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Background/Objectives: Increasing evidence shows an involvement of brain plasticity mechanisms in both motor and central manifestations of neuromuscular disorders (NMDs). These mechanisms could be specifically addressed with neuromodulation or rehabilitation protocols. The aim of this scoping review is to summarise the evidence on plasticity mechanisms' involvement in NMDs to encourage future research. Methods: A scoping review was conducted searching the PubMed and Scopus electronic databases. We selected papers addressing brain plasticity and central nervous system (CNS) studies through non-invasive brain stimulation techniques in myopathies, muscular dystrophies, myositis and spinal muscular atrophy. Results: A total of 49 papers were selected for full-text examination. Regardless of the variety of pathogenetic and clinical characteristics of NMDs, studies show widespread changes in intracortical inhibition mechanisms, as well as disruptions in glutamatergic and GABAergic transmission, resulting in altered brain plasticity. Therapeutic interventions with neurostimulation techniques, despite being conducted only anecdotally or on small samples, show promising results; Conclusions: despite challenges posed by the rarity and heterogeneity of NMDs, recent evidence suggests that synaptic plasticity may play a role in the pathogenesis of various muscular diseases, affecting not only central symptoms but also strength and fatigue. Key questions remain unanswered about the role of plasticity and its potential as a therapeutic target. As disease-modifying therapies advance, understanding CNS involvement in NMDs could lead to more tailored treatments. [ABSTRACT FROM AUTHOR]

The reactivity of an electroencephalogram (EEG) to external stimuli is impaired in comatose patients showing burst-suppression (BS) patterns following hypoxic–ischemic brain injury (HIBI). We explored the reactivity of BS induced by isoflurane in rat models of HIBI and controls using intermittent photic stimulation (IPS) delivered to one eye. The relative time spent in suppression referred to as the suppression ratio (SR) was measured on the contralateral fronto-occipital cortical EEG channel. The BS reactivity (BSR) was defined as the decrease in the SR during IPS from the baseline before stimulation (SRPRE). We found that BSR increased with SRPRE. To standardize by anesthetic depth, we derived the BSR index (BSRi) as BSR divided by SRPRE. We found that the BSRi was decreased at 3 days after transient global cerebral ischemia in rats, which is a model of brain injury after cardiac arrest. The BSRi was also reduced 2 months after experimental perinatal asphyxia in rats, a model of birth asphyxia, which is a frequent neonatal complication in humans. Furthermore, Oxytocin attenuated BSRi impairment, consistent with a neuroprotective effect in this model. Our data suggest that the BSRi is a promising translational marker in HIBI which should be considered in future neuroprotection studies. [ABSTRACT FROM AUTHOR]

Over the past three decades, substantial advancements have occurred in non-invasive brain stimulation (NIBS). These developments encompass various non-invasive techniques aimed at modulating brain function. Among the most widely utilized methods today are transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES), which include direct- or alternating-current transcranial stimulation (tDCS/tACS). In addition to these established techniques, newer modalities have emerged, broadening the scope of non-invasive neuromodulation approaches available for research and clinical applications in movement disorders, particularly for Parkinson's disease (PD) and, to a lesser extent, atypical Parkinsonism (AP). All NIBS techniques offer the opportunity to explore a wide range of neurophysiological mechanisms and exert influence over distinct brain regions implicated in the pathophysiology of Parkinsonism. This paper's first aim is to provide a brief overview of the historical background and underlying physiological principles of primary NIBS techniques, focusing on their translational relevance. It aims to shed light on the potential identification of biomarkers for diagnostic and therapeutic purposes, by summarising available experimental data on individuals with Parkinsonism. To date, despite promising findings indicating the potential utility of NIBS techniques in Parkinsonism, their integration into clinical routine for diagnostic or therapeutic protocols remains a subject of ongoing investigation and scientific debate. In this context, this paper addresses current unsolved issues and methodological challenges concerning the use of NIBS, focusing on the importance of future research endeavours for maximizing the efficacy and relevance of NIBS strategies for individuals with Parkinsonism. [ABSTRACT FROM AUTHOR]

The NeuroAnalyst role is relatively new with the NA-CLTM credential first becoming available in 2021. Many institutions express interest in utilizing this new role in neurodiagnostic departments, but there is a relative dearth of information about the benefits and challenges of developing a NeuroAnalyst role to support clinical neurophysiologists. The aim of this article is to share the positive experience of one institution in developing a team of NeuroAnalysts. The addition of the role can decrease EEG report turnaround time and balance the workload of clinical neurophysiologists, which improves patient care and allows physicians to increase productivity in other ways [ABSTRACT FROM AUTHOR]

Main Topic: Artificial Intelligence and Digitalization: Applications to Neurosurgery and Neuroradiology. On behalf of the SSNS and SSNR, we are pleased to present the Abstracts of the Joint Annual Meeting, which is held at the Congress Kursaal Interlaken, Switzerland, 20–21 June 2024. In total, 62 abstracts were selected, of which 19 abstracts are oral presentations and 43 abstracts are for ePoster. We congratulate all the presenters on their research work and contribution. [ABSTRACT FROM AUTHOR]

On behalf of the SNS, we are pleased to present the Abstracts of the Annual Meeting which is held at the Congress Center in Basel, Switzerland, from 6–7 June 2024. In total, 83 abstracts were selected, whereof we include 8 abstracts for the Plenary Sessions, 6 abstracts for the SAYN GemSession, 30 abstracts for Poster flash presentations, and 39 abstracts as ePosters. We congratulate all the presenters on their research work and contributions. [ABSTRACT FROM AUTHOR]

Background: Clinical neurophysiology (CNP) involves the use of neurophysiological techniques to make an accurate clinical diagnosis, to quantify the severity, and to measure the treatment response. Despite several studies showing CNP to be a useful diagnostic tool in Movement Disorders (MD), its more widespread utilization in clinical practice has been limited. Objectives: To better understand the current availability, global perceptions, and challenges for implementation of diagnostic CNP in the clinical practice of MD. Methods: The International Parkinson and Movement Disorders Society (IPMDS) formed a Task Force on CNP. The Task Force distributed an online survey via email to all the members of the IPMDS between August 5 and 30, 2021. Descriptive statistics were used for analysis of the survey results. Some results are presented by IPMDS geographical sections namely PanAmerican (PAS), European (ES), African (AFR), Asian and Oceanian (AOS). Results: Four hundred and ninety‐one IPMDS members (52% males), from 196 countries, responded. The majority of responders from the AFR (65%) and PAS (63%) sections had no formal training in diagnostic CNP (40% for AOS and 37% for ES). The most commonly used techniques are electroencephalography (EEG) (72%) followed by surface EMG (71%). The majority of responders think that CNP is somewhat valuable or very valuable in the assessment of MD. All the sections identified "lack of training" as one of the biggest challenges for diagnostic CNP studies in MD. Conclusions: CNP is perceived to be a useful diagnostic tool in MD. Several challenges were identified that prevent widespread utilization of CNP in MD. [ABSTRACT FROM AUTHOR]

