In contrast to needle electromyography, the diagnostic performance of muscle ultrasound (MUS) for differentiating neurogenic from myopathic disorders remains unclear. We examined the clinical utility of “fascicular twitch,” a visible movement of muscle bundles during isometric contraction, and evaluated its ability to differentiate neurogenic from myopathic changes.
Methods
We quantified fascicular twitches on MUS during isometric contraction as normalized twitch pixels (nTP) using an original image analysis method based on background subtraction. We analyzed echogenicity and nTP values in the biceps brachii muscle of 89 patients with neuromuscular disorders and 42 controls.
Results
The neurogenic group demonstrated substantially higher nTP values than the myopathic group and controls, achieving a sensitivity of 90.5% and specificity of 88.1% at an nTP cutoff of 0.04. Although echogenicity distinguished patients with neuromuscular disorders from controls, it failed to discriminate between the neurogenic and myopathic groups.
Conclusions
Quantification of fascicular twitch via nTP effectively differentiates neurogenic from myopathic disorders, thereby demonstrating that MUS is a valuable, noninvasive diagnostic method for assessing neuromuscular diseases.
Significance
This study introduces fascicular twitch quantification as a novel ultrasound biomarker that uniquely discriminates neurogenic from myopathic pathology, offering a high‑performance, noninvasive approach to neuromuscular diagnosis.
{"title":"“Fascicular twitch” on muscle ultrasonography in neuromuscular disorders: quantitative video-image analysis","authors":"Shun Matoba , Kenji Sekiguchi , Yoshikatsu Noda , Ryosuke Sugisawa , Hirotomo Suehiro , Katsuya Nishida , Riki Matsumoto","doi":"10.1016/j.clinph.2025.2111447","DOIUrl":"10.1016/j.clinph.2025.2111447","url":null,"abstract":"<div><h3>Objective</h3><div>In contrast to needle electromyography, the diagnostic performance of muscle ultrasound (MUS) for differentiating neurogenic from myopathic disorders remains unclear. We examined the clinical utility of “fascicular twitch,” a visible movement of muscle bundles during isometric contraction, and evaluated its ability to differentiate neurogenic from myopathic changes.</div></div><div><h3>Methods</h3><div>We quantified fascicular twitches on MUS during isometric contraction as normalized twitch pixels (nTP) using an original image analysis method based on background subtraction. We analyzed echogenicity and nTP values in the biceps brachii muscle of 89 patients with neuromuscular disorders and 42 controls.</div></div><div><h3>Results</h3><div>The neurogenic group demonstrated substantially higher nTP values than the myopathic group and controls, achieving a sensitivity of 90.5% and specificity of 88.1% at an nTP cutoff of 0.04. Although echogenicity distinguished patients with neuromuscular disorders from controls, it failed to discriminate between the neurogenic and myopathic groups.</div></div><div><h3>Conclusions</h3><div>Quantification of fascicular twitch via nTP effectively differentiates neurogenic from myopathic disorders, thereby demonstrating that MUS is a valuable, noninvasive diagnostic method for assessing neuromuscular diseases.</div></div><div><h3>Significance</h3><div>This study introduces fascicular twitch quantification as a novel ultrasound biomarker that uniquely discriminates neurogenic from myopathic pathology, offering a high‑performance, noninvasive approach to neuromuscular diagnosis.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111447"},"PeriodicalIF":3.6,"publicationDate":"2025-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616691","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-23DOI: 10.1016/j.clinph.2025.2111436
