Corticospinal excitability can be quantified using motor-evoked potentials (MEP) following transcranial magnetic stimulation (TMS). However, the inherent variability of MEPs poses significant challenges. We establish a framework using personal and experimental factors to select the optimal number of trials () required for reliable MEP estimates.
Methods
47 healthy younger underwent single-pulse TMS over the left primary motor cortex (M1). Per participant, 550 MEPs were collected at intensities ranging from 110 % to 150 % of the resting motor threshold (rMT), in 10 % increments. Per intensity, we calculated . We analyzed which personal and experimental factors affected
Results
decreased with increasing TMS intensity, lower rMT baseline values, and exclusion of single-trial outliers. Sex had no significant effect.
Conclusions
Our study indicates that even when TMS is used as an outcome measure, custom-tailoring its protocol to study-related circumstances is key, as TMS intensity, outliers, baseline rMT, and the desired precision level affect the number of TMS trials needed to obtain a reliable MEP. Thus, we underscore the absence of a universal rule-of-thumb rule, although our predictive equations and online tool provide future TMS experimenters with the means to estimate the required number of TMS trials based on individual characteristics and specific experimental conditions.
Significance
Our predictive equations offer a tailored approach for selecting , enhancing the reliability of TMS-derived corticospinal excitability measurements.
{"title":"Accurate determination of motor evoked potential amplitude in TMS: The impact of personal and experimental factors","authors":"Marten Nuyts , Stefanie Verstraelen , Joana Frieske , Raf Meesen , Sybren Van Hoornweder","doi":"10.1016/j.clinph.2024.12.009","DOIUrl":"10.1016/j.clinph.2024.12.009","url":null,"abstract":"<div><h3>Objective</h3><div>Corticospinal excitability can be quantified using motor-evoked potentials (MEP) following transcranial magnetic stimulation (TMS). However, the inherent variability of MEPs poses significant challenges. We establish a framework using personal and experimental factors to select the optimal number of trials (<span><math><msub><mi>n</mi><mrow><mi>opt</mi></mrow></msub></math></span>) required for reliable MEP estimates.</div></div><div><h3>Methods</h3><div>47 healthy younger underwent single-pulse TMS over the left primary motor cortex (M1). Per participant, 550 MEPs were collected at intensities ranging from 110 % to 150 % of the resting motor threshold (rMT), in 10 % increments. Per intensity, we calculated <span><math><msub><mi>n</mi><mrow><mi>opt</mi></mrow></msub></math></span>. We analyzed which personal and experimental factors affected <span><math><mrow><msub><mi>n</mi><mrow><mi>opt</mi></mrow></msub><mo>.</mo></mrow></math></span></div></div><div><h3>Results</h3><div><span><math><msub><mi>n</mi><mrow><mi>opt</mi></mrow></msub></math></span> decreased with increasing TMS intensity, lower rMT baseline values, and exclusion of single-trial outliers. Sex had no significant effect.</div></div><div><h3>Conclusions</h3><div>Our study indicates that even when TMS is used as an outcome measure, custom-tailoring its protocol to study-related circumstances is key, as TMS intensity, outliers, baseline rMT, and the desired precision level affect the number of TMS trials needed to obtain a reliable MEP. Thus, we underscore the absence of a universal rule-of-thumb rule, although our predictive equations and online tool provide future TMS experimenters with the means to estimate the required number of TMS trials based on individual characteristics and specific experimental conditions.</div></div><div><h3>Significance</h3><div>Our predictive equations offer a tailored approach for selecting <span><math><msub><mi>n</mi><mrow><mi>opt</mi></mrow></msub></math></span>, enhancing the reliability of TMS-derived corticospinal excitability measurements.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"170 ","pages":"Pages 123-131"},"PeriodicalIF":3.7,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142871572","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 : 2025-01-31DOI: 10.1016/j.clinph.2025.01.012
Enrico Michele Salamone , Matteo Carpi , Giuseppe Noce , Claudio Del Percio , Susanna Lopez , Roberta Lizio , Dharmendra Jakhar , Ali Eldellaa , Veronica Henao Isaza , Burcu Bölükbaş , Andrea Soricelli , Marco Salvatore , Bahar Güntekin , Görsev Yener , Federico Massa , Dario Arnaldi , Francesco Famà , Matteo Pardini , Raffaele Ferri , Michele Salerni , Claudio Babiloni
Objectives
Alzheimer’s disease patients with mild cognitive impairment (ADMCI) show abnormal resting-state eyes-closed electroencephalographic (rsEEG) alpha rhythms (8–12 Hz) and may suffer from daytime sleepiness. Our exploratory study tested the hypothesis that they may present characteristic EEG rhythms from quiet wakefulness to light sleep during diurnal recordings.
