrement was orbicularis oculi. The results of CN-jitter were similar between patients with different serological groups. Of 13 patients with generalized weakness, all had high jitter in both muscles studied whereas of 17 patients only with ocular weakness, 15 had high jitter in at least one muscle studied., Conclusion: Abnormal RNS was present in 77% of newly diagnosed MG patients, being less than CN-jitter (93%) but more than antibody positivity (73.3%)., (Copyright © 2018 Elsevier Masson SAS. All rights reserved.)

Introduction: Electrodiagnostic evaluation provides an important extension to the neurological examination for the evaluation of pediatric neuromuscular disease. Many pediatric neuromuscular diseases are analogous to those seen in the adult. However, the relative frequency of these illnesses varies greatly when different age populations are compared. The purpose of the present study is to provide a retrospective analysis of children referred to our electromyography (EMG) laboratory for electrophysiological examinations., Methods: We retrospectively reviewed electrodiagnostic records of patients aged between 0-15 years, from January 2004 to June 2013. Patients were classified as having plexopathy, nerve root lesions, polyneuropathy, myopathy, mononeuropathy, anterior horn cell disease, neuromuscular transmission disorder, facial nerve palsy, and other rare disorders., Results: We reviewed totally 5563 pediatric records, which was on the average 578 studies per year. It was about 14% of the all EMG examinations performed in our laboratory. When we looked at all the procedures, 3271 of the records included needle EMGs, 170 of them were single fiber EMGs, 100 of them were repetitive nerve stimulations, and 52 of them were evoked potentials. The results were normal in 55% of the cases. As a result of electrophysiological examinations, the common diagnoses were: plexopathy (28.6%), polyneuropathy (7.4%), and myopathy (6.6%) in patients aged 0-5 years (41.2% of all records); myopathy (9.4%), PNP (8.5%), mononeuropathy (6.4%), and plexopathy (5.9%) in 6-10 years (28.2% of all records); PNP (11.3%), myopathy (6.6%), and mononeuropathy (5.6%) in 11-15 years (30.6% of all records)., Conclusion: Infants and toddlers mostly suffered from brachial plexopathy which can be prevented by proper obstetrical management. Nerve conduction studies and EMG yielded diagnostic importance for demyelinating neuropathy and myopathy in patients older than 6 years of age., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors.

Motor unit action potential (MUAP), which consists of individual muscle fiber action potentials (MFAPs), represents the electrical activity of the motor unit. The values of the MUAP features are changed by denervation and reinnervation in neurogenic involvement as well as muscle fiber loss with increased diameter variability in myopathic diseases. The present study is designed to investigate how increased muscle fiber diameter variability affects MUAP parameters in simulated motor units. In order to detect this variation, simulated MUAPs were calculated both at the innervation zone where the MFAPs are more synchronized, and near the tendon, where they show increased temporal dispersion. Reinnervation in neurogenic state increases MUAP amplitude for the recordings at both the innervation zone and near the tendon. However, MUAP duration and the number of peaks significantly increased in a case of myopathy for recordings near the tendon. Furthermore, of the new features, "number of peaks×spike duration" was found as the strongest indicator of MFAP dispersion in myopathy. MUAPs were also recorded from healthy participants in order to investigate the biological counterpart of the simulation data. MUAPs which were recorded near to tendon revealed significantly prolonged duration and decreased amplitude. Although the number of peaks was increased by moving the needle near to tendon, this was not significant., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Introduction: The aim of this study was to re-evaluate jitter values of healthy subjects in whom pairs of single-fiber-like potentials were recorded from voluntary activated periocular muscles using a disposable 37-mm concentric needle electrode (CNE) with 2-kHz low-cut filtering., Methods: We reviewed the recordings of 129 subjects (85 women; 44 men; mean age, 43.8±15.3 years). The m. frontalis group included 116 subjects, and the m. orbicularis oculi group included 18 subjects. Jitter values were expressed as the mean consecutive difference (MCD) of 20 different pairs., Results: The mean MCD (n=2680) was 22.5±9.7 μs (range, 5-121 μs), and the upper 95% confidence limit (CL) was 39 μs. The mean of 134 MCD values for each subject was 22.5±3.7 μs (range, 15-33 μs), and the upper 95% CL was 30 μs. The outer limit of the 18th highest MCD values out of 20 recordings for each subject was 31.3±6.5 μs (range, 18-53 μs), with an upper 95% CL of 43.3 μs., Conclusion: Using a conventional 37-mm CNE with 2-kHz low-cut filtering may be a cost effective alternative to a single-fiber electrode in periocular muscles if strict criteria are used for acceptable signals. Jitter values of >44 μs that were calculated from single-fiber-like action potential pairs should alert the physician regarding the possibility of neuromuscular junction disorders and constitute an indication for a further diagnostic investigation., Competing Interests: Conflict of Interest: No conflict of interest was declared by the authors.