Andrea Antal, Jovana Bjekić, Ana Ganho-Ávila, Ivan Alekseichuk, Sara Assecondi, Til Ole Bergmann, Marom Bikson, Jerome Brunelin, Andre R Brunoni, Leigh Charvet, Robert Chen, Roi Cohen Kadosh, Lukas Diedrich, Giordano D'Urso, Roberta Ferrucci, Saša R Filipović, Paul B Fitzgerald, Agnes Flöel, Flavio Fröhlich, Mark S George, Roy H Hamilton, Jens Haueisen, Mark Hallett, Christoph S Herrmann, Friedhelm C Hummel, Shapour Jaberzadeh, Berthold Langguth, Michal Lavidor, Jean-Pascal Lefaucheur, Carlo Miniussi, Vera Moliadze, Mika Nikander, Stevan Nikolin, Michael A Nitsche, Alexander Opitz, Jacinta O'Shea, Frank Padberg, Christian Plewnia, Alberto Priori, Perianen Ramasawmy, Lais B Razza, Simone Rossi, John Rothwell, Maria A Rueger, Giulio Ruffini, Alexander T Sack, Ricardo Salvador, Klaus Schellhorn, Teresa Schuhmann, Yuichiro Shirota, Hartwig Roman Siebner, Axel Thielscher, Yoshikazu Ugawa, Susanne Uusitalo, Anna Wexler, Walter Paulus, Marie-Anne Vanderhasselt, Vincent Van Waes, Maximilian J Wessel, Miles Wischnewski, Chris Baeken, Ulf Ziemann
This guideline summarizes updated safety data (2017-2025) and provides expert recommendations on the use of low intensity transcranial electrical stimulation (tES) in humans. tES encompasses several techniques including transcranial direct current stimulation (tDCS), oscillatory transcranial direct current stimulation (otDCS), transcranial alternating current stimulation (tACS), transcranial random noise stimulation (tRNS), transcranial temporal interference stimulation (tTIS), and their combinations or variations. Across over 300,000 sessions involving healthy individuals, patients with neuropsychiatric conditions, and other clinical populations, no tES-related serious adverse events (AEs) have been reported. Moderate AEs are rare and limited to a small range of specific applications. Mild AEs are common and include transient symptoms such as localized sensations (e.g., tingling or burning), headaches, and fatigue. Similar mild AEs are also reported by individuals receiving placebo stimulation. The frequency, magnitude, and type of AEs are comparable across healthy, clinical, and vulnerable groups, including children, elderly, or pregnant women. Combined interventions (e.g., co-application with EEG, TMS, or neuroimaging) have not shown increased safety risks. Safety is well-established for both bipolar and multichannel tES when applied up to 4 mA and up to 60 min per day. Higher intensities and longer stimulation durations may also be safe. Nevertheless, the number of studies using intensities above 4 mA or stimulating longer than 60 min is low. Home-based use of treatments is growing rapidly, leveraging remote supervision to provide patients with greater access and enable repeated, sustained dosing paradigms. We recommend using screening and AE questionnaires in future controlled studies, in particular when planning to extend the stimulation parameters applied. We discuss recent regulatory and ethical issues.
{"title":"Low intensity transcranial electric stimulation: Safety, ethical, legal regulatory and application guidelines (2017-2025: An update) - endorsed by the European Society for Brain Stimulation (ESBS) and by the International Federation for Clinical Neurophysiology (IFCN).","authors":"Andrea Antal, Jovana Bjekić, Ana Ganho-Ávila, Ivan Alekseichuk, Sara Assecondi, Til Ole Bergmann, Marom Bikson, Jerome Brunelin, Andre R Brunoni, Leigh Charvet, Robert Chen, Roi Cohen Kadosh, Lukas Diedrich, Giordano D'Urso, Roberta Ferrucci, Saša R Filipović, Paul B Fitzgerald, Agnes Flöel, Flavio Fröhlich, Mark S George, Roy H Hamilton, Jens Haueisen, Mark Hallett, Christoph S Herrmann, Friedhelm C Hummel, Shapour Jaberzadeh, Berthold Langguth, Michal Lavidor, Jean-Pascal Lefaucheur, Carlo Miniussi, Vera Moliadze, Mika Nikander, Stevan Nikolin, Michael A Nitsche, Alexander Opitz, Jacinta O'Shea, Frank Padberg, Christian Plewnia, Alberto Priori, Perianen Ramasawmy, Lais B Razza, Simone Rossi, John Rothwell, Maria A Rueger, Giulio Ruffini, Alexander T Sack, Ricardo Salvador, Klaus Schellhorn, Teresa Schuhmann, Yuichiro Shirota, Hartwig Roman Siebner, Axel Thielscher, Yoshikazu Ugawa, Susanne Uusitalo, Anna Wexler, Walter Paulus, Marie-Anne Vanderhasselt, Vincent Van Waes, Maximilian J Wessel, Miles Wischnewski, Chris