Methods
Datasets of 34 ADMCI and 22 matched healthy elderly (Nold) subjects were obtained from international archives. EEG recordings lasted approximately 30 min. Transitions of EEG activity from quiet wakefulness (alpha-dominant) to light sleep (theta-dominant ripples) were scored according to Hori’s vigilance stages. Cortical source activities were computed using the eLORETA software.
Results
ADMCI (t-ADMCI, N = 18) over Nold (t-Nold, N = 11) participants were characterized by greater frontal EEG delta source activities and a lesser reduction (reactivity) in the posterior alpha source activities from quiet wakefulness to ripples. Notably, EEG delta source activities during quiet wakefulness were also greater in the ADMCI group transitioning to light sleep as compared to patients without said vigilance reduction.
Conclusions
These results suggest that ADMCI patients with a greater susceptibility to daytime sleepiness may show characteristic EEG delta and alpha rhythms in the transition from quiet vigilance to daytime sleep.
Significance
Our study showed a derangement of EEG rhythms during the transition to sleep possibly specific to AD.
{"title":"Abnormal electroencephalographic rhythms from quiet wakefulness to light sleep in Alzheimer’s disease patients with mild cognitive impairment","authors":"Enrico Michele Salamone , Matteo Carpi , Giuseppe Noce , Claudio Del Percio , Susanna Lopez , Roberta Lizio , Dharmendra Jakhar , Ali Eldellaa , Veronica Henao Isaza , Burcu Bölükbaş , Andrea Soricelli , Marco Salvatore , Bahar Güntekin , Görsev Yener , Federico Massa , Dario Arnaldi , Francesco Famà , Matteo Pardini , Raffaele Ferri , Michele Salerni , Claudio Babiloni","doi":"10.1016/j.clinph.2025.01.012","DOIUrl":"10.1016/j.clinph.2025.01.012","url":null,"abstract":"<div><h3>Objectives</h3><div>Alzheimer’s disease patients with mild cognitive impairment (ADMCI) show abnormal resting-state eyes-closed electroencephalographic (rsEEG) alpha rhythms (8–12 Hz) and may suffer from daytime sleepiness. Our exploratory study tested the hypothesis that they may present characteristic EEG rhythms from quiet wakefulness to light sleep during diurnal recordings.</div></div><div><h3>Methods</h3><div>Datasets of 34 ADMCI and 22 matched healthy elderly (Nold) subjects were obtained from international archives. EEG recordings lasted approximately 30 min. Transitions of EEG activity from quiet wakefulness (alpha-dominant) to light sleep (theta-dominant ripples) were scored according to Hori’s vigilance stages. Cortical source activities were computed using the eLORETA software.</div></div><div><h3>Results</h3><div>ADMCI (t-ADMCI, N = 18) over Nold (t-Nold, N = 11) participants were characterized by greater frontal EEG delta source activities and a lesser reduction (reactivity) in the posterior alpha source activities from quiet wakefulness to ripples. Notably, EEG delta source activities during quiet wakefulness were also greater in the ADMCI group transitioning to light sleep as compared to patients without said vigilance reduction.</div></div><div><h3>Conclusions</h3><div>These results suggest that ADMCI patients with a greater susceptibility to daytime sleepiness may show characteristic EEG delta and alpha rhythms in the transition from quiet vigilance to daytime sleep.</div></div><div><h3>Significance</h3><div>Our study showed a derangement of EEG rhythms during the transition to sleep possibly specific to AD.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 164-181"},"PeriodicalIF":3.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143240324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-31DOI: 10.1016/j.clinph.2024.12.021
Miguel Ley , Riccardo Zucca , Klaus Langohr , Panadés-de Oliveira Luisa , Alessandro Principe , Jaume Capellades , María Yolanda Aguilar , Rodrigo Rocamora
Objective
Limited knowledge exists regarding how electrical source imaging (ESI) of interictal epileptiform discharges (IEDs) aligns with findings from other neuroimaging modalities. This study investigates the relationships of interictal ESI with MRI, 18FDG PET, SISCOM, and voxel-based morphometry (VBM) during presurgical evaluation of drug-resistant epilepsy (DRE).
Methods
A cross-sectional study evaluated the concordance of IED locations from ESI using various inverse solutions (CLARA, LAURA, LORETA, SLORETA, SWLORETA, SSLOFO) with MRI lesions, 18FDG PET, SISCOM, and VBM grey matter abnormalities. The role of ESI in presurgical evaluation of DRE was assessed.
