Electrical excitability of cancer cells-CELEX model updated.

The normal functioning of every cell in the body depends on its bioelectric properties and many diseases are caused by genetic and/or epigenetic dysregulation of the underlying ion channels. Metastasis, the main cause of death from cancer, is a complex multi-stage process in which cells break away from a primary tumour, invade the surrounding tissues, enter the circulation by encountering a blood vessel and spread around the body, ultimately lodging in distant organs and reproliferating to form secondary tumours leading to devastating organ failure. Such cellular behaviours are well known to involve ion channels. The CELEX model offers a novel insight to metastasis where it is the electrical excitation of the cancer cells that is responsible for their aggressive and invasive behaviour. In turn, the hyperexcitability is underpinned by concomitant upregulation of functional voltage-gated sodium channels and downregulation of voltage-gated potassium channels. Here, we update the in vitro and in vivo evidence in favour of the CELEX model for carcinomas. The results are unequivocal for the sodium channel. The potassium channel arm is also broadly supported by existing evidence although these data are complicated by the impact of the channels on the membrane potential and consequent secondary effects. Finally, consistent with the CELEX model, we show (i) that carcinomas are indeed electrically excitable and capable of generating action potentials and (ii) that combination of a sodium channel inhibitor and a potassium channel opener can produce a strong, additive anti-invasive effect. We discuss the possible clinical implications of the CELEX model in managing cancer.

How much does clinical prediagnosis correlate with electrophysiological findings?: a retrospective study.

Background: Electrodiagnostic testing (EDX) is important in the diagnosis and follow-up of neuropathic and myopathic diseases. This study aimed to demonstrate the compatibility between clinical prediagnosis and electrophysiological findings. Methods: EDX results from 2004 to 2020 at the physical medicine and rehabilitation (PM&R) clinic were screened. Tests with missing data, reevaluation studies, and cases of peripheral facial paralysis were excluded. The clinical prediagnosis and EDX results were recorded, and their compatibility was evaluated. Results: A total of 2,153 tests were included in this study. The mean age was 49.0±13.9 years and 1,533 of them (71.2%) were female. The most frequently referred clinic was the PM&R clinic (90.0%). Numbness (73.6%) was the most common complaint, followed by pain (15.3%) and weakness (13.9%). The most common prediagnosis was entrapment neuropathy (55.3%), radiculopathy (16.1%), and polyneuropathy (15.7%). Carpal tunnel syndrome was the most frequently identified type of entrapment neuropathy (78.3%). Six hundred and seventy EDX results (31.1%) were within normal limits. While the EDX results were consistent with the prediagnosis in 1,328 patients (61.7%), a pathology different from the prediagnosis was detected in 155 patients (7.2%). In the discrepancy group, the most common pathologies were entrapment neuropathy (51.7%), polyneuropathy (17.3%), and radiculopathy (15.1%). The most common neuropathy type was carpal tunnel syndrome (79.3%). Conclusion: After adequate anamnesis and physical and neurological examinations, requesting further appropriate tests will increase the prediagnosis accuracy and prevent unnecessary expenditure of time and labor.

Electrodiagnostic subtyping in Guillain-Barré syndrome patients in the International Guillain-Barré Outcome Study.

BACKGROUND AND PURPOSE: Various electrodiagnostic criteria have been developed in Guillain-Barré syndrome (GBS). Their performance in a broad representation of GBS patients has not been evaluated. Motor conduction data from the International GBS Outcome Study (IGOS) cohort were used to compare two widely used criterion sets and relate these to diagnostic amyotrophic lateral sclerosis criteria. METHODS: From the first 1500 patients in IGOS, nerve conduction studies from 1137 (75.8%) were available for the current study. These patients were classified according to nerve conduction studies criteria proposed by Hadden and Rajabally. RESULTS: Of the 1137 studies, 68.3% (N = 777) were classified identically according to criteria by Hadden and Rajabally: 111 (9.8%) axonal, 366 (32.2%) demyelinating, 195 (17.2%) equivocal, 35 (3.1%) inexcitable and 70 (6.2%) normal. Thus, 360 studies (31.7%) were classified differently. The areas of differences were as follows: 155 studies (13.6%) classified as demyelinating by Hadden and axonal by Rajabally; 122 studies (10.7%) classified as demyelinating by Hadden and equivocal by Rajabally; and 75 studies (6.6%) classified as equivocal by Hadden and axonal by Rajabally. Due to more strictly defined cutoffs fewer patients fulfilled demyelinating criteria by Rajabally than by Hadden, making more patients eligible for axonal or equivocal classification by Rajabally. In 234 (68.6%) axonal studies by Rajabally the revised El Escorial (amyotrophic lateral sclerosis) criteria were fulfilled; in axonal cases by Hadden this was 1.8%. CONCLUSIONS AND DISCUSSION: This study shows that electrodiagnosis in GBS is dependent on the criterion set utilized, both of which are based on expert opinion. Reappraisal of electrodiagnostic subtyping in GBS is warranted.