Baeken, Ulf Ziemann","doi":"10.1016/j.clinph.2025.2111436","DOIUrl":"https://doi.org/10.1016/j.clinph.2025.2111436","url":null,"abstract":"<p><p>This guideline summarizes updated safety data (2017-2025) and provides expert recommendations on the use of low intensity transcranial electrical stimulation (tES) in humans. tES encompasses several techniques including transcranial direct current stimulation (tDCS), oscillatory transcranial direct current stimulation (otDCS), transcranial alternating current stimulation (tACS), transcranial random noise stimulation (tRNS), transcranial temporal interference stimulation (tTIS), and their combinations or variations. Across over 300,000 sessions involving healthy individuals, patients with neuropsychiatric conditions, and other clinical populations, no tES-related serious adverse events (AEs) have been reported. Moderate AEs are rare and limited to a small range of specific applications. Mild AEs are common and include transient symptoms such as localized sensations (e.g., tingling or burning), headaches, and fatigue. Similar mild AEs are also reported by individuals receiving placebo stimulation. The frequency, magnitude, and type of AEs are comparable across healthy, clinical, and vulnerable groups, including children, elderly, or pregnant women. Combined interventions (e.g., co-application with EEG, TMS, or neuroimaging) have not shown increased safety risks. Safety is well-established for both bipolar and multichannel tES when applied up to 4 mA and up to 60 min per day. Higher intensities and longer stimulation durations may also be safe. Nevertheless, the number of studies using intensities above 4 mA or stimulating longer than 60 min is low. Home-based use of treatments is growing rapidly, leveraging remote supervision to provide patients with greater access and enable repeated, sustained dosing paradigms. We recommend using screening and AE questionnaires in future controlled studies, in particular when planning to extend the stimulation parameters applied. We discuss recent regulatory and ethical issues.</p>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":" ","pages":"2111436"},"PeriodicalIF":3.6,"publicationDate":"2025-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146099555","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-21DOI: 10.1016/j.clinph.2025.2111450
Cindy Shin-Yi Lin , Jowy Tani , Ting Wei Hsu , Yi-Chen Lin , Yun-Ru Liu , Jia-Ying Sung M.D. PhD.
Objective
This study aims to characterize sensory axonal changes in patients with non-painful and painful type 2 diabetes mellitus (T2DM) to explore the mechanisms underlying diabetic neuropathic pain in relation to pregabalin treatment.
Methods
Clinical evaluations, including nerve conduction studies, nerve excitability testing (NET) and visual analogue scale (VAS), were conducted on 200 T2DM, resulting 131 qualifying for inclusion. Cohort stratification utilized VAS scores: 43 had VAS ≥ 4 (painful), and 88 had VAS < 4 (non-painful). The painful cohort was categorized into low pain (4 ≤ VAS < 7) and high pain (VAS ≥ 7). A subgroup receiving pregabalin (15) was assessed to investigate neurophysiological differences.
Results
The painful cohort differed significantly from the non-painful cohort in sensory nerve excitability parameters including stimulus for 50% maximum amplitude, refractoriness, superexcitability, subexcitability, and depolarization thresholds. Higher VAS scores correlated with reduced TEd40(Accom) and TEh(overshoot). Pregabalin-treated patients demonstrated improved stimulus–response slope, S2 accommodation and TEd40(Accom) compared to untreated patients.
Conclusions
Our findings suggest that diabetic neuropathic pain may be associated with axonal hyperpolarization and accommodative properties with implications to potassium channel dysfunction.
Significance
These findings elucidate mechanisms of diabetic pain pathophysiology, highlighting the clinical significance of sensory NET and the role of potassium channel modulation in T2DM pain management.
