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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).)

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.)