Clinical Neurophysiology Practice最新文献

{"title":"Impact of stress on EEG functional connectivity during procedural learning","authors":"Francis L. Kirk,&nbsp;Alexander F. Friend,&nbsp;Sudhanva Suvarna,&nbsp;Emmett E. Whitaker,&nbsp;Gregory L. Holmes","doi":"10.1016/j.cnp.2026.07.017","DOIUrl":"10.1016/j.cnp.2026.07.017","url":null,"abstract":"<div><h3>Objective</h3><div>In a procedural learning environment, trainees acquire skills for managing life-threatening emergencies, a context that inherently elicits stress. While moderate stress can enhance memory consolidation, excessive stress (distress) may impair learning and performance. Here we elucidated the neurophysiological effects of stress on learners during a procedural learning task.</div></div><div><h3>Methods</h3><div>We examined the effects of stress on learning by assessing EEG functional connectivity (FC) in medical trainees during endotracheal intubation. The cohort comprised medical trainees who were monitored at baseline (rest) and during two high-fidelity simulation scenarios: a calm condition and a stressful condition (intubation during anesthesia induction). Concurrent data were collected, including heart rate, eye blinks and self-reported measures of perceived stress and cognitive load.</div></div><div><h3>Results</h3><div>High-fidelity simulation reliably provokes a physiological stress response, predominantly mediated by sympathetic nervous system activation. Across conditions, FC increased relative to baseline, indicating heightened neural network synchronization during task engagement. Notably, under the stressful condition, FC was further elevated compared with the calm scenario, suggesting that stress within a defined range may enhance neural communication efficiency and learning capacity.</div></div><div><h3>Conclusions</h3><div>These findings imply a potential neurophysiological signature of stress that could be leveraged to design personalized educational interventions, calibrating stress levels to optimize learning while mitigating deleterious effects.</div></div><div><h3>Significance</h3><div>The study demonstrates the feasibility of using real-time EEG to monitor stress-related neural dynamics in medical trainees and underscores the importance of integrating neurophysiological insights into the development of training environments.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 679-688"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148737276","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolving epileptic activity under focal rhythmic Delta activity: insights from simultaneous intracranial and scalp EEG","authors":"Ayumi Sakata,&nbsp;Nobutaka Mukae,&nbsp;Takafumi Shimogawa,&nbsp;Takahiko Mukaino,&nbsp;Kimiaki Hashiguchi,&nbsp;Kazuhisa Kuwabara,&nbsp;Kou Matsumoto,&nbsp;Takahiro Yamaguchi,&nbsp;Taira Uehara,&nbsp;Toshiki Okadome,&nbsp;Yasunari Sakai,&nbsp;Yuri Sonoda,&nbsp;Satoshi Akamine,&nbsp;Pin Fee Chong,&nbsp;Kenta Kajiwara,&nbsp;Eriko Watanabe,&nbsp;Noriko Isobe,&nbsp;Koji Yoshimoto,&nbsp;Takato Morioka,&nbsp;Yuya Kunisaki,&nbsp;Hiroshi Shigeto","doi":"10.1016/j.cnp.2026.08.001","DOIUrl":"10.1016/j.cnp.2026.08.001","url":null,"abstract":"<div><h3>Objective</h3><div>Focal rhythmic delta activity (RDA) is a subtype of lateralized RDA (LRDA). Although several studies have compared scalp and intracranial electroencephalography (EEG) recordings to determine whether LRDA observed on scalp EEG reflects epileptic abnormalities occurring intracranially during the acute phase, to our knowledge, no studies have examined focal RDA. Therefore, we investigated the extent to which focal RDA on scalp EEG during the acute phase reflects epileptic activity observed on intracranial EEG.</div></div><div><h3>Methods</h3><div>We retrospectively reviewed cases with simultaneous intracranial and scalp EEG (January 2003–August 2024). Patients who developed an intracranial hematoma during electrode placement were identified and included. For each case, we evaluated whether RDA, spikes, polyspikes, electrographic seizures (ESz), electrographic status epilepticus (ESE), and high-frequency oscillations (HFOs) observed on intracranial EEG near the hematoma were reflected on scalp EEG in terms of appearance, timing, frequency, and amplitude.