Results
Significant relationships were identified between the localization and distribution of IEDs identified by ESI and the various sets of neuroimages. SLORETA and SWLORETA exhibited the highest concordance and interlobar associations with MRI, 18FDG PET and SISCOM. The main cluster of IEDs proved helpful in locating the epileptogenic zone (EZ).
Conclusions
The distribution of IEDs identified by the ESI technique exhibited a high degree of significant relationships with other neuroimaging sources. Its use may prove valuable in defining the epileptogenic zone.
Significance
Combining ESI of IEDs with other neuroimaging techniques may be useful in the presurgical evaluation of DRE.
{"title":"On the concordance between electrical source imaging, anatomical and functional neuroimaging in patients with focal epilepsy","authors":"Miguel Ley , Riccardo Zucca , Klaus Langohr , Panadés-de Oliveira Luisa , Alessandro Principe , Jaume Capellades , María Yolanda Aguilar , Rodrigo Rocamora","doi":"10.1016/j.clinph.2024.12.021","DOIUrl":"10.1016/j.clinph.2024.12.021","url":null,"abstract":"<div><h3>Objective</h3><div>Limited knowledge exists regarding how electrical source imaging (ESI) of interictal epileptiform discharges (IEDs) aligns with findings from other neuroimaging modalities. This study investigates the relationships of interictal ESI with MRI, 18FDG PET, SISCOM, and voxel-based morphometry (VBM) during presurgical evaluation of drug-resistant epilepsy (DRE).</div></div><div><h3>Methods</h3><div>A cross-sectional study evaluated the concordance of IED locations from ESI using various inverse solutions (CLARA, LAURA, LORETA, SLORETA, SWLORETA, SSLOFO) with MRI lesions, 18FDG PET, SISCOM, and VBM grey matter abnormalities. The role of ESI in presurgical evaluation of DRE was assessed.</div></div><div><h3>Results</h3><div>Significant relationships were identified between the localization and distribution of IEDs identified by ESI and the various sets of neuroimages. SLORETA and SWLORETA exhibited the highest concordance and interlobar associations with MRI, 18FDG PET and SISCOM. The main cluster of IEDs proved helpful in locating the epileptogenic zone (EZ).</div></div><div><h3>Conclusions</h3><div>The distribution of IEDs identified by the ESI technique exhibited a high degree of significant relationships with other neuroimaging sources. Its use may prove valuable in defining the epileptogenic zone.</div></div><div><h3>Significance</h3><div>Combining ESI of IEDs with other neuroimaging techniques may be useful in the presurgical evaluation of DRE.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"172 ","pages":"Pages 22-32"},"PeriodicalIF":3.7,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403709","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 : 2025-01-30DOI: 10.1016/j.clinph.2025.01.011
Atsuro Daida, Yuanyi Ding, Yipeng Zhang, Shingo Oana, Saarang Panchavati, Benjamin D Edmonds, Samuel S Ahn, Noriko Salamon, Raman Sankar, Aria Fallah, Richard J Staba, Jerome Engel, William Speier, Vwani Roychowdhury, Hiroki Nariai
Objective: To investigate high-frequency activities (HFA) associated with thalamic sleep spindles.
Methods: We studied a cohort of ten pediatric patients with medication resistant epilepsy who were identified as potential candidates for thalamic neuromodulation. These patients had thalamic sampling as well as presumed epileptogenic zones, using stereotactic EEG (SEEG) with a sampling frequency of 2,000 Hz. We quantified the summated high-frequency activity (HFA) in the fast ripple band associated with sleep spindles using 20-minute scalp EEG and SEEG recordings during non-REM sleep and analyzed its correlation with spindle characteristics.
Results: HFA, with a median peak frequency of 330 Hz, was distinctively observed in the thalamus and temporally correlated with thalamic sleep spindles. Such HFA demonstrated significant coupling with the sleep spindle range of 11-16 Hz. The duration of HFA positively correlated with higher density and longer duration of accompanying thalamic spindles. Thalamic HFA's duration negatively correlated with the presence of cortical interictal epileptiform discharges. Thalamic spindles generated in channels with HFA often coincided with sleep spindles in various brain regions.
Conclusion: Fast ripple band HFA associated with sleep spindles was observed exclusively in the thalamus.
Significance: Thalamic HFA associated with thalamic spindles may represent a thalamus-specific physiological phenomenon.
