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Pure midbrain infarctions not involving surrounding structures are an uncommon clinical phenomenon. A midbrain infarction that results in isolated bilateral ptosis as the only neurological deficit is much rarer and an easy diagnosis to miss; therefore, potentially leading to further downstream complications. We describe the case of an elderly patient who presented with isolated bilateral ptosis, initially thought to be consequent to myasthenia gravis but subsequently identified to have a perforator infarct in the midbrain, resulting in his symptoms.

Independent gait following stroke is ultimate goal of rehabilitation. Non-invasive neuromodulation achieving it has never been reported. A 74-year-old woman suffered from subarachnoid haemorrhage, followed by hydrocephalus. Both were treated successfully. Even 1 year after the ictus, ambulation was difficult due to truncal instability with lateropulsion mainly to the left side. Transcranial direct current stimulation (tDCS) was applied to the parietal area (2mA for 20 min/day; anode on left side, cathode on right) for 16 days. The intervention improved her truncal instability and she achieved independent gait. tDCS of the parietal area could be a novel treatment option for gait disturbance due to postural instability following stroke.

Contains fulltext : 244189.pdf (Publisher’s version ) (Open Access) 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.

Guillain-Barré syndrome (GBS) is an acute, monophasic, polyradiculoneuropathy usually provoked by a preceding infection. The cardinal features are progressive weakness in the upper and lower limbs accompanied by loss of deep tendon reflexes. The diagnosis is made on the basis of the clinical history and examination findings, supported by typical cerebrospinal fluid and electrophysiology findings. Trauma and surgery are well understood but rare precipitants of GBS, which clinicians should be aware of, in order not to miss an opportunity to use immunomodulatory therapies. Furthermore, the presence of postsurgical or post-traumatic GBS should prompt careful assessment for underlying malignancy or autoimmune disease associated with an acute demyelinating polyradiculoneuropathy. Here, we present a case of post-traumatic GBS and discuss the potential mechanisms that might underlie this, as well as the investigations and treatment that should be considered.

The Norwegian physician Carl Wilhelm Sem-Jacobsen (1912–1991) was a pioneer in deep brain stimulation and aerospace neurophysiology, but for several reasons, his story has remained untold. During WW2, he collaborated with a renowned military underground resistance group against the Nazi occupants and then had to flee to neutral Sweden. He returned to participate in the liberation of Northern Norway as a Captain in the US Special Forces also working with the OSS (Office of Strategic Services—precursor for CIA) and received a citation from General Eisenhower for his contributions. Sem-Jacobsen then spent several years in the US training in psychiatry and clinical neurophysiology at the Mayo Clinic. He constructed his own medical technical devices, was among the first to develop deep brain stimulation, and made the smallest EEG and EKG recording systems yet produced, also used by the American astronauts walking on the Moon. But he was more an inventor than a researcher, and few of his observations were published in peer-reviewed medical journals. He built his own neurophysiologic institute for neurosurgery, deep brain recordings, and deep brain stimulation in Oslo's main psychiatric hospital, but was sponsored by US military forces and NASA. He knew CIA Director William E. Colby personally, and rumors soon flourished that Sem-Jacobsen conducted secret mind control experiments for American authorities and the CIA. These accusations were investigated, and long after his death, he was officially absolved by a Hearing Committee appointed by the Norwegian Government. Nevertheless, all his personal files were burnt by his family who was still harassed by investigative journalists. Sem-Jacobsen also documented some of his work on film, but the whereabouts of these films have remained unknown. I searched for them for several years and recently discovered numerous films and photographs in an old barn in rural Norway. These films and photographs document in-action neurophysiology recordings in divers, pilots, and astronauts, and they show how Sem-Jacobsen in collaboration with experienced neurosurgeons in Oslo conducted the very first trials with deep brain stimulation in patients with Parkinson disease. He apparently even tried subthalamic stimulation as early as in the 1950s.

This is the second chapter of the series on the use of clinical neurophysiology for the study of movement disorders. It focusses on methods that can be used to probe neural circuits in brain and spinal cord. These include use of spinal and supraspinal reflexes to probe the integrity of transmission in specific pathways; transcranial methods of brain stimulation such as transcranial magnetic stimulation and transcranial direct current stimulation, which activate or modulate (respectively) the activity of populations of central neurones; EEG methods, both in conjunction with brain stimulation or with behavioural measures that record the activity of populations of central neurones; and pure behavioural measures that allow us to build conceptual models of motor control. The methods are discussed mainly in relation to work on healthy individuals. Later chapters will focus specifically on changes caused by pathology.

Clinical neurophysiology studies can contribute important information about the physiology of human movement and the pathophysiology and diagnosis of different movement disorders. Some techniques can be accomplished in a routine clinical neurophysiology laboratory and others require some special equipment. This review, initiating a series of articles on this topic, focuses on the methods and techniques. The methods reviewed include EMG, EEG, MEG, evoked potentials, coherence, accelerometry, coherence, posturography (balance), gait, and sleep studies. Functional MRI (fMRI) is also reviewed as a physiological method that can be used independently or together with other methods. A few applications to patients with movement disorders are discussed as examples, but the detailed applications will be the subject of other articles.

Diagnostic criteria for amyotrophic lateral sclerosis (ALS) are complex, incorporating multiple levels of certainty from possible through to definite, and are thereby prone to error. Specifically, interrater variability was previously established to be poor, thereby limiting utility as diagnostic enrollment criteria for clinical trials. In addition, the different levels of diagnostic certainty do not necessarily reflect disease progression, adding confusion to the diagnostic algorithm. Realizing these inherent limitations, the World Federation of Neurology, the International Federation of Clinical Neurophysiology, the International Alliance of ALS/MND Associations, the ALS Association (United States), and the Motor Neuron Disease Association convened a consensus meeting (Gold Coast, Australia, 2019) to consider the development of simpler criteria that better reflect clinical practice, and that could merge diagnostic categories into a single entity. The diagnostic accuracy of the novel Gold Coast criteria was subsequently interrogated through a large cross-sectional study, which established an increased sensitivity for ALS diagnosis when compared with previous criteria. Diagnostic accuracy was maintained irrespective of disease duration, functional status, or site of disease onset. Importantly, the Gold Coast criteria differentiated atypical phenotypes, such as primary lateral sclerosis, from the more typical ALS phenotype. It is proposed that the Gold Coast criteria should be incorporated into routine practice and clinical trial settings.

Introduction Electroencephalogram (EEG) is used in the neurological prognostication after cardiac arrest. “Highly malignant” EEG patterns classified according to Westhall have a high specificity for poor neurological outcome when applied within protocols of recent studies. However, their predictive performance when applied in everyday clinical practice has not been investigated. We studied the prognostic accuracy and the interrater agreement when standardized EEG patterns were analysed and compared to neurological outcome in a patient cohort at a tertiary centre not involved in the original study of the standardized EEG pattern classification. Methods Comatose patients treated for out-of-hospital cardiac arrest were included. Poor outcome was defined as Cerebral Performance Category 3–5. Two senior consultants and one resident in clinical neurophysiology, blinded to clinical data and outcome, independently reviewed their EEG registrations and categorised the pattern as “highly malignant”, “malignant” or “benign”. These categories were compared to neurological outcome at hospital discharge. Interrater agreement was assessed using Cohen’s Kappa. Results In total, 62 patients were included. The median (IQR) time to EEG was 59 (42–91) h after return of spontaneous circulation. Poor outcome was found in 52 (84%) patients. In 21 patients at least one of the raters considered the EEG to contain a “highly malignant” pattern, all with poor outcome (42% sensitivity, 100% specificity). The interrater agreement varied from kappa 0.62 to 0.29. Conclusion “Highly malignant” patterns predict poor neurological outcome with a high specificity in everyday practice. However, interrater agreement may vary substantially even between experienced EEG interpreters.