</div></div><div><h3>Results</h3><div>Of the 116 patients, six developed intracranial hematoma and were included in the analysis. Focal RDA was observed on scalp EEG in all six cases, whereas intracranial RDA appeared earlier than focal RDA on scalp EEG. In all cases, spikes and polyspikes were superimposed on the RDA in the intracranial EEG, whereas these findings were observed on scalp EEG in only three cases. ESz, ESE, and HFOs were observed in all intracranial recordings but were not detected on scalp EEG.</div></div><div><h3>Significance</h3><div>Focal RDA observed on scalp EEG during the acute phase may reflect growing epileptic activity and serve as a potential target for antiseizure medication therapy.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 697-706"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148737278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Response to: ‘Re-assessing the clinical significance of long-term neuromuscular alterations following onabotulinumtoxinA in chronic migraine’","authors":"Tina Plensäll,&nbsp;Maarika Liik,&nbsp;Artor Pogosean,&nbsp;Annika Eriksson,&nbsp;Malin Garrett,&nbsp;Jan Olszowy,&nbsp;Sven Jackmann,&nbsp;Anna Rostedt Punga","doi":"10.1016/j.cnp.2026.08.011","DOIUrl":"10.1016/j.cnp.2026.08.011","url":null,"abstract":"","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 764-765"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148958288","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Normative data of laser evoked potentials using Nd:YAP laser","authors":"Egle Sukockiene,&nbsp;Caroline Perchet,&nbsp;Christelle Créac'h,&nbsp;Luis Garcia-Larrea,&nbsp;Agustina M. Lascano","doi":"10.1016/j.cnp.2026.10.002","DOIUrl":"10.1016/j.cnp.2026.10.002","url":null,"abstract":"<div><h3>Objectives</h3><div>To establish a robust multi-centre normative database for Nd:YAP laser-evoked potentials (LEPs) across distal and proximal stimulation sites, and to quantify the impact of laser spot size (energy density) and demographic factors on LEP parameters.</div></div><div><h3>Methods</h3><div>One hundred nine healthy adults (57 females) were recruited from three centres (Geneva, Lyon, Saint-Etienne). Nd:YAP laser pulses were delivered with a 3-mm beam (Centre 1) or 4-mm beam (Centres 2–3). LEPs were recorded from standard EEG sites (including Fz/Cz/Pz and contralateral temporal leads). Stimulation sites included hand dorsum (<em>n</em> = 109), foot dorsum (<em>n</em> = 80), thigh and upper neck (both <em>n</em> = 43). N1, N2, and P2 latencies and amplitudes were measured and normal limits estimated as mean ± 99.9% confidence interval. ANCOVA (age-corrected) tested spot-size effects; repeated-measures ANOVA tested site effects; correlations assessed age/height associations.</div></div><div><h3>Results</h3><div>The vertex N2–P2 complex was consistently recorded across centres and sites (100% for hand, thigh, neck; ∼97% for foot). N1 detection was less consistent, particularly with larger spot size and at the foot. Smaller spot size (higher energy density) yielded shorter N2/P2 latencies and larger N2–P2 amplitudes for hand stimulation, and shorter P2 latency for foot stimulation. Sex and height showed no significant effects. Increasing age was associated with longer N2/P2 latencies and reduced N2–P2 amplitudes for distal sites, with minimal age effects at proximal sites.</div></div><div><h3>Conclusions</h3><div>This study provides the most comprehensive Nd:YAP LEP normative dataset to date, including distal and proximal sites and spot-size–specific reference limits.</div></div><div><h3>Significance</h3><div>These data support standardized, high-specificity clinical interpretation of LEPs for assessing small-fibre and spinothalamic pathway dysfunction.