This study was designed to evaluate firing rate variability in patients with upper/lower motor neuron disorders. Twenty healthy subjects and 19 patients with motor neuron disorders participated in the study. Consecutive motor unit action potential pairs from extensor digitorum communis (EDC) muscle were recorded from each subject with trigger-delay line mode. Patients with motor neuron disorders (17.7 ± 10.8 ms) showed significantly higher mean time variability of interpotential interval value than healthy volunteers (10.3 ± 0.1 ms) (p < 0.001).

Purpose: Identification of abnormal motor unit potentials (MUP), in particular those caused by myopathic processes, is generally difficult in facial muscles because the MUPs are already low in amplitude and short in duration. Therefore, quantitative measures for the limits of abnormality are needed more frequently for these muscles, especially for the pathological processes predominantly affecting the craniofacial area. In this study, we aimed to determine some quantitative values that may help us to differentiate "myogenic" and "neurogenic" processes in periocular muscles., Methods: The frontalis muscle was examined unilaterally with multi-MUP and interference pattern analyses in 32 normal subjects, 31 patients with different types of myopathy, and 13 patients with facial palsy. Abnormality limits were calculated by using five previously suggested methods, two of which were based on group means and the other three on determining the outlier values. The sensitivity and specificity of multi-MUP and interference pattern parameters in discriminating abnormal findings by using these different methods were analyzed., Results: Statistically significant differences for all MUP parameters, except for the frequency, was found between the groups (P < 0.001). Motor unit potential duration, size index, and amplitude were the most valuable parameters for distinguishing the individual abnormalities. However, their discriminating power was higher for neuropathies than for myopathies. Interference pattern analysis was found not to have any superior sensitivity to MUP analysis. In this study, the outlier analysis that depends on the 5th to 95th percentile limits of the pooled data provided the best power for the discrimination of both neuropathies and myopathies from normal subjects., Conclusion: Multi-MUP analysis seems to be helpful in differentiating the patients with neurogenic and-to a lesser extent-myogenic facial muscle involvement.

Objectives: The purpose of our study was to show neuromuscular transmission abnormality in the masseter muscle of generalised myasthenia gravis (MG) patients and to compare motor end-plate failure of the masseter with the extensor digitorum communis (EDC) and periocular muscles., Methods: Motor end-plate function was evaluated during voluntary contraction of the masseter muscle of 20 generalised MG patients aged between 16 and 63 years, as well as 20 age-matched healthy volunteers. The mean jitter value was calculated for each group and compared. The upper limit of normal jitter was also calculated and the number of jitters exceeding this cut-off value was counted for each group for comparison. In MG patients, jitter analysis was also performed in periocular and EDC muscles along with the masseter and the number of single fibre-like potentials with abnormal jitter was counted for each muscle. All tests were performed during the same session with a concentric needle electrode (CNE)., Results: For the masseter muscle, the mean jitter of all potential pairs was significantly higher in the patient group (24.7 ± 9.6 μs in healthy volunteers, 71.9 ± 41 μs in patients). The calculated mean jitter for the 18th highest value in healthy volunteers was 33.8 ± 5.9 μs (upper 95% confidence limit was 45.6 μs). The number of abnormal jitters (≥ 46 μs) was significantly higher in the patient group (276 out of 402 jitters) compared to healthy volunteers (10 out of 400 jitters). In the patient group, the number of single fibre-like potentials with abnormal jitter was found to be similar for the masseter, periocular and EDC muscles., Conclusion: The masseter muscle has diagnostic importance in generalised MG. The ratio of high jitters to all of the calculated jitters in a particular muscle was similar for masseter, periocular and EDC muscles., Significance: Jitter analysis of the masseter muscle during voluntary contraction is easy to perform and it was found as informative as other muscles in patients with generalised MG., (Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