Restructuring of healthcare services during the COVID-19 pandemic has led to lockdown of Epilepsy Monitoring Units (EMUs) in many hospitals. The ad-hoc taskforce of the International League Against Epilepsy (ILAE) and the International Federation of Clinical Neurophysiology (IFCN) highlights the detrimental effect of postponing video-EEG monitoring of patients with epilepsy and other paroxysmal events. The taskforce calls for action to continue functioning of Epilepsy Monitoring Units during emergency situations, such as the COVID-19 pandemic. Long-term video-EEG monitoring is an essential diagnostic service. Access to video-EEG monitoring of the patients in the EMUs must be given high priority. Patients should be screened for COVID-19, before admission, according to the local regulations. Local policies for COVID-19 infection control should be adhered to during the video-EEG monitoring. In cases of differential diagnosis where reduction of antiseizure medication is not required, consider home video-EEG monitoring as an alternative in selected patients.

Introduction To guide the neurologist and neurophysiologist with interpretation and implementation of clinical neurophysiological examinations, we aim to provide a systematic review on evidence of electrophysiological features used to differentiate between hyperkinetic movement disorders. Methods A PRISMA systematic search and QUADAS quality evaluation has been performed in PubMed to identify diagnostic test accuracy studies comparing electromyography and accelerometer features. We included papers focusing on tremor, dystonia, myoclonus, chorea, tics and ataxia and their functional variant. The features were grouped as 1) basic features (e.g., amplitude, frequency), 2) the influence of tasks on basic features (e.g., entrainment, distraction), 3) advanced analyses of multiple signals, 4) and diagnostic tools combining features. Results Thirty-eight cross-sectional articles were included discussing tremor (n = 28), myoclonus (n = 5), dystonia (n = 5) and tics (n = 1). Fifteen were rated as 'high quality'. In tremor, the basic and task-related features showed great overlap between clinical tremor syndromes, apart from rubral and enhanced physiological tremor. Advanced signal analyses were best suited for essential, parkinsonian and functional tremor, and cortical, non-cortical and functional jerks. Combinations of electrodiagnostic features could identify essential, enhanced physiological and functional tremor. Conclusion Studies into the diagnostic accuracy of electrophysiological examinations to differentiate between hyperkinetic movement disorders have predominantly been focused on clinical tremor syndromes. No single feature can differentiate between them all; however, a combination of analyses might improve diagnostic accuracy.

The article presents two clinical cases of intensive care unit (ICU) patients with periodic discharges. Examination according to the American Clinical Neurophysiology Society (ACNS) protocol with the use of electroencephalography and functional probes allows differential diagnosis of periodic discharges, which makes it possible to conduct early pathophysiological treatment, to assess its effectiveness in dynamics and to avoid unjustified prescription of antiepileptic drugs. At the same time, the prognosis of the disease and the effectiveness of treatment are largely determined by the etiology of the disease. Evaluation of periodic discharges of three-phase morphology in ICU, considering its nosological nonspecificity, is rational to carry out according to the ACNS recommendations, indicating the ictal genesis, background activity, response to antiepileptic drugs.

Patients with a drug-resistant form of epilepsy can be treated by neurosurgery through the destruction or separation of the epileptic focus. If the results of clinical, neuro-imaging and neurophysiological methods are discordant, then the localization of the epileptogenic zone is performed based on the results of long-term invasive monitoring of the bioelectrical activity of the cortex and deep structures of the brain. The aim of this work was the retrospective analysis of the results of invasive monitoring of the bioelectrical activity of the brain to clarify the mechanisms of the formation of patterns of interictal and ictal activity in structural epilepsy. The study included 35 patients (18 men, 17 women) with drug-resistant temporal lobe epilepsy, who were treated at the Polenov Neurosurgical Institute. The examination included video-EEG monitoring, long-term invasive monitoring of bioelectrical activity of the cortex, and deep brain structures. The patients were divided into two groups according to the type of surgical treatment: 1) micro-surgical resection of the epileptic focus, including the zone of structural changes (24 patients); 2) stereotactic destruction of the amygdala-hippocampal complex (6 patients). The follow-up of the outcomes of the surgical treatment took place over 2-3 years. Depending on the results of the surgical treatment, the patients were divided into two groups: 1) patients with a favorable outcome (Engel 1–2) — 15 patients and 2) patients with no positive dynamics and a relatively poor outcome (Engel 3–4) — 15 patients. The results obtained showed that the patterns of interictal and ictal activity in their totality determine the neurophysiology, i.e the phenotype of temporal lobe epilepsy, reflecting the interference of pathogenetic and sanogenetic mechanisms. The localization of the epileptogenic zone should be based on the cumulative assessment of interictal and ictal activity. The presence of more than one focus of interictal activity, the secondary spread of epileptiform activity from the primary focus, are prognostically unfavorable factors.

Objective To describe iatrogenic lesions of the peripheral nervous system and their relationship with different orthopaedic and traumatological procedures, through their assessment by means of electromyographic study. Material and methods Retrospective descriptive study of the electromyographies performed in the clinical neurophysiology service of the Hospital General Universitari de Castello between July 2015 and March 2019, recovering those in which the aetiology was diagnosed as iatrogenic in relation to surgical procedures and analysing those that were initiated after orthopaedic and traumatological procedures. Results Of the total number of electromyographies reviewed, 1.37% corresponded to iatrogenic surgical lesions and 55.1% of these were secondary to orthopaedic surgery and traumatology procedures, the incidence in relation to the procedures performed was 0.65%. The most frequent locations related to injuries were the lumbar spine, hip and hand/wrist. Injuries due to postural causes not directly related to the surgical field are noteworthy. Conclusion Iatrogenic injuries to the peripheral nervous system after orthopaedic surgery and traumatology procedures are infrequent, but given their mechanism of injury and the high severity of most of them, it would be advisable to implement corrective mechanisms to reduce their incidence. Level of evidence: IV.

This case series describes three patients affected by severe acute respiratory syndrome coronavirus 2, who developed polyradiculoneuritis as a probable neurological complication of coronavirus disease 2019 (COVID‐19). A diagnosis of Guillain Barré syndrome was made on the basis of clinical symptoms, cerebrospinal fluid analysis, and electroneurography. In all of them, the therapeutic approach included the administration of intravenous immunoglobulin (0.4 gr/kg for 5 days), which resulted in the improvement of neurological symptoms. Clinical neurophysiology revealed the presence of conduction block, absence of F waves, and in two cases, a significant decrease in amplitude of compound motor action potential cMAP. Due to the potential role of inflammation on symptoms development and prognosis, interleukin‐6 (IL‐6) and IL−8 levels were measured in serum and cerebrospinal fluid during the acute phase, while only serum was tested after recovery. Both IL‐6 and IL‐8 were found increased during the acute phase, both in the serum and cerebrospinal fluid, whereas 4 months after admission (at complete recovery), only IL‐8 remained elevated in the serum. These results confirm the inflammatory response that might be linked to peripheral nervous system complications and encourage the use of IL‐6 and IL‐8 as prognostic biomarkers in COVID‐19.

