Journal of Clinical Neurophysiology最新文献

{"title":"Passive Language Mapping With High-Gamma Modulations.","authors":"Brian Ervin, Eishi Asano, Nathan E Crone","doi":"10.1097/WNP.0000000000001296","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001296","url":null,"abstract":"<p><strong>Summary: </strong>Passive language mapping using high-gamma modulation (HGM) has emerged as a valuable tool in both presurgical evaluation for epilepsy and neuroscientific discovery. HGM mapping leverages task-related synchronization in high-gamma frequencies to identify language areas without the risks associated with electrical stimulation mapping. This review outlines the principles and techniques used in the field of HGM-based mapping, including electrode types, referencing schemes, power analysis, and localization techniques. We survey a range of cognitive tasks-speech production, auditory processing, reading, and memory-that elicit language-related HGM responses and discuss their relevance to comprehensive language mapping. We examine perspectives on methodologic challenges, including artifact management, variability across patients, and spatial sampling. We assess validation studies comparing HGM with electrical stimulation mapping and neuropsychological outcomes, noting HGM's unique role in identifying language cortex in pediatric and cognitively impaired populations. Finally, we speculate on the future directions of the field, including integration with corticocortical evoked potentials and the potential for HGM-informed speech synthesis. As the field matures, HGM mapping is poised to contribute to improved clinical outcomes and enhance our understanding of the dynamics and development of the human language network.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182230","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":"Sustained Seizure Freedom After Stereo-Electroencephalography Without Definitive Intervention: Evidence for Network Modulation by Invasive EEG.","authors":"Tessa A Harland, Sawyer Farmer, Caesar Ferrari, Michelle Terry, Matthew Cullen, Majorie Bunch, Matthew A Adamo","doi":"10.1097/WNP.0000000000001309","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001309","url":null,"abstract":"<p><strong>Summary: </strong>Stereo-electroencephalography (sEEG) is a diagnostic technique used to localize seizure-onset networks in drug-resistant epilepsy, typically guiding resection, ablation, or neuromodulation. Sustained seizure freedom after diagnostic implantation alone is rarely described. We describe two patients who achieved long-term remission after sEEG monitoring without definitive surgical intervention. A 39-year-old man with posttraumatic right hemispheric epilepsy underwent implantation of 11 depth electrodes, during which no habitual seizures were captured despite medication withdrawal and provocation. After electrode explantation, he discontinued all antiseizure medications and has remained seizure-free for 71 months. A 63-year-old woman with left temporal epilepsy underwent implantation of 12 depth electrodes; monitoring again failed to capture habitual seizures, although abundant mesial temporal interictal discharges were recorded. After explantation, which was complicated by a small tract hemorrhage, she has remained seizure-free for 20 months on stable cenobamate therapy. These cases add to a limited body of evidence suggesting that sEEG implantation may induce microlesional or network-modulatory effects capable of interrupting seizure propagation, analogous to remission reported after intracranial electrode placement in prior series. Recognition of this phenomenon is clinically important. When no habitual seizures are recorded and early postoperative improvement is observed, a period of extended follow-up may be warranted before pursuing resection, ablation, or neuromodulation. Further study is needed to define predictors of remission, clarify underlying mechanisms, and guide patient counseling regarding this uncommon but meaningful effect of invasive EEG.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149171512","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":"Understanding MEG Source Profiles in Tuberous Sclerosis.","authors":"Kalor Greve, Sarah Ihnen, Ravindra Arya, Hisako Fujiwara, Hansel M Greiner, Katherine D Holland, Paul S Horn, Kelly M Kremer, Darcy A Krueger, Francesco T Mangano, Jesse Skoch, Jeffrey R Tenney","doi":"10.1097/WNP.0000000000001304","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001304","url":null,"abstract":"<p><strong>Purpose: </strong>Patients with tuberous sclerosis complex (TSC) and medically refractory epilepsy are increasingly referred for epilepsy surgery, but presurgical evaluation is challenging due to multiple tubers and complex seizure onset zones. The aim of this retrospective study was to correlate key characteristics of magnetoencephalography (MEG) sources with intracranial EEG and surgical outcomes in patients with TSC.