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 858-866"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149153365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Falls in demented patients are associated with reduced EEG functional connectivity of the dorsal attention network","authors":"Agnes Pirker-Kees,&nbsp;Kirsten Platho-Elwischger,&nbsp;Clemens Lang,&nbsp;Christoph Baumgartner","doi":"10.1016/j.cnp.2026.07.015","DOIUrl":"10.1016/j.cnp.2026.07.015","url":null,"abstract":"<div><h3>Objective</h3><div>Falls are common in individuals with dementia and pose a significant problem in acute hospital care. Aging and dementia affect functional brain networks including the default mode network (DMN), dorsal attention network (DAN) and salience network (SAN). The DAN and SAN are essential for the rapid detection of responses to unexpected stimuli. We hypothesize that global efficiency within these networks is reduced in patients with dementia who experience falls compared with those who do not.</div></div><div><h3>Methods</h3><div>We analyzed 347 inpatients with dementia from a neurological clinic in Vienna, Austria. Of 153 available EEGs, only those with normal findings were included. FC was calculated using the phase-locking-value across delts, theta, alpha, and beta bands. The characteristic path length of the DAN, SAN and DMN was computed.</div></div><div><h3>Results</h3><div>Fallers showed reduced global efficiency in the DAN. FC between the right rostral middle frontal gyrus and left middle frontal gyrus was decreased in delta, theta, and alpha bands – regions involved in visual stimulus processing and executive control.</div></div><div><h3>Conclusions</h3><div>Reduced DAN connectivity may impair the ability to respond to unexpected stimuli, increasing fall risk in individuals with dementia. This supports the role of attention network dysfunction in motoric cognitive risk syndrome.</div></div><div><h3>Significance</h3><div>Falls are a significant problem in dementia, not well understood so far. Identifying network level dysfunction in dementia related falls offers a novel biomarker for risk stratification and possible targets for future interventions.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 657-663"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148634195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Home use of low-intensity transcranial electrical stimulation in clinical practice: an IFCN handbook chapter","authors":"Perianen Ramasawmy ,&nbsp;Marom Bikson ,&nbsp;Jerome Brunelin ,&nbsp;Kyle Donnery ,&nbsp;Alexander Hunold ,&nbsp;Jean-Pascal Lefaucheur ,&nbsp;Marine Mondino ,&nbsp;Teresa Schuhmann ,&nbsp;Antonio Oliviero ,&nbsp;Andrea Antal","doi":"10.1016/j.cnp.2026.03.006","DOIUrl":"10.1016/j.cnp.2026.03.006","url":null,"abstract":"<div><div>Non-invasive brain stimulation (NIBS) includes a growing set of techniques aimed at modulating brain activity without surgery or implants. Transcranial magnetic (TMS) and electrical stimulation (tES) are among the most established methods. tES delivers low-intensity current via scalp electrodes, offering a cheaper and portable option, especially for home-based use. Clinical evidence suggests that the effects of tES are cumulative with consecutive applications needed to achieve meaningful changes. The therapeutic application of the clinic-based tES usually involves a minimum of two weeks of daily visits to the clinical institute, which poses a large burden and stress on patients. Home-based tES, e.g. under remote supervision (RS-tES), following adequate training by trained professionals paves the path to increasing the accessibility of the technology to patients. In 2025, the US FDA approved the first home-based tDCS system for the treatment of “moderate to severe major depressive disorder in the current episode, either as monotherapy or as an adjunctive treatment, in patients 18 years and older who are not considered treatment refractory to medication. In this work, the latest knowledge related to home-use of tES is introduced, including the methodology, most frequent clinical applications, advances and limitations.