{"title":"Potassium channel dysfunction and distinct sensory axonal profiles in painful type 2 diabetes","authors":"Cindy Shin-Yi Lin , Jowy Tani , Ting Wei Hsu , Yi-Chen Lin , Yun-Ru Liu , Jia-Ying Sung M.D. PhD.","doi":"10.1016/j.clinph.2025.2111450","DOIUrl":"10.1016/j.clinph.2025.2111450","url":null,"abstract":"<div><h3>Objective</h3><div>This study aims to characterize sensory axonal changes in patients with non-painful and painful type 2 diabetes mellitus (T2DM) to explore the mechanisms underlying diabetic neuropathic pain in relation to pregabalin treatment.</div></div><div><h3>Methods</h3><div>Clinical evaluations, including nerve conduction studies, nerve excitability testing (NET) and visual analogue scale (VAS), were conducted on 200 T2DM, resulting 131 qualifying for inclusion. Cohort stratification utilized VAS scores: 43 had VAS ≥ 4 (painful), and 88 had VAS < 4 (non-painful). The painful cohort was categorized into low pain (4 ≤ VAS < 7) and high pain (VAS ≥ 7). A subgroup receiving pregabalin (15) was assessed to investigate neurophysiological differences.</div></div><div><h3>Results</h3><div>The painful cohort differed significantly from the non-painful cohort in sensory nerve excitability parameters including stimulus for 50% maximum amplitude, refractoriness, superexcitability, subexcitability, and depolarization thresholds. Higher VAS scores correlated with reduced TEd<sup>40</sup>(Accom) and TEh(overshoot). Pregabalin-treated patients demonstrated improved stimulus–response slope, S2 accommodation and TEd<sup>40</sup>(Accom) compared to untreated patients.</div></div><div><h3>Conclusions</h3><div>Our findings suggest that diabetic neuropathic pain may be associated with axonal hyperpolarization and accommodative properties with implications to potassium channel dysfunction.</div></div><div><h3>Significance</h3><div>These findings elucidate mechanisms of diabetic pain pathophysiology, highlighting the clinical significance of sensory NET and the role of potassium channel modulation in T2DM pain management.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111450"},"PeriodicalIF":3.6,"publicationDate":"2025-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616618","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.clinph.2025.2111449
Marina S. Cherchi , Miguel A. Hernández-Hernández , Javier Hernández-Cabello , Eduardo Torres Díez , Pedro Orizaola , Tetyana Stakhurska-Bilynska , Rubén Martín-Láez , José L. Fernández-Torre
Objective
To assess the ability of routine electroencephalography (rEEG) to predict delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH).
Methods
Single-center prospective study including adult patients with aSAH. Two rEEG recordings with quantitative analysis and transcranial Doppler sonography (TCD) were performed, within the first 72 h (EEG1 and TCD1) and between days 4–7 (EEG2 and TCD2). Multivariate logistic regression was performed to identify DCI predictors.
Results
Seventeen (25.4 %) of 67 patients developed DCI. In qualitative analysis, no patient with a normal EEG1 had DCI, while in EEG2, the absence of bilateral posterior alpha rhythm was more frequently observed in patients with DCI (52.9 % vs 20 %; p = 0.009). Quantitative EEG2 analysis revealed significantly higher total, delta, and theta power in DCI patients, with lower alpha–beta/theta-delta ratio and edge. Delta power ≥ 4.5 μV in EEG2 showed higher sensitivity than vasospasm on TCD2 but lower specificity. Age (OR 1.08; p = 0.04), vasospasm on TCD2 (OR 41.01; p = 0.003) and delta power ≥ 4.5 μV in EEG2 (OR 4.30; p = 0.06) were independent predictors of DCI.
Conclusions
rEEG with quantitative analysis is a useful tool for predicting DCI.
Significance
Integration of rEEG and TCD may improve detection of DCI in aSAH patients.
目的：探讨常规脑电图（rEEG）对动脉瘤性蛛网膜下腔出血（aSAH）迟发性脑缺血（DCI）的预测价值。方法：纳入成年aSAH患者的单中心前瞻性研究。在头72小时（EEG1和TCD1）和第4-7天（EEG2和TCD2）进行2次rEEG定量分析和经颅多普勒超声（TCD）记录。采用多元逻辑回归来确定DCI预测因子。结果：67例患者中17例（25.4%）发生DCI。在定性分析中，EEG1正常的患者没有DCI，而在EEG2中，DCI患者更常观察到双侧后α节律缺失（52.9% vs 20%; p = 0.009）。定量EEG2分析显示，DCI患者的总功率、δ和θ功率显著较高，α - β / δ - δ比值和边缘较低。EEG2 δ功率≥4.5 μV对TCD2的敏感性高于血管痉挛，但特异性较低。年龄（OR 1.08; p = 0.04）、TCD2血管痉挛（OR 41.01; p = 0.003）和EEG2 δ功率≥4.5 μV （OR 4.30; p = 0.06）是DCI的独立预测因子。结论：rEEG结合定量分析是预测DCI的有效工具。意义：结合rEEG和TCD可提高aSAH患者DCI的检出率。