</p><p><strong>Methods: </strong>Patients with TSC and MRE who underwent MEG, stereo-EEG (sEEG) monitoring, and have at least 1-year postsurgical follow-up were included. MEG source number, laterality, location, and type (interictal or ictal) were compared with the seizure onset zones, defined by sEEG and postoperative seizure outcomes.</p><p><strong>Results: </strong>Thirty-three patients (15 female patients and 18 male patients) (mean age 8.0 ± 8.2 years) were included. No significant correlation between the laterality of MEG sources (unilateral or bilateral) and surgical outcomes (χ2(1, n = 33) = 0.11, P = 0.75) was found, and there was no significant correlation between the number of MEG sources and surgical outcomes (P = 0.68). MEG-sEEG concordance scores showed a high specificity (86.7%) and positive predictive value (75%) as a predictor of postoperative seizure outcomes, and the concordance score was significantly higher in patients with an ictal MEG (4.4 (ictal) versus 3.0 [interictal]) (P = 0.04).</p><p><strong>Conclusions: </strong>This study demonstrates a localization concordance between MEG and sEEG that is related to postsurgical seizure outcomes in patients with TSC. However, no correlation between MEG source number, laterality (unilateral vs. bilateral), and surgical outcomes was found, supporting the continued use of MEG as a presurgical epilepsy tool in this patient population, no matter the number of potential source locations.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149168754","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":"Clinical and Electrophysiological Characteristics of Peripheral Neuropathy in Immune-Related Adverse Event of Immune Checkpoint Inhibitors: A Retrospective Study and Literature Review.","authors":"Lei Zhang, Fengzhi Liu, Yuhui Chen, Jia Guo, Xiang Wang, Huiyan Yu","doi":"10.1097/WNP.0000000000001308","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001308","url":null,"abstract":"<p><strong>Purpose: </strong>To summarize clinical and laboratory characteristics of peripheral neurological immune-related adverse event (irAEs-PN) patients, to improve understanding and provide reference for early diagnosis of irAEs-PN caused by immune checkpoint inhibitors.</p><p><strong>Methods: </strong>We screened 61 patients with irAEs in our center from September 2020 to June 2025. In addition, studies with detailed clinical data related to irAEs-PN were collected in PubMed database from January 2015 to June 2025. A total of 50 patients with irAEs-PN were included, including 8 cases from our center and 42 cases reported in literature. The patients' demographic information, clinical characteristics, electrophysiological examination, therapy and outcomes were retrospectively analyzed and summarized.</p><p><strong>Results: </strong>Among the eight patients in our center, the first symptom was paresthesia, occurring in two cases, and limb weakness, occurring in six cases. Electrophysiology identified two axonal neuropathies, three demyelinating, and three mixed axonal and demyelinating neuropathies. Among the 42 patients reported in literature, the first symptom was paresthesia, occurring in 39 cases, and limb weakness, occurring in 41 cases. Electromyography identified 13 axonal neuropathies, 25 demyelinating neuropathies, and 4 mixed axonal and demyelinating neuropathies.</p><p><strong>Conclusions: </strong>In most patients, irAEs-PN is characterized by demyelinating sensorimotor involvement of both the upper and lower limbs. In individuals receiving immune checkpoint inhibitors, prompt electromyography after the onset of neuropathic symptoms can aid in detecting neurological involvement and facilitate earlier treatment.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149166841","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":"Predicting ICU Seizures Using 1 hour of cEEG.","authors":"Souvik Phadikar, Santiago Philibert-Rosas, Steven E Haworth, Safoora Fatima, Maximilian Grobbelaar, Chenxi Sun, Jin Jing, Sahar Zafar, Jennifer A Kim, Brandon M Westover, Aaron F Struck","doi":"10.1097/WNP.0000000000001301","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001301","url":null,"abstract":"<p><strong>Purpose: </strong>Continuous electroencephalography (cEEG) is the gold standard for detecting electrographic seizures in the intensive care unit (ICU), but limited resources limit prolonged monitoring for all patients. We developed an automated, interpretable pipeline that uses a single hour of cEEG to estimate near-term seizure risk across multiple prediction windows.