The clinical neurophysiological tests allow us to determine the type, extent, and nature of brachial plexus damage. They are crucial in decision making regarding surgical procedures or conservative treatment. This report aimed to present an algorithm for rehabilitation procedures in patients with brachial plexus injury of various origins based on the results of neurophysiology findings for the selection of procedures supporting the process of nerve and muscle regeneration. The research group consisted of patients whose medical documentation was analysed concerning the reason, level, and localization of damage to the brachial plexus structures, surgical and or rehabilitative treatment, as well as the MRI results. Among the group of fourteen patients, the clinical studies showed the greatest incidence of brachial plexus injuries of the mixed (both pre- and postganglionic), all trunks, and cervical root injuries, respectively. Results of the motor evoked potentials (MEP) and electroneurography (ENG) recordings induced at levels of spinal roots and Erb's point showed a decrease of more than 40% in amplitudes on the symptomatic side in comparison to the asymptomatic side. This diffeence was recorded for the axillary and radial innervation and the C5, C6, and C7 root domains, ranging from 57% to 66%; the lowest decrease was recorded following electrical stimulation at Erb's point for the ulnar nerve (34%). The latency prolongation on the symptomatic side in CMAP and MEP tests ranged from 0.2 to 1.7 ms, with the most following magnetic stimulation of the C5 cervical root for the axillary innervation. Most of the results indicated the axonotmesis and neuropraxia type of injury in motor fibers (40%) confirmed by EMG results. The sensory conduction studies (SNCS) in distal nerve branches did not confirm the severe advancement of the brachial plexus injury (63%). The proposed algorithm of the physiotherapeutic procedures should be mainly targeted for recovery of motor dysfunction as the consequence of brachial plexus injury. Rehabilitation should incorporate the treatment supporting nerve regeneration, muscle strengthening, and maintaining functional ranges of motion of the injured extremities. The rehabilitation treatment for patients with brachial plexus injuries is an individualised process, and the selection of procedures and the effectiveness of the treatment undertaken should be confronted with results of neurophysiological tests verifying the motor neural transmission from the level of the cervical motor centre to the effector, peripheral nerve function, and muscle's motor unit activity. [ABSTRACT FROM AUTHOR]

We proposed that the brain's electrical activity is composed of a sequence of alternating states with repeating topographic spectral distributions on scalp electroencephalogram (EEG), referred to as oscillatory macrostates. The macrostate showing the largest decrease in the probability of occurrence, measured as a percentage (reactivity), during sensory stimulation was labelled as the default EEG macrostate (DEM). This study aimed to assess the influence of awareness on DEM reactivity (DER). We included 11 middle cerebral artery ischaemic stroke patients with impaired awareness having a median Glasgow Coma Scale (GCS) of 6/15 and a group of 11 matched healthy controls. EEG recordings were carried out during auditory 1 min stimulation epochs repeating either the subject's own name (SON) or the SON in reverse (rSON). The DEM was identified across three SON epochs alternating with three rSON epochs. Compared with the patients, the DEM of controls contained more posterior theta activity reflecting source dipoles that could be mapped in the posterior cingulate cortex. The DER was measured from the 1 min quiet baseline preceding each stimulation epoch. The difference in mean DER between the SON and rSON epochs was measured by the salient EEG reactivity (SER) theoretically ranging from −100% to 100%. The SER was 12.4 ± 2.7% (Mean ± standard error of the mean) in controls and only 1.3 ± 1.9% in the patient group (P < 0.01). The patient SER decreased with the Glasgow Coma Scale. Our data suggest that awareness increases DER to SON as measured by SER. [ABSTRACT FROM AUTHOR]

Background/Objectives: Increasing evidence shows an involvement of brain plasticity mechanisms in both motor and central manifestations of neuromuscular disorders (NMDs). These mechanisms could be specifically addressed with neuromodulation or rehabilitation protocols. The aim of this scoping review is to summarise the evidence on plasticity mechanisms’ involvement in NMDs to encourage future research. Methods: A scoping review was conducted searching the PubMed and Scopus electronic databases. We selected papers addressing brain plasticity and central nervous system (CNS) studies through non-invasive brain stimulation techniques in myopathies, muscular dystrophies, myositis and spinal muscular atrophy. Results: A total of 49 papers were selected for full-text examination. Regardless of the variety of pathogenetic and clinical characteristics of NMDs, studies show widespread changes in intracortical inhibition mechanisms, as well as disruptions in glutamatergic and GABAergic transmission, resulting in altered brain plasticity. Therapeutic interventions with neurostimulation techniques, despite being conducted only anecdotally or on small samples, show promising results; Conclusions: despite challenges posed by the rarity and heterogeneity of NMDs, recent evidence suggests that synaptic plasticity may play a role in the pathogenesis of various muscular diseases, affecting not only central symptoms but also strength and fatigue. Key questions remain unanswered about the role of plasticity and its potential as a therapeutic target. As disease-modifying therapies advance, understanding CNS involvement in NMDs could lead to more tailored treatments.

Background: Dementia and mild cognitive impairment are characterised by symptoms of cognitive decline, which are typically assessed using neuropsychological assessments (NPAs), such as the Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB). Magnetoencephalography (MEG) is a novel clinical assessment technique that measures brain activities (summarised as oscillatory parameters), which are associated with symptoms of cognitive impairment. However, the relevance of MEG and regional cerebral blood flow (rCBF) data obtained using single-photon emission computed tomography (SPECT) has not been examined using clinical datasets. Therefore, this study aimed to investigate the relationships among MEG oscillatory parameters, clinically validated biomarkers computed from rCBF, and NPAs using outpatient data retrieved from hospital records. Methods: Clinical data from 64 individuals with mixed pathological backgrounds were retrieved and analysed. MEG oscillatory parameters, including relative power (RP) from delta to high gamma bands, mean frequency, individual alpha frequency, and Shannon's spectral entropy, were computed for each cortical region. For SPECT data, three pathological parameters--'severity', 'extent', and 'ratio'--were computed using an easy z-score imaging system (eZIS). As for NPAs, the MMSE and FAB scores were retrieved. Results: MEG oscillatory parameters were correlated with eZIS parameters. The eZIS parameters associated with Alzheimer's disease pathology were reflected in theta power augmentation and slower shift of the alpha peak. Moreover, MEG oscillatory parameters were found to reflect NPAs. Global slowing and loss of diversity in neural oscillatory components correlated with MMSE and FAB scores, whereas the associations between eZIS parameters and NPAs were sparse. Conclusion: MEG oscillatory parameters correlated with both SPECT (i.e. eZIS) parameters and NPAs, supporting the clinical validity of MEG oscillatory parameters as pathological and symptomatic indicators. The findings indicate that various components of MEG oscillatory characteristics can provide valuable pathological and symptomatic information, making MEG data a rich resource for clinical examinations of patients with cognitive impairments. SPECT (i.e. eZIS) parameters showed no correlations with NPAs. The results contributed to a better understanding of the characteristics of electrophysiological and pathological examinations for patients with cognitive impairments, which will help to facilitate their co-use in clinical application, thereby improving patient care. [ABSTRACT FROM AUTHOR]

