Resolving a "W-Shaped" P100 Waveform: Is It Normal or Abnormal?

SUMMARY: Pattern-reversal visual evoked potentials are used to assess the visual pathways. The main waveform of interest is the P100, which is best recorded with electrodes over the mid-occipital region. Most often, the P100 waveform has negative-positive-negative components. Occasionally, it is "W-shaped," with positive-negative-positive components. Although most often a W-shaped P100 waveform indicates an abnormality in the visual pathway, occasionally, it can be normal. A case is presented in which a W-shaped P100 waveform is seen after monocular full-field stimulation of both eyes with 30' checks. To resolve this finding, the pattern-reversal visual evoked potentials is repeated with 60' and 15' checks. With 15' checks a single typical single-peak P100 waveform is seen with normal latency. Evaluation of a W-shaped P100 waveform should involve analysis of various montages, stimulation with different check sizes, and hemifield stimulation to confirm whether the W-shaped waveform is normal or abnormal.

Development of an International Standard Set of Outcomes and Measurement Methods for Routine Practice for Infants, Children, and Adolescents with Epilepsy: The International Consortium for Health Outcomes Measurement Consensus Recommendations.

At present, there is no internationally accepted set of core outcomes or measurement methods for epilepsy clinical practice. The International Consortium for Health Outcomes Measurement (ICHOM) convened an international working group of experts in epilepsy, people with epilepsy, and their representatives to develop minimum sets of standardized outcomes and outcome measurement methods for clinical practice. Using modified Delphi consensus methods with consecutive rounds of online voting over 12 months, a core set of outcomes and corresponding measurement tool packages to capture the outcomes were identified for infants, children, and adolescents with epilepsy. Consensus methods identified 20 core outcomes. In addition to the outcomes identified for the ICHOM Epilepsy adult standard set, behavioral, motor, and cognitive/language development outcomes were voted as essential for all infants and children with epilepsy. The proposed set of outcomes and measurement methods will facilitate the implementation of the use of patient-centered outcomes in daily practice.

A Novel Technique for Intraoperative Mapping of the Somatosensory Cortex.

OBJECTIVE: Intraoperative mapping of the nervous system is used to identify "eloquent" cortical areas. In this technical report, we describe a novel way of mapping the somatosensory cortex so that injury to those critical pathways can be avoided. METHODS: An 8-year-old female with drug resistant epilepsy presented for resection of a right posterior parietal focal cortical dysplasia. Left median nerve stimulation was used to record somatosensory evoked potentials (SEPs) directly from the somatosensory cortex with a strip electrode. A handheld monopolar electrode was also used to record both the median and tibial SEP. Total intravenous anesthesia with propofol and remifentanil was used. RESULTS: SEP recordings were obtained from a 4-contact strip electrode placed across the central sulcus. A phase reversal was identified and the most likely post central gyrus was noted. With the strip electrode left in place, a monopolar handheld electrode was used to record the median nerve SEPs from different locations on the postcentral gyrus. The tibial nerve was also stimulated to record where the highest amplitude tibial nerve SEP was present. This map was used delineate functionally "eloquent" areas to avoid during surgery. During resection, the median nerve SEP was recorded from the strip electrode continuously. No significant change in the SEP was noted, and the patient awoke without any sensory deficits. CONCLUSIONS: Sensory mapping of the cortex is possible with a handheld monopolar electrode. This technique is easy to perform and can help reduce neurological morbidity.

Development of an International Standard Set of Outcomes and Measurement Methods for Routine Practice for Adults with Epilepsy: The International Consortium for Health Outcomes Measurement Consensus Recommendations.