</p><p><strong>Methods: </strong>We retrospectively studied 50 adults who underwent ICU cEEG monitoring at a single tertiary center. From a 1-hour segment, we computed automated interictal-ictal continuum (IIC) burden probabilities for lateralized periodic discharges (LPDs), generalized periodic discharges (GPDs), and lateralized rhythmic delta activity (LRDA), along with quantitative background EEG features reflecting signal organization and hemispheric asymmetry. Segments were labeled by seizure occurrence within the subsequent 1, 2, 4, 8, 12, or 24 hours. Support vector machine (SVM) and bagged-tree classifiers were trained using clinical-only, background-only, and combined feature sets with a 70/30 patient-level train-test split and cross-validation within the training set.</p><p><strong>Results: </strong>For the 4-hour horizon, the combined-feature SVM achieved 76% accuracy and the lowest Brier score (0.25), outperforming clinical-only (72%) and background-only (70%) models. Across horizons, SVM accuracy declined from 94% (1 hour) to 79% (24 hours) with increasing Brier scores, indicating reduced calibration at longer intervals. AUC-receiver operating characteristic increased with wider prediction windows, consistent with higher seizure prevalence at longer lead times.</p><p><strong>Conclusions: </strong>Integrating automated IIC probabilities with quantitative background EEG features enables moderate, interpretable near-term seizure prediction from a single hour of ICU cEEG. Initial external validation on an independent multicenter ICU cohort supports generalizability, although broader prospective and multicenter evaluation are needed before clinical deployment.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149171532","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":"A Structured Framework for Translation of the ACNS Standardized Critical Care EEG Terminology Into Spanish.","authors":"Clio Rubinos, Daniel San-Juan, Carlos Alva-Diaz, Maritza Beato, Juan Enrique Bender Del Busto, Paloma Balugo Bengoechea, Saskia Bermudez R, Sixto Bogantes, Yamille Calle-Lopez, Lucia Cibils, Guilca Contreras, Jose Carlos Cordero, Victoria Fernandez, Cynthia Florentín, Henry Hugo Galvez, Ivan Gaona, Maria Del Carmen Garcia, Nicolas Garofalo Gomez, Rosaly Gonzalez, Alfonso Gutierrez, Laura Hernandez, Mariana Legnani, Angelica Lizcano, Daniel Magos, Nancy Malpartida, Jorge A Mateos, Laura Mendoza, Anna Milan, Ramiro Montenegro Lopez, Guillermo Martin Palomeque, Elma Paredes-Aragon, Monica Perassolo, Eunice Ramirez, Ana Ramos, Victor Rivas, Natali Sanchez Ortiz, Oscar Servin, Sebastián Silva-Soto, Humberto Su, Arnold Thompson, Vanessa Thonon, Adriana Ulate-Campos, Reinaldo Uribe-San-Martin, Jean Paul Vergara, Manuel Vides-Rosales, Ivan Viñan Vazquez, Álvaro-Alejandro Zavala-Reina, Jessica Daily, Jessica Grant, Rosemary Frasso, Andres Fernandez, Maria Jose Bruzzone","doi":"10.1097/WNP.0000000000001303","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001303","url":null,"abstract":"<p><strong>Purpose: </strong>The American Clinical Neurophysiology Society (ACNS) Critical Care EEG Terminology provides standardized language for describing electroencephalographic (EEG) patterns in critically ill patients but has not been formally translated into Spanish. We aimed to develop a consensus-based Spanish translation of the ACNS Critical Care EEG Terminology using a multi-phase methodology involving physicians from Spanish-speaking countries.</p><p><strong>Methods: </strong>This qualitative study aimed to establish a standardized Spanish ACNS Critical Care EEG terminology through a three-phase process: Phase 1: Initial iterative translation by 14 Spanish-speaking physicians working in subgroups. Discrepancies were documented for further discussion. Phase 2: Focus groups with specialists practicing in Spanish-speaking countries, guided by qualitative research experts. Sessions explored terminology preferences, implementation challenges, and regional variations. Phase 3: Qualitative analysis and final consensus using a modified Delphi methodology. Ranked choice voting analysis to achieve ≥75% consensus was used and when needed, a two-option runoff determined the final selected term.