Purpose: Glioma is associated with pathologically high (peri)tumoral brain activity, which relates to faster progression. Functional connectivity is disturbed locally and throughout the entire brain, associating with symptomatology. We, therefore, investigated how local activity and network measures relate to better understand how the intricate relationship between the tumor and the rest of the brain may impact disease and symptom progression. Methods: We obtained magnetoencephalography in 84 de novo glioma patients and 61 matched healthy controls. The offset of the power spectrum, a proxy of neuronal activity, was calculated for 210 cortical regions. We calculated patients' regional deviations in delta, theta and lower alpha network connectivity as compared to controls, using two network measures: clustering coefficient (local connectivity) and eigenvector centrality (integrative connectivity). We then tested group differences in activity and connectivity between (peri)tumoral, contralateral homologue regions, and the rest of the brain. We also correlated regional offset to connectivity. Results: As expected, patients' (peri)tumoral activity was pathologically high, and patients showed higher clustering and lower centrality than controls. At the group-level, regionally high activity related to high clustering in controls and patients alike. However, within-patient analyses revealed negative associations between regional deviations in brain activity and clustering, such that pathologically high activity coincided with low network clustering, while regions with 'normal' activity levels showed high network clustering. Conclusion: Our results indicate that pathological activity and connectivity co-localize in a complex manner in glioma. This insight is relevant to our understanding of disease progression and cognitive symptomatology. [ABSTRACT FROM AUTHOR]

• Guidelines to develop national curricula for clinical neurophysiology as a medical mono- and/or subspecialty are proposed. • Recommendations on governance and regulation of training, and on requirements for competence, are given. • Primary (EEG, EMG/NCS and EP) and complementary (sleep, neuromonitoring, neuromodulation, etc.) training modules are suggested. There are significant differences in duration and intensity of clinical neurophysiology specialty training within the countries of the Europe, Middle East and Africa Chapter of the International Federation of Clinical Neurophysiology. We address these differences by proposing recommendations which may facilitate harmonisation of training and education within the Chapter. They arose from two workshops whose recommendations were then circulated widely within national societies in the Chapter for feedback and for consensus. The recommendations are applicable to clinical neurophysiology as a medical monospecialty and/or as a subspecialty (usually of neurology). We make a number of recommendations on governance and regulation of training, on the requirements for competence and the numbers of various examinations and tests performed by trainees, some under supervision. We also recommend a modular approach considering primary and complementary modules. Primary modules are electroencephalography, electromyography, nerve conduction studies and evoked potentials, while complementary ones include sleep analysis, intraoperative monitoring, small fibre testing, peripheral nerve and muscle ultrasound, intracortical recordings, and analysis of movement disorders. It is recommended that national examinations should include a variety of techniques to assess knowledge and judgement, practical skills, teamwork, communication skills, as well as safety and quality. The aim of the suggested recommendations is to harmonize clinical neurophysiology training in the member societies throughout the Chapter. It is realised that this may mean that the numbers for competence are aspirational for some, though ways to mitigate this, for instance through supranational training centres, are also discussed. [ABSTRACT FROM AUTHOR]

On behalf of the SNS and SSNS, we are pleased to present the abstracts of the Joint Annual Meeting to be held in Zurich, Switzerland, on 23–24 November, 2023. In total, 119 abstracts have been selected: 4 abstracts for the Plenary Sessions, 12 abstracts for Free Communications, 18 abstracts for Poster flash presentations, 6 abstracts for the SAYN GemSession, and 79 abstracts as ePosters. We congratulate all the presenters on their research work and contributions. [ABSTRACT FROM AUTHOR]

The reactivity of an electroencephalogram (EEG) to external stimuli is impaired in comatose patients showing burst-suppression (BS) patterns following hypoxic–ischemic brain injury (HIBI). We explored the reactivity of BS induced by isoflurane in rat models of HIBI and controls using intermittent photic stimulation (IPS) delivered to one eye. The relative time spent in suppression referred to as the suppression ratio (SR) was measured on the contralateral fronto-occipital cortical EEG channel. The BS reactivity (BSR) was defined as the decrease in the SR during IPS from the baseline before stimulation (SRPRE). We found that BSR increased with SRPRE. To standardize by anesthetic depth, we derived the BSR index (BSRi) as BSR divided by SRPRE. We found that the BSRi was decreased at 3 days after transient global cerebral ischemia in rats, which is a model of brain injury after cardiac arrest. The BSRi was also reduced 2 months after experimental perinatal asphyxia in rats, a model of birth asphyxia, which is a frequent neonatal complication in humans. Furthermore, Oxytocin attenuated BSRi impairment, consistent with a neuroprotective effect in this model. Our data suggest that the BSRi is a promising translational marker in HIBI which should be considered in future neuroprotection studies.

Over the past three decades, substantial advancements have occurred in non-invasive brain stimulation (NIBS). These developments encompass various non-invasive techniques aimed at modulating brain function. Among the most widely utilized methods today are transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (TES), which include direct- or alternating-current transcranial stimulation (tDCS/tACS). In addition to these established techniques, newer modalities have emerged, broadening the scope of non-invasive neuromodulation approaches available for research and clinical applications in movement disorders, particularly for Parkinson’s disease (PD) and, to a lesser extent, atypical Parkinsonism (AP). All NIBS techniques offer the opportunity to explore a wide range of neurophysiological mechanisms and exert influence over distinct brain regions implicated in the pathophysiology of Parkinsonism. This paper’s first aim is to provide a brief overview of the historical background and underlying physiological principles of primary NIBS techniques, focusing on their translational relevance. It aims to shed light on the potential identification of biomarkers for diagnostic and therapeutic purposes, by summarising available experimental data on individuals with Parkinsonism. To date, despite promising findings indicating the potential utility of NIBS techniques in Parkinsonism, their integration into clinical routine for diagnostic or therapeutic protocols remains a subject of ongoing investigation and scientific debate. In this context, this paper addresses current unsolved issues and methodological challenges concerning the use of NIBS, focusing on the importance of future research endeavours for maximizing the efficacy and relevance of NIBS strategies for individuals with Parkinsonism.