{"title":"Routine EEG with quantitative analysis to detect delayed cerebral ischemia in aneurysmal subarachnoid hemorrhage","authors":"Marina S. Cherchi , Miguel A. Hernández-Hernández , Javier Hernández-Cabello , Eduardo Torres Díez , Pedro Orizaola , Tetyana Stakhurska-Bilynska , Rubén Martín-Láez , José L. Fernández-Torre","doi":"10.1016/j.clinph.2025.2111449","DOIUrl":"10.1016/j.clinph.2025.2111449","url":null,"abstract":"<div><h3>Objective</h3><div>To assess the ability of routine electroencephalography (rEEG) to predict delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH).</div></div><div><h3>Methods</h3><div>Single-center prospective study including adult patients with aSAH. Two rEEG recordings with quantitative analysis and transcranial Doppler sonography (TCD) were performed, within the first 72 h (EEG1 and TCD1) and between days 4–7 (EEG2 and TCD2). Multivariate logistic regression was performed to identify DCI predictors.</div></div><div><h3>Results</h3><div>Seventeen (25.4 %) of 67 patients developed DCI. In qualitative analysis, no patient with a normal EEG1 had DCI, while in EEG2, the absence of bilateral posterior alpha rhythm was more frequently observed in patients with DCI (52.9 % vs 20 %; p = 0.009). Quantitative EEG2 analysis revealed significantly higher total, delta, and theta power in DCI patients, with lower alpha–beta/theta-delta ratio and edge. Delta power ≥ 4.5 μV in EEG2 showed higher sensitivity than vasospasm on TCD2 but lower specificity. Age (OR 1.08; p = 0.04), vasospasm on TCD2 (OR 41.01; p = 0.003) and delta power ≥ 4.5 μV in EEG2 (OR 4.30; p = 0.06) were independent predictors of DCI.</div></div><div><h3>Conclusions</h3><div>rEEG with quantitative analysis is a useful tool for predicting DCI.</div></div><div><h3>Significance</h3><div>Integration of rEEG and TCD may improve detection of DCI in aSAH patients.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111449"},"PeriodicalIF":3.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145602517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.clinph.2025.2111448
Denise Lima Medeiros de Melo, Dayanne Rodrigues da Cunha Alves Bento Oliveira, Patricia Lago dos Santos Madureira
{"title":"Trigemino-cervical reflex can be recorded simultaneously with other trigeminal reflexes after V3 stimulation under general anesthesia","authors":"Denise Lima Medeiros de Melo, Dayanne Rodrigues da Cunha Alves Bento Oliveira, Patricia Lago dos Santos Madureira","doi":"10.1016/j.clinph.2025.2111448","DOIUrl":"10.1016/j.clinph.2025.2111448","url":null,"abstract":"","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111448"},"PeriodicalIF":3.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145602548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.clinph.2025.2111451
Tomasz Szymon Szczepanski , Petter Moe Omland , Øystein Dunker , Trond Sand , Martijn Tannemaat , Robert Reijntjes , Anis Yazidi , Kerstin Bach , John Anker Zwart , Joe Jabre , Kristian Bernhard Nilsen
Objective
To compare four novel methods – extrapolated norms (E-norms), extrapolated reference values (E-Ref), multivariable extrapolated reference values (MeRef) and mixture model clustering (MMC) – for obtaining reference limits for nerve conduction studies (NCS) from historical data containing both normal and abnormal studies.
Methods
Reference limits for 29 commonly clinically used NCS measurements were calculated from a historical database containing measurements from 24 618 patients using E-norms, E-ref, MeRef and MMC. The resulting reference limits were compared to reference limits for NCS calculated from 680 healthy subjects using Youden’s J statistics.
Results
Except for distal latencies, E-norms produced reference limits with the highest Youden’s J statistics with higher sensitivity, but lower specificity. E-Ref, MeRef and MMC produced reference limits with high specificity, but lower sensitivity than E-norms.
Conclusions
There are substantial differences in the performance of E-norms, E-Ref, MeRef and MMC. A dynamic approach, where the methods used are changed based on the type of NCS measurement and the amount of historical data available, may yield the highest accuracy.
Significance
When combining the different novel methods, it is possible to create clinically useful reference limits using historical data.