Combat-related peripheral nerve injuries.

Active-duty service members (ADSM) and military Veterans represent a population with increased occupational risk for nerve injuries sustained both during training operations and wartime. Mechanisms of war-related nerve injuries have evolved over time, from the musket ball-related traumas described by S.W. Mitchell to complex blast injuries and toxic exposures sustained during Middle East conflicts in the 21st century. Commonly encountered nerve injury etiologies in this population currently include compression, direct trauma, nutritional deficits, traumatic limb amputation, toxic chemical exposures, or blast-related injuries. Expeditious identification and comprehensive, interdisciplinary treatment of combat-associated neuropathies, as well as prevention of these injuries whenever possible is critical to reduce chronic morbidity and disability for service members and to maintain a well-prepared military. However, diagnosis of a combat-associated nerve injury may be particularly challenging due to comorbid battlefield injuries or delayed presentation of neuropathy from military toxic exposures. Advances in imaging for nerve injury, including MRI and ultrasound, provide useful tools to compliment EMG in establishing a diagnosis of combat-associated nerve injury, particularly in the setting of anatomic disruption or edema. Surgical techniques can improve pain control or restoration of function. In all cases, comprehensive interdisciplinary rehabilitation provides the best framework for optimization of recovery. Further work is needed to prevent combat-associated nerve injuries and promote nerve recovery following injury.

Refining quality measures for electrodiagnostic testing in suspected carpal tunnel syndrome to account for acceptable variations in practice: Expert review process.

INTRODUCTION/AIMS: Using a set of process-of-care quality measures for electrodiagnostic testing in suspected carpal tunnel syndrome (CTS), the research team previously documented large variations in electrodiagnostic testing practices and adherence to quality measures. This study sought to enhance the applicability and validity of the quality measures by integrating acceptable variations in testing practices. METHODS: We recruited 13 expert electrodiagnostic medicine specialists from five specialty societies. The experts iteratively refined five quality measures, and then rated the validity of the refined quality measures (1-9 scale). During this process, the experts reviewed data on adherence to existing quality measures and variations in electrodiagnostic testing practices, and considered recently published quality measures from the American Association of Neuromuscular and Electrodiagnostic Medicine. RESULTS: Three quality measures (electrodiagnostic testing before surgery for CTS, temperature assessment during electrodiagnostic testing, and electrodiagnostic criteria for severe median neuropathy) underwent few refinements and were rated valid (medians 8-9). Two measures (essential components of electrodiagnosis, criteria for interpreting electrodiagnostic tests as median neuropathy) were judged valid (medians 8) after revisions. For these measures, experts' ratings on the recommended components of sensory or mixed nerve conduction studies varied: agreement among the experts about the use of sensory peak latency was greater than for onset latency or sensory velocity. DISCUSSION: This study produced quality measures that provide minimum standards for electrodiagnostic testing for suspected CTS that are more comprehensive and nuanced than prior versions. Future work can assess the feasibility, reliability, and validity of these refined measures in diverse physician practices.

Fibular (peroneal) neuropathy.

Fibular neuropathy has variable presenting features depending on the site of the lesion. Anatomical features make it susceptible to injury from extrinsic factors, particularly the superficial location of the nerve at the head of the fibula. There are many mechanisms of compression or other traumatic injury of the fibular nerve, as well as entrapment and intrinsic nerve lesions. Intraneural ganglion cysts are increasingly recognized when the mechanism of neuropathy is not clear from the medical history. Electrodiagnostic testing can contribute to the localization as well as the characterization of the pathologic process affecting the nerve. When the mechanism of injury is unclear from the analysis of the presentation, imaging with MRI and ultrasound may identify nerve lesions that warrant surgical intervention. The differential diagnosis of foot drop includes fibular neuropathy and other neurologic conditions, which can be distinguished through clinical and electrodiagnostic assessment. Rehabilitation measures, including ankle splinting, are important to improve function and safety when foot drop is present. Fibular neuropathy is less frequently painful than many other nerve lesions, but when it is painful, neuropathic medication may be required. Failure to spontaneously recover or the detection of a mass lesion may require surgical management.