Introduction Thoracic Outlet Syndrome (TOS) is a group of conditions characterized by compression of the nerves, arteries and veins in the lower neck and upper chest area. On average, six physicians of different specialities need 4.3 years to develop TOS diagnosis. Early detection of changes in transmission of nerve impulses within the brachial plexus may lead to faster and more effective treatment of patients. Aim The aim of the study is to present the scheme of diagnostic tests of clinical neurophysiology contributing to the objective diagnosis of TOS, as well as the positive results of tests in a group of sixteen patients with clinically confirmed pathological symptoms. Material and methods Sixteen patients with clinically diagnosed TOS and sixteen healthy people as a control group aged from 18 to 36 participated in this study. In both groups of subjects, bilateral clinical neurophysiological diagnostics tests were carried out: an examination of the sensory perception with von Frey’s filaments within C4-C8 dermatomes, examination of surface electromyography (sEMG) during maximal contractions when recordings from proximal and distal muscles of the upper extremities were performed, the electroneurographic transmission of nerve impulses in selected nerves of the upper extremities (ENG) and motor evoked potentials recordings induced with the magnetic field (MEP) following oververtebral C5 and C6 stimulation. Results Comparing to studies performed in a control group of healthy volunteers, more than 50% of patients with clinical symptoms of TOS had confirmed abnormalities in the diagnostic tests of clinical neurophysiology, unilaterally or bilaterally. Conclusions In the diagnosis of TOS, sEMG recordings from the distal muscles of upper extremities during maximal contractions after induction of ischemia (“hand-raised test”), ENG segmental examination of nerve impulses transmission in motor fibers after stimulation of the median and ulnar nerves, and MEP examination after oververtebral C5 and C6 stimulation are particularly useful. Confirmation of a relatively high percentage of positive TOS tests in patients requires a greater number of neurophysiological examinations. Keywords: Thoracic Outlet Syndrome, neurophysiological diagnostics, motor evoked potentials

Objective: While integrity of spinal pathways below injury is generally thought to be an important factor in the success-rate of neuromodulation strategies for spinal cord injury (SCI), it is still unclear how the integrity of these pathways conveying the effects of stimulation should be assessed. In one of our institutional case series of five patients receiving dorsal root ganglion (DRG)-stimulation for elicitation of immediate motor response in motor complete SCI, only two out of five patients presented as responders, showing immediate muscle activation upon DRG-stimulation. The current study focuses on post hoc clinical-neurophysiological tests performed within this patient series to illustrate their use for prediction of spinal pathway integrity, and presumably, responder-status. Materials and Methods: In a series of three nonresponders and two responders (all male, American Spinal Injury Association [ASIA] impairment scale [AIS] A/B), a test-battery consisting of questionnaires, clinical measurements, as well as a series of neurophysiological measurements was performed less than eight months after participation in the initial study. Results: Nonresponders presented with a complete absence of spasticity and absence of leg reflexes. Additionally, nonresponders presented with close to no compound muscle action potentials (CMAPs) or Hofmann(H)-reflexes. In contrast, both responders presented with clear spasticity, elicitable leg reflexes, CMAPs, H-reflexes, and sensory nerve action potentials, although not always consistent for all tested muscles. Conclusions: Post hoc neurophysiological measurements were limited in clearly separating responders from nonresponders. Clinically, complete absence of spasticity-related complaints in the nonresponders was a distinguishing factor between responders and nonresponders in this case series, which mimics prior reports of epidural electrical stimulation, potentially illustrating similarities in mechanisms of action between the two techniques. However, the problem remains that explicit use and report of preinclusion clinical-neurophysiological measurements is missing in SCI literature. Identifying proper ways to assess these criteria might therefore be unnecessarily difficult, especially for nonestablished neuromodulation techniques.

Previous literature has shown that social identity influences consumer decision-making towards branded products. However, its influence on ones’ own sensory perception of an ingroup (or outgroup) associated brand’s product (i.e. sponsor) is seldom documented and little understood. Here, we investigate the impact of social identity (i.e. team identification) with a football team on the sensorial experience and willingness to buy a beverage, said to be sponsoring the ingroup or the outgroup team. Ninety subjects participated in one of three sensorial experience conditions (matched identity: ingroup beverage; mismatched identity: outgroup beverage; control: no group preference). Each participant tasted the new sponsoring beverage and answered a questionnaire about their subjective sensorial experience of the beverage. EEG and BVP were synchronously collected throughout. Analyses revealed that team identification does not influence subjective responses and only slightly modulates physiological signals. All participants reported high valence and arousal values while physiological signals consistently translated negative affects across groups, which showed that participants reported to be happy/excited about trying the beverage while their physiological signals showed that they were feeling sad/depressed/angry. Crucially, despite a similar sensorial experience, and similar socially desirable report of the subjective experience, only participants in the matched identity group demonstrate higher willingness to buy, showing that the level of team identification, but not taste or beverage quality, influences willingness to buy the said sponsor’s product.

The human auditory system often relies on relative pitch information to extract and identify auditory objects; such as when the same melody is played in different keys. The current study investigated the mental chronometry underlying the active discrimination of unfamiliar melodic six-tone patterns by measuring behavioural performance and event-related potentials (ERPs). In a roving standard paradigm, such patterns were either repeated identically within a stimulus train, carrying absolute frequency information about the pattern, or shifted in pitch (transposed) between repetitions, so only relative pitch information was available to extract the pattern identity. Results showed that participants were able to use relative pitch to detect when a new melodic pattern occurred. Though in the absence of absolute pitch sensitivity significantly decreased and behavioural reaction time to pattern changes increased. Mismatch-Negativity (MMN), an ERP indicator of auditory deviance detection, was elicited at approximately 206 ms after stimulus onset at frontocentral electrodes, even when only relative pitch was available to inform pattern discrimination. A P3a was elicited in both conditions, comparable in amplitude and latency. Increased latencies but no differences in amplitudes of N2b, and P3b suggest that processing at higher levels is affected when, in the absence of absolute pitch cues, relative pitch has to be extracted to inform pattern discrimination. Interestingly, the response delay of approximately 70 ms on the behavioural level, already fully manifests at the level of N2b. This is in accordance with recent findings on implicit auditory learning processes and suggests that in the absence of absolute pitch cues a slowing of target selection rather than a slowing of the auditory pattern change detection process causes the deterioration in behavioural performance.

Background: We present two patients with the Lewis-Sumner variant of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), charting the diagnostic challenge posed by their clinical presentation and electrodiagnostic findings. The learning points center on the use of magnetic resonance imaging (MRI) in establishing a definitive diagnosis when clinical and neurophysiology data do not otherwise add up. Cases: The first patient presented with slowly progressive asymmetric distal weakness of the lower limbs with wasting, weakness, areflexia and numbness on examination. The second patient experienced stepwise asymmetric hand/forearm weakness with deformity and areflexia, plus mild distal sensory impairment. Neurophysiological studies for both patients were initially most suggestive of mononeuritis multiplex, with no evidence of demyelination. Conclusion: The possibility of asymmetric or multifocal CIDP, the Lewis-Sumner variant, should not be forgotten in suspected mononeuritis multiplex and the value of MRI in such cases is discussed.