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 218-251"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147600112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Simultaneous ultrasound and needle electromyography recording of fasciculations in amyotrophic lateral sclerosis","authors":"Takamichi Sugimoto ,&nbsp;Keisuke Tachiyama ,&nbsp;Akemi Hironaka ,&nbsp;Hiroyuki Naito ,&nbsp;Masahiro Nakamori ,&nbsp;Shiro Aoki ,&nbsp;Yu Yamazaki ,&nbsp;Hirofumi Maruyama","doi":"10.1016/j.cnp.2026.06.008","DOIUrl":"10.1016/j.cnp.2026.06.008","url":null,"abstract":"<div><h3>Objective</h3><div>Fasciculations can be detected using both muscle ultrasonography and needle electromyography, yet the correspondence between ultrasonographically observed fasciculations (U-fas) and needle electromyography–detected fasciculation potentials (N-fas) has not been clarified. This study investigated their correspondence using fully synchronized recordings.</div></div><div><h3>Methods</h3><div>Adult patients showing fasciculation-like contractions on muscle ultrasonography were enrolled; all were subsequently diagnosed with amyotrophic lateral sclerosis. Ultrasound and needle electromyography were recorded simultaneously in up to three muscles per patient, with a recording duration of 3 min per muscle. For each ultrasonographically observed fasciculation, the presence of a corresponding electromyographic event and contraction duration assessed by M-mode imaging were evaluated.</div></div><div><h3>Results</h3><div>Ten patients with amyotrophic lateral sclerosis were included. A total of 472 focused U-fas events were analyzed. Corresponding N-fas were detected in 437 events, yielding an overall concordance rate of 92.6% (95% confidence interval, 90.2–95.0%). U-fas contraction duration ranged from 343 to 971 ms, whereas N-fas duration ranged from 10.9 to 76.4 ms. The number of phases of N-fas observed during U-fas events ranged from 1 to 10.</div></div><div><h3>Conclusions</h3><div>Most ultrasonographically observed fasciculations corresponded to electromyography-detected events on simultaneous recording.</div></div><div><h3>Significance</h3><div>Ultrasonographically detected fasciculations may serve as a supplementary indicator of lower motor neuron involvement in amyotrophic lateral sclerosis.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 448-452"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148362857","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effective connectivity between homologous cortices mediated by the corpus callosum: An axono-cortical evoked potentials study","authors":"Takumi Mitsuhashi,&nbsp;Yasushi Iimura,&nbsp;Hiroharu Suzuki,&nbsp;Tetsuya Ueda,&nbsp;Kazuki Nishioka,&nbsp;Kazuki Nomura,&nbsp;Madoka Nakajima,&nbsp;Hidenori Sugano,&nbsp;Akihide Kondo","doi":"10.1016/j.cnp.2026.02.002","DOIUrl":"10.1016/j.cnp.2026.02.002","url":null,"abstract":"<div><h3>Objective</h3><div>To demonstrate the role of the corpus callosum in interhemispheric effective connectivity and investigate the distribution of the connectivity originating from it using axono-cortical evoked potentials.</div></div><div><h3>Methods</h3><div>A 14-year-old girl with drug-resistant focal epilepsy underwent total callosotomy. Intraoperatively, we placed four subdural strip electrode contacts on the corpus callosum and eight on each hemisphere. We applied single-pulse electrical stimulation to eight pairs of contacts placed on the corpus callosum and cerebral cortex, recording axono-cortical, cortico-axonal, and cortico-cortical evoked potentials. Propagation latencies and anatomical distributions were determined based on the first negative deflection within 10–50 ms.</div></div><div><h3>Results</h3><div>Stimulation of the rostral to the anterior midbody elicited responses in bilateral anterior premotor cortices. The anterior to posterior midbody stimulation elicited responses in more posterior premotor cortices. The sum of latencies from the corpus callosum to each hemisphere (23.5 + 21.75 = 45.25 ms) approximated the interhemispheric neural propagation latency (44.5 ms). No significant responses were observed within the corpus callosum.</div></div><div><h3>Conclusion</h3><div>The corpus callosum mediated effective connectivity between homologous cortices aligned along the anterior–posterior axis, consistent with known structural connectivity.</div></div><div><h3>Significance</h3><div>This study provides the first direct neurophysiological evidence of the contribution of the corpus callosum to interhemispheric effective connectivity, highlighting its structural–functional correspondence and limitations in generating local field potentials.