A 3-hour hands-on EEG workshop was conducted as a part of resident rotation in clinical neurophysiology to determine its feasibility and educational value for neurology residents, medical students, and EEG technologists, with the learning objectives of motivating interest in clinical electroencephalography, enhancing ability to recognize a normal EEG and identify physiological and non-physiological artifacts, and enhancing teaching, organizational and communication skills of EEG technologists. The workshop included a demonstration of EEG electrode placement according to the 10–20 System on a resident volunteer by the EEG technologist. Activation procedures (photic stimulation and hyperventilation) were demonstrated to the residents during the 25-minute recording. A board-certified epileptologist later reviewed the record with the residents. Resident and EEG technologist feedback on the workshop was obtained via non-formal e-mail request. All residents rated the workshop highly and found it more engaging and motivating than the didactic EEG lecture in which basics of EEG recording are reviewed. The residents gained improved awareness and appreciation of the role of the technologist and the skill and time involved in obtaining an EEG record. The EEG technologist appreciated the face-to-face interaction with the residents and felt part of the patient care team. A hands-on EEG workshop as a part of resident clinical neurophysiology rotation is feasible, effective, and motivating in teaching residents and medical students the basis of EEG recording and recognition of common physiological and non-physiological artifacts in a normal record. [ABSTRACT FROM AUTHOR]

Background. After-discharge (AD) activity is a pattern that differs from background corticography, represented by rhythmic stereotypical slow waves and/or repetitive spike discharges with ≥1 Hz frequency, recorded after cessation of electrical stimulation and lasting for more than 2 seconds. Despite the accumulated experience in the field of intraoperative neuromonitoring, there is no unified protocol for high-frequency stimulation of cortical functional areas (FAs) upon the AD event.Objective: to demonstrate a need to change the intraoperative FAs mapping protocol in patients with brain tumor on awakening in cases of AD recording.Material and methods. Two clinical cases of awake surgical functional mapping followed by resection of the brain tumor are presented. Multimodal monitoring included high-frequency stimulation according to the approved intrahospital protocol with maximum stimulation force of auditory-speech zones of 2.5 mA, electrocorticography, and subcortical dynamic mapping.Results. In the first case, AD was registered while FAs mapping in a patient with a history of one epileptic seizure, upon reaching the maximum stimulation force of 2.5 mA, that was replaced by recording focal epileptiform activity with the following evolution to ictal generalized event and development of intraoperative convulsive seizure. In the second patient with a history of recurrent epileptic seizures, AD with spatiotemporal evolution of the pattern development of clinical ictal event was registered with stimulation at 2.5 mA. In both cases, the appearance of AD required to change mapping protocol with a stepwise decrease in stimulus strength to obtain cortical FAs data.Conclusion. Registration of AD is the basis for changing the protocol of high-frequency cortical stimulation in surgical treatment of brain tumor FAs.

The clinical neurophysiological tests allow us to determine the type, extent, and nature of brachial plexus damage. They are crucial in decision making regarding surgical procedures or conservative treatment. This report aimed to present an algorithm for rehabilitation procedures in patients with brachial plexus injury of various origins based on the results of neurophysiology findings for the selection of procedures supporting the process of nerve and muscle regeneration. The research group consisted of patients whose medical documentation was analysed concerning the reason, level, and localization of damage to the brachial plexus structures, surgical and or rehabilitative treatment, as well as the MRI results. Among the group of fourteen patients, the clinical studies showed the greatest incidence of brachial plexus injuries of the mixed (both pre- and postganglionic), all trunks, and cervical root injuries, respectively. Results of the motor evoked potentials (MEP) and electroneurography (ENG) recordings induced at levels of spinal roots and Erb’s point showed a decrease of more than 40% in amplitudes on the symptomatic side in comparison to the asymptomatic side. This diffeence was recorded for the axillary and radial innervation and the C5, C6, and C7 root domains, ranging from 57% to 66%; the lowest decrease was recorded following electrical stimulation at Erb’s point for the ulnar nerve (34%). The latency prolongation on the symptomatic side in CMAP and MEP tests ranged from 0.2 to 1.7 ms, with the most following magnetic stimulation of the C5 cervical root for the axillary innervation. Most of the results indicated the axonotmesis and neuropraxia type of injury in motor fibers (40%) confirmed by EMG results. The sensory conduction studies (SNCS) in distal nerve branches did not confirm the severe advancement of the brachial plexus injury (63%). The proposed algorithm of the physiotherapeutic procedures should be mainly targeted for recovery of motor dysfunction as the consequence of brachial plexus injury. Rehabilitation should incorporate the treatment supporting nerve regeneration, muscle strengthening, and maintaining functional ranges of motion of the injured extremities. The rehabilitation treatment for patients with brachial plexus injuries is an individualised process, and the selection of procedures and the effectiveness of the treatment undertaken should be confronted with results of neurophysiological tests verifying the motor neural transmission from the level of the cervical motor centre to the effector, peripheral nerve function, and muscle’s motor unit activity.

The Guidelines for Qualifications of Neurodiagnostic Personnel (QNP) document has been created through the collaboration of the American Clinical Neurophysiology Society (ACNS), the American Society of Neurophysiological Monitoring (ASNM), the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM), and ASET – The Neurodiagnostic Society (ASET). The quality of patient care is optimized when neurophysiological procedures are performed and interpreted by appropriately trained and qualified practitioners at every level. These Societies recognize that Neurodiagnostics is a large field with practitioners who have entered the field through a variety of training paths. This document suggests job titles, associated job responsibilities, and the recommended levels of education, certification, experience, and ongoing education appropriate for each job. This is important because of the growth and development of standardized training programs, board certifications, and continuing education in recent years. This document matches training, education, and credentials to the various tasks required for performing and interpreting Neurodiagnostic procedures. This document does not intend to restrict the practice of those already working in Neurodiagnostics. It represents recommendations of these Societies with the understanding that federal, state, and local regulations, as well as individual hospital bylaws, supersede these recommendations. As Neurodiagnostics is a growing and dynamic field, we fully intend this document to change over time. [ABSTRACT FROM AUTHOR]