In this paper, classification of Juvenile Myoclonic Epilepsy (JME) patients and healthy volunteers included into Normal Control (NC) groups was established using Feed-Forward Neural Networks (NN), Support Vector Machines (SVM), Decision Trees (DT), and Naïve Bayes (NB) methods by utilizing the data obtained through the scanning EMG method used in a clinical study. An experimental setup was built for this purpose. 105 motor units were measured. 44 of them belonged to JME group consisting of 9 patients and 61 of them belonged to NC group comprising ten healthy volunteers. k-fold cross validation was applied to train and test the models. ROC curves were drawn for k values of 4, 6, 8 and 10. 100% of detection sensitivity was obtained for DT, NN, and NB classification methods. The lowest FP number, which was obtained by NN, was 5.

Botulinum toxin prevents acetylcholine release at motor nerve terminals. Group B vitamins (B-vit) are essential for proper nerve function. The present study addresses the question of whether B-vit accelerate recovery in rat skeletal muscle after botulinum toxin A (Btx-A) injection. Forty-four adult male Wistar albino rats were used in this experimental study. Rats were divided into three groups: group 1 rats were given Btx-A injection only, group 2 rats were given B-vit supplementation before Btx-A injection, and group 3 rats were given Btx-A and B-vit injections together. During the experiment, compound muscle action potential (CMAP) of the gastrocnemius muscle was recorded before Btx-A injection and sequentially ten times after toxin injection. The statistical significance of the CMAP amplitude change among the groups was analyzed. All groups showed similar amplitude change between consecutive measurement points. In conclusion, combining Btx-A injection with B-vit supplement does not decrease the efficacy of the toxin.

Objectives: This study was designed to search potential changes in trigemino-facial system in blind subjects by the use of relatively well-established electrophysiological methods. Excitability changes in the motor cortex were also investigated by transcranial magnetic stimulation studies (TMS) with the expectation of finding some abnormal interactions between the cortex and brainstem., Methods: Twenty blind (BS) and 13 control subjects (CoS) were included in the study. Blink reflex and its recovery with paired electrical stimulation were studied at 150, 200, 300, 400 and 500 ms interstimulus intervals (ISI). Facial F waves elicited by buccal branch stimulation were recorded from nasalis muscles. Motor cortex excitability with recordings from left first dorsal interosseus muscle was studied by using magnetically elicited silent periods and paired magnetic stimuli, subthreshold conditioning and suprathreshold test, given at ISIs of 2, 3, 4, 10, 12, 15 and 20 ms., Results: Blink reflex recovery was significantly reduced in BS group comparing to CoS at 400 and 500 ms ISIs. This difference between the groups was more prominent for the responses evoked by the initial stimulation side and faded away with stimulations on the contralateral side. Facial F wave amplitudes and F/M amplitude ratios were higher in BS group. In TMS studies, the early inhibitions at 2 and 4 ms were found to be significantly less in BS as compared to that of CoS., Conclusions: The reduced blink reflex recovery and its fast restoration with continuing stimulation might be explained by conditioning and extinction processes which have been shown to be mainly carried out by cerebellar-brainstem pathways. Our TMS studies showed reduced intracortical inhibition in the motor cortices of BS cases and facial F wave studies revealed the possible effect of this altered excitability on the facial motor nuclei., Significance: Firing probabilities of facial motor neurons in BS are probably determined by the equilibrium between the low-set excitability of blink reflex interneurons and the enhanced excitability brought on by the descending motor pathways., (Copyright © 2011 International Federation of Clinical Neurophysiology. All rights reserved.)

Objectives: To study motor unit number estimation (MUNE) in acutely transected peripheral nerves, and to retest our previous observation which had revealed a discordance between the loss of compound muscle action potential (CMAP) size and decrease in MUNE during Wallerian degeneration., Methods: In eight patients with nine transected median or ulnar nerves, a total of 18 electrophysiological studies were performed before the complete nerve degeneration ensues. CMAP recordings and incremental MUNE studies were performed by stimulation of the nerves at the wrist level and recording from the appropriate hand muscles. The same studies repeated on the contralateral side., Results: Injury side to intact side ratios of the MUNEs were significantly higher than the CMAP ratios. Mean step areas in MUNE studies were found to be lower on the transected sides after 72 hours post-injury., Discussion: These findings support the existence of an electrophysiologically observable asynchrony in neuromuscular synapse dysfunction during Wallerian degeneration.

