Journal of Clinical Neurophysiology最新文献

{"title":"Methods of Evaluating EEG Reactivity in Adult Intensive Care Units: A Review.","authors":"Jaeho Hwang, Sung-Min Cho, Romergryko Geocadin, Eva K Ritzl","doi":"10.1097/WNP.0000000000001078","DOIUrl":"10.1097/WNP.0000000000001078","url":null,"abstract":"<p><strong>Purpose: </strong>EEG reactivity (EEG-R) has become widely used in intensive care units for diagnosing and prognosticating patients with disorders of consciousness. Despite efforts toward standardization, including the establishment of terminology for critical care EEG in 2012, the processes of testing and interpreting EEG-R remain inconsistent.</p><p><strong>Methods: </strong>A review was conducted on PubMed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Inclusion criteria consisted of articles published between January 2012, and November 2022, testing EEG-R on adult intensive care unit patients. Exclusion criteria included articles focused on highly specialized stimulation equipment or animal, basic science, or small case report studies. The Quality In Prognostic Studies tool was used to assess risk of bias.</p><p><strong>Results: </strong>One hundred and five articles were identified, with 26 variables collected for each. EEG-R testing varied greatly, including the number of stimuli (range: 1-8; 26 total described), stimulus length (range: 2-30 seconds), length between stimuli (range: 10 seconds-5 minutes), frequency of stimulus application (range: 1-9), frequency of EEG-R testing (range: 1-3 times daily), EEG electrodes (range: 4-64), personnel testing EEG-R (range: neurophysiologists to nonexperts), and sedation protocols (range: discontinuing all sedation to no attempt). EEG-R interpretation widely varied, including EEG-R definitions and grading scales, personnel interpreting EEG-R (range: EEG specialists to nonneurologists), use of quantitative methods, EEG filters, and time to detect EEG-R poststimulation (range: 1-30 seconds).</p><p><strong>Conclusions: </strong>This study demonstrates the persistent heterogeneity of testing and interpreting EEG-R over the past decade, and contributing components were identified. Further many institutional efforts must be made toward standardization, focusing on the reproducibility and unification of these methods, and detailed documentation in the published literature.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":"577-588"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141300783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Does Hyperventilation Increase the Diagnostic Yield of the Routine Electroencephalogram: A Retrospective Analysis of Adult and Pediatric Cohorts.","authors":"Neerrajah Nadarajah, Michael Fahey, Udaya Seneviratne","doi":"10.1097/WNP.0000000000001066","DOIUrl":"10.1097/WNP.0000000000001066","url":null,"abstract":"<p><strong>Purpose: </strong>While hyperventilation (HV) increases the diagnostic yield of EEG in children, there is conflicting evidence to support its application in adults. For the first time in history, a large cohort of patients has undergone EEGs without HV during the COVID-19 pandemic. Utilizing this opportunity, we sought to investigate whether HV increases the diagnostic yield of EEG in children compared with adults.</p><p><strong>Methods: </strong>Patients aged six years and above who had routine EEGs at Monash Health between January 2019 and December 2020 were studied. The cohort was divided into two, pediatric (younger than 18 years) and adult (18 years or older). Epileptiform abnormalities (ictal and interictal) were the outcomes investigated. The effect of HV was examined with logistic regression to determine odds ratios with 95% confidence intervals.</p><p><strong>Results: </strong>In total, we studied 3,273 patients (pediatric = 830, adult = 2,443). In the pediatric cohort, HV significantly increased the diagnostic yield of absence seizures ( p = 0.01, odds ratios 2.44, 95% confidence intervals 1.21-4.93). In adults, HV did not increase the yield of absence seizures ( p = 0.34, odds ratios 0.36, 95% confidence intervals 0.05-2.88). Interictal epileptiform discharges during HV were significantly more frequent in children compared with adults ( p < 0.001, odds ratios 3.81, 95% confidence intervals 2.51-5.77).</p><p><strong>Conclusions: </strong>Hyperventilation is useful to increase the yield of interictal epileptiform discharges and absence seizures in pediatric patients but not in adults. Hence, routine EEG may be recorded in adults without HV when it is unsafe to perform.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":"640-651"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141446286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Four State Sleep Staging From a Multilayered Algorithm Using Electrocardiographic and Actigraphic Data.","authors":"Mario Garingo, Chaim Katz, Kramay Patel, Stephan Meyer Zum Alten Borgloh, Parisa Sabetian, Jeffrey Durmer, Sharon Chiang, Vikram R Rao, John M Stern","doi":"10.1097/WNP.0000000000001038","DOIUrl":"10.1097/WNP.0000000000001038","url":null,"abstract":"<p><strong>Purpose: </strong>Sleep studies are important to evaluate sleep and sleep-related disorders. The standard test for evaluating sleep is polysomnography, during which several physiological signals are recorded separately and simultaneously with specialized equipment that requires a technologist. Simpler recordings that can model the results of a polysomnography would provide the benefit of expanding the possibilities of sleep recordings.