{"title":"Fast ripple band high-frequency activity associated with thalamic sleep spindles in pediatric epilepsy.","authors":"Atsuro Daida, Yuanyi Ding, Yipeng Zhang, Shingo Oana, Saarang Panchavati, Benjamin D Edmonds, Samuel S Ahn, Noriko Salamon, Raman Sankar, Aria Fallah, Richard J Staba, Jerome Engel, William Speier, Vwani Roychowdhury, Hiroki Nariai","doi":"10.1016/j.clinph.2025.01.011","DOIUrl":"https://doi.org/10.1016/j.clinph.2025.01.011","url":null,"abstract":"<p><strong>Objective: </strong>To investigate high-frequency activities (HFA) associated with thalamic sleep spindles.</p><p><strong>Methods: </strong>We studied a cohort of ten pediatric patients with medication resistant epilepsy who were identified as potential candidates for thalamic neuromodulation. These patients had thalamic sampling as well as presumed epileptogenic zones, using stereotactic EEG (SEEG) with a sampling frequency of 2,000 Hz. We quantified the summated high-frequency activity (HFA) in the fast ripple band associated with sleep spindles using 20-minute scalp EEG and SEEG recordings during non-REM sleep and analyzed its correlation with spindle characteristics.</p><p><strong>Results: </strong>HFA, with a median peak frequency of 330 Hz, was distinctively observed in the thalamus and temporally correlated with thalamic sleep spindles. Such HFA demonstrated significant coupling with the sleep spindle range of 11-16 Hz. The duration of HFA positively correlated with higher density and longer duration of accompanying thalamic spindles. Thalamic HFA's duration negatively correlated with the presence of cortical interictal epileptiform discharges. Thalamic spindles generated in channels with HFA often coincided with sleep spindles in various brain regions.</p><p><strong>Conclusion: </strong>Fast ripple band HFA associated with sleep spindles was observed exclusively in the thalamus.</p><p><strong>Significance: </strong>Thalamic HFA associated with thalamic spindles may represent a thalamus-specific physiological phenomenon.</p>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":" ","pages":""},"PeriodicalIF":3.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143364119","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 : 2025-01-28DOI: 10.1016/j.clinph.2025.01.004
Keith R. Murphy , Tulika Nandi , Benjamin Kop , Takahiro Osada , Maximilian Lueckel , W. Apoutou N’Djin , Kevin A. Caulfield , Anton Fomenko , Hartwig R. Siebner , Yoshikazu Ugawa , Lennart Verhagen , Sven Bestmann , Eleanor Martin , Kim Butts Pauly , Elsa Fouragnan , Til Ole Bergmann
Low-intensity Transcranial Ultrasonic Stimulation (TUS) is a non-invasive brain stimulation technique enabling cortical and deep brain targeting with unprecedented spatial accuracy. Given the high rate of adoption by new users with varying levels of expertise and interdisciplinary backgrounds, practical guidelines are needed to ensure state-of-the-art TUS application and reproducible outcomes. Therefore, the International Transcranial Ultrasonic Stimulation Safety and Standards (ITRUSST) consortium has formed a subcommittee, endorsed by the International Federation of Clinical Neurophysiology (IFCN), to develop recommendations for best practices in human TUS applications. The practical guide presented here provides a brief introduction into ultrasound physics and sonication parameters. It explains the requirements of TUS lab equipment and transducer selection and discusses experimental design and procedures alongside potential confounds and control conditions. Finally, the guide elaborates on essential steps of application planning for stimulation safety and efficacy, as well as considerations when combining TUS with neuroimaging, electrophysiology, or other brain stimulation techniques. We hope that this practical guide to TUS will assist both novice and experienced users in planning and conducting high-quality studies and provide a solid foundation for further advancements in this promising field.
{"title":"A practical guide to transcranial ultrasonic stimulation from the IFCN-endorsed ITRUSST consortium","authors":"Keith R. Murphy , Tulika Nandi , Benjamin Kop , Takahiro Osada , Maximilian Lueckel , W. Apoutou N’Djin , Kevin A. Caulfield , Anton Fomenko , Hartwig R. Siebner , Yoshikazu Ugawa , Lennart Verhagen , Sven Bestmann , Eleanor Martin , Kim Butts Pauly , Elsa Fouragnan , Til Ole Bergmann","doi":"10.1016/j.clinph.2025.01.004","DOIUrl":"10.1016/j.clinph.2025.01.004","url":null,"abstract":"<div><div>Low-intensity Transcranial Ultrasonic Stimulation (TUS) is a non-invasive brain stimulation technique enabling cortical and deep brain targeting with unprecedented spatial accuracy. Given the high rate of adoption by new users with varying levels of expertise and interdisciplinary backgrounds, practical guidelines are needed to ensure state-of-the-art TUS application and reproducible outcomes. Therefore, the International Transcranial Ultrasonic Stimulation Safety and Standards (ITRUSST) consortium has formed a subcommittee, endorsed by the International Federation of Clinical Neurophysiology (IFCN), to develop recommendations for best practices in human TUS applications. The practical guide presented here provides a brief introduction into ultrasound physics and sonication parameters. It explains the requirements of TUS lab equipment and transducer selection and discusses experimental design and procedures alongside potential confounds and control conditions. Finally, the guide elaborates on essential steps of application planning for stimulation safety and efficacy, as well as considerations when combining TUS with neuroimaging, electrophysiology, or other brain stimulation techniques. We hope that this practical guide to TUS will assist both novice and experienced users in planning and conducting high-quality studies and provide a solid foundation for further advancements in this promising field.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 192-226"},"PeriodicalIF":3.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143376825","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-27DOI: 10.1016/j.clinph.2025.01.006
Andrés Torres Sánchez , Marie Dawant , Venethia Danthine , Inci Cakiroglu , Roberto Santalucia , Enrique Ignacio Germany Morrison , Antoine Nonclercq , Riëm El Tahry
Purpose
The Locus Coeruleus (LC) plays a vital role by releasing norepinephrine, which contributes to the antiepileptic effects of Vagus Nerve Stimulation (VNS). LC activity also influences pupil dilation. Investigating VNS dose-dependent Pupillary Dilation Response (PDR) may provide novel neurophysiological insights into therapeutic response and allow for an objective and personalized optimization of stimulation parameters.