The objective of this clinical practice guideline (CPG) is to provide recommendations for healthcare personnel working with patients with epilepsy on the use of wearable devices for automated seizure detection in patients with epilepsy, in outpatient, ambulatory settings. The Working Group of the International League Against Epilepsy (ILAE) and the International Federation of Clinical Neurophysiology (IFCN) developed the CPG according to the methodology proposed by the ILAE Epilepsy Guidelines Working Group. We reviewed the published evidence using The Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement and evaluated the evidence and formulated the recommendations following the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. We found high level of evidence for the accuracy of automated detection of generalized tonic-clonic seizures (GTCS) and focal-to-bilateral tonic-clonic seizures (FBTCS) and recommend the use of wearable automated seizure detection devices for selected patients when accurate detection of GTCS and FBTCS is recommended as a clinical adjunct. We also found a moderate level of evidence for seizure types without GTCS or FBTCS. However, it was uncertain whether the detected alarms resulted in meaningful clinical outcomes for the patients. We recommend using clinically validated devices for automated detection of GTCS and FBTCS, especially in unsupervised patients, where alarms can result in rapid intervention (weak/conditional recommendation). At present, we do not recommend clinical use of the currently available devices for other seizure types (weak/conditional recommendation). Further research and development are needed to improve the performance of automated seizure detection and to document their accuracy and clinical utility.

One of the most important fields in clinical neurophysiology is an electroencephalogram (EEG). It is a test used to detect problems related to the brain electrical activity, and it can track and records patterns of brain waves. EEG continues to play an essential role in diagnosis and management of patients with epileptic seizure disorders. Nevertheless, the outcome of EEG as a tool for evaluating epileptic seizure is often interpreted as a noise rather than an ordered pattern. The mathematical modelling of EEG signals provides valuable data to neurologists, and is heavily utilized in the diagnosis and treatment of epilepsy. EEG signals during the seizure can be modeled as ordinary differential equation (ODE). In this study we will present an alternative form of ODE of EEG signals through the seizure.

Clinical neurophysiological testing is an important integral part of neurological diagnosis and management. During Covid-19 pandemic non-emergency clinics have suffered adversely. WHO declared Covid-19 pandemic in March 2020. Clinical records from March 2019 to March 2021 were analyzed, for impact of pandemic on profile of 924 patients referred for nerve conduction studies (NCS). It was observed that percentage of referrals showing normal NCS decreased from 48.64% to 28.45%, Carpal tunnel syndrome (CTS) cases - decreased from 60.45% to 46.58%of the total abnormal cases, mild CTS cases - decreased from 36.11% of to 26.2% of total CTS patients, traumatic nerve injuries -increased from 6.96% before Covid-19 to 18.02% during the pandemic and the radiculopathies diagnosed - increased from 7.8% to 11.8%. Pandemics are difficult situations and these findings prompt us to question “Is the prolonged stay at home, and work from home damaging our spine and increasing radiculopathies?” “Are we inadvertently missing the milder cases?” “Is the pandemic stress taking its toll in increased percentage of traumatic nerve injuries?” There is a urgent need to study more about this effect. This will help us to be better prepared for such pandemics in future, and bring about necessary changes in our healthcare system.&nbsp

Background: Hypoxic-ischemic encephalopathy (HIE) is one of the main causes of neurodevelopmental disorders. We developed a model that has diagnostic and prognostic value in predicting the neurodevelopmental outcomes in newborns with HIE. HIE staging allows us to start therapeutic interventions early in newborns with suspected encephalopathy. Methods: This was a retrospective study in a cohort of 58 full-term neonates with clinical suspicion of HIE. We assessed electroclinical variables at birth [etiology of hypoxia, neonatal seizures, HIE stages based on Sarnat criteria, use of therapeutic hypothermia, neuroimaging tests and electroencephalography (EEG) findings] and two years of follow up (EEG findings, development of epilepsy, the presence of cognitive deficits, behavioral issues, language problems, visual or hearing disturbances, and cerebral palsy). Results: There was a high electro-clinical correlation to severe HIE (88.8%) and moderate HIE (50%). There was a considerable proportion of patients affected by mild HIE, based on clinical examination, who presented with an abnormal EEG (32.3%). There is a relationship between the onset of neonatal seizures, epilepsy, and severe HIE diagnosed with EEG (88.9%). A higher percentage of patients with moderate and severe HIE, based on EEG findings, present abnormal results in cranial ultrasound and cerebral magnetic resonance imaging (62.5%). At two years of age, functional neurodevelopment disturbances were observed most frequently in patients affected with severe and moderate HIE based on EEG. Conclusions: This study shows a model with diagnostic and prognostic value in predicting newborns' neurodevelopmental outcomes with suspected HIE. This knowledge allows us to assess the role of performing serial EEG in patients with suspected HIE and the relevance of EEG findings in the prognosis of neurodevelopmental disorders.

The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation. Underpinnings in the understanding of dystonia span from the peripheral, segmental and suprasegmental levels to the cortex, and various electrophysiological tests have been applied in the course of time to elucidate the origin of dystonia pathophysiology. While loss of inhibition remains to be the key finding in this regard, intricacies and variabilities exist, thus leading to a notion that perhaps dystonia should best be gleaned as network disorder. Interestingly, the complex process has now spanned towards the understanding in terms of networks related to the cerebellar circuitry and the neuroplasticity. What is evolving towards a better and cohesive view will be neurophysiology attributes combined with structural dynamic imaging. Such a sound approach will significantly lead to better therapeutic modalities in the future.

الملخص: أهداف البحث: صممت الدراسة لتقييم النتاج والنمط والعوامل التي ترتبط بشكل مستقل بتشوهات التخطيط الدماغي في صرع الطفولة لدى السعوديين. طرق البحث: وصفنا السمات الأولى لمخطط كهربية الدماغ وقيمنا العوامل المرتبطة بها في عينة من الأطفال المصابين بالصرع في المجتمع السعودي. اعتمد الاتحاد الدولي لجمعيات تخطيط كهربية الدماغ والفيزيولوجيا العصبية السريرية تعريف التصريفات الصرعية بين النشبات (نشاط الصرع بين النشبات) في الدراسة. النتائج: كان ٧٥٦ مريضا من الأطفال منهم ٤٢٧ (٥٦.٥٪) من الذكور و٣٢٩ (٤٣.٥٪) من الإناث مع التشخيص السريري للصرع لديهم تخطيط كهربية الدماغ. سريريا، النوبة كانت معممة في ٦١٩ (٨١.٩٪) مريضا وبؤرية في ١٣٧ (١٨.١٪) مريضا. عانى ٣٩٧ مريضا (٥٢.٥١٪) من شذوذ في مخطط كهربية الدماغ، بينما كان مخطط كهربية الدماغ طبيعيا عند ٣٥٩ مريضا (٤٧.٤٩٪). كان تواتر النوبة والجنس ووجود تاريخ عائلي للصرع والعمر منبئات مستقلة لوجود تشوهات تخطيط كهربية الدماغ. الاستنتاجات: كشفت الدراسة أن نتاج ٥٢٪ من مخطط كهربية الدماغ غير طبيعي لدى الأطفال المصابين بالصرع. وكان العمر والجنس والتاريخ العائلي وتواتر النوبات منبئات مستقلة لوجود شذوذ في مخطط كهربية الدماغ في صرع الطفولة. Abstract: Objective: The study was designed to evaluate the yield, pattern, and factors that are independently associated with electroencephalography (EEG) abnormalities in childhood epilepsy in a Saudi population. Methods: We characterised the features of the first EEG and evaluated the associated factors in children with epilepsy in a Saudi population. The features of interictal epileptiform discharges (interictal epileptiform activity (IEA)) adopted by the International Federation of Societies for Electroencephalography and Clinical Neurophysiology were used in the study. Result: A total of 756 paediatric patients, comprised of 427 men (56.5%) and 329 women (43.5%) with a clinical diagnosis of epilepsy, underwent EEG. Clinically, seizure was generalised in 619 (81.9%) patients and focal in 137 (18.1%). Among the patients, 397 (52.51%) had an abnormal EEG, while EEG was normal in 359 (47.49%) patients. Seizure frequency, gender, family history of epilepsy, and age were independent predictors of the presence of EEG abnormalities. Conclusion: This study revealed a yield of 52% abnormal EEG findings in children with epilepsy. Age, gender, family history, and seizure frequency were independent predictors of the presence of EEG abnormalities in childhood epilepsy.