Synchronized oscillations within and between brain areas facilitate normal processing, but are often amplified in disease. A prominent example is the abnormally sustained beta-frequency (∼20 Hz) oscillations recorded from the cortex and subthalamic nucleus of Parkinson's disease patients. Computational modeling suggests that the amplitude of such oscillations could be modulated by applying stimulation at a specific phase. Such a strategy would allow selective targeting of the oscillation, with relatively little effect on other activity parameters. Here, activity was recorded from 10 awake, parkinsonian patients (6 male, 4 female human subjects) undergoing functional neurosurgery. We demonstrate that stimulation arriving on a particular patient-specific phase of the beta oscillation over consecutive cycles could suppress the amplitude of this pathophysiological activity by up to 40%, while amplification effects were relatively weak. Suppressive effects were accompanied by a reduction in the rhythmic output of subthalamic nucleus (STN) neurons and synchronization with the mesial cortex. While stimulation could alter the spiking pattern of STN neurons, there was no net effect on firing rate, suggesting that reduced beta synchrony was a result of alterations to the relative timing of spiking activity, rather than an overall change in excitability. Together, these results identify a novel intrinsic property of cortico-basal ganglia synchrony that suggests the phase of ongoing neural oscillations could be a viable and effective control signal for the treatment of Parkinson's disease. This work has potential implications for other brain diseases with exaggerated neuronal synchronization and for probing the function of rhythmic activity in the healthy brain.SIGNIFICANCE STATEMENT In Parkinson's disease (PD), movement impairment is correlated with exaggerated beta frequency oscillations in the cerebral cortex and subthalamic nucleus (STN). Using a novel method of stimulation in PD patients undergoing neurosurgery, we demonstrate that STN beta oscillations can be suppressed when consecutive electrical pulses arrive at a specific phase of the oscillation. This effect is likely because of interrupting the timing of neuronal activity rather than excitability, as stimulation altered the firing pattern of STN spiking without changing overall rate. These findings show the potential of oscillation phase as an input for "closed-loop" stimulation, which could provide a valuable neuromodulation strategy for the treatment of brain disorders and for elucidating the role of neuronal oscillations in the healthy brain.

The present study aimed to assess the function of muscular and nervous systems in high-maneuvering jet fighters with the chosen method of clinical neurophysiology, which methodologically has not yet been presented in detail. Fifteen pilots with the experience of more than 1700 flying hours at 7G overloading on average and fifteen healthy subjects for the comparison of health status declared to participate in this study. The dermatomal perception from C4 to S1 was examined using von Frey's filaments tactile method. Surface electromyography (sEMG) recordings examined the activity of proximal and distal muscles in the upper and lower extremities, the transmission of motor nerve impulses peripherally was diagnosed by electroneurography (ENG), the efferent transmission from C5–C7 and L4–L5 spinal centers to muscles was entirely verified with recordings of motor-evoked potentials induced oververtebrally with the magnetic field (MEP). The pilots estimated more lumbosacral than cervical pain at about 2 on the 10-point visual analog scale (VAS). Sensory perception studies did not reveal abnormal symptoms in the C2–S1 dermatomes innervation. Clinical neurophysiology studies indicated, in general, the lack of pathology during sEMG tests in comparison to healthy subjects or even better muscle motor unit contractile properties in pilots, both in the upper and lower extremities. In pilots, the parameters of ENG and MEP examinations show a statistically significant sensitivity for detecting the slight changes and their consequences in the transmission of neural impulses within L4–L5 ventral root fibers. The research results enable specifying the algorithm of future preventing rehabilitative treatment in high-maneuvering jet fighters with an average flight experience of 2000 h and working conditions at 7G on average. This study, for the first time, describes the application of a set of diagnostic neurophysiological methods with the particular importance of MEPs in the clinical evaluation of the jet fighters' health status. [ABSTRACT FROM AUTHOR]

Introduction: Even if electromyography (EMG) is routinely used to confirm the diagnosis of amyotrophic lateral sclerosis (ALS), few studies have analysed the correlation between electrophysiological parameters and clinical characteristics of ALS. We assessed if the quantification of active denervation (AD) and chronic denervation (CD) provides clinicians with information about phenotype, disease progression and survival in ALS patients. Methods: We studied a cohort of 689 ALS patients recording the following parameters: age and site of onset, survival, MRC scale for muscle strength evaluation, burden of upper and lower motor signs as measured with specific scales (PUMNS and LMNS, respectively), ALSFRS-R, progression rate (ΔFS), MITOS and King's Staging systems (KSS). We performed EMG on 11 muscles, and calculated semiquantitative AD and CD scores for each limb, as well as for the bulbar and spinal regions. Results: We found a positive correlation between AD and CD scores with LMNS (respectively p = 4.4 × 10–37 and p = 2.8 × 10–45) and a negative correlation with MRC (respectively p = 4.5 × 10–35 and p = 3.0 × 10–35). Furthermore, patients with higher spinal AD and CD scores had significantly lower ALSFRS-R scores, and higher KSS and MITOS stages. Conversely, only AD was associated to higher ΔFS (p = 1.0 × 10–6) and shorter survival (p = 1.1 × 10–5). Conclusion: Our results confirmed that EMG examination represents not only a diagnostic instrument, but also a prognostic tool. In this context, AD seems to be a reliable predictor of disease's progression and survival while CD better describes functional disability. [ABSTRACT FROM AUTHOR]

Objective: to study the clinical and neurophysiological features in the Chornobyl clean-up workers with a verified chronic cerebrovascular disease/cerebral small vessels disease (SVD) exposed to low doses of ionizing radiation (IR), employees of the Chornobyl Nuclear Power Plant (SSE ChNPP), who were exposed to the stress factor of a full-scale war as a result of being held captive by the Russian military at their workplaces, and individuals of the non-irradiated comparison group. Design, object and methods. A cross-sectional clinical study with parallel external control groups. We studied and carried out an expert statistical analysis of the clinical and neurophysiological characteristics of 62 male subjects, from which three examination groups were formed: 1) a randomized sample from the Clinical Epidemiological Register (CER) of the State Institution «National Research Center for Radiation Medicine of the National Academy of Medical Sciences of Ukraine» (NRCRM) of 22 Chornobyl clean-up workers ('Chornobyl liquidators') in 1986-1990, examined during 2020-2021, aged 50-68 years at the time of examination (M ± SD: (58.1 ± 5.2) years) with a documented external radiation dose of 0.03-2.30 Sv; 2) 24 SSE ChNPP employees exposed to the stress factor impact of a full-scale war as a result of being held captive by the Russian military at their workplaces. The average age of the examined was (54.5 ± 5.8) years (range 46-71 years). 3) Comparison group -- 16 non-exposed men with verified chronic cerebrovascular disease/cerebral small vessels disease (SVD). The average age of the examined was (57.8 ± 5.6) years (range 50-70 years). Results. Neurophysiological studies confirm the presence of the pronounced dysfunction of the cortico-limbic system of the left dominant hemisphere of the brain with special involvement of the hippocampus in the Chornobyl clean-up workers. In the SSE ChNPP group, for the first time, the disorders of cerebral neurodynamics were detected in the form of functional hypofrontality and hyperfunction of the cortico-limbic system with lateralization to the right hemisphere. Conclusions. Today there exists a long-term thorough methodological and evidence base for a possible neurophysiological diagnosis and differential diagnosis of the combined cerebral effects of IR and psycho-emotional stress associated with the conditions of military conflicts. Neurophysiological technologies can be used in the objective professional and qualification selection of employees in a number of professions that require quick and responsible decision-making. Employees of SSE ChNPP need further medical and psychological support due to an increased risk of developing mental health disorders. [ABSTRACT FROM AUTHOR]