Methods
Fourteen VNS-implanted patients (9 responders, 5 non-responders) treated for at least 6 months were retrospectively recruited. VNS intensities were adjusted from 0.25 mA to 2.25 mA, or to the highest tolerable level. Concurrently, we tracked pupil size in the left eye and gathered patients’ subjective perception scores. Individual curve fitting was used to explore the relationship between VNS intensity and PDR.
Results
PDR increased with stimulation intensity, particularly in responders. In 6 patients, an inverted U-shaped relationship between intensity and PDR was observed 2–3 s after stimulation onset. A significant interaction was found between VNS intensity and responder status, independent of subjective perception.
Conclusions
VNS induces a dose-dependent PDR, which differs between responders and non-responders. In nearly half the patients, the dose–response relationship was characterized by an inverted U-shape with a maximal VNS effect.
Significance
We propose VNS-induced PDR as a novel biomarker of VNS response.
{"title":"VNS-induced dose-dependent pupillary response in refractory epilepsy","authors":"Andrés Torres Sánchez , Marie Dawant , Venethia Danthine , Inci Cakiroglu , Roberto Santalucia , Enrique Ignacio Germany Morrison , Antoine Nonclercq , Riëm El Tahry","doi":"10.1016/j.clinph.2025.01.006","DOIUrl":"10.1016/j.clinph.2025.01.006","url":null,"abstract":"<div><h3>Purpose</h3><div>The Locus Coeruleus (LC) plays a vital role by releasing norepinephrine, which contributes to the antiepileptic effects of Vagus Nerve Stimulation (VNS). LC activity also influences pupil dilation. Investigating VNS dose-dependent Pupillary Dilation Response (PDR) may provide novel neurophysiological insights into therapeutic response and allow for an objective and personalized optimization of stimulation parameters.</div></div><div><h3>Methods</h3><div>Fourteen VNS-implanted patients (9 responders, 5 non-responders) treated for at least 6 months were retrospectively recruited. VNS intensities were adjusted from 0.25 mA to 2.25 mA, or to the highest tolerable level. Concurrently, we tracked pupil size in the left eye and gathered patients’ subjective perception scores. Individual curve fitting was used to explore the relationship between VNS intensity and PDR.</div></div><div><h3>Results</h3><div>PDR increased with stimulation intensity, particularly in responders. In 6 patients, an inverted U-shaped relationship between intensity and PDR was observed 2–3 s after stimulation onset. A significant interaction was found between VNS intensity and responder status, independent of subjective perception.</div></div><div><h3>Conclusions</h3><div>VNS induces a dose-dependent PDR, which differs between responders and non-responders. In nearly half the patients, the dose–response relationship was characterized by an inverted U-shape with a maximal VNS effect.</div></div><div><h3>Significance</h3><div>We propose VNS-induced PDR as a novel biomarker of VNS response.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 67-75"},"PeriodicalIF":3.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143064123","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 : 2025-01-27DOI: 10.1016/j.clinph.2025.01.005
Arnaldo Fim Neto , Fabio Godinho , Luiz Ricardo Trajano da Silva , Julia Baldi de Luccas , André Kazuo Takahata , Eberval Gadelha Figueiredo , Carlos Gilberto Carlotti Junior , Maria Sheila Guimarães Rocha , Diogo Coutinho Soriano
Introduction: Freezing of gait (FOG) is a disabling symptom that affects over half of Parkinson’s disease patients (PD) and hinders the ability to walk. Subthalamic nucleus (STN) deep brain stimulation (DBS) effectiveness in ameliorating the FOG remains controversial, lacking a reliable electrophysiological biomarker from local field potentials (LFP). Methods: The LFP-STN rhythms bandpower and dynamics were characterized at rest across groups in a cohort of 23 patients (14 with FOG, and 9 without, n-FOG). Results: FOG patients presented enhanced alpha bandpower (FOG vs. n-FOG: 0.331 ± 0.087 vs. 0.248 ± 0.089; p = 0.011) and intermittent (burst) alpha amplitude (FOG vs. n-FOG: 0.610 ± 0.068 vs. 0.524 ± 0.086; p = 0.005). Both intermittent alpha (r = 0.330, p = 0.046) and intermittent high beta amplitude (r = 0.415, p = 0.011) correlated with the FOG score. Alpha burst amplitude correlated with FOG severity (r = 0.479, p = 0.003), and high beta burst amplitude inversely correlated (r = −0.411, p = 0.014) with the performance-oriented mobility assessment (POMA) index. Conclusion: These results suggest that alpha and high beta subthalamic oscillations impact FOG symptoms. Significance: The investigation suggests potentially newer co-biomarkers of FOG to guide multi-rhythm paradigms in DBS treatment.