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 126-132"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173193","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applications of pelvic neurophysiology testing in clinical practice","authors":"Jalesh N. Panicker ,&nbsp;Sara Simeoni ,&nbsp;Sarah Wright ,&nbsp;Claire Hentzen ,&nbsp;Prasad Malladi","doi":"10.1016/j.cnp.2026.01.008","DOIUrl":"10.1016/j.cnp.2026.01.008","url":null,"abstract":"<div><div>Pelvic neurophysiology testing uniquely provides an evaluation of the sacral S2, 3 and 4 segmental somatic innervation. Since the tests are involved and some are invasive, a clear clinical question is essential in order to tailor the tests appropriately. Results should always be interpreted in conjunction with the clinical presentation and other investigation findings. The tests provide objective quantitative evidence for nerve injury and there are specific indications where these tests become of paramount importance such as the evaluation of suspected cauda equina syndrome, suspected MSA, chronic urinary retention, pelvic pain, sexual dysfunction and situations where MRI findings are inconclusive. Neurophysiology testing is a useful adjunct to clinical examination, and adds value to the diagnostic workup of patients presenting with neuro-urological disorders.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 142-162"},"PeriodicalIF":2.0,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spastic co-contraction: A misdirected central command","authors":"Jean-Michel Gracies,&nbsp;Robert J. Kahoud,&nbsp;Maria Vinti,&nbsp;Simon C. Gandevia,&nbsp;David Burke,&nbsp;Maud Pradines","doi":"10.1016/j.cnp.2026.08.005","DOIUrl":"10.1016/j.cnp.2026.08.005","url":null,"abstract":"<div><h3>Objective</h3><div>Antagonist co-contraction triggered by voluntary agonist command in spastic paresis is poorly understood. Using an isometric ankle paradigm designed to minimize movement-related stretch reflexes, we aimed to characterize the severity, modulation, and neurophysiological origin of spastic co-contraction.</div></div><div><h3>Methods</h3><div>Thirteen subjects with chronic hemi/paraparesis (<em>n</em> = 14 limbs) were seated with the ankle at 90° dorsiflexion, and performed submaximal then maximal isometric voluntary ankle plantar- and dorsiflexion efforts, with the knee flexed then extended (gastrocnemii slack then stretched). Surface and intramuscular EMG recordings (the latter using hook wire electrodes) from agonist and antagonist muscles were combined with ankle torque measurements. Co-contraction severity was classified as <em>absent</em>, no antagonist EMG activity during agonist effort; <em>mild</em>, presence of antagonist EMG activity without torque reversal; or <em>severe</em>, antagonist EMG activity associated with torque in the unintended direction.</div></div><div><h3>Results</h3><div>Antagonist co-contraction occurred in all limbs during dorsi- and plantar flexor efforts. Its severity increased from submaximal to maximal efforts, whether in knee flexion (<em>p</em> = 0.046, Wilcoxon) or knee extension (<em>p</em> = 0.014). Severe plantar flexor co-contraction was more prevalent with the knee extended than flexed (64% <em>vs</em> 0%; <em>p</em> = 0.004, McNemar). Antagonist activity preceded agonist activation in 18% of efforts. In some intramuscular recordings, the first motor unit recruited in co-contractions was identified as that first-recruited when the same muscle was contracted voluntarily as agonist.</div></div><div><h3>Conclusions</h3><div>Spastic co-contraction likely reflects misdirected descending supraspinal command, potentiated by stretch-related peripheral afferent signals.</div><div><strong>Significance</strong>. Spastic co-contraction is an <em>effort-dependent</em>, <em>stretch-sensitive</em> phenomenon distinct from spasticity, and can severely impair force generation in spastic paresis.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"11 ","pages":"Pages 714-726"},"PeriodicalIF":2.3,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148770097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}