</p><p><strong>Results: </strong>Forty-five physicians from all Spanish-speaking countries except Nicaragua participated in 10 focus groups to review 25 terms. Seven terms generated two possible Spanish translations, four generated three, five generated four, and nine generated five. A consensus-based Spanish terminology was established, prioritizing semantic fidelity to the ACNS terminology while also accounting for terms already in wide regional use. Examples of final consensus terms included: Generalized Periodic Discharges → Descargas Periódicas Generalizadas (98%, Round 1); Lateralized Rhythmic Delta Activity → Actividad Delta Rítmica Lateralizada (100%, round 1); and Sharp Wave → Onda Aguda (82%, round 1). The outdated term periodic lateralized epileptiform discharges remained widely used because of familiarity among intensivists.</p><p><strong>Conclusions: </strong>This effort provides the first structured Spanish adaptation of the ACNS Critical Care EEG terminology. The resulting lexicon reflects linguistic diversity across regions and supports consistent communication, training, research, and broader adoption of evidence-based continuous EEG practices.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149137017","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":"Ulnar Neuropathy at the Elbow: Evaluation of Discriminatory Performance of Multitiered Electrodiagnostic-Based Severity Classifications.","authors":"Nathan J Savage, John S McKell","doi":"10.1097/WNP.0000000000001286","DOIUrl":"10.1097/WNP.0000000000001286","url":null,"abstract":"<p><strong>Purpose: </strong>Ulnar neuropathy at the elbow (UNE) is a common entrapment neuropathy for which electrodiagnostic (EDX) testing is routinely used to confirm diagnosis. Multitiered EDX-based classifications of UNE severity have been proposed; however, their ability to discriminate between consecutive severity categories has not been rigorously evaluated.</p><p><strong>Methods: </strong>This retrospective analysis of prospectively collected cross-sectional data included 299 elbows from 262 patients referred for EDX testing for suspected UNE. Elbows were categorized using two commonly cited multitiered EDX-based classifications (Padua and Zeidman) and compared with consolidated binary categorizations (\"Negative\" or \"UNE\"). Linear mixed-effects models were used to evaluate differences in key electrophysiologic variables across consecutive EDX-based severity categories and between consolidated binary categorizations. Additional analyses examined the influence of sex and age category on relevant electrophysiologic findings.</p><p><strong>Results: </strong>Multitiered classifications demonstrated limited discriminatory capability between consecutive severity categories. Only 17% of comparisons in the Padua classification and 44% in the Zeidman classification significantly differentiated adjacent categories. In contrast, all consolidated binary categorizations demonstrated consistent and significant differences in electrophysiologic findings, with moderate to large effect sizes. Sex and age category significantly influenced ulnar motor nerve conduction across the elbow, with men and older patients generally exhibiting slower conduction velocities.</p><p><strong>Conclusions: </strong>Multitiered EDX-based classifications of UNE severity demonstrate poor discrimination between adjacent categories. Consolidated binary categorizations of UNE provide superior discriminatory capability and may offer greater clinical utility. These findings apply specifically to electrophysiologic assessment and should not be interpreted as measures of clinical symptom severity. Sex and age category should be considered when interpreting EDX results in patients with suspected UNE.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148603429","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":"Electrical Stimulation With stereoelectroencephalography for Defining the Surgical Target: A Contemporary Approach.","authors":"S Katie Z Ihnen, Agnes Trebuchon","doi":"10.1097/WNP.0000000000001297","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001297","url":null,"abstract":"<p><strong>Summary: </strong>This review aims to summarize important concepts related to electrical stimulation for the induction of seizures as it is understood in 2026. We discuss the history of electrical stimulation; we describe important methodological considerations when stimulating; we review key recent publications regarding the clinical validity of stimulated seizures; and we mention emerging areas of interest and opportunities for continued exploration.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148990299","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":"Abnormal ECG Findings in Children Undergoing Seizure Evaluation.","authors":"Maria A Montenegro, Deniz Akman, Shifteh Sattar, Felipe Baccin, Cigdem I Akman, Vinita Knight, Ana C Coan, Laura Valli, Anuja Jindal, Jeffrey Gold, Lawrence J Hirsch","doi":"10.1097/WNP.0000000000001295","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001295","url":null,"abstract":"<p><strong>Purpose: </strong>The objective of this study was to describe electrocardiogram (ECG) abnormalities captured during video electroencephalogram monitoring in a series of children and adolescents.