{"title":"Alpha and high beta subthalamic intermittent activity correlates with freezing of gait severity in Parkinson’s disease","authors":"Arnaldo Fim Neto , Fabio Godinho , Luiz Ricardo Trajano da Silva , Julia Baldi de Luccas , André Kazuo Takahata , Eberval Gadelha Figueiredo , Carlos Gilberto Carlotti Junior , Maria Sheila Guimarães Rocha , Diogo Coutinho Soriano","doi":"10.1016/j.clinph.2025.01.005","DOIUrl":"10.1016/j.clinph.2025.01.005","url":null,"abstract":"<div><div><strong>Introduction:</strong> Freezing of gait (FOG) is a disabling symptom that affects over half of Parkinson’s disease patients (PD) and hinders the ability to walk. Subthalamic nucleus (STN) deep brain stimulation (DBS) effectiveness in ameliorating the FOG remains controversial, lacking a reliable electrophysiological biomarker from local field potentials (LFP). <strong>Methods:</strong> The LFP-STN rhythms bandpower and dynamics were characterized at rest across groups in a cohort of 23 patients (14 with FOG, and 9 without, n-FOG). <strong>Results:</strong> FOG patients presented enhanced alpha bandpower (FOG <em>vs</em>. n-FOG: 0.331 ± 0.087 <em>vs</em>. 0.248 ± 0.089; p = 0.011) and intermittent (burst) alpha amplitude (FOG <em>vs</em>. n-FOG: 0.610 ± 0.068 <em>vs</em>. 0.524 ± 0.086; p = 0.005). Both intermittent alpha (r = 0.330, p = 0.046) and intermittent high beta amplitude (r = 0.415, p = 0.011) correlated with the FOG score. Alpha burst amplitude correlated with FOG severity (r = 0.479, p = 0.003), and high beta burst amplitude inversely correlated (r = −0.411, p = 0.014) with the performance-oriented mobility assessment (POMA) index. <strong>Conclusion:</strong> These results suggest that alpha and high beta subthalamic oscillations impact FOG symptoms. <strong>Significance:</strong> The investigation suggests potentially newer co-biomarkers of FOG to guide multi-rhythm paradigms in DBS treatment.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 51-60"},"PeriodicalIF":3.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143064014","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 : 2025-01-24DOI: 10.1016/j.clinph.2025.01.010
Maxine J. Shanks , John Cirillo , Cathy M. Stinear , Winston D. Byblow
Objective
To use peri-threshold transcranial magnetic stimulation (TMS) intensities to elicit motor evoked potentials (MEPs) during the subacute stage after stroke and assess their association with upper limb motor recovery.
Methods
Twenty-five MEP+ patients participated in three sessions at 1, 3, and 6 months post-stroke. Single-pulse TMS across a range of stimulation intensities was used to elicit MEPs in four muscles of the paretic and non-paretic upper limb. At each timepoint, threshold matrices were constructed based on MEP amplitude and persistence. A matrix element was suprathreshold if five out of ten stimulations elicited MEPs ≥ 50 μV. A subthreshold element produced MEPs below this criterion. Dexterity was assessed using the nine hole peg test.
Results
There were fewer suprathreshold, and more subthreshold elements on the paretic compared to the non-paretic side. The number of suprathreshold elements on the paretic side increased between 1 and 6 months post-stroke. Neither sub- nor supra-threshold elements were associated with dexterity recovery.