{"title":"Deriving reference limits from historical data – A comparison of four novel methods","authors":"Tomasz Szymon Szczepanski , Petter Moe Omland , Øystein Dunker , Trond Sand , Martijn Tannemaat , Robert Reijntjes , Anis Yazidi , Kerstin Bach , John Anker Zwart , Joe Jabre , Kristian Bernhard Nilsen","doi":"10.1016/j.clinph.2025.2111451","DOIUrl":"10.1016/j.clinph.2025.2111451","url":null,"abstract":"<div><h3>Objective</h3><div>To compare four novel methods – extrapolated norms (E-norms), extrapolated reference values (E-Ref), multivariable extrapolated reference values (MeRef) and mixture model clustering (MMC) – for obtaining reference limits for nerve conduction studies (NCS) from historical data containing both normal and abnormal studies.</div></div><div><h3>Methods</h3><div>Reference limits for 29 commonly clinically used NCS measurements were calculated from a historical database containing measurements from 24<!--> <!-->618 patients using E-norms, E-ref, MeRef and MMC. The resulting reference limits were compared to reference limits for NCS calculated from 680 healthy subjects using Youden’s J statistics.</div></div><div><h3>Results</h3><div>Except for distal latencies, E-norms produced reference limits with the highest Youden’s J statistics with higher sensitivity, but lower specificity. E-Ref, MeRef and MMC produced reference limits with high specificity, but lower sensitivity than E-norms.</div></div><div><h3>Conclusions</h3><div>There are substantial differences in the performance of E-norms, E-Ref, MeRef and MMC. A dynamic approach, where the methods used are changed based on the type of NCS measurement and the amount of historical data available, may yield the highest accuracy.</div></div><div><h3>Significance</h3><div>When combining the different novel methods, it is possible to create clinically useful reference limits using historical data.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111451"},"PeriodicalIF":3.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145616692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-20DOI: 10.1016/j.clinph.2025.2111446
Wilder-Smith E , Tournev I , Chamova T , Asenov O , Bohlhalter S , Antimov P , Mihaylova V
Objective
The aim of our study was to perform high-resolution nerve ultrasound in asymptomatic carriers of transthyretin (TTR) p.Glu89Gln (p.Glu109Gln) mutation and to evaluate its role as a complementary non-invasive diagnostic tool in early detection of amyloid deposits in peripheral nerves.
Methods
The study included 21 asymptomatic carriers of TTR p.Glu89Gln (p.Glu109Gln). History, neurological examination, nerve conduction studies, sympathetic skin response, SudoScan and high-resolution nerve ultrasound were performed.
Results
Ultrasound pattern sum score was abnormal in 70% of the carriers. Despite the younger age of male carriers compared to the female carriers the abnormal ultrasound findings were more frequently encountered in males. The latter also demonstrated more pronounced cross-sectional area enlargement of the peroneal nerve at the fibular head and had more frequently ultrasound evidence of median nerve swelling at the wrist. Sural nerves were not enlarged in contrast to radial and fibular superficial nerves which showed male preponderance.
Conclusions
Our data suggest early ultrasound detection of amyloid deposition in presymptomatic TTR p. Glu89Gln (p.Glu109Gln) carriers and demonstrated sex related differences with earlier amyloid deposition in male carriers.
Significance
As a non-invasive tool nerve ultrasound may be added to the established follow up program for the asymptomatic TTR carriers.
目的对无症状转甲状腺素（TTR） p.Glu89Gln （p.Glu109Gln）突变携带者进行高分辨率神经超声检查，并评价其作为一种辅助的非侵入性诊断工具在早期检测周围神经淀粉样蛋白沉积中的作用。方法选取21例无症状TTR p.Glu89Gln （p.Glu109Gln）携带者。进行病史、神经学检查、神经传导研究、交感皮肤反应、SudoScan和高分辨率神经超声检查。结果70%的携带者超声模式综合评分异常。尽管男性携带者比女性携带者年龄小，但异常超声结果在男性中更常见。后者也表现出腓骨头腓神经更明显的横截面积扩大，并且在手腕处有更频繁的正中神经肿胀的超声证据。腓肠神经没有扩张，而桡骨和腓骨浅神经则以男性为主。结论早期超声可检出TTR p. Glu89Gln （p. glu109gln）症状前携带者的淀粉样蛋白沉积，且与男性携带者的早期淀粉样蛋白沉积存在性别差异。意义：神经超声作为一种无创工具，可加入到已建立的无症状TTR携带者随访计划中。