At present, there is no internationally accepted set of core outcomes or measurement methods for epilepsy clinical practice. Therefore, the International Consortium for Health Outcomes Measurement (ICHOM) convened an international working group of experts in epilepsy, people with epilepsy and their representatives to develop minimum sets of standardized outcomes and outcomes measurement methods for clinical practice that support patient-clinician decision-making and quality improvement. Consensus methods identified 20 core outcomes. Measurement tools were recommended based on their evidence of strong clinical measurement properties, feasibility, and cross-cultural applicability. The essential outcomes included many non-seizure outcomes: anxiety, depression, suicidality, memory and attention, sleep quality, functional status, and the social impact of epilepsy. The proposed set will facilitate the implementation of the use of patient-centered outcomes in daily practice, ensuring holistic care. They also encourage harmonization of outcome measurement, and if widely implemented should reduce the heterogeneity of outcome measurement, accelerate comparative research, and facilitate quality improvement efforts.

Facilitation of motor evoked potentials after tetanic peripheral nerve stimulation.

OBJECTIVE: Tetanic stimulation of a peripheral nerve prior to transcranial electrical stimulation (TES) may enhance motor evoked potential (MEP) amplitudes. The purpose of this study was to investigate the post-tetanic MEP (p-MEP) technique in improving MEP amplitudes. METHODS: Conventional TES MEPs (c-MEP) and p-MEPs with left upper limb stimulation (p-MEPUL) or left lower limb stimulation (p-MEPLL) were performed in 26 patients. Bilateral hand and foot MEP amplitudes obtained with each protocol were compared. Subgroup comparisons were performed for myelopathy and peripheral neuropathy patients. Within-subject amplitude differences between c-MEP and each p-MEP technique were compared using a Wilcoxon test. RESULTS: The mean age of the patients was 52.7 years (range, 12-79 years). Overall, p-MEPUL resulted in MEP improvement in 25 of 26 (96%) patients, and p-MEPLL improved MEPs in 19 of 26 (73%) patients. The increase in MEP amplitudes were statistically significant in all muscle groups except left foot. Similar improvements were seen in the myelopathy group; in the neuropathy group, p-MEPUL produced similar results, but p-MEPLL did not. CONCLUSIONS: The p-MEP technique can improve MEP amplitudes, including in patients with myelopathy. In patients with peripheral neuropathy, the results were mixed. SIGNIFICANCE: Tetanic stimulation can enhance intraoperative MEP amplitudes.

Intravenous Ganaxolone: Pharmacokinetics, Pharmacodynamics, Safety, and Tolerability in Healthy Adults.

Ganaxolone, a neuroactive steroid anticonvulsant that modulates both synaptic and extrasynaptic γ-aminobutyric acid type A (GABAA ) receptors, is in development for treatment of status epilepticus (SE) and rare epileptic disorders, and has been approved in the United States for treatment of seizures associated with cyclin-dependent kinase-like 5 deficiency disorder in patients ≥2 years old. This phase 1 study in 36 healthy volunteers evaluated the pharmacokinetics, pharmacodynamics, and safety of intravenous ganaxolone administered as a (i) single bolus, (ii) infusion, and (iii) bolus followed by continuous infusion. After a single bolus over 2 minutes (20 mg) or 5 minutes (10 or 30 mg), ganaxolone was detected in plasma with a median Tmax of 5 minutes, whereas a 60-minute infusion (10 or 30 mg) or a bolus (6 mg over 5 minutes) followed by infusion (20 mg/h) for 4 hours achieved a median Tmax of approximately 1 and 3 hours, respectively. Cmax was dose and administration-time dependent, ranging from 73.8 ng/mL (10 mg over 5 minutes) to 1240 ng/mL (30 mg over 5 minutes). Bolus doses above 10 mg of ganaxolone markedly influenced the bispectral index score with a rapid decline; smaller changes occurred on the Modified Observer's Assessment of Alertness/Sedation scale and in quantitative electroencephalogram. Most adverse events were of mild severity, with 2 events of moderate severity; none were reported as serious. No effects on systemic hemodynamics or respiratory functions were reported. Overall, ganaxolone was generally well tolerated at the doses studied and demonstrated pharmacokinetic and pharmacodynamic properties suitable to treat SE.

Dosing and transition characteristics in people with narcolepsy transitioning from sodium oxybate to low-sodium oxybate: Data from the real-world TENOR study.