Objective: To measure normal variability in neuromuscular transmission in the extensor digitorum communis (EDC) muscle voluntarily activated using a disposable monopolar needle electrode (MNPE)., Methods: We examined the EDC muscle using MNPE in 50 healthy volunteers (12 male and 38 female, mean age: 41.5+/-12.9 years, age range: 18-74 years). The high-pass filter setting was 3 kHz., Results: Jitter values are expressed as the mean consecutive difference (MCD) of 20 potential pairs. Mean MCD (n=50) was 21.3+/-3 micros (upper 95% confidence limit (CL): 27.3 micros). Mean MCD in all potential pairs (n=1000) was 21.3+/-6.6 micros (upper 95% CL: 34 micros). Mean MCD for the 18th highest value was 28+/-4.7 micros (upper 95% CL: 37.5 micros)., Conclusion: The suggested practical upper limit for mean MCD was set to 28 micros; for outliers it was 38 micros., Significance: The present study defines the normative value for jitter recorded with disposable MNPE, which is a low-cost alternative for the evaluation of neuromuscular transmission, although certain precautions must be taken., (Copyright 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.)

In this work, a new signal processing method was proposed in order to predict externally applied forces to human hands by deriving a relationship between the surface electromyographic (SEMG) signals and experimentally known forces. This relationship was investigated by analyzing the spectral features of the SEMG signals. SEMG signals were recorded from three subjects during isometric contraction and from another three subjects during anisometric contraction. In order to determine force-SEMG signal relationship, higher order frequency moments (HOFMs) of the signals were calculated and used as characterizing features of SEMG signals. Subsequently, artificial neural networks (ANN) with backpropagation algorithm were trained by using the HOFMs. Root mean square difference (RMSD) between the actual and predicted forces was calculated to evaluate force prediction performance of the ANN. In addition to RMSD, cross-correlation coefficients between actual and predicted force time histories were also calculated for anisometric experiment results. The RMSD values ranged from 0.34 and 0.02 in the isometric contraction experiments. In the anisometric contraction tests, RMSD results were between 0.23 and 0.09 and cross-correlation coefficients ranged from 0.91 to 0.98. In order to compare the performance of the HOFMs with a widely used EMG signal processing technique, root-mean-squared (RMS) values of the EMG signals were also calculated and used to train the ANN as another characterizing feature of the signal. Predicted forces using HOFMs technique were in general closer to the actual forces than those of obtained by using RMS values. The results indicated that the proposed signal processing method showed an encouraging performance for predicting the forces applied to the human hands, and the spectral features of the EMG signal might be used as input parameter for the myoelectric controlled prostheses., (2009 Elsevier Ireland Ltd. All rights reserved.)

In this study, the scanning EMG technique was implemented to investigate electrophysiological cross-sections of the motor unit (MU) territories in healthy volunteers and in subjects with juvenile myoclonic epilepsy and spinal muscular atrophy. Measurements were taken intramuscularly by means of two concentric needle electrodes from biceps brachialis muscles. 3-D maps of the MU territories were plotted for each MU to determine the lengths of MU cross-section and the maximum amplitudes of each MU. There was evidence of a preponderance of large MUs in patients with juvenile myoclonic epilepsy.

Meniscus is a well innervated tissue with four types of receptors. These receptors are mainly concentrated at the anterior and posterior horns. Although they are intended to be a part in reflex arc, this function has not been thoroughly evaluated. We hypothesized that electrical stimulation of the normal meniscus would elicit electromyographic activity of the hamstring muscle via the reflex arc. Five adult domestic male rabbits were used in this study. Under general anesthesia, knee arthrotomy and thigh dissection were done to expose medial meniscus and semimembranosus muscle. Menisci were stimulated by Teflon-coated bipolar needle electrodes. Needles were placed in the posterior horn of the medial menisci. Two Teflon-coated monopolar needle electrodes were placed in semimembranosus muscle. A four-channel electromyograph was used for recording. Two different potentials were recorded from the target muscle. The first response had a very short distal latency and its amplitude was changing in accordance with the strength of the stimulus, suggesting that this response was being elicited by direct muscle stimulation. The second delayed response with less amplitude also appeared in some traces. The latency and the amplitude of this second response were fairly stable stating that this delayed response was being generated by a reflex pathway and seen in all subjects.