{"title":"Nerve ultrasound in asymptomatic hereditary transthyretin amyloidosis carriers","authors":"Wilder-Smith E , Tournev I , Chamova T , Asenov O , Bohlhalter S , Antimov P , Mihaylova V","doi":"10.1016/j.clinph.2025.2111446","DOIUrl":"10.1016/j.clinph.2025.2111446","url":null,"abstract":"<div><h3>Objective</h3><div>The aim of our study was to perform high-resolution nerve ultrasound in asymptomatic carriers of transthyretin (<em>TTR</em>) p.Glu89Gln (p.Glu109Gln) mutation and to evaluate its role as a complementary non-invasive diagnostic tool in early detection of amyloid deposits in peripheral nerves.</div></div><div><h3>Methods</h3><div>The study included 21 asymptomatic carriers of <em>TTR</em> p.Glu89Gln (p.Glu109Gln). History, neurological examination, nerve conduction studies, sympathetic skin response, SudoScan and high-resolution nerve ultrasound were performed.</div></div><div><h3>Results</h3><div>Ultrasound pattern sum score was abnormal in 70% of the carriers. Despite the younger age of male carriers compared to the female carriers the abnormal ultrasound findings were more frequently encountered in males. The latter also demonstrated more pronounced cross-sectional area enlargement of the peroneal nerve at the fibular head and had more frequently ultrasound evidence of median nerve swelling at the wrist. Sural nerves were not enlarged in contrast to radial and fibular superficial nerves which showed male preponderance.</div></div><div><h3>Conclusions</h3><div>Our data suggest early ultrasound detection of amyloid deposition in presymptomatic <em>TTR</em> p. Glu89Gln (p.Glu109Gln) carriers and demonstrated sex related differences with earlier amyloid deposition in male carriers.</div></div><div><h3>Significance</h3><div>As a non-invasive tool nerve ultrasound may be added to the established follow up program for the asymptomatic <em>TTR</em> carriers.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111446"},"PeriodicalIF":3.6,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.clinph.2025.2111444
Sabira Alibhai-Najarali , John P. de Grosbois , Aaron E. Philipp-Muller , Jennifer Shao , Matthew J. Hawken , Matea Skenderija , Jed A. Meltzer
Objective
To investigate whether post-movement beta rebound (PMBR), a proposed marker of cortical inhibition, reflects interhemispheric inhibition as measured by the ipsilateral silent period (iSP) following voluntary movement and to assess hemispheric asymmetries.
Methods
Twenty right-handed participants underwent transcranial magnetic stimulation (TMS) to elicit iSPs at baseline (no button-press) and eight timepoints following movement of the opposite hand, iSPs and motor-evoked potentials (MEPs) were recorded for both hemispheres. Six participants completed magnetoencephalography (MEG) to characterize beta oscillatory activity during the task. Five participants completed the task without the TMS as a control.
Results
iSP magnitude did not significantly change during PMBR period. Instead, post-movement iSP increased in the right hemisphere and decreased in the left, yielding a significant hemispheric difference (p = 0.014). MEG data confirmed symmetrical PMBR across hemispheres. MEPs showed increased excitability post-movement, particularly at early timepoints. Movement alone, without TMS, did not account for hemispheric asymmetry.
Conclusions
PMBR and iSP appear to reflect distinct inhibitory mechanisms. The dissociation suggests PMBR does not index transcallosal inhibition (TCI). Hemispheric asymmetry in iSP suggests stronger TCI following non-dominant hand movements.
Significance
The dissociation between iSP and PMBR underscores the complexity of motor control, informs understanding lateralized motor function and rehabilitation.
