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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).)

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.)

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

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.

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: 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.

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.

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.