Background: Patients with Parkinson's disease (PD) and rest tremor may also have tremor during posture holding, with tremor being transiently suppressed during the transition between resting and posture holding. Other PD patients show no tremor suppression between resting and posture holding. The mechanisms responsible for tremor suppression in PD are unknown. Understanding the mechanisms of tremor suppression would expand our knowledge of tremor pathophysiology in PD. Objective: To investigate whether tremor suppression reflects the activity of the primary motor cortex (M1) and assess whether tremor features are different in patients with and without tremor suppression. Methods: We compared corticomuscular coherence (CMC) at tremor frequency and transcranial magnetic stimulation tremor resetting between 10 PD patients with tremor suppression and 10 patients without suppression. We also compared tremor spectral features between the two groups. Results: Patients with tremor suppression had higher CMC at tremor frequency during both rest tremor and postural tremor, and a higher postural tremor resetting index and stability when compared with patients without tremor suppression. Rest tremor frequency was similar between the two groups, but postural tremor frequency was lower in patients with tremor suppression as compared to patients without. Conclusion: M1 plays a major role in tremor suppression in PD, and the mechanisms of postural tremor may differ between patients with and without tremor suppression. [ABSTRACT FROM AUTHOR]

Clinical neurophysiology constructs a wealth of dynamic information pertaining to the integrity and function of both central and peripheral nervous systems. As with many technological fields, there has been an explosion of data in neurophysiology over recent years, and this requires considerable analysis by experts. Computational algorithms and especially advances in machine learning (ML) have the ability to assist with this task and potentially reveal hidden insights. In this update article, we will provide a brief overview where such technology is being applied in clinical neurophysiology and possible future directions. [ABSTRACT FROM AUTHOR]

Background and purpose: We evaluated the clinical and neurophysiological efficacy of rituximab (RTX) in a neurophysiologically homogeneous group of patients with monoclonal gammopathy and immunoglobulin M (IgM) anti‐myelin‐associated glycoprotein antibody (anti‐MAG) demyelinating polyneuropathy. Methods: Twenty three anti‐MAG‐positive polyneuropathic patients were prospectively evaluated before and for 2 years after treatment with RTX 375 mg/m2. The Inflammatory Neuropathy Cause and Treatment (INCAT) disability scale (INCAT‐ds), modified INCAT sensory score (mISS), Medical Research Council sum score, Patients' Global Impression of Change scale were used, IgM levels were assessed and extensive electrophysiological examinations were performed before (T0) and 1 year (T1) and 2 years (T2) after RTX treatment. Results: At T1 and T2 there was a significant reduction from T0 both in mISS and in INCAT‐ds, with a p value < 0.001 in the inferential Friedman's test overall analysis. Ulnar nerve Terminal Latency Index and distal motor latency significantly changed from T0 to T1 and in the overall analysis (p = 0.001 and p = 0.002), and ulnar nerve sensory nerve action potential (SNAP) amplitude was significantly increased at T2 from T1, with a p value < 0.001 in the overall analysis. Analysis of the receiver‐operating characteristic curves showed that a 41.8% increase in SNAP amplitude in the ulnar nerve at T2 from T0 was a fair predictor of a mISS reduction of ≥2 points (area under the curve 0.85; p = 0.005; sensitivity: 90.9%, specificity: 83.3%). Conclusions: This study suggests that RTX is effective in patients with clinically active demyelinating anti‐MAG neuropathy over 2 years of follow‐up, and that some neurophysiological variables might be useful for monitoring this efficacy. [ABSTRACT FROM AUTHOR]

This paper presents results from the first survey of training and education undertaken by the Europe-Middle East-Africa (EMEAC), the Latin America (LAC) and the Asia-Oceania (AOC) Chapters of the International Federation of Clinical Neurophysiology (IFCN). The survey was conducted initially by the EMEAC in 2012 and updated in 2016, 2019, and 2020. It had the following categories: status of specialty and training in member country (21 questions), competency and accreditation (12 questions), practice and concerns (23 questions). An abbreviated version of the survey was conducted by the LAC and AOC in 2018–2019.Clinical neurophysiology (CN) was a single specialty in a minority of member societies’ countries: 8/33 EMEAC, 2/12 AOC and 2/10 LAC. In others it was usually a subspecialty of neurology. Training periods in CN were split fairly evenly between 1, 2, 3, 4 and 5 years in EMEAC, while neurology takes 4 to 5 years. In the AOC, neurology training was for 3 to 4 years and CN for up to 2 years. In LAC a majority of countries trained for 2 to 3 years in both neurology and CN. An exit exam was performed in 16/30 EMEAC respondents, 8/12 in the AOC and 3/10 in the LAC.Competence was considered to require a wide range of numbers of tests performed under supervision, from 750 in EMEAC and AOC, with the EMEAC tending to require more. The main concerns were in recruitment and workload in EMEAC, training in AOC and the need for more recognition of the specialty in some countries within the LAC.This survey, the first across the three chapters, revealed considerable differences in training durations and numbers of tests performed for competence between national societies.

The current concepts on the clinical neurophysiology examinations for the differential diagnosis of rheumatic diseases are presented. The review aims to provide experience and practical guidelines, especially regarding electromyography. More needle than surface electromyography examinations at muscle rest or during its maximal contraction may reveal the characteristic effects of the myogenic injury caused by particular rheumatic diseases. The diagnosis of myopathic disorders, often found in rheumatic diseases is difficult because of the frequent vasculitis coexistence in the patients evoking subsequent changes in nerve fibres leading to degenerative neurogenic changes that may overlap the diagnostic picture of the primary myogenic changes caused by rheumatic diseases. In these cases, the neurophysiological studies of efferent and afferent neural transmission often reveal peripheral neuropathies just at the subclinical level. [ABSTRACT FROM AUTHOR]

Ptosis and proximal weakness may develop in multiple diseases including oculopharyngeal muscular dystrophy (OPMD) and myasthenia gravis (MG). These two entities can be challenging to differentiate since they may have important clinical and neurophysiological overlap. Systemic lupus erythematosus (SLE), a common autoimmune disease, has been described in association with MG.We present a woman in her 60s with fluctuating bilateral ptosis and proximal muscle weakness. Single fibre electromyography showed increased jitter. Her brother has genetically proven OPMD. The investigation revealed a positive genetic test for OPMD and positive antibodies for acetylcholine receptor. Additionally, she has SLE, treated with hydroxychloroquine for more than 30 years.This case highlights the importance of a thoughtful anamnesis with personal and familial history and raises awareness for the rare coexistence of three pathologies with some common clinical characteristics but different treatments and management., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