2012 erarbeitete eine EEG-Expertengruppe der American Clinical Neurophysiology Society (ACNS) eine standardisierte Terminologie fur EEG Muster, die bei kritisch kranken Patienten haufig sind. Bis dahin existierte keine einheitlich akzeptierte Nomenklatur fur diese EEG Muster, wie zum Beispiel periodische Entladungen, fluktuierende rhythmische Muster und Kombinationen der beiden. Dabei bestand auch kein Konsens welche Muster mit welchem neuronalen Schaden korrelieren, welche Muster behandelt werden mussen oder wie aggressiv die Behandlung erfolgen sollte. Um diese Fragen anzugehen entwickelte diese Gruppe eine standardisierte Terminologie zunachst fur den wissenschaftlichen Einsatz. Ziel war es die Kommunikation zu erleichtern, indem Begriffe mit klinischer Konnotation vermieden wurden und um damit multizentrische Forschung zu erleichtern. In 2012 a group of experts in electroencephalography of the American Clinical Neurophysiology Society (ACNS) elaborated a standardized terminology for EEG patterns that are common in critically ill patients. Till that date there was no uniformly accepted nomenclature for these EEG patterns, such as periodic discharges, fluctuating rhythmic patterns, and combinations of the two. In addition, there was also no consensus on which patterns correlate with neuronal damage, which patterns need to be treated, or how aggressively to treat them. In order to address these issues, the group developed a standardized terminology to be used primarily in the research setting. The goal is to facilitate communication eliminating terms with clinical connotations and therefore allowing multicenter research projects.

Highlights • Intercostal neuralgia and latissimus dorsi muscle jerks can occur after posterolateral thoracotomy. • Clinical neurophysiology helps to determine targeted treatments for the different neuromuscular pathologies. • Ehlers-Danlos Syndrome increases the predisposition of iatrogenic nerve injuries., Introduction Post-thoracotomy pain syndrome (PTPS) is a common complication related to intercostal nerve injury. During this type of surgery, although less frequently, thoracodorsal and long thoracic nerves can also be injured, and jerks of peripheral origins may appear. We report a case with intercostal neuralgia and latissimus dorsi muscle jerks after posterolateral thoracotomy. Case report A 55-year-old woman with Ehlers-Danlos Syndrome presented with a typical picture of PTPS along the right T5 dermatome following posterolateral thoracotomy at the level of the fifth intercostal space. Approximately six months after the surgery she developed frequent jerk-like involuntary movements of the right latissimus dorsi muscle. Neuropathic pain along the T5 dermatome was partially relieved with thoracic epidural block. No special attention was paid to the jerks until three years later. A neurophysiological study demonstrated a peripheral origin of these movements and the patient was then treated with periodic injections of botulinum toxin. In response, involuntary movements of the latissimus dorsi muscle disappeared. Significance To our knowledge, this is the first case with PTPS and post-thoracotomy latissimus dorsi muscle jerks in a patient with Ehlers-Danlos Syndrome. A correct diagnosis together with identification of iatrogenic neuropathic disorders allow the delivery of targeted treatments. In such cases clinical neurophysiology helps to determine a correct diagnosis.

Tertiary care centers in Russia were subdivided on two categories during recent COVID-19 outbreak and counter infection measures, undertaken by the government. In the first category were the centers, providing medical care solely to the COVID-19 cases; in second hospitals worked with all other cases, excluding COVID-19 ones. COVID-19-oriented centers are taking strict protective measures against the infection, with medical and other staff working in the individual biohazard protection suits, full disinfection at the border between the clean and unclean zones, thorough medical supervision over the health of all the employees. In the second category centers observation regime was implemented, with the obligatory medical masks and disposable lab coats. wearing, as well as thorough medical supervision over the health of all the employees. These different regimes determine some features of clinical neurophysiology in these centers. In the case of electroencephalography (EEG) main point is the real need of the procedure in the certain clinical situation. In COVID-19 cases all functional tests should be excluded from the protocol; procedure have to be performed in shortest time possible. EEG is performed according to good clinical practice and consensus protocols with thorough and strict disinfection of the devise and all cables, caps etc. If the patient was in the prone position during the procedure, this should be noted for the neurophysiologist. Conduction studies may be performed in the possible coronavirus-associated Guillain–Barré syndrome or critical illness polyneuropathies. Needle myography may be needed only in the rare cases of coronavirus-associated acute myelitis, in all other cases conduction studies are more than enough.

The photoparoxysmal response (PPR) is defined as the occurrence of generalized spike, spike-wave or polyspike-wave discharges consistently elicited by intermittent photic stimulation (IPS). PPR is not well studied in Sub-Saharan African people. We prospectively studied the epidemiological, clinical, and EEG characteristics of PPR among consecutive patients recorded at the clinical neurophysiology unit of Fann University Hospital (Dakar, Senegal). Among 6,808 EEG recordings including 3,065 pathological EEGs, we collected 56 EEGs with PPR (0.8% of all recorded EEGs and 1.8% of anormal EEGs), from 31 women and 25 men (sex ratio: 0.8). The mean age was 13.3 years (range: 8 months to 59 years). The peak of photosensitivity was found in the range of 6 to 10 years. Of the PPR cases, 12 had clinical manifestations during IPS. Generalized epilepsy was diagnosed in 23 (41%) patients and 18 (32%) had focal epilepsies. The most epileptogenic stimulation frequencies were between 12 and 24 Hz (range: 1-28 Hz). PPR were mainly triggered during eye closure (64%), and 41 patients (73% of PPR cases) were classified as Type 4 (Waltz classification). Our results confirm lower rates of photosensitivity in African Sub-Saharan people compared with others. Although the current data do not support a role of short-term ambient light levels, subject to consistent data from larger cohorts, it may be interesting to study the probable epigenetic-mediated protective role of sunshine against photosensitivity.

Intraoperative neuromonitoring was introduced in the second half of the 20th century with the goal of preventing patient morbidity for patients undergoing complex operations of the central and peripheral nervous system. Since its early use for scoliosis surgery, the growth and utilization of IOM techniques expanded dramatically over the past 50 years to include spinal tumor resection and evaluation of cerebral ischemia. The importance of IOM has been broadly acknowledged, and in 1989, the American Academy of Neurology (AAN) released a statement that the use of SSEPs should be standard-of-care during spine surgery. In 2012, both the AAN and the American Clinical Neurophysiology Society (ACNS) recommended that: “Intraoperative monitoring (IOM) using SSEPs and transcranial MEPs be established as an effective means of predicting an increased risk of adverse outcomes, such as paraparesis, paraplegia, and quadriplegia, in spinal surgery.” With a multimodal approach that combines SSEPs, MEPs, and sEMG with tEMG and D waves, as appropriate, sensitivity and specificity can be maximized for the diagnosis of reversible insults to the spinal cord, nerve roots, and peripheral nerves. As with most patient safety efforts in the operating room, IOM requires contributions from and communication between a number of different teams. This comprehensive review of neuromonitoring techniques for surgery on the central and peripheral nervous system will highlight the technical, surgical and anesthesia factors required to optimize outcomes. In addition, this review will discuss important trouble shooting measures to be considered when managing ION changes concerning for potential injury.