Objective: To evaluate the value of single-fibre electromyography (SFEMG) with monopolar electrode (MNPE) in revealing neuromuscular transmission dysfunction., Material and Methods: We examined the extensor digitorum communis muscle by using single-fibre electrode (SFE) and MNPE sequentially, in randomly assigned 20 healthy volunteers and in 17 patients with known myasthenia gravis (MG). The high-pass filter setting was 3 kHz for MNPE. Ten individual jitter values were calculated for each electrode in every muscle. Repetitive nerve stimulation (RNS) test on trapezius muscle was performed on 15 patients., Results: In controls, the mean jitter values were 27 +/- 9 (10-59) micro s with SFE, and 21 +/- 7.2 (9-56) micro s with MNPE (P = 0.001). In the MG group, the mean jitter values were 52.4 +/- 38 (12-221) micro s with SFE, and 51.8 +/- 34.7 (12-179) micro s with MNPE. Both electrodes identified junction dysfunction in 14 patients. RNS revealed decrement in four patients but 11., Conclusion: SFEMG with SFE is still the gold standard; however, SFEMG with MNPE is superior to RNS like SFEMG with SFE.

The decrement pattern at low rates of repetitive nerve stimulation in myasthenia gravis (MG) is characterized by a decrease of compound muscle action potential size within the first 4-5 responses. With subsequent stimuli, compound muscle action potential size either increases or does not change. Following an observation that the pattern of decrement might be different in patients with Lambert-Eaton myasthenic syndrome (LEMS), we retrospectively studied traces from eight LEMS patients and 14 patients with seropositive generalized MG, calculating decrement percent from first to fourth and from first to ninth compound muscle action potential. In the LEMS patients, compound muscle action potential amplitude decreased progressively from first to ninth stimulus at 2, 3 or 5Hz in all traces but one. In contrast, MG patients demonstrated the expected improvement after the initial decrement in all traces except one. In the evaluation of patients suspected of having myasthenia gravis, the finding of progressive decrement pattern at low rates of repetitive nerve stimulation may alert the electromyographer to the possibility of Lambert-Eaton syndrome and prompt the performance of further electrodiagnostic tests.

Objective: To clarify the optimum trace count for jitter calculation., Materials and Methods: Single-fiber electromyography was performed during voluntary contraction (VC-SFEMG) of extensor digitorum muscle in six healthy and five myasthenic subjects. Twenty single-fiber action potential (SFAP) pairs were recorded from each subject. For each pair, 100 consecutive traces were recorded and stored for off-line analysis. Ten different jitters were calculated in 10 consecutive steps for each SFAP pair by increasing the number of traces included to analysis (from 10 to 100). The jitter calculated in each step was compared with that calculated from 100 traces., Results: Sixty was the optimum number of trace count for both myasthenics and normal controls. Using less than 60 traces for jitter calculation revealed lower values., Conclusion: Jitter calculation should be performed from at least 60 traces in VC-SFEMG. Less numbers yield lower jitter and may cause diagnostic error.

Objective: To identify and investigate any dysfunction of neuromuscular transmission in episodic cluster headache., Background: Abnormal neuromuscular transmission has been shown in migraine with aura and in migraine without aura by using single fiber electromyography. Especially for migraine with aura, a genetic cause has been postulated. Episodic cluster headache is a primary headache disorder in which genetic factors may, at times, play a strong role., Methods: Single fiber electromyography during voluntary contraction of the extensor digitorum communis muscle, nerve conduction studies of upper and lower extremities, and concentric needle electromyography of the extensor digitorum communis were performed on 6 patients with episodic cluster headache and 6 age-matched normal controls. Twenty potential pairs were recorded from each subject. Twenty individual jitter values and a mean jitter value were calculated for each subject. Both mean individual jitter values and numbers of abnormal individual jitter values were compared in patients with cluster headache versus normal controls., Results: Three of 6 patients with episodic cluster headache showed pronounced neuromuscular transmission abnormalities by single fiber electromyography. None of the controls had any neuromuscular transmission abnormality. Another patient with episodic cluster headache had borderline dysfunction of neuromuscular transmission. Transmission was clearly normal in only 2 of 6 patients with cluster headache., Conclusion: These results suggest that episodic cluster headache may share the same abnormality of neuromuscular transmission observed in migraine.

