Clinical Neurophysiology Practice最新文献

{"title":"Prognostic models for seizures and epilepsy after stroke, tumors and traumatic brain injury","authors":"Kai Michael Schubert,&nbsp;Anton Schmick,&nbsp;Miranda Stattmann,&nbsp;Marian Galovic","doi":"10.1016/j.cnp.2025.02.008","DOIUrl":"10.1016/j.cnp.2025.02.008","url":null,"abstract":"<div><div>Epilepsy is a frequent consequence of acute brain injuries, such as stroke, brain tumors, and traumatic brain injury (TBI). Accurate prediction of epilepsy is essential for early intervention and improved patient outcomes. This review evaluates the best-established prognostic models, including the SeLECT and CAVE scores, which estimate the risk of developing seizures and epilepsy following these injuries. The review highlights their clinical applicability, predictive accuracy, and limitations for different etiologies. In addition to providing practical tables for risk estimation, we also offer user-friendly online calculators for these models at <span><span>www.predictepilepsy.com</span><svg><path></path></svg></span> to facilitate clinical implementation. These tools help identify high-risk patients and support decision-making for follow-up and treatment. Furthermore, we discuss the potential of integrating electrophysiological data, including EEG biomarkers, to further enhance prediction accuracy and patient care. These insights highlight the need for further refinement and validation of predictive models, enabling more personalized treatment strategies and better patient care.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"10 ","pages":"Pages 116-128"},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143628171","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":"Case report: Potential physiological sources of the late response in epidural spinal recordings induced by spinal cord stimulation during intraoperative neuromonitoring","authors":"Steven Falowski ,&nbsp;Mingyue Tang ,&nbsp;Ashlesha Deshmukh ,&nbsp;Ameya Nanivadekar ,&nbsp;David Page ,&nbsp;Mingming Zhang","doi":"10.1016/j.cnp.2024.12.005","DOIUrl":"10.1016/j.cnp.2024.12.005","url":null,"abstract":"<div><h3>Objective</h3><div>This study aims to investigate the sources of later response in epidural spinal recordings (ESRs) obtained from implanted leads during spinal cord stimulation, a topic has not been widely studied in previous research.</div></div><div><h3>Methods</h3><div>Two patients with lower back and lower extremity pain underwent SCS implantation with intraoperative neuromonitoring (IONM). The timing of extracted peaks in ESRs and intramuscular electromyography (EMG) recordings were analyzed and compared to a Monte Carlo simulation for synchronization analysis.</div></div><div><h3>Results</h3><div>Our data show that, when using two most caudal electrodes for stimulation, late response in ESRs collected from SCS leads was not synchronized with EMG recordings from lower extremity muscles. However, parts of the late responses were synchronized with EMG recordings from abdominal muscle groups.</div></div><div><h3>Conclusions</h3><div>Late response in ESRs is believed to result from muscle contractions, although the exact sources have not been fully identified. They are likely to originate from muscles near the implanted leads.</div></div><div><h3>Significance</h3><div>This research indicates that components of the late response may originate beyond the abdominal region, potentially offering additional information for current IONM practice. Additionally, understanding the sources of the late response may be useful for emerging clinical applications in neurorehabilitation.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"10 ","pages":"Pages 22-29"},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11760812/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143048233","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":"Muscle excitability testing: Age and sex dependency of normative data","authors":"Matthias Thomas Exl ,&nbsp;Belén Rodriguez ,&nbsp;Karl Ng ,&nbsp;Stella Veronica Tan ,&nbsp;James Howells ,&nbsp;Hugh Bostock ,&nbsp;Hatice Tankisi ,&nbsp;Werner J. Z’Graggen","doi":"10.1016/j.cnp.2025.03.002","DOIUrl":"10.1016/j.cnp.2025.03.002","url":null,"abstract":"<div><h3>Objective</h3><div>To establish normative data for muscle excitability testing in the tibialis anterior muscle of a healthy population, and to determine their dependence on age and sex.</div></div><div><h3>Methods</h3><div>Parameters of muscle velocity recovery cycle recordings with 1, 2 and 5 conditioning stimuli of 197 healthy subjects and frequency ramp recordings of 151 healthy subjects were retrospectively analysed for age and sex differences.</div></div><div><h3>Results</h3><div>There were no differences by sex and only small age differences were found in healthy subjects older than 60 years for the muscle excitability parameters muscle relative refractory period, early supernormality and latency to the first response in a train at 15 Hz and 30 Hz.</div></div><div><h3>Conclusions</h3><div>In this study, based on a large sample of muscle velocity recovery cycle and frequency ramp recordings, we have provided normative data and shown that muscle excitability testing is not influenced by sex, and that age only has an influence from the age of 60 years onwards on parameters reflecting muscle membrane potential.