</p><p><strong>Methods: </strong>This is a multicenter case series from four pediatric comprehensive epilepsy centers. There was no systematic review of a database; this was a case series with variable methods of patient recall/identification. Patients were divided into three groups according to ECG findings: (1) ictal ECG abnormalities (excluding sinus tachycardia), (2) cardiac disease mimicking seizures, and (3) incidental ECG abnormalities found during electroencephalogram/video-electroencephalogram monitoring. Ictal asystole was defined as an RR interval longer than 3 seconds and at least twice as long as the previous RR interval.</p><p><strong>Results: </strong>There were 22 patients identified with pathologic ECG findings (7 females, 15 males), ranging from 5 months old to 17 years old (mean = 9.3 years). Ictal ECG abnormalities were seen in five patients: asystole in three, and bradycardia and second-degree heart block in one each. Cardiac arrhythmia triggering syncope/altered mental status was seen in 11 patients: asystole in three; Wolff-Parkinson-White syndrome in three; premature ventricular contraction in two; and ventricular tachycardia, second-degree heart block, and Brugada syndrome in one each. Incidental ECG abnormalities were found in six patients (premature ventricular contraction in four, second-degree heart block and bradycardia in one each).</p><p><strong>Conclusions: </strong>The identification of cardiac abnormalities in children undergoing evaluation for a possible seizure disorder allows not only optimization of seizure management but also guides differential diagnosis, specific cardiological interventions, and avoidance of antiseizure medication that might exacerbate cardiac arrhythmias. It is crucial to pay attention to the ECG channel of the electroencephalogram recordings, especially in the peri-ictal period.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148982651","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":"Nonuniform Motor Dysfunction in Carpal Tunnel Syndrome: Implications From APB and Second Lumbrical CMAPs.","authors":"Keita Nishiwaki, Haruka Kawakami, Fuki Sugioka, Yu Isomura, Keitaro Ito, Kenji Inoue, Yudai Suzuki, Masahiro Natsume, Eiji Ito, Takeshi Ohshima","doi":"10.1097/WNP.0000000000001300","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001300","url":null,"abstract":"<p><strong>Objective: </strong>In severe carpal tunnel syndrome, compound muscle action potentials (CMAPs) from the abductor pollicis brevis (APB) are often unrecordable, limiting motor nerve assessment. We investigated whether second lumbrical (2L) CMAP reflects motor dysfunction similarly to APB CMAP.</p><p><strong>Methods: </strong>We retrospectively analyzed 123 patients with carpal tunnel syndrome. Compound muscle action potential amplitudes of APB and 2L were recorded following wrist stimulation. Associations with electrophysiological severity (Bland classification) were evaluated. In surgical cases (n = 47), preoperative and postoperative changes were assessed. Recordability was analyzed on a hand-by-hand basis. Multivariate logistic regression was performed to identify factors associated with APB CMAP absence.</p><p><strong>Results: </strong>2L CMAP amplitude decreased with increasing electrophysiological severity. Both APB and 2L CMAP amplitudes improved postoperatively, but improvement was significantly greater in APB (P < 0.001). Among 18 hands with absent APB CMAP, 2L CMAP was recordable in 17 (94.4%). Recordability was significantly higher for 2L than APB (99.4% vs. 88.7%, P < 0.001). In multivariate analysis, log-transformed 2L CMAP amplitude was independently associated with APB CMAP absence (odds ratio 0.086, 95% confidence interval 0.028-0.259, P < 0.001).</p><p><strong>Conclusions: </strong>Motor dysfunction in carpal tunnel syndrome may not be uniformly distributed across distal median nerve branches. Abductor pollicis brevis and 2L CMAPs may reflect different functional aspects of motor impairment.</p><p><strong>Significance: </strong>These findings provide additional insight into motor nerve conduction studies and may improve diagnostic evaluation, particularly in severe carpal tunnel syndrome where conventional motor assessment is limited.</p>","PeriodicalId":15516,"journal":{"name":"Journal of Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":1.8,"publicationDate":"2026-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148982714","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}