INTRODUCTION: This series characterises 9 patients with neurohistopathologically proven peripheral nerve neurolymphomatosis. METHODS: A search of the hospital neuropathology database from 2002-2019 identified biopsy proven cases. Clinical data, investigation modalities, treatments and outcomes were collated. RESULTS: Median age at neuropathy onset was 47 years, commonly as the initial disease manifestation. Most (8/9) presented with painful asymmetrical sensory disturbance, with additional cranial nerve involvement in three. Neurophysiology typically demonstrated multiple axonal mononeuropathies. Cerebrospinal fluid protein was often raised (6/8). Magnetic resonance imaging suggested peripheral nerve infiltration in 6/9 and positron emission tomography CT in 4/9. Bone marrow biopsy was abnormal in 6/8. Treatment involved systemic or intrathecal chemotherapy and radiotherapy. Median survival was 23 months. DISCUSSION: Neurolymphomatosis is a rare but important cause of neuropathy, particularly in those lacking systemic evidence of lymphoma as correct aggressive treatment can prolong survival. Nerve biopsy is essential to classify lymphoma type and rule out alternatives. Keywords [181] Peripheral neuropathy, [216] Nerve tumour, [283] All clinical neurophysiology, [58] Natural history studies, [150] Haematologic This article is protected by copyright. All rights reserved.

Objective To find and validate the optimal combination of criteria that define interictal epileptiform EEG discharges (IEDs). Our target was a specificity over 95%, to avoid over-reading in clinical EEG. Methods We constructed 63 combinations of the six criteria from the operational definition of IEDs, recently issued in the EEG-glossary of the International Federation of Clinical Neurophysiology (IFCN). The diagnostic gold standard was derived from video-EEG recordings. In a testing EEG dataset from 100 patients, we selected the best performing combinations of criteria and then we validated them in an independent dataset from 70 patients. We compared their performance with subjective, expert-scorings and we determined inter-rater agreement (IRA). Results Without using criteria, the specificity of expert-scorings was lower than the pre-defined threshold (86%). The best performing combination of criteria was the following: waves with spiky morphology, followed by a slow-afterwave and voltage map suggesting a source in the brain. In the validation dataset this achieved a specificity of 97% and a sensitivity of 89%. IRA was substantial. Conclusions The optimized set of criteria for defining IEDs has high accuracy and IRA. Significance Using these criteria will contribute to decreasing over-reading of EEG and avoid misdiagnosis of epilepsy.

Discrimination in the workplace when documented is illegal but is seen to still exist in some forms whether based on culture, race, or gender. Each of these disparities warrants further discussion and study because of their significant impacts on hiring decisions, career advancement, and compensation. In this article, the authors have focused their attention on gender disparity in the fields of neurology and clinical neurophysiology and shared the data currently available to them. At a time when the field of clinical neurophysiology has seen enormous growth, gender disparity in leadership and compensation remain. Despite the increasing number of women entering the fields of neurology and clinical neurophysiology, women remain underrepresented in national leadership positions. Many women physicians report experiencing gender discrimination despite increasing efforts by universities and medical centers to improve inclusivity and diversity. Equity and inclusivity are not the same and there is a disconnect between the increased numbers of women and their shared experiences in the workplace. Implicit bias undermines the ability of women to advance in their careers. For neurologists, data indicate that the latest gender pay gap is $56,000 (24%), increased from $37,000 in 2015, and is one of the largest pay gaps in any medical specialty. One third of the top 12 medical schools in the United States require that maternity leave be taken through disability coverage and/or sick benefits, and most family leave policies constrain benefits to the discretion of departmental leadership. The authors recommend strategies to improve gender disparity include institutional training to Identify and overcome biases, changes to professional organizations and national scientific meeting structure, transparency in academic hiring, promotion and compensation, and mentorship and sponsorship programs.

SUMMARY Our increasing understanding of the immunopathogenesis of multiple sclerosis has led to the development of many disease-modifying therapies that have revolutionized the care of patients with relapsing forms of the disease. Our understanding of the pathophysiologic basis of progressive forms of the disease is much more limited but has dramatically changed over the past several decades. We are now on the verge of developing therapies that promote remyelination, reduce axonal loss, and restore axonal function. This progress is challenged by inadequate animal models of progressive disease and incomplete biomarkers of progression. In measuring central nervous system function, evoked potentials may have an advantage over biomarkers, which measure only pathologic change. Monitoring multifocal visual evoked potential amplitude may be one possible means of monitoring disease progression in multiple sclerosis. Additional clinical studies are required to document whether evoked potentials can adequately serve as effective biomarkers of progression.

BACKGROUND: During COVID-19 lockdown, non-urgent medical procedures were suspended. Grade of urgency of electroencephalography (EEG) may vary according to the clinical indication, setting, and status of infection of SARS-CoV-2 virus. "Italian Society of Clinical Neurophysiology" (SINC), "Italian League Against Epilepsy" (LICE), and the "Italian Association of Neurophysiology Technologists" (AITN) aimed to provide clinical and technical recommendation for EEG indications and recording standards in this pandemic era. METHODS: Presidents of SINC, LICE, and AITN endorsed three members per each society to formulate recommendations: classification of the degree of urgency of EEG clinical indications, management and behavior of physicians and neurophysiology technologists, hygiene and personal protection standards, and use of technical equipment. RESULTS: Scientific societies endorsed a paper conveying the recommendation for EEG execution in accordance with clinical urgency, setting (inpatients/outpatients), status of SARS-CoV-2 virus infection (positive, negative and uncertain), and phase of governmental restrictions (phase 1 and 2). Briefly, in phase 1, EEG was recommended only for those acute/subacute neurological symptoms where EEG is necessary for diagnosis, prognosis, or therapy. Outpatient examinations should be avoided in phase 1, while they should be recommended in urgent cases in phase 2 when they could prevent an emergency room access. Reduction of staff contacts must be encouraged through rescheduling job shifts. The use of disposable electrodes and dedicated EEG devices for COVID-19-positive patients are recommended. CONCLUSIONS: During the different phases of COVID-19 pandemic, the EEG should be reserved for patients really benefiting from its execution in terms of diagnosis, treatment, prognosis, and avoidance of emergency room access.

Our aim was to determine parameters of motor evoked potential (MEP) from the tongue in healthy persons.Methods. 25 healthy individuals (average age 22.4 ± 6.2 years, range 18–41 years, 12 females & 13 males) were enrolled. All underwent diagnostic TMS, single-pulse protocol, 90-sm round coil, Neiro-MS-D device. Coil was placed on Fz point, registration was performed by the surface electrode on the middle line of the tongue.Results. MEP was registered in all cases, its average latency was 7.14 ± 0.63 ms, average amplitude — 1.79 ± 1.09 μV. There were no gender & age differences.Conclusion. In healthy people aged 18–41 years MEP from the tongue may be registered in 100% of the cases; its average latency is 7.14 ± 0.63 ms, average amplitude — 1.79 ± 1.09 μV; there are no significant age & gender differences. TMS of the tongue according to this protocol is relatively simple, not time-and efforts-consuming & may be widely implemented in clinical neurophysiology.