[Cutting edge of diagnosis and treatment for chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) based on the EAN/PNS guideline 2021].

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a most common chronic immune-mediated demyelinating neuropathy, and includes a number of clinical subtypes. The major phenotype is "typical CIDP", which is characterized by symmetric polyneuropathy and "proximal and distal" muscle weakness. During the historical changes in the concept of CIDP, multifocal motor neuropathy, anti-myelin-associated glycoprotein (MAG) neuropathy, and autoimmune nodopathy have been excluded. Currently CIDP is considered as a syndrome including typical CIDP and CIDP variant such as distal CIDP and multifocal CIDP. In 2021, the international guideline of diagnosis and treatment for CIDP, European Academy of Neurology (EAN)/Peripheral Nerve Society (PNS) Guideline, was published. This review article introduces the putline of the guideline with medical-social situation in Japan. The diagnosis of CIDP is based on (1) phenotype of typical CIDP or variant, (2) electrophysiologic evidence of peripheral nerve demyelination, and (3) exclusion criteria. The first-line treatments are corticosteroids or immunoglobulin therapy, and plasma exchange should be considered if the 2 treatments were not effective sufficiently. This guideline recommends intravenous or subcutaneous immunoglobulin as a maintenance therapy, and suggests other immune-suppressive agents. In the near future, new treatment with biologics, such as monoclonal antibodies against neonatal Fc receptors, complements, and CD19/20 will be approved.

Surface Electromyography in Dentistry-Past, Present and Future.

Surface electromyography (sEMG) is a technique for measuring and analyzing the electrical signals of muscle activity using electrodes placed on the skin's surface. The aim of this paper was to outline the history of the development and use of surface electromyography in dentistry, to show where research and technical solutions relating to surface electromyography currently lie, and to make recommendations for further research. sEMG is a diagnostic technique that has found significant application in dentistry. The historical section discusses the evolution of sEMG methods and equipment, highlighting how technological advances have influenced the accuracy and applicability of this method in dentistry. The need for standardization of musculoskeletal testing methodology is highlighted and the needed increased technical capabilities of sEMG equipment and the ability to specify parameters (e.g., sampling rates, bandwidth). A higher sampling rate (the recommended may be 2000 Hz or higher in masticatory muscles) allows more accurate recording of changes in the signal, which is essential for accurate analysis of muscle function. Bandwidth is one of the key parameters in sEMG research. Bandwidth determines the range of frequencies effectively recorded by the sEMG system (the recommended frequency limits are usually between 20 Hz and 500 Hz in masticatory muscles). In addition, the increased technical capabilities of sEMG equipment and the ability to specify electromyographic parameters demonstrate the need for a detailed description of selected parameters in the methodological section. This is necessary to maintain the reproducibility of sEMG testing. More high-quality clinical trials are needed in the future.

Role of Electrodiagnostic Modalities in Detection of Nasal Septal Deviation.

Nasal Septal Deviation (NSD) is a common sign in otorhinolaryngology that can lead to facial asymmetry. In this case-control observational study, we assessed the role of EMG and NCS in the diagnosis of NSD and its effect on neuromuscular function. Participants were divided into two groups based on paranasal sinus computed tomography scan (PNS CT) results: NSD cases (n = 21) and controls without NSD (n = 13). EMG and NCS were performed on both groups to assess nasal alar muscles at the root of the zygomatic nerve. Our findings showed a significant correlation between NSD and EMG/NCS tests (P-value = 000) and a significant association between septal deviation and nasal alar lateralization (P-value = 000). EMG/NCS can be useful in assessing NSD by providing a better understanding of related neuromuscular structures and neuromuscular function of the nasal alar dilator muscles and aid in the diagnosis of NSD. Nasal Septal Deviation, EMG (electromyography), NCS (nerve conduction studies), Neuromuscular function, Facial asymmetry, Otorhinolaryngology, Paranasal sinus, Computed tomography, Nasal alar muscles, Zygomatic nerve, Nasal Obstruction, Nasal alar lateralization, Diagnosis.

Electrodiagnostic studies and new diagnostic modalities for evaluation of peripheral nerve disorders.