OBJECTIVE: The Transition Experience of persons with Narcolepsy taking Oxybate in the Real-world (TENOR) study assessed the real-world experience of people with narcolepsy switching from sodium oxybate (SXB) to low-sodium oxybate (LXB; 92 % less sodium than SXB). METHODS: TENOR is a patient-centric, prospective, observational, virtual-format study. Eligible participants included US adults with narcolepsy transitioning from SXB to LXB (±7 days from LXB initiation). Longitudinal data were collected from baseline (taking SXB) through 21 weeks post-transition. RESULTS: TENOR included 85 participants with narcolepsy (type 1, n = 45; type 2, n = 40). Mean (SD) age was 40.3 (13.0) years; the majority (73 %) were female and White (87 %). At study completion, wake-promoting agents were the most common concomitant medications (47 %). Mean (SD) SXB treatment duration was 57.8 (52.1) months; 96 % took SXB twice nightly. After transitioning, 97 % continued on twice-nightly regimens. Mean (SD) dose of both total nightly SXB (n = 85) and baseline LXB (n = 84) was 7.7 (1.5) g; SXB-LXB dose conversions at baseline were gram-for-gram in 87 % of participants. The mean final total nightly dose of LXB was 7.9 g. The most common participant-reported reasons for transitioning included lower sodium content for improved long-term health (93 %), physician recommendation (47 %), to avoid cardiovascular issues (39 %), to avoid side effects (31 %), and to improve control of narcolepsy symptoms (18 %). CONCLUSION: Most participants transitioned from SXB to LXB using a gram-for-gram strategy. The most commonly cited reason for transition was long-term health benefits due to lower sodium.

Impairment in Functioning and Quality of Life in Patients with Idiopathic Hypersomnia: The Real World Idiopathic Hypersomnia Outcomes Study (ARISE).

Purpose: Idiopathic hypersomnia is a debilitating neurologic sleep disorder characterized by excessive daytime sleepiness, sleep inertia, and prolonged sleep. Its impact on patients' quality of life and daily functioning has not been fully elucidated. The Real World Idiopathic Hypersomnia Outcomes Study (ARISE) evaluated the daily functioning, relationships, cognition, emotional well-being, and productivity/employment of participants with idiopathic hypersomnia. Patients and Methods: ARISE was a US-based virtual cross-sectional survey comprising multiple patient-reported outcome measures (Functional Outcomes of Sleep Questionnaire, short version [FOSQ-10], Quality of Life in Neurological Disorders [Neuro-QoL] Social Roles and Stigma domains, British Columbia Cognitive Complaints Inventory [BC-CCI], Patient Health Questionnaire [PHQ-9], and the Work Productivity and Activity Impairment Questionnaire: Specific Health Problem [WPAI:SHP]). Participants were adults 21-65 years of age with idiopathic hypersomnia. Data were analyzed for all participants and for subgroups with/without long sleep time (LST; self-reported sleep ≥11 hours in 24 hours). Results: Of 75 participants enrolled, most were female (81.3%) and the mean (SD) age was 34.1 (10.7) years. Participants' scores on the FOSQ-10 (mean [SD] score: 10.7 [2.8]) and the Neuro-QoL Social Roles (43.4 [4.2]) and Stigma (57.3 [5.9]) domains reflected impairments in daily functioning and quality of life. More than half of participants reported moderate to severe cognitive complaints (BC-CCI; 62.7%) and moderate to severe depressive symptoms (PHQ-9; 66.7%). Scores on the WPAI:SHP showed substantial impairments in absenteeism, presenteeism, overall work productivity, and overall regular daily activity (mean percent [SD]: 12.3 [23.6], 47.6 [22.7], 51.4 [24.7], and 64.0 [21.9], respectively). These considerable impairments were found in participants with and without LST. Conclusion: ARISE participants with idiopathic hypersomnia demonstrated poor quality of life and impaired functioning across multiple symptom domains.

Effectiveness and tolerability in people with narcolepsy transitioning from sodium oxybate to low-sodium oxybate: Data from the real-world TENOR study.