Background and purposeEpilepsy is most common in lower-income settings where access to electroencephalography (EEG) is generally poor. A low-cost tablet-based EEG device may be valuable, but the quality and reproducibility of the EEG output are not established.MethodsTablet-based EEG was deployed in a heterogeneous epilepsy cohort in the Republic of Guinea (2018-2019), consisting of a tablet wirelessly connected to a 14-electrode cap. Participants underwent EEG twice (EEG1 and EEG2), separated by a variable time interval. Recordings were scored remotely by experts in clinical neurophysiology as to data quality and clinical utility.ResultsThere were 149 participants (41% female; median age 17.9years; 66.6% ≤21years of age; mean seizures per month 5.7±SD 15.5). The mean duration of EEG1 was 53±12.3min and that of EEG2 was 29.6±12.8min. The mean quality scores of EEG1 and EEG2 were 6.4 [range, 1 (low) to 10 (high); both medians 7.0]. A total of 44 (29.5%) participants had epileptiform discharges (EDs) at EEG1 and 25 (16.8%) had EDs at EEG2. EDs were focal/multifocal (rather than generalized) in 70.1% of EEG1 and 72.5% of EEG2 interpretations. A total of 39 (26.2%) were recommended for neuroimaging after EEG1 and 22 (14.8%) after EEG2. Of participants without EDs at EEG1 (n=53, 55.8%), seven (13.2%) had EDs at EEG2. Of participants with detectable EDs on EEG1 (n=23, 24.2%), 12 (52.1%) did not have EDs at EEG2.ConclusionsTablet-based EEG had a reproducible quality level on repeat testing and was useful for the detection of EDs. The incremental yield of a second EEG in this setting was ~13%. The need for neuroimaging access was evident.

Highlights • These guidelines provide orientation to perform clinical neurophysiological studies during COVID-19 pandemic. • Guide to perform protective procedures for healthcare personal doing clinical neurophysiological studies. • Offer a protocol for the disinfection of equipment and supplies in clinical neurophysiological studies., On 31st December 2019, China notified the World Health Organization of an outbreak of atypical pneumonia from patients at a local seafood market in Wuhan, Hubei, China, responsible for a new coronavirus called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) that caused COVID-19 disease, which spread rapidly around the world. WHO declared a state of pandemic (11th March, 2020), which has caused more than 1 million infected and more than 110,000 deaths; it was observed that up to 29% of those infected were health care personnel. The main route of transmission of SARS-CoV2 is through respiratory secretions and direct contact with contaminated surfaces and material. The pandemic induced an international saturation of health care services and a rupture in the supply chain of protective equipment for healthcare personnel, which poses a high occupational risk to all. Based on the different healthcare systems, human resources, infrastructure and medical emergencies that will warrant the conduct of clinical neurophysiology studies and the lack of a guide for the management of the situation, it was decided by an expert task force of the Latin American Chapter of the International Federation of Clinical Neurophysiology to carry out these guidelines for the protection of patient and healthcare professionals conducting clinical neurophysiological studies.

Background:Early consciousness recovery after cardiac arrest (CA) is one of the most explicit and self-evident prognostic factors for clinical outcomes. We aimed to evaluate the prognostic value of electroencephalography (EEG) phenotypes according to the American Clinical Neurophysiology Society’s Critical Care EEG classification for predicting early recovery after CA.Methods:Consecutive patients admitted to the ICU after CA were enrolled. We analyzed Glasgow Coma Scale (GCS) score within 10 days after CA and evaluated mortality within 28 days according to EEG pattern subtype.Results:Among the total of 71 patients, 9 had periodic discharges (PDs) EEG pattern, 4 had rhythmic delta activity (RDA), 8 had spike-and-wave (SW), 22 had low voltage, 5 had burst suppression, and 23 had other EEG patterns. Initial GCS scores, GCS scores 3 days after CA (or 3 days after targeted temperature management [TTM]), and 10 days after CA (or 10 days after TTM) were significantly different among EEG subtypes (p < 0.001, respectively) (Table 2). GCS scores were significantly higher in RDA and the other EEG group compared to the PDs, SW, low voltage, and burst suppression groups (p < 0.001). Significant group × time interactions were observed for the follow-up period between EEG phenotypes (p < 0.001) demonstrating the most increase in the other EEG pattern group.Conclusions:Consciousness states were significantly worse in the PDs, SW, burst suppression, and low-voltage groups compared to the RDA and the other EEG pattern within 10 days after CA. The degree of consciousness recovery differed significantly by EEG pattern subtype within 10 days.

ObjectiveAfter cardiac arrest (CA), epileptiform EEG, occurring in about 1/3 of patients, often but not invariably heralds poor prognosis. We tested the hypothesis that a combination of specific EEG features identifies patients who may regain consciousness despite early epileptiform patterns.MethodsWe retrospectively analyzed a registry of comatose patients post-CA (2 Swiss centers), including those with epileptiform EEG. Background and epileptiform features in EEGs 12–36 hours or 36–72 hours from CA were scored according to the American Clinical Neurophysiology Society nomenclature. Best Cerebral Performance Category (CPC) score within 3 months (CPC 1–3 vs 4–5) was the primary outcome. Significant EEG variables were combined in a score assessed with receiver operating characteristic curves, and independently validated in a US cohort; its correlation with serum neuron-specific enolase (NSE) was also tested.ResultsOf 488 patients, 107 (21.9%) had epileptiform EEG p < 0.00001 each), 12–36 and 36–72 hours reactivity (p < 0.0001 each), 36–72 hours normal background amplitude (p = 0.0004), and stimulus-induced discharges (p = 0.0001) correlated with favorable outcome. The combined 6-point score cutoff ≥2 was 100% sensitive (95% confidence interval [CI], 78%–100%) and 70% specific (95% CI, 59%–80%) for CPC 1–3 (area under the curve [AUC], 0.98; 95% CI, 0.94–1.00). Increasing score correlated with NSE (ρ = −0.46, p = 0.0001). In the validation cohort (41 patients), the score was 100% sensitive (95% CI, 60%–100%) and 88% specific (95% CI, 73%–97%) for CPC 1–3 (AUC, 0.96; 95% CI, 0.91–1.00).ConclusionPrognostic value of early epileptiform EEG after CA can be estimated combining timing, continuity, reactivity, and amplitude features in a score that correlates with neuronal damage.

Background Parkinson's disease patients may show a tremor that appears after a variable delay while the arms are kept outstretched (re-emergent tremor). The objectives of this study were to investigate re-emergent tremor pathophysiology by studying the role of the primary motor cortex in this tremor and making a comparison with rest tremor. Methods We enrolled 10 Parkinson's disease patients with both re-emergent and rest tremor. Tremor was assessed by spectral analysis, corticomuscular coherence and tremor-resetting produced by transcranial magnetic stimulation over the primary motor cortex. We also recorded transcranial magnetic stimulation-evoked potentials generated by motor cortex stimulation during rest tremor, tremor suppression during wrist extension, and re-emergent tremor. Spectral analysis, corticomuscular coherence, and tremor resetting were compared between re-emergent tremor and rest tremor. Results Re-emergent tremor showed significant corticomuscular coherence, causal relation between motor cortex activity and tremor muscle and tremor resetting. The P60 component of transcranial magnetic stimulation-evoked potentials reduced in amplitude during tremor suppression, recovered before re-emergent tremor, was facilitated at re-emergent tremor onset, and returned to values similar to those of rest tremor during re-emergent tremor. Compared with rest tremor, re-emergent tremor showed similar corticomuscular coherence and tremor resetting, but slightly higher frequency. Conclusions Re-emergent tremor is causally related with the activity of the primary motor cortex, which is likely a convergence node in the network that generates re-emergent tremor. Re-emergent tremor and rest tremor share common pathophysiological mechanisms in which the motor cortex plays a crucial role. © 2020 International Parkinson and Movement Disorder Society.