Electrodiagnostic studies (EDx) are frequently performed in the diagnostic evaluation of peripheral nerve disorders. There is increasing interest in the use of newer, alternative diagnostic modalities, in particular imaging, either to complement or replace established EDx protocols. However, the evidence to support this approach has not been expansively reviewed. In this paper, diagnostic performance data from studies of EDx and other diagnostic modalities in common peripheral nerve disorders have been analyzed and described, with a focus on radiculopathy, plexopathy, compressive neuropathies, and the important neuropathy subtypes of Guillain-Barré syndrome, chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), vasculitic neuropathy and diabetic neuropathy. Overall EDx retains its place as a primary diagnostic modality in the evaluated peripheral nerve disorders. Magnetic resonance imaging and ultrasound have developed important complementary diagnostic roles in compressive and traumatic neuropathies and atypical CIDP, but their value is more limited in other neuropathy subtypes. Identification of hourglass constriction in nerves of patients with neuralgic amyotrophy may have therapeutic implications. Investigation of radiculopathy is confounded by poor correlation between clinical features and imaging findings and the lack of a diagnostic gold standard. There is a need to enhance the literature on the utility of these newer diagnostic modalities.

Serial electrodiagnostic testing: Utility and indications in adult neurological disorders.

Although existing guidelines address electrodiagnostic (EDX) testing in identifying neuromuscular conditions, guidance regarding the uses and limitations of serial (or repeat) EDX testing is limited. By assessing neurophysiological change longitudinally across time, serial electrodiagnosis can clarify a diagnosis and potentially provide valuable prognostic information. This monograph presents four broad indications for serial electrodiagnosis in adult peripheral neurological disorders. First, where clinical change has raised suspicion for a new or ongoing lesion, EDX reassessment for spatial spread of abnormality, involvement of previously normal muscle or nerve, and/or evolving pathophysiology can clarify a diagnosis. Second, where diagnosis of a progressive neuromuscular condition is uncertain, electrophysiological data from a second time point can confirm or refute suspicion. Third, to establish prognosis after a static nerve injury, a repeat study can assess the presence and extent of reinnervation. Finally, faced with a limited initial study (as when complicated by patient or environmental factors), a repeat EDX study can supplement missing or limited data to provide needed clarity. Repeat EDX studies carry certain limitations, however, such as with prognostication in the setting of remote or chronic lesions, sensory predominant fascicular injury, or mild axonal injury. Nevertheless, serial electrodiagnosis remains a valuable and underused tool in the diagnostic and prognostic evaluation of neuromuscular conditions.

Neuromuscular consequences of spinal cord injury: New mechanistic insights and clinical considerations.

The spinal cord facilitates communication between the brain and the body, containing intrinsic systems that work with lower motor neurons (LMNs) to manage movement. Spinal cord injuries (SCIs) can lead to partial paralysis and dysfunctions in muscles below the injury. While traditionally this paralysis has been attributed to disruptions in the corticospinal tract, a growing body of work demonstrates LMN damage is a factor. Motor units, comprising the LMN and the muscle fibers with which they connect, are essential for voluntary movement. Our understanding of their changes post-SCI is still emerging, but the health of motor units is vital, especially when considering innovative SCI treatments like nerve transfer surgery. This review seeks to collate current literature on how SCI impact motor units and explore neuromuscular clinical implications and treatment avenues. SCI reduced motor unit number estimates, and surviving motor units had impaired signal transmission at the neuromuscular junction, force-generating capacity, and excitability, which have the potential to recover chronically, yet the underlaying mechanisms are unclear. Furthermore, electrodiagnostic evaluations can aid in assessing the health lower and upper motor neurons, identify suitable targets for nerve transfer surgeries, and detect patients with time sensitive injuries. Lastly, many electrodiagnostic abnormalities occur in both chronic and acute SCI, yet factors contributing to these abnormalities are unknown. Future studies are required to determine how motor units adapt following SCI and the clinical implications of these adaptations.

A Proposal for Neurography Referral in Patients with Carpal Tunnel Syndrome Based on Clinical Symptoms and Demographic Variables of 797 Patients.