OBJECTIVES: The Transition Experience of persons with Narcolepsy taking Oxybate in the Real-world (TENOR) study was conducted to provide real-world insight into the experience of people with narcolepsy switching from sodium oxybate (SXB) to low-sodium oxybate (LXB; 92% less sodium than SXB). METHODS: TENOR is a patient-centric, prospective, observational, virtual-format study. Participants were adults with narcolepsy (type 1 or 2) who were transitioning from SXB to LXB treatment (±7 days from LXB initiation). Effectiveness and tolerability data were collected online from baseline (taking SXB) through 21 weeks (taking LXB) via daily and weekly diaries and questionnaires, including the Epworth Sleepiness Scale (ESS), the Functional Outcomes of Sleep Questionnaire, short version (FOSQ-10), and the British Columbia Cognitive Complaints Inventory (BC-CCI). RESULTS: TENOR participants (N = 85) were 73% female with a mean (SD) age of 40.3 (13.0) years. Mean (SD) ESS scores decreased numerically throughout the transition from SXB to LXB (baseline: 9.9 [5.2]; week 21: 7.5 [4.7]), with 59.5% and 75.0% of participants having scores in the normal range (≤10) at baseline and week 21, respectively. Mean (SD) FOSQ-10 scores (baseline: 14.4 [3.4]; week 21: 15.2 [3.2]) and BC-CCI scores (baseline: 6.1 [4.4]; week 21: 5.0 [4.3]) also remained stable. The most common symptoms related to tolerability reported by participants at baseline were sleep inertia, hyperhidrosis, and dizziness (45.2%, 40.5%, and 27.4%, respectively), which decreased in prevalence by week 21 (33.8%, 13.2%, and 8.8%, respectively). CONCLUSIONS: Findings from TENOR confirm maintenance of effectiveness and tolerability when transitioning from SXB to LXB treatment.

Guidelines for Qualifications of Neurodiagnostic Personnel: A Joint Position Statement of the American Clinical Neurophysiology Society, the American Association of Neuromuscular & Electrodiagnostic Medicine, the American Society of Neurophysiological Monitoring, and ASET The Neurodiagnostic Society.

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. Because neurodiagnostics is a growing and dynamic field, the authors fully intend this document to change over time.

Automated Interpretation of Clinical Electroencephalograms Using Artificial Intelligence.

Importance: Electroencephalograms (EEGs) are a fundamental evaluation in neurology but require special expertise unavailable in many regions of the world. Artificial intelligence (AI) has a potential for addressing these unmet needs. Previous AI models address only limited aspects of EEG interpretation such as distinguishing abnormal from normal or identifying epileptiform activity. A comprehensive, fully automated interpretation of routine EEG based on AI suitable for clinical practice is needed. Objective: To develop and validate an AI model (Standardized Computer-based Organized Reporting of EEG-Artificial Intelligence [SCORE-AI]) with the ability to distinguish abnormal from normal EEG recordings and to classify abnormal EEG recordings into categories relevant for clinical decision-making: epileptiform-focal, epileptiform-generalized, nonepileptiform-focal, and nonepileptiform-diffuse. Design, Setting, and Participants: In this multicenter diagnostic accuracy study, a convolutional neural network model, SCORE-AI, was developed and validated using EEGs recorded between 2014 and 2020. Data were analyzed from January 17, 2022, until November 14, 2022. A total of 30 493 recordings of patients referred for EEG were included into the development data set annotated by 17 experts. Patients aged more than 3 months and not critically ill were eligible. The SCORE-AI was validated using 3 independent test data sets: a multicenter data set of 100 representative EEGs evaluated by 11 experts, a single-center data set of 9785 EEGs evaluated by 14 experts, and for benchmarking with previously published AI models, a data set of 60 EEGs with external reference standard. No patients who met eligibility criteria were excluded. Main Outcomes and Measures: Diagnostic accuracy, sensitivity, and specificity compared with the experts and the external reference standard of patients' habitual clinical episodes obtained during video-EEG recording. Results: The characteristics of the EEG data sets include development data set (N = 30 493; 14 980 men; median age, 25.3 years [95% CI, 1.3-76.2 years]), multicenter test data set (N = 100; 61 men, median age, 25.8 years [95% CI, 4.1-85.5 years]), single-center test data set (N = 9785; 5168 men; median age, 35.4 years [95% CI, 0.6-87.4 years]), and test data set with external reference standard (N = 60; 27 men; median age, 36 years [95% CI, 3-75 years]). The SCORE-AI achieved high accuracy, with an area under the receiver operating characteristic curve between 0.89 and 0.96 for the different categories of EEG abnormalities, and performance similar to human experts. Benchmarking against 3 previously published AI models was limited to comparing detection of epileptiform abnormalities. The accuracy of SCORE-AI (88.3%; 95% CI, 79.2%-94.9%) was significantly higher than the 3 previously published models (P < .001) and similar to human experts. Conclusions and Relevance: In this study, SCORE-AI achieved human expert level performance in fully automated interpretation of routine EEGs. Application of SCORE-AI may improve diagnosis and patient care in underserved areas and improve efficiency and consistency in specialized epilepsy centers.