</p><p><strong>Methods: </strong>Using the publicly available sleep data set from the multiethnic study of atherosclerosis and 1769 nights of sleep, we extracted a distinct data subset with engineered features of the biomarkers collected by actigraphic, oxygenation, and electrocardiographic sensors. We then applied scalable models with recurrent neural network and Extreme Gradient Boosting (XGBoost) with a layered approach to produce an algorithm that we then validated with a separate data set of 177 nights.</p><p><strong>Results: </strong>The algorithm achieved an overall performance of 0.833 accuracy and 0.736 kappa in classifying into four states: wake, light sleep, deep sleep, and rapid eye movement (REM). Using feature analysis, we demonstrated that heart rate variability is the most salient feature, which is similar to prior reports.</p><p><strong>Conclusions: </strong>Our results demonstrate the potential benefit of a multilayered algorithm and achieved higher accuracy and kappa than previously described approaches for staging sleep. The results further the possibility of simple, wearable devices for sleep staging. Code is available at https://github.com/NovelaNeuro/nEureka-SleepStaging .</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":"610-617"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11186678/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41131850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Corticothalamic Responsive Neurostimulation for Focal Epilepsy: A Single-Center Experience.","authors":"David Burdette, Sanjay Patra, Lise Johnson","doi":"10.1097/WNP.0000000000001060","DOIUrl":"10.1097/WNP.0000000000001060","url":null,"abstract":"<p><strong>Purpose: </strong>Owing to its extensive, reciprocal connectivity with the cortex and other subcortical structures, the thalamus is considered an important target for neuromodulation in drug-resistant focal epilepsy. Using corticothalamic stimulation, it is possible to modulate both the thalamus and the cortical seizure onset zone. Limited published clinical experience describes corticothalamic stimulation with depth leads targeting one of the anterior (ANT), centromedian (centromedian nucleus), or pulvinar (PUL) thalamic nuclei. However, it is not clear which of these nuclei is the \"best\" therapeutic target.</p><p><strong>Methods: </strong>This study comprised a single-center experience with corticothalamic responsive neurostimulation using the RNS System to target these three thalamic nuclei. Presented here are the methods for target selection and device programming as well as clinical outcomes and a comparison of ictal and nonictal electrophysiological features.</p><p><strong>Results: </strong>In this small retrospective study ( N = 19), responsive corticothalamic neurostimulation was an effective therapy for 79% of patients (≥50% reduction in disabling seizure frequency), regardless of whether the thalamic lead was implanted in the ANT ( N = 2), PUL ( N = 6), or centromedian nucleus ( N = 11). Twenty-six percent of patients reported a reduction in disabling seizure frequency ≥90%. Both high frequency (≥100 Hz) and low (≤20 Hz) frequency were used to stimulate the thalamus depending on the patient's response and ability to tolerate higher charge densities. In all patients, a longer burst duration (2000-5000 ms) was ultimately implemented on the thalamic leads. Across patients, peaks in the intracranial EEG were observed at theta, beta, gamma, and sleep spindle frequencies. Changes in frequency content and distribution were observed over time in all three nuclei.</p><p><strong>Conclusions: </strong>These results indicate that both high frequency and low frequency corticothalamic responsive neurostimulation can potentially be an effective adjunctive therapy in drug-resistant focal epilepsy. These data can also contribute to a broader understanding of thalamic electrophysiology in the context of focal epilepsy.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":"630-639"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11520339/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139403121","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Correlations Between Quantitative EEG Parameters and Cortical Blood Flow in Patients Undergoing Extracorporeal Membrane Oxygenation With and Without Encephalopathy.","authors":"Imad R Khan, Irfaan A Dar, Thomas W Johnson, Emily Loose, Yama Y Xu, Esmeralda Santiago, Kelly L Donohue, Mark A Marinescu, Igor Gosev, Giovanni Schifitto, Ross K Maddox, David R Busch, Regine Choe, Olga Selioutski","doi":"10.1097/WNP.0000000000001035","DOIUrl":"10.1097/WNP.0000000000001035","url":null,"abstract":"<p><strong>Purpose: </strong>The neurologic examination of patients undergoing extracorporeal membrane oxygenation (ECMO) is crucial for evaluating irreversible encephalopathy but is often obscured by sedation or neuromuscular blockade. Noninvasive neuromonitoring modalities including diffuse correlation spectroscopy and EEG measure cerebral perfusion and neuronal function, respectively. We hypothesized that encephalopathic ECMO patients with greater degree of irreversible cerebral injury demonstrate less correlation between electrographic activity and cerebral perfusion than those whose encephalopathy is attributable to medications.