A man in his 30s with a history of refractory classical Hodgkin's lymphoma presented with subacute onset asymmetric sensory disturbance, and severe weakness affecting his right more than left hand. Symptom onset was 18 weeks after commencing brentuximab vedotin (BV) treatment, an anti-CD30 antibody drug-conjugate for relapsed/refractory classical Hodgkin's lymphoma. Symptoms progressed to his lower limbs with distal sensory loss, gait imbalance, bilateral foot drop and mild proximal leg weakness. He was globally areflexic. Neurophysiology revealed a mildly asymmetric, non-length dependent, motor >sensory polyradiculoneuropathy, with mixed axonal and demyelinating features. Extensive laboratory work-up, lumbar puncture and MRI of the brachial plexus, brain, spine and chest were unremarkable. Treatment with plasma exchange, followed by intravenous immunoglobulin, resulted in objective clinical improvement 4 weeks after. BV is a potent antimicrotubule agent, thus well known to cause a length-dependent sensory axonal polyneuropathy. Demyelinating polyneuropathy, with more prominent motor involvement, in association with BV is much rarer., Competing Interests: Competing interests: CO has received a speaker fee on plasma exchange from Terumo BCT. NM, HJH and RA have no conflicts of interest to declare., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Study Objectives: To examine the difference in psychiatric comorbidity of Danish patients with Narcolepsy type 1 (NT1), Narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH)., Methods: Polysomnography (PSG), Multiple Sleep Latency Test (MSLT), and lumbar puncture were performed on 505 patients referred to a sleep clinic for diagnostic evaluation of hypersomnia. Diagnosis, clinical characteristics, electrophysiologic data, and cerebrospinal fluid hypocretin-1 (Csf-Hcrt-1) results were retrieved. Subsequently, the patients were identified in the Danish national health registers to collect information on psychiatric diagnoses and psychotropic medication use 10 years before the sleep disorder diagnosis. The prevalence of psychiatric comorbidities per hypersomnia group was compared to a 1:4 general population control group matched on age, gender, and educational level., Results: A diagnosis of NT2 and IH was significantly associated with total psychiatric comorbidity compared to the matched controls but not NT1 (NT1: OR = 1.5; NT2: OR = 6.1; IH: OR = 5.2). NT1 was not significantly associated with any psychiatric disorder. NT2 was significantly associated with schizophrenia spectrum disorders (OR = 8.5), mood disorders (OR = 6.7), neurotic disorders (OR = 3.8), personality disorders (OR = 3.1), and behavioral and emotional disorders (OR = 4.3). IH was significantly associated with schizophrenia spectrum disorders (OR = 3.3), mood disorders (OR = 5.9), neurotic disorders (OR = 3.0), and behavioral and emotional disorders (OR = 4.0)., Conclusions: NT2 and IH had a close relationship to psychiatric disorders before diagnosis of their sleep disorder, while NT1 did not. This supports previous studies finding higher rates of psychiatric illness in patients with hypersomnia; however, it highlights the similarity between NT2 and IH. We believe this link to psychiatric disorders could play a role in the pathophysiology. Future studies evaluating the relation between hypersomnias of central origin and psychiatric diseases should include hypersomnia subclassifications to further the understanding of the differences in these disorders., (© The Author(s) 2024. Published by Oxford University Press on behalf of Sleep Research Society.)

BackgroundA number studies have been conducted on abnormalities in the cortical circuitry of gamma oscillations, including deficit in auditory steady-state response (ASSR) to gamma-frequency (≧ 30-Hz) stimulation, in patients with bipolar disorder (BD). In the current study, we investigated neural responses during click stimulation by blood oxygen level-dependent (BOLD) signals. We focused on Broadman 41 and 42, the main sources of ASSR.Materials and methodsWe acquired BOLD responses elicited by click trains of 80-, 40-, 30- and 20-Hz frequencies from 25 patients with BD to 27 healthy controls (HC) with normal hearing between 22 and 59 years of age assessed via a standard general linear-model-based analysis. We extracted contrast values by identifying the primary auditory cortex and Brodmann areas 41 and 42 as regions of interest (ROI)s.ResultsBD group showed significantly decreased ASSR-BOLD signals in response to 40-Hz stimuli compared to the HC group in the right Brodmann areas 41 and 42. We found significant negative correlations between the BOLD change in the right Brodmann areas 41 and 42 and Structured Interview Guide for the Hamilton Depression Rating Scale (SIGH-D) scores, also the BOLD change in the right Brodmann areas 41 and 42 and the Positive and Negative Syndrome Scale (PANSS)-Negative scores.ConclusionThe observed decrease in BOLD signal patterns in the right primary auditory cortex during 40-Hz ASSR may be a potential biomarker option for bipolar disorder.

A concomitant presentation of relapsing remitting multiple sclerosis (RRMS) and amyotrophic lateral sclerosis (ALS) is quite rare. However, a review of the literature showed an increased co-occurrence of both diseases, including in genetically determined cases. We report the case of a 49-year-old woman with a history of RRMS who developed a progressive subacute loss of strength in her left arm. The patient's father died from ALS, and her paternal uncle had Parkinson's disease. Brain and cervical MRIs were performed, and new demyelinating lesions were excluded. Electromyography (EMG) of the upper limbs showed fibrillations and fasciculations in distal muscles of both arms. In the following months, the patient presented a progressive loss of strength in the proximal and distal muscles of the right arm and hyperreflexia in the lower limbs. EMG and central motor conduction were consistent with ALS. A genetic test was carried out, revealing a mutation in the FUS gene (exon 15; c. 1562 G>A). To our knowledge, the co-occurrence of MS and ALS in patients with FUS mutation is extremely rare. We hypothesize a common pathway for both diseases based on the possibility of a shared oligodendroglial dysfunction due to FUS mutation. [ABSTRACT FROM AUTHOR]