Conclusion
The proportion of sub- and supra-threshold elements reflect neurophysiological recovery during the subacute stage after stroke. A threshold matrix framework can identify patients with stable versus dynamic neurophysiology post-stroke.
Significance
A compositional analysis framework can quantify neurophysiological recovery after stroke.
{"title":"A novel TMS framework for assessing neurophysiological recovery at the subacute stage after stroke","authors":"Maxine J. Shanks , John Cirillo , Cathy M. Stinear , Winston D. Byblow","doi":"10.1016/j.clinph.2025.01.010","DOIUrl":"10.1016/j.clinph.2025.01.010","url":null,"abstract":"<div><h3>Objective</h3><div>To use peri-threshold transcranial magnetic stimulation (TMS) intensities to elicit motor evoked potentials (MEPs) during the subacute stage after stroke and assess their association with upper limb motor recovery.</div></div><div><h3>Methods</h3><div>Twenty-five MEP+ patients participated in three sessions at 1, 3, and 6 months post-stroke. Single-pulse TMS across a range of stimulation intensities was used to elicit MEPs in four muscles of the paretic and non-paretic upper limb. At each timepoint, threshold matrices were constructed based on MEP amplitude and persistence. A matrix element was suprathreshold if five out of ten stimulations elicited MEPs ≥ 50 μV. A subthreshold element produced MEPs below this criterion. Dexterity was assessed using the nine hole peg test.</div></div><div><h3>Results</h3><div>There were fewer suprathreshold, and more subthreshold elements on the paretic compared to the non-paretic side. The number of suprathreshold elements on the paretic side increased between 1 and 6 months post-stroke. Neither sub- nor supra-threshold elements were associated with dexterity recovery.</div></div><div><h3>Conclusion</h3><div>The proportion of sub- and supra-threshold elements reflect neurophysiological recovery during the subacute stage after stroke. A threshold matrix framework can identify patients with stable versus dynamic neurophysiology post-stroke.</div></div><div><h3>Significance</h3><div>A compositional analysis framework can quantify neurophysiological recovery after stroke.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 82-94"},"PeriodicalIF":3.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143074282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-24DOI: 10.1016/j.clinph.2025.01.007
Fabrizio Vecchio , Francesca Miraglia , Chiara Pappalettera , Paolo Maria Rossini
Objective
Directional cues have a profound impact on cognitive processes and behavior, and studying the involved brain networks can provide insights into their processing. This research aimed to investigate the neural network modulation associated with cognitive processing after the administration of directional cues using connectivity and graph theory.
Methods
Twenty healthy volunteers were enrolled and underwent EEG recording while they were asked to perform a visuomotor task, such as directional (DS) and non-directional (nDS). From EEG data, network parameters such as Small-World (SW) and Lagged linear connectivity across different EEG frequency bands were evaluated, analyzing the response to DS and nDS.
Results
The results revealed significant differences in the SW index, particularly in the Alpha 1 band, where participants exhibited a higher SW index when presented with DS compared to nDS. Moreover, the analysis of Alpha 1 band Lagged linear connectivity revealed close to statistically significant differences predominantly in the frontal and central regions.
Conclusions
This research contributes to our understanding of the neural mechanisms underlying the processing of directional cues.
Significance
It has potential implications for rehabilitation settings, for example in the rehabilitation of visual dysfunction and motor impairment following a stroke, by optimizing cognitive processing to enhance functional outcomes.
{"title":"Brain network modulation in response to directional and Non-Directional Cues: Insights from EEG connectivity and graph theory","authors":"Fabrizio Vecchio , Francesca Miraglia , Chiara Pappalettera , Paolo Maria Rossini","doi":"10.1016/j.clinph.2025.01.007","DOIUrl":"10.1016/j.clinph.2025.01.007","url":null,"abstract":"<div><h3>Objective</h3><div>Directional cues have a profound impact on cognitive processes and behavior, and studying the involved brain networks can provide insights into their processing. This research aimed to investigate the neural network modulation associated with cognitive processing after the administration of directional cues using connectivity and graph theory.</div></div><div><h3>Methods</h3><div>Twenty healthy volunteers were enrolled and underwent EEG recording while they were asked to perform a visuomotor task, such as directional (DS) and non-directional (nDS). From EEG data, network parameters such as Small-World (SW) and Lagged linear connectivity across different EEG frequency bands were evaluated, analyzing the response to DS and nDS.</div></div><div><h3>Results</h3><div>The results revealed significant differences in the SW index, particularly in the Alpha 1 band, where participants exhibited a higher SW index when presented with DS compared to nDS. Moreover, the analysis of Alpha 1 band Lagged linear connectivity revealed close to statistically significant differences predominantly in the frontal and central regions.</div></div><div><h3>Conclusions</h3><div>This research contributes to our understanding of the neural mechanisms underlying the processing of directional cues.</div></div><div><h3>Significance</h3><div>It has potential implications for rehabilitation settings, for example in the rehabilitation of visual dysfunction and motor impairment following a stroke, by optimizing cognitive processing to enhance functional outcomes.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 146-153"},"PeriodicalIF":3.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159713","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 : 2025-01-24DOI: 10.1016/j.clinph.2025.01.008
Lingyan Mao , Gaoxing Zheng , Yang Cai , Wenyi Luo , Yijun Zhang , Kuidong Wu , Jing Ding , Xin Wang
Objectives
To develop a predicted algorithm for drug-resistant epilepsy (DRE) in newly diagnosed temporal lobe epilepsy (TLE) patients.