</p><p><strong>Methods: </strong>We performed a prospective observational study of adults undergoing ECMO who underwent simultaneous continuous EEG and diffuse correlation spectroscopy monitoring. (Alpha + beta)/delta ratio and alpha/delta Rartio derived from quantitative EEG analysis were correlated with frontal cortical blood flow index. Patients who awakened and followed commands during sedation pauses were included in group 1, whereas patients who could not follow commands for most neuromonitoring were placed in group 2. (Alpha + beta)/delta ratio-blood flow index and ADR-BFI correlations were compared between the groups.</p><p><strong>Results: </strong>Ten patients (five in each group) underwent 39 concomitant continuous EEG and diffuse correlation spectroscopy monitoring sessions. Four patients (80%) in each group received some form of analgosedation during neuromonitoring. (Alpha + beta)/delta ratio-blood flow index correlation was significantly lower in group 2 than group 1 (left: 0.05 vs. 0.52, P = 0.03; right: -0.12 vs. 0.39, P = 0.04). Group 2 ADR-BFI correlation was lower only over the right hemisphere (-0.06 vs. 0.47, P = 0.04).</p><p><strong>Conclusions: </strong>Correlation between (alpha + beta)/delta ratio and blood flow index were decreased in encephalopathic ECMO patients compared with awake ones, regardless of the analgosedation use. The combined use of EEG and diffuse correlation spectroscopy may have utility in monitoring cerebral function in ECMO patients.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":"597-605"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71482164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Book Review for Neuromuscular and Electrodiagnostic Medicine Board Review.","authors":"Nicholas Purcell, Pitcha Chompoopong","doi":"10.1097/WNP.0000000000001111","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001111","url":null,"abstract":"","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":"41 7","pages":"652-653"},"PeriodicalIF":2.3,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142545769","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Diagnostic Value of Bereitschaftspotential in People With Functional Seizures.","authors":"Christoph S Dietze, Dieke van Waart-Houtman, Anne Marthe Meppelink, Mireille Bourez-Swart, Job van der Palen, Maeike Zijlmans, Sandra M A van der Salm","doi":"10.1097/WNP.0000000000001123","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001123","url":null,"abstract":"<p><strong>Purpose: </strong>Bereitschaftspotential (BP) or readiness potential in people with functional movement disorders can aid diagnostic workup. We evaluated the diagnostic value of BP as an interictal EEG marker in people with functional seizures (FS).</p><p><strong>Methods: </strong>We recorded and analyzed BP interictal before intended movements in 17 adults with FS and 17 controls with alternative diagnoses. We evaluated the signals for the presence of BP, latency, amplitude, and early versus late BP.</p><p><strong>Results: </strong>Bereitschaftspotential was present in all except one person with FS. We found no significant differences in the latency and amplitude of BP between participants with FS and controls. The early BP showed the most significant variance in amplitude, latency, and presence.</p><p><strong>Conclusions: </strong>We found interictal typical BP values in participants with FS and variable semiology, while earlier research found interictal no BP in functional movement disorders. These findings do not support the use of BP as an interictal diagnostic tool for FS. Differences in early BP and focus on FS with pure motor semiology are starting points for further research evaluating potential interictal markers in people with FS.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142365431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chronobiological Spatial Clusters of Cortical Regions in the Human Brain.","authors":"Ravindra Arya, Gabrielle T Petito, Jeremy Housekeeper, Jason Buroker, Craig Scholle, Brian Ervin, Clayton Frink, Paul S Horn, Wei Liu, Marc Ruben, David F Smith, Jesse Skoch, Francesco T Mangano, Hansel M Greiner, Katherine D Holland","doi":"10.1097/WNP.0000000000001119","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001119","url":null,"abstract":"<p><strong>Purpose: </strong>We demonstrate that different regions of the cerebral cortex have different diurnal rhythms of spontaneously occurring high-frequency oscillations (HFOs).</p><p><strong>Methods: </strong>High-frequency oscillations were assessed with standard-of-care stereotactic electroencephalography in patients with drug-resistant epilepsy. To ensure generalizability of our findings beyond patients with drug-resistant epilepsy, we excluded stereotactic electroencephalography electrode contacts lying within seizure-onset zones, epileptogenic lesions, having frequent epileptiform activity, and excessive artifact. For each patient, we evaluated twenty-four 5-minute stereotactic electroencephalography epochs, sampled hourly throughout the day, and obtained the HFO rate (number of HFOs/minute) in every stereotactic electroencephalography channel. We analyzed diurnal rhythms of the HFO rates with the cosinor model and clustered neuroanatomic parcels in a standard brain space based on similarity of their cosinor parameters. Finally, we compared overlap among resting-state networks, described in the neuroimaging literature, and chronobiological spatial clusters discovered by us.