Objectives: To determine a new artifact discharge produced from the disposable concentric needle (DCN) electromyography (EMG) electrodes., Methods: We have recorded the activity obtained after the first insertion of 41 DCN (37 mm) and 36 DCN (50 mm) in several muscles during the rest. The number of the patients was 77 (26 males, 51 female)., Results: We observed an artifact discharge (AD) resembling positive sharp waves (PSWs) in 31 patients of 77 insertions. The AD occurred with 18 of 41 insertions of DCN 37 mm and 13 of DCN 50 mm. The artifact resolved when the needle has been moved in the muscle or in the adipose subcutaneous tissue., Conclusion: This AD should be recognized when using DCN electrodes to avoid confusion with PSWs. Recognizing these artifacts during needle EMG is important to avoid false positive results.

In this experimental study, we investigated the varieties of excitability of gastrocnemius muscle via sciatic nerve as per different death models (asphyxia, abundant-bleeding and gradual-bleeding) on rats and the significance for the estimation of postmortem interval was evaluated. For this purpose, the rats were applied different stimulus intensities (5, 20, 40 mA) with 0.1 ms duration, before, during and every 5 min after death, using rectangular impulses, and the mean amplitude, onset latency and area values for each compound muscle action potential (CMAP) were elicited. It was detected that amplitude and area increased and onset latencies prolonged in the first postmortem 15 min. From the 15 min, CMAP area and amplitude showed an ever-increasing decrease and the prolongation of onset latencies became apparent. The decrease rate of area and amplitude was found to be statistically significantly different in asphyxia and abundant-bleeding models compared with in gradual-bleeding model, at 30 min measurements. However, there was not any significant difference in onset latency increase rates of three groups. Separately, any significant correlation between the agony and excitability periods among the groups could not be detected. The fact that the increase rate of onset latency did not show a significant difference as per death models indicated that onset latency ratios would be more appropriate criteria in determination of postmortem interval, regardless the reason of death.

Jitter values are calculated in reference to a triggering potential during single-fiber electromyography (SFEMG) performed during voluntary contraction. When there are more than two single-fiber action potentials (SFAP) and the selected triggering potential is from an abnormal end-plate, all the jitters calculated from the same trace will be affected. In this study, the effect of triggering potential on calculated jitter was investigated in myasthenic and healthy volunteers by switching the triggering potential and recalculating the jitter off-line. Selecting a triggering potential from an abnormal end-plate increased the number of abnormal individual jitters as well as the mean jitter. Therefore, if the equipment software has the capacity to change the trigger potential, the triggering potential should not be from an abnormal end-plate if all possible jitter values are to be calculated for traces having three or more single-fiber potentials. Otherwise, only one jitter value should be included from any one trace to prevent false-positive results., (Copyright 2002 Wiley Periodicals, Inc.)

Surface stimulation for single-fiber electromyography has been proposed previously as a novel technique based on a study performed on healthy subjects. The current study was designed to determine the diagnostic value of surface stimulation single-fiber electromyography in patients with myasthenia gravis. Ten patients with myasthenia gravis were recruited for the study. Surface stimulation of the facial nerve trunk, as well as extramuscular needle stimulation of its zygomatic branch was performed. Twenty single-fiber potentials were recorded from the orbicularis oculi muscle for each stimulation type in each patient. For both stimulation techniques, mean jitter values and the total number of abnormal individual junctions were found to be abnormally high. Jitter values obtained by surface stimulation were comparable with those obtained by needle stimulation.

We used a concentric needle electrode (CNE) with 2 kHZ low-cut filter and a single fiber electrode (SFE) in the same subjects for neuromuscular jitter measurement in the extensor digitorum communis (EDC) and orbicularis oculi (OOc) muscles. At the same session, 20 jitter values were obtained from each subject with each electrode. For EDC (during voluntary contraction), mean jitter values with SFE and CNE were 23.4 +/- 8 micros and 23.3 +/- 8 micros in 10 normals; and 56.8 +/- 28 micros and 57.4 +/- 33 micros in 10 myasthenics. For OOc (during electrical stimulation), mean jitter values with SFE and CNE were 17.9 +/- 5 micros and 16.3 +/- 4 micros in 11 normal subjects, and 41.2 +/- 29 micros and 36.7 +/- 27 micros in 10 myasthenics. For both muscles, the numbers of individual abnormal jitter values with SFE and CNE were highly comparable. Both needles labeled the same patients as having "normal" or "abnormal" neuromuscular transmission. CNE may be an alternative to SFE in neuromuscular jitter analysis., (Copyright 2000 John Wiley & Sons, Inc.)