In 1999, the International Federation of Clinical Neurophysiology (IFCN) published "IFCN Guidelines for topographic and frequency analysis of EEGs and EPs" (Nuwer et al., 1999). Here a Workgroup of IFCN experts presents unanimous recommendations on the following procedures relevant for the topographic and frequency analysis of resting state EEGs (rsEEGs) in clinical research defined as neurophysiological experimental studies carried out in neurological and psychiatric patients: (1) recording of rsEEGs (environmental conditions and instructions to participants; montage of the EEG electrodes; recording settings); (2) digital storage of rsEEG and control data; (3) computerized visualization of rsEEGs and control data (identification of artifacts and neuropathological rsEEG waveforms); (4) extraction of "synchronization" features based on frequency analysis (band-pass filtering and computation of rsEEG amplitude/power density spectrum); (5) extraction of "connectivity" features based on frequency analysis (linear and nonlinear measures); (6) extraction of "topographic" features (topographic mapping; cortical source mapping; estimation of scalp current density and dura surface potential; cortical connectivity mapping), and (7) statistical analysis and neurophysiological interpretation of those rsEEG features. As core outcomes, the IFCN Workgroup endorsed the use of the most promising "synchronization" and "connectivity" features for clinical research, carefully considering the limitations discussed in this paper. The Workgroup also encourages more experimental (i.e. simulation studies) and clinical research within international initiatives (i.e., shared software platforms and databases) facing the open controversies about electrode montages and linear vs. nonlinear and electrode vs. source levels of those analyses. (C) 2019 International Federation of Clinical Neurophysiology. Published by Elsevier B.V.

ObjectiveTo define and validate criteria for accurate identification of EEG interictal epileptiform discharges (IEDs) using (1) the 6 sensor space criteria proposed by the International Federation of Clinical Neurophysiology (IFCN) and (2) a novel source space method. Criteria yielding high specificity are needed because EEG over-reading is a common cause of epilepsy misdiagnosis.MethodsSeven raters reviewed EEG sharp transients from 100 patients with and without epilepsy (diagnosed definitively by video-EEG recording of habitual events). Raters reviewed the transients, randomized, and classified them as epileptiform or nonepileptiform in 3 separate rounds: in 2, EEG was reviewed in sensor space (scoring the presence/absence of each IFCN criterion for each transient or classifying unrestricted by criteria [expert scoring]); in the other, review and classification were performed in source space.ResultsCutoff values of 4 and 5 criteria in sensor space and analysis in source space provided high accuracy (91%, 88%, and 90%, respectively), similar to expert scoring (92%). Two methods had specificity exceeding the desired threshold of 95%: using 5 IFCN criteria as cutoff and analysis in source space (both 95.65%); the sensitivity of these methods was 81.48% and 85.19%, respectively.ConclusionsThe presence of 5 IFCN criteria in sensor space and analysis in source space are optimal for clinical implementation. By extracting these objective features, diagnostic accuracy similar to expert scorings is achieved.Classification of evidenceThis study provides Class III evidence that IFCN criteria in sensor space and analysis in source space have high specificity (>95%) and sensitivity (81%–85%) for identification of IEDs.

The attentional blink (AB) phenomenon reveals a bottleneck of human information processing: the second of two targets is often missed when they are presented in rapid succession among distractors. In our previous work, we showed that the size of the AB can be changed by applying transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (lDLPFC) (London & Slagter, Journal of Cognitive Neuroscience, 33, 756–68, 2021). Although AB size at the group level remained unchanged, the effects of anodal and cathodal tDCS were negatively correlated: if a given individual’s AB size decreased from baseline during anodal tDCS, their AB size would increase during cathodal tDCS, and vice versa. Here, we attempted to replicate this finding. We found no group effects of tDCS, as in the original study, but we no longer found a significant negative correlation. We present a series of statistical measures of replication success, all of which confirm that both studies are not in agreement. First, the correlation here is significantly smaller than a conservative estimate of the original correlation. Second, the difference between the correlations is greater than expected due to sampling error, and our data are more consistent with a zero-effect than with the original estimate. Finally, the overall effect when combining both studies is small and not significant. Our findings thus indicate that the effects of lDPLFC-tDCS on the AB are less substantial than observed in our initial study. Although this should be quite a common scenario, null findings can be difficult to interpret and are still under-represented in the brain stimulation and cognitive neuroscience literatures. An important auxiliary goal of this paper is therefore to provide a tutorial for other researchers, to maximize the evidential value from null findings.

Background Cognitive models indicated that social anxiety disorder (SAD) would be caused and maintained by a biased attentional processing of threatening information. This study investigates whether socially anxious children may present impaired attentional engagement and disengagement from negative emotional faces, as well as their underlying event-related potential responses. Methods and findings Fifteen children with high levels of social anxiety (HSA; 9 boys; mean age = 9.99y; SD = 1.14) and twenty low socially anxious children (LSA; 16 boys; mean age = 10.47y; SD = 1.17) participated in a spatial cueing task in which they had to detect targets following neutral/disgusted faces in a valid or invalid location. No group effect was reported on reaction times [p>.05]. However, electrophysiological data showed lower P3a amplitude in HSA children compared with the LSA group when processing facial stimuli. They also reported larger N2 amplitudes for valid-disgusted targets and a larger P3a amplitude for the invalid-disgusted ones. Conclusion In terms of electrophysiological data, our results validated, the hypothesis of attentional disengagement difficulties in SAD children. We also confirm the idea that high levels of social anxiety are associated with cognitive control impairments and have a greater impact on the processing efficiency than on the performance effectiveness.

The digitalization process for organizations, which was inevitably accelerated by the COVID-19 pandemic, raises relevant challenges for Human Resource Management (HRM) because every technological implementation has a certain impact on human beings. Between many organizational HRM practices, recruitment and assessment interviews represent a significant moment where a social interaction provides the context for evaluating candidates’ skills. It is therefore relevant to investigate how different interaction frames and relational conditions affect such task, with a specific focus on the differences between face-to-face (FTF) and remote computer-mediated (RCM) interaction settings. In particular, the possibility of qualifying and quantifying the mechanisms shaping the efficiency of interaction in the recruiter-candidate dyad—i.e. interpersonal attunement—is potentially insightful. We here present a neuroscientific protocol aimed at elucidating the impact of FTF vs. RCM modalities on social dynamics within assessment interviews. Specifically, the hyperscanning approach, understood as the concurrent recording and integrated analysis of behavioural-physiological responses of interacting agents, will be used to evaluate recruiter-candidate dyads while they are involved in either FTF or RCM conditions. Specifically, the protocol has been designed to collect self-report, oculometric, autonomic (electrodermal activity, heart rate, heart rate variability), and neurophysiological (electroencephalography) metrics from both inter-agents to explore the perceived quality of the interaction, automatic visual-attentional patterns of inter-agents, as well as their cognitive workload and emotional engagement. The proposed protocol will provide a theoretical evidence-based framework to assess possible differences between FTF vs. RMC settings in complex social interactions, with a specific focus on job interviews.