</p><p><strong>Results: </strong>We found five clusters that localized predominantly or exclusively to the left perisylvian, left perirolandic and left temporal, right perisylvian and right parietal, right frontal, and right insular-opercular cortices, respectively. These clusters were characterized by similarity of the HFO rates according to the time of the day. Also, these chronobiological spatial clusters preferentially overlapped with specific resting-state networks, particularly default mode network (clusters 1 and 3), frontoparietal network (cluster 1), visual network (cluster 1), and mesial temporal network (cluster 2).</p><p><strong>Conclusions: </strong>This is probably the first human study to report clusters of cortical regions with similar diurnal rhythms of electrographic activity. Overlap with resting-state networks attests to their functional significance and has implications for understanding cognitive functions and epilepsy-related mortality.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142361632","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Classifying High-Frequency Oscillations by Morphologic Contrast to Background, With Surgical Outcome Correlates.","authors":"Kurt Qing, Erica Von Stein, Lisa Yamada, Adam Fogarty, Paul Nuyujukian","doi":"10.1097/WNP.0000000000001121","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001121","url":null,"abstract":"<p><strong>Purpose: </strong>Ictal high-frequency oscillations (HFOs) are a reliable indicator of a seizure onset zone for intracranial EEG recordings. Interictal HFOs often are also observed and may be a useful biomarker to supplement ictal data, but distinguishing pathologic from physiologic HFOs continues to be a challenging task. We present a method of classifying HFOs based on morphologic contrast to the background.</p><p><strong>Methods: </strong>We retrospectively screened 31 consecutive patients who underwent intracranial recordings for epilepsy at Stanford Medical Center during a 2-year period, and 13 patients met the criteria for inclusion. Interictal EEG data were analyzed using an automated event detector followed by morphologic feature extraction and k-means clustering. Instead of only using event features, the algorithm also incorporated features of the background adjacent to the events. High-frequency oscillations with higher morphologic contrast to the background were labeled as pathologic, and \"hotspots\" with the most active pathologic HFOs were identified and compared with clinically determined seizure onset zones.</p><p><strong>Results: </strong>Clustering with contrast features produced groups with better separation and more consistent boundaries. Eleven of the 13 patients proceeded to surgery, and patients whose hotspots matched seizure onset zones had better outcomes, with 4 out of 5 \"match\" patients having no disabling seizures at 1+ year postoperatively (Engel I or International League Against Epilepsy Class 1-2), while all \"mismatch\" patients continued to have disabling seizures (Fisher exact test P-value = 0.015).</p><p><strong>Conclusions: </strong>High-frequency oscillations with higher contrast to background more likely represent paroxysmal bursts of pathologic activity. Patients with HFO hotspots outside of identified seizure onset zones may not respond as well to surgery.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142361633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is Intraoperative Muscle Motor Evoked Potential Variability due to Fluctuating Lower Motor Neuron Background Excitability?","authors":"Martín J Segura, María E Talarico, Lucas Piantoni, Mariano A Noel, David B MacDonald","doi":"10.1097/WNP.0000000000001118","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001118","url":null,"abstract":"<p><strong>Purpose: </strong>This pilot study tests the contribution of fluctuating lower motor neuron excitability to motor evoked potential (MEP) variability.</p><p><strong>Methods: </strong>In six pediatric patients with idiopathic scoliosis and normal neurologic examination, cascades of 30 intraoperative H-reflexes (HRs) and MEPs were evoked in the soleus muscle using constant-current stimulators and recorded through surface electrodes with a 20-second interstimulus interval. First, HRs were obtained with an intensity capable of evoking the maximum response. Subsequently, MEPs were obtained with double trains and an intensity of 700 to 900 mA. Coefficients of variation (CVs) of amplitude and area under the curve from HRs and MEPs were compared using a paired two-tailed Student t test. Coefficients of correlation between the mean CVs of HR and MEP parameters were also assessed.</p><p><strong>Results: </strong>Pooling the results from the six patients, the mean CV of amplitude from the MEP (24.6 ± 3) was significantly higher than that from the HR (3.5 ± 4.4) (P = 0.000091). The mean CV of the MEP area under the curve (21.8 ± 4.8) was also statistically significantly higher than that from the HR area under the curve (3.4 ± 4.5) (P = 0.00091). The coefficients of correlation of the mean CV of the HR amplitude and area under the curve compared with the corresponding values of the MEP were low (r = 0.29) and very low (r = 0.03), respectively.</p><p><strong>Conclusions: </strong>Our results suggest that fluctuations in lower motor neuron excitability may be less important than previously thought to explain the magnitude of MEP variability. The efficacy of corticospinal volleys to recruit a larger and more stable lower motor neuron population would be critical to obtain reproducible MEPs.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":2.3,"publicationDate":"2024-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142361634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}