Introduction: Clinical neurophysiology deals with nervous system functions assessed with electrophysiological and ultrasound-based imaging techniques. Even though the need for highly specialized neurophysiologists has increased, residency training rarely takes today's requirements into account. This study aimed to snapshot the neurophysiological training provided by Italian specialization schools in neurology.Methods: A single-page web-based survey comprising 13 multiple-choice categorical and interval scale questions was sent via e-mail to neurology specialization school directors. The survey addressed the programs' structural neurophysiology organization, time dedicated to each clinical neurophysiology subspecialty, and descriptors assessing the discipline's importance (e.g., residents who attempted residential courses, gained certifications, or awards gained).Results: The most studied neurophysiological techniques were electroencephalography (EEG) and electromyography (EMG). Most specialization schools devoted less than 3 months each to multimodal evoked potentials (EPs), ultrasound sonography (US), and intra-operative monitoring. Of the 35 specialization schools surveyed, 77.1% reported that four students, or fewer, participated in the Italian Society of Clinical Neurophysiology Examination in Neurophysiology. Of the 35 specialization centers surveyed, 11.4% declared that the final evaluation required students to discuss a neurophysiological test.Discussion: Our survey underlined the poorly standardized technical requirements in postgraduate neurology specialization schools, wide variability among training programs, and limited training on multi-modal evoked potentials, intraoperative monitoring, and sonography. These findings underline the need to reappraise and improve educational and training standards for clinical neurophysiology during postgraduate specialization schools in neurology with an international perspective. [ABSTRACT FROM AUTHOR]

Comparative studies on the second exteroceptive suppression period (ES2) of the masseter or temporalis muscle in migraineurs and controls have provided conflicting results. As the interneurons responsible for ES2 are probably close to the trigeminal nucleus caudalis and receive afferents also from the anti-nociceptive system, the study of ES2 could provide information on neural circuits involved in migraine pathophysiology. The aim of this observational, pilot study was to assess whether erenumab treatment may affect the exteroceptive suppression reflex of the temporalis muscle activity in migraineurs. The exteroceptive suppression reflex of the temporalis muscle activity was previously studied in a small case series of three chronic female migraineurs and after 4 months of beneficial erenumab treatment, administered according to current clinical indications. There was a statistically significant decrease in ES2 latency (p-value 0.039) and duration (p-value 0.030) after treatment. The change observed in the temporalis ES2 during erenumab treatment indicates that ES2 may play some kind of role as a neurophysiological marker and that this monoclonal antibody can modulate the brainstem circuits involved in migraine pathophysiology, at least indirectly. Further studies are required to confirm this intriguing hypothesis. [ABSTRACT FROM AUTHOR]

Introduction: Triphasic waves (TW) constitute an electroencephalographic pattern associated with certain kinds of encephalopathy. Brain atrophy may be a predisposing factor linked with TW. Objective: To compare the degree of brain atrophy and white matter disease between patients with acute encephalopathy with and without TW. Methods: A retrospective observational study including adult patients with encephalopathy, with and without TW, hospitalized between 2016 and 2017. The degree of brain atrophy and white matter lesion were defined using the Global Cortical Atrophy and Age Related White Matter Changes (ARWMC) scales, respectively. Scores were compared between groups. Mortality rates were registered. Results: Sixteen patients with TW were identified matched by age and sex with 30 patients without TW. The mean age was 80 years in the TW group. Women represented 87.5%. Multifactorial encephalopathy was the most frequent diagnosis followed by metabolic encephalopathy. Patients with TW had more brain atrophy (10.43 vs 6.9, p= 0.03). Mean ARWMC was 9.43±6.5 and 8.5 ±7.89 in patients with and without TW respectively (p= 0.5). Mortality rate was higher in the TW group (31.25 vs 6.66% p= 0.02). Conclusions: Patients with acute encephalopathy and TW had higher degree of cerebral atrophy. It is possible that this structural alteration predisposes to the appearance of TW. There was no significant difference in white matter lesion degree. The mortality of the TW group was high, so future studies are necessary to determine their prognostic value. [ABSTRACT FROM AUTHOR]

To test the robustness and signal-to-noise ratio of pain-related evoked potentials following intra-epidermal electrical stimulation (IES) compared to contact heat stimulation in healthy controls, and to explore the feasibility and potential added value of IES in the diagnosis of spinal disorders. Pain-related evoked potentials induced by IES (custom-made, non-invasive, concentric triple pin electrode with steel pins protruding 1 mm from the anode, triangularly separated by 7–10 mm respectively) and contact heat stimulation were compared in 30 healthy subjects. Stimuli were applied to four different body sites. Two IES intensities, i.e., high (individually adapted to contact heat painfulness) and low (1.5 times pain threshold), were used. Additionally, a 40-year-old patient with unilateral dissociated sensory loss due to a multi-segmental syringohydromyelia was assessed comparing IES and contact heat stimulation. Both IES and contact heat stimulation led to robust pain-related evoked potentials recorded in all healthy subjects. Low intensity IES evoked potentials (14.1–38.0 µV) had similar amplitudes as contact heat evoked potentials (11.8–32.3 µV), while pain ratings on the numeric rating scale were lower for IES (0.8–2.5, compared to 1.5–3.9 for contact heat stimulation). High intensity IES led to evoked potentials with higher signal-to-noise ratio than low intensity IES and contact heat stimulation. The patient case showed impaired pain-related evoked potentials in segments with hypoalgesia for both IES modes. IES evoked potentials were preserved, with delayed latencies, while contact heat evoked potentials were abolished. IES evoked robust pain-related cortical potentials, while being less painful in healthy controls. The improved signal-to-noise ratio supports the use of IES for objective segmental testing of nociceptive processing. This was highlighted in a spinal syndrome case, where IES as well as contact heat stimulation reliably detected impaired segmental nociception. [ABSTRACT FROM AUTHOR]

Introduction/Aims: Neurogenic thoracic outlet syndrome (NTOS) is a heterogeneous and often disputed entity. An electrodiagnostic pattern of T1 > C8 axon involvement is considered characteristic for the diagnosis of NTOS. However, since the advent of high‐resolution nerve ultrasound (US) imaging, we have encountered several patients with a proven entrapment of the lower brachial plexus who showed a different, variable electrodiagnostic pattern. Methods: In this retrospective case series, 14 patients with an NTOS diagnosis with a verified source of compression of the lower brachial plexus and abnormal findings on their electrodiagnostic testing were included. Their medical records were reviewed to obtain clinical, imaging, and electrodiagnostic data. Results: Seven patients showed results consistent with the "classic" T1 axon > C8 pattern of involvement. Less typical findings included equally severe involvement of T1 and C8 axons, more severe C8 involvement, pure motor abnormalities, neurogenic changes on needle electromyography in the flexor carpi radialis and biceps brachii muscles, and one patient with an abnormal sensory nerve action potential (SNAP) amplitude for the median sensory response recorded from the third digit. Patients with atypical findings on electrodiagnostic testing underwent nerve imaging more often compared to patients with classic findings (seven of seven patients vs. five of seven respectively), especially nerve ultrasound. Discussion When there is a clinical suspicion of NTOS, an electrodiagnostic finding other than the classic T1 > C8 pattern of involvement does not rule out the diagnosis. High resolution nerve imaging is valuable to diagnose additional patients with this treatable condition. See Editorial on pages 4‐6 in this issue. [ABSTRACT FROM AUTHOR]