Methods
A total of 139 newly diagnosed TLE patients were prospectively enrolled, and long-term video EEG monitoring was recorded. Clinical evaluations, including seizure frequency and antiseizure medications (ASMs) usage, were collected and prospectively followed up for 24 months. Interictal EEG data were used for feature extraction, identifying 216 EEG network features. Traditional machine learning and ensemble learning techniques were employed to predict DRE outcomes.
Results
Over two years, TLE patients with DRE exhibited significant EEG differences, particularly in frontotemporal θ-band networks, characterized by increased connectivity metrics such as phase lag index (P = 0.000), etc. The predictive algorithm based on EEG features achieved accuracies between 59.2 %-84.6 % (AUC: 0.60–0.87). When compared to the whole brain, EEG features of the frontotemporal network showed improved classification performance in Naïve Bayes (P = 0.032), Tree Bagger (P = 0.021), and Subspace Discriminant (P = 0.022) models. The ensemble learning technique (Tree Bagger) delivered the best prediction results, achieving 91.5 % accuracy, 97 % sensitivity, 81 % specificity, and AUC of 0.92.
Conclusions
Increased frontotemporal EEG connectivity was observed in TLE patients with 2-year DRE. A predictive model based on routine EEG provides an accessible method for forecasting ASMs efficacy.
Significance
This study highlights the clinical utility of EEG-based algorithms in identifying DRE early, aiding personalized treatment strategies and improving patient outcomes.
{"title":"Machine learning-based algorithm of drug-resistant prediction in newly diagnosed patients with temporal lobe epilepsy","authors":"Lingyan Mao , Gaoxing Zheng , Yang Cai , Wenyi Luo , Yijun Zhang , Kuidong Wu , Jing Ding , Xin Wang","doi":"10.1016/j.clinph.2025.01.008","DOIUrl":"10.1016/j.clinph.2025.01.008","url":null,"abstract":"<div><h3>Objectives</h3><div>To develop a predicted algorithm for drug-resistant epilepsy (DRE) in newly diagnosed temporal lobe epilepsy (TLE) patients.</div></div><div><h3>Methods</h3><div>A total of 139 newly diagnosed TLE patients were prospectively enrolled, and long-term video EEG monitoring was recorded. Clinical evaluations, including seizure frequency and antiseizure medications (ASMs) usage, were collected and prospectively followed up for 24 months. Interictal EEG data were used for feature extraction, identifying 216 EEG network features. Traditional machine learning and ensemble learning techniques were employed to predict DRE outcomes.</div></div><div><h3>Results</h3><div>Over two years, TLE patients with DRE exhibited significant EEG differences, particularly in frontotemporal θ-band networks, characterized by increased connectivity metrics such as phase lag index (<em>P</em> = 0.000), etc. The predictive algorithm based on EEG features achieved accuracies between 59.2 %-84.6 % (AUC: 0.60–0.87). When compared to the whole brain, EEG features of the frontotemporal network showed improved classification performance in Naïve Bayes (<em>P</em> = 0.032), Tree Bagger (<em>P</em> = 0.021), and Subspace Discriminant (<em>P</em> = 0.022) models. The ensemble learning technique (Tree Bagger) delivered the best prediction results, achieving 91.5 % accuracy, 97 % sensitivity, 81 % specificity, and AUC of 0.92.</div></div><div><h3>Conclusions</h3><div>Increased frontotemporal EEG connectivity was observed in TLE patients with 2-year DRE. A predictive model based on routine EEG provides an accessible method for forecasting ASMs efficacy.</div></div><div><h3>Significance</h3><div>This study highlights the clinical utility of EEG-based algorithms in identifying DRE early, aiding personalized treatment strategies and improving patient outcomes.</div></div>","PeriodicalId":10671,"journal":{"name":"Clinical Neurophysiology","volume":"171 ","pages":"Pages 154-163"},"PeriodicalIF":3.7,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143159705","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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