Guidelines for Qualifications of Neurodiagnostic Personnel: A Joint Position Statement of the American Clinical Neurophysiology Society, the American Association of Neuromuscular & Electrodiagnostic Medicine, the American Society of Neurophysiological Monitoring, and ASET - The Neurodiagnostic Society.

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.

Symptom Severity and Treatment Satisfaction in Patients with Idiopathic Hypersomnia: The Real World Idiopathic Hypersomnia Outcomes Study (ARISE).

Objective: Idiopathic hypersomnia is a debilitating sleep disorder characterized by excessive daytime sleepiness, sleep inertia, and prolonged sleep duration. The patient burden of idiopathic hypersomnia is poorly understood. The Real World Idiopathic Hypersomnia Outcomes Study (ARISE) evaluated symptoms and treatment effectiveness/satisfaction in participants with idiopathic hypersomnia. Methods: ARISE was a United States-based virtual cross-sectional survey. Participants were adults 21-65 years of age with idiopathic hypersomnia recruited from social media, the Hypersomnia Foundation website, and a patient panel. Self-assessments included the Epworth Sleepiness Scale (ESS), Idiopathic Hypersomnia Severity Scale (IHSS), Treatment Satisfaction Questionnaire for Medication, version II (TSQM-vII), and additional treatment questions. Data were analyzed for all participants and for subgroups with/without long sleep time (LST; ≥11 hours in 24 hours). Results: Of 75 participants enrolled, most were female (81.3%). The mean (SD) age was 34.1 (10.7) years and 49% had LST. Most participants took off-label prescription medications (89.3%) and/or used other measures (93.3%) to manage their symptoms. The mean (SD) ESS score was 14.5 (3.5) and the mean IHSS score was 35.2 (7.6). Treatment satisfaction was low (mean [SD] TSQM-vII score: overall, 61.9 [21.2]; with LST, 57.9 [21.4]; without LST, 66.7 [20.3]), primarily driven by dissatisfaction with treatment effectiveness. The most common classes of prescription medications used were stimulants (61.3%), wake-promoting agents (28.0%), and antidepressants (18.7%); non-prescription measures used to manage symptoms included caffeine (73.3%), planned naps (34.7%), and individual accommodations (32.0%). Conclusion: Overall, participants with idiopathic hypersomnia, with or without LST, had substantial symptom burden despite most of the study population taking off-label medications and using nonprescription measures to manage symptoms.

Guidelines for Qualifications of Neurodiagnostic Personnel: A Joint Position Statement of the American Clinical Neurophysiology Society, the American Association of Neuromuscular & Electrodiagnostic Medicine, the American Society of Neurophysiological Monitoring, and ASET-The Neurodiagnostic Society.

SUMMARY: 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. Because neurodiagnostics is a growing and dynamic field, the authors fully intend this document to change over time.