The clinical manifestation of median nerve entrapment at the carpal tunnel level is known as carpal tunnel syndrome (CTS). Electroneurography (ENG) is considered the gold standard in CTS evaluation. We conducted a retrospective study and analyzed some clinical and demographic variables, relating them to the degree of neuropathy using ENG, to better understand the role of ENG in this very common disease. We studied 816 patients referred to our service for neurographic evaluation. Their symptoms were classified as compatible with CTS (cCTS) (n = 646) and atypical for CTS (aCTS) (n = 170). A blind ENG was performed on 797 patients. Patient characteristics were coded as variables and analyzed to study whether they could predict neuropathy severity (sensory and motor involvement or grade ≥ 3 in our classification). We found a correlation between typical symptomatology, age over 50 years, male gender, positivity of Phalen's maneuver and Tinel's sign, and a neuropathy grade ≥ 3. We also found a correlation with CTS in the contralateral hand if the other hand showed neuropathy, despite the lack of symptoms in this hand. We propose a practical algorithm for ENG referral based on clinical symptoms, demographic factors, and neurophysiological variables.

Electrodiagnostic reporting preferences of referring physicians: An exploratory survey.

INTRODUCTION/AIMS: Electrodiagnostic (EDX) studies play a crucial role in the evaluation of patients with peripheral nervous system disorders. Accurate and succinct communication of test results is critical to patient safety and clinical decision-making. The objective of this study was to explore EDX reporting preferences of referring physicians to improve quality of communication and patient care. METHODS: An online survey was developed, and a purposive sampling strategy was used to recruit physicians in the authors' professional networks. Quantitative and qualitative survey data underwent frequency and thematic analyses, respectively. RESULTS: There were 40 respondents, including: 21 non-surgical specialists, 12 surgical specialists, and 7 family physicians. Sections rated as most critical were diagnostic impression (97%) and summary/interpretation (72%). Only 18% reported numeric data as critical to their needs, preferring this data to be formatted as bullet points or tables without nerve conduction study waveforms. Regarding the format of the data summary and diagnostic impression sections, the majority of respondents preferred bullet points rather than paragraphs. DISCUSSION: The results of this exploratory survey suggest that physicians who refer patients for EDX studies prefer reports that emphasize the interpretation of EDX data and a clear diagnostic impression, particularly in bullet point format. This project highlights important preferences and how they compare to recommended reporting guidelines, which may help improve communication and ultimately patient care. Future efforts should explore larger sample sizes with all key stakeholders in the EDX process to better understand reporting styles and preferences with greater nuance and context.

Electrodiagnostic methods to verify Guillain-Barré syndrome subtypes in Istanbul: A prospective multicenter study.

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.

Comparison of electrodiagnostic findings in acute traumatic versus chronic non-traumatic ulnar neuropathy at the elbow.

INTRODUCTION/AIMS: A common concept is that traumatic nerve injuries are more likely axonal, and that compressive neuropathies are more likely demyelinating. The purpose of this study was to compare traumatic versus non-traumatic ulnar neuropathy at the elbow (UNE) to look for electrodiagnostic differences between the two groups. METHODS: A retrospective 3 year review of UNE patients at two academic health science centers was conducted. Patients were grouped into acute traumatic UNE versus chronic non-traumatic UNE based on clinical history. Electrodiagnostic measurements were compared between the two groups. RESULTS: There were 50 subjects with acute traumatic UNE and 41 with chronic non-traumatic UNE. Mean age and sex distribution were similar but those with traumatic UNE had a 7 month duration of symptoms, while those with chronic UNE had 29 month duration (p < .001). All electrodiagnostic measurements were similar between the two groups including compound muscle action potential amplitudes, motor conduction velocities, frequency of conduction block, sensory nerve studies, and needle electromyography. DISCUSSION: We did not find a difference between the two groups. One should not make inferences regarding acuity or etiology based on electrodiagnostic features alone.

Electrodiagnostic findings in amyotrophic lateral sclerosis: Variation with region of onset and utility of thoracic paraspinal muscle examination.