{"title":"Hemispheric asymmetry of the ipsilateral silent period following voluntary movement of the opposite hand","authors":"Sabira Alibhai-Najarali , John P. de Grosbois , Aaron E. Philipp-Muller , Jennifer Shao , Matthew J. Hawken , Matea Skenderija , Jed A. Meltzer","doi":"10.1016/j.clinph.2025.2111444","DOIUrl":"10.1016/j.clinph.2025.2111444","url":null,"abstract":"<div><h3>Objective</h3><div>To investigate whether post-movement beta rebound (PMBR), a proposed marker of cortical inhibition, reflects interhemispheric inhibition as measured by the ipsilateral silent period (iSP) following voluntary movement and to assess hemispheric asymmetries.</div></div><div><h3>Methods</h3><div>Twenty right-handed participants underwent transcranial magnetic stimulation (TMS) to elicit iSPs at baseline (no button-press) and eight timepoints following movement of the opposite hand, iSPs and motor-evoked potentials (MEPs) were recorded for both hemispheres. Six participants completed magnetoencephalography (MEG) to characterize beta oscillatory activity during the task. Five participants completed the task without the TMS as a control.</div></div><div><h3>Results</h3><div>iSP magnitude did not significantly change during PMBR period. Instead, post-movement iSP increased in the right hemisphere and decreased in the left, yielding a significant hemispheric difference (p = 0.014). MEG data confirmed symmetrical PMBR across hemispheres. MEPs showed increased excitability post-movement, particularly at early timepoints. Movement alone, without TMS, did not account for hemispheric asymmetry.</div></div><div><h3>Conclusions</h3><div>PMBR and iSP appear to reflect distinct inhibitory mechanisms. The dissociation suggests PMBR does not index transcallosal inhibition (TCI). Hemispheric asymmetry in iSP suggests stronger TCI following non-dominant hand movements.</div></div><div><h3>Significance</h3><div>The dissociation between iSP and PMBR underscores the complexity of motor control, informs understanding lateralized motor function and rehabilitation.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111444"},"PeriodicalIF":3.6,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145647444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-19DOI: 10.1016/j.clinph.2025.2111445
Nicholas Cothros , Catherine Lowrey , Stephen H. Scott , Alex Medina Escobar , Sean Dukelow , Davide Martino , Tamara Pringsheim
Objective
Essential tremor (ET) likely includes deficits outside tremor, though this is under-examined in youth. We tested the hypothesis that reaching movements in youth with ET are characterized by greater incoordination.
Methods
Fifteen youth with ET (ages 11 to 17) recruited from the Calgary Tourette and Pediatric Movement Disorders Clinic completed a visually-guided reaching task using the Kinarm Exoskeleton Lab. Performance in several kinematic parameters was compared with age-matched controls.
Results
Youth with ET differed from controls in multiple parameters. In the dominant arm, the initial portion of reaching movements was slower and smaller-amplitude, with longer reaction time and greater posture speed at movement end when the hand should be at rest. In the non-dominant arm, those with ET differed from controls in a larger number of parameters. All but three with ET were impaired in at least one task parameter, scoring outside age-predicted norms.
Conclusion
Our study supports the notion of ET as a disorder with abnormalities beyond tremor, and that motoric abnormalities are demonstrable in youth with ET.
Significance
This is the first study showing youth with ET differ from age-matched controls in multiple aspects of reaching movements, including initial trajectory control, movement smoothness, overall trajectory, and endpoint control.
{"title":"Youth with essential tremor differ from age-matched controls in multiple aspects of visually-guided reaching movements","authors":"Nicholas Cothros , Catherine Lowrey , Stephen H. Scott , Alex Medina Escobar , Sean Dukelow , Davide Martino , Tamara Pringsheim","doi":"10.1016/j.clinph.2025.2111445","DOIUrl":"10.1016/j.clinph.2025.2111445","url":null,"abstract":"<div><h3>Objective</h3><div>Essential tremor (ET) likely includes deficits outside tremor, though this is under-examined in youth. We tested the hypothesis that reaching movements in youth with ET are characterized by greater incoordination.</div></div><div><h3>Methods</h3><div>Fifteen youth with ET (ages 11 to 17) recruited from the Calgary Tourette and Pediatric Movement Disorders Clinic completed a visually-guided reaching task using the Kinarm Exoskeleton Lab. Performance in several kinematic parameters was compared with age-matched controls.</div></div><div><h3>Results</h3><div>Youth with ET differed from controls in multiple parameters. In the dominant arm, the initial portion of reaching movements was slower and smaller-amplitude, with longer reaction time and greater posture speed at movement end when the hand should be at rest. In the non-dominant arm, those with ET differed from controls in a larger number of parameters. All but three with ET were impaired in at least one task parameter, scoring outside age-predicted norms.</div></div><div><h3>Conclusion</h3><div>Our study supports the notion of ET as a disorder with abnormalities beyond tremor, and that motoric abnormalities are demonstrable in youth with ET.</div></div><div><h3>Significance</h3><div>This is the first study showing youth with ET differ from age-matched controls in multiple aspects of reaching movements, including initial trajectory control, movement smoothness, overall trajectory, and endpoint control.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"182 ","pages":"Article 2111445"},"PeriodicalIF":3.6,"publicationDate":"2025-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145571209","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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