</div></div><div><h3>Significance</h3><div>Our results suggest that future studies no longer need to control for sex when using a healthy control group.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"10 ","pages":"Pages 129-133"},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681141","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":"Multimodal tele-epileptology: Challenges on the way to interoperable medical data","authors":"Sigrid Mues ,&nbsp;Arndt Ebert ,&nbsp;Marc Kämmerer ,&nbsp;Marcus Kremers ,&nbsp;Ulrich Sliwka ,&nbsp;Rüdiger Hilker-Roggendorf ,&nbsp;Dirk Woitalla ,&nbsp;Iris Adelt ,&nbsp;Thomas Günnewig ,&nbsp;Ana Miron ,&nbsp;Sulev Haldre ,&nbsp;Tipakorn Tumnark ,&nbsp;Kanjana Unnwongse ,&nbsp;Wenke Grönheit ,&nbsp;Tim Wehner ,&nbsp;Vanessa Behrens ,&nbsp;Jörg Wellmer","doi":"10.1016/j.cnp.2025.02.004","DOIUrl":"10.1016/j.cnp.2025.02.004","url":null,"abstract":"<div><h3>Objective</h3><div>To realize multi-modal data exchange for telemedicine in epilepsy.</div></div><div><h3>Methods</h3><div>TE Ruhr is a multicenter, prospective pilot study. Primary endpoint of the study was the technical implementation of a platform between an epilepsy center and regional neurological departments and international cooperating epilepsy centers, respectively. A multi-professional board was established to develop technical workflows. After completion of the study a survey was conducted among users of the regional arm.</div></div><div><h3>Results</h3><div>Two workflows were developed, 1) a combination of web-application and use of an established teleradiology network, and 2) a web-application only data exchange. Technical workflow 1 comprised local EEG conversion into to a standard format (.besa) and its shipping as DICOM RAW object. Technically, both workflows could be implemented. Yet, workflow 1 was not realisable in peripheral hospitals. Via workflow 2, 149 consults for 144 patients were completed. Users of the regional arm were satisfied (1.6 on a grading scale of 1–6 (1-very good, 6- very bad)).</div></div><div><h3>Conclusion</h3><div>Technical feasibility alone does not determine the actual use of telemedicine. Web applications enables multimodal data exchange, but usability is limited due to lack of interoperability.</div></div><div><h3>Significance</h3><div>Genuine interoperability of medical data remains the desired goal for multi modal data exchange.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"10 ","pages":"Pages 56-62"},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143552404","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":"Neurophysiology and muscle histopathology in ICU-acquired muscle weakness: Lessons learned from COVID-19","authors":"Eva K. Hejbøl ,&nbsp;Atle V. Lomstein ,&nbsp;Henrik D. Schrøder ,&nbsp;Benjamin Khan ,&nbsp;Thomas Harbo ,&nbsp;Hatice Tankisi","doi":"10.1016/j.cnp.2025.05.001","DOIUrl":"10.1016/j.cnp.2025.05.001","url":null,"abstract":"<div><h3>Objective</h3><div>To describe different electrophysiological, histopathological, and ultrastructural patterns of muscle pathology in COVID-19-associated intensive care unit acquired weakness (ICUAW) and raise the question of whether COVID-19-associated critical illness myopathy (CIM) is a distinct entity or is similar to CIM of other causes.</div></div><div><h3>Methods</h3><div>A series of three patients with COVID-19-associated ICUAW were presented.</div><div>Clinical examination, electrophysiological testing, and muscle pathology with light and electron microscopy were reported systematically.</div></div><div><h3>Results</h3><div>All three patients were clinically affected with severe proximal and distal weakness of upper and lower extremities, increased plasma levels of muscle enzymes, and had myopathic electromyography. Furthermore, in two patients, electrophysiological signs of inflammatory myopathy with profuse denervation activity were present. Muscle pathologies were prominent but very diverse. One patient had signs of CIM, another showed severe inflammatory myopathy, and the main finding in the third patient was mitochondrial changes.</div></div><div><h3>Conclusion</h3><div>Although the three cases showed similar clinical and electrophysiological patterns, muscle pathology revealed distinct underlying features. This spectrum of muscle disease among patients with severe COVID-19 includes CIM, autoimmune response to the COVID-19 infection, and mitochondrial dysfunction.</div></div><div><h3>Significance</h3><div>Electrophysiology and histopathology complement each other and are important for determining the etiology, as well as guiding treatment and prognosis.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"10 ","pages":"Pages 172-180"},"PeriodicalIF":2.0,"publicationDate":"2025-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144068562","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":"Clinical neurophysiology of REM parasomnias: Diagnostic aspects and insights into pathophysiology","authors":"Melanie Bergmann ,&nbsp;Birgit Högl ,&nbsp;Ambra Stefani","doi":"10.1016/j.cnp.2023.10.003","DOIUrl":"10.1016/j.cnp.2023.10.003","url":null,"abstract":"<div><p>Parasomnias are due to a transient unstable state dissociation during entry into sleep, within sleep, or during arousal from sleep, and manifest with abnormal