INTRODUCTION/AIMS: Limited data exist regarding variation of electrodiagnostic (EDX) findings in amyotrophic lateral sclerosis (ALS) patients with different onset regions and specificity of thoracic paraspinal muscle (TPSP) examination for confirming a diagnosis of ALS. We aimed to demonstrate the variation of EDX features and characterize the utility of TPSP muscle examination in the electrodiagnosis of ALS. METHODS: This is a retrospective study of a large cohort of ALS patients who had a comprehensive EDX evaluation. RESULTS: The study included 448 patients; all fulfilled the Gold Coast criteria for ALS. The average age at the time of EDX study was 64 years, and 41.1% were women. The onset region was identified as follows: bulbar (N = 149), cervical (N = 127), lumbosacral (N = 162), and other (N = 10). In contrast to limb onset, bulbar-onset patients more frequently demonstrated a pattern of normal or near normal needle electromyography (EMG) (p < .0001) and less frequently had abnormalities on EMG of TPSP (p = .002). Clinical or EDX diagnosis of sensory polyneuropathy was present in 12.6% patients, more frequently in the lumbosacral onset subgroup (p < .03). EMG showed active denervation in 9.6% and chronic denervation in 59% of craniobulbar muscles examined, without observed difference among different onset regions. TPSP showed higher frequencies of active and chronic denervation in ALS than a group of patients with non-ALS neuromuscular disorders. DISCUSSION: EDX features may differ among ALS patients of different onset regions. TPSP EMG is highly useful in differentiating ALS from non-ALS neuromuscular disorders while the yield of craniobulbar muscles, especially for active denervation, is low.

Training factors that influence electrodiagnostic medicine knowledge.

INTRODUCTION/AIMS: Self-assessment examinations (SAEs) help trainees assess their progress in education. SAEs also provide feedback to training programs as to how factors in training influence examination performance. This study's goal was to examine the relationship between the number of months of training in electrodiagnostic (EDx) medicine, the number of EDx studies during training, and scores on the American Association of Neuromuscular and Electrodiagnostic Medicine SAE. METHODS: This was a retrospective study of the 2023 AANEM-SAE results. In addition to the examination score, participants were asked approximately how many EDx studies they performed in training and how many months of training they had completed. Analysis included correlation of the examination scores with months of training as well as number of EDx studies. In addition, a multivariate linear regression model was developed. RESULTS: A total of 756 participants completed the proctored examination in May 2023. Examination score was moderately and positively correlated with the number of months of training (Pearson r = .5; p < .001) as well as the number of EDx studies during training (Pearson r = .55; p < .001). Scores steadily improved with additional months of training, but leveled off after 300-400 EDx studies. Regression analysis indicated that higher numbers of EDx studies were correlated with a higher examination score even after accounting for the number of months of study. DISCUSSION: We believe that a greater number of months of training is associated with better performance on the AANEM-SAE and that greatest improvement in examination performance occurs during the first 300-400 EDx studies.

What is the Next Step after an Electrodiagnostic Study in Children with Polyneuropathies? Rationale for Laboratory and Other Diagnostic Tests.

The etiology of polyneuropathies varies in the pediatric population, where hereditary or metabolic disorders are far more common than in adults. However, treatable polyneuropathies, also prevalent in these settings, are those to prioritize. Moreover, diagnosing subacute and chronic symptoms in children can be challenging compared to adults. Therefore, selecting the best and most relevant laboratory investigations and paraclinical studies is critical. This taskcan be relatively challenging in countries with limited resources or insurance coverage. This study describe the various types of polyneuropathies found in children and their characteristics and suggest an algorithm for using the best laboratory tests in the context of the Iranian healthcare system.

Elastosonography and electrodiagnosis in relation to symptomatic and functional grading of carpal tunnel syndrome.

Objectives: This study focused on the symptomatic and the functional evaluation in correlations to median nerve elasticity, its ultrasound parameters, and the electrodiagnostic grading of primary carpal tunnel syndrome (CTS) patients. Patients and methods: In the case-control study, 100 wrists of 57 CTS patients (54 females, 3 males; mean age: 39±9.8 years; range, 20 to 60 years) clinically diagnosed according to the American Academy of Neurology Clinical Diagnostic Criteria were evaluated between December 2019 and December 2020. The control group included 110 nondiseased wrists of 55 sex- and age-matched healthy subjects (males 7, females 48; mean age: 35.7±10.3 years; range 20 to 58 years). Functional assessment using Hi-Ob-Db clinical scale, electrodiagnosis, ultrasonographic screening, and elasticity evaluation were done for all patients. Results: CTS patients had an increased stiffness of the median nerve compared to controls. Functional stages were positively correlated with the ultrasonographic parameters and the electrodiagnostic stages of CTS. The elastogram of clinically diagnosed patients was revealed more stiffness of the MN, with negative electrodiagnosis results. Conclusion: Clinically diagnosed CTS could be missed by the electrodiagnosis but then properly figured by ultrasonography and potentially graded by sonoelastography. Sonoelastography may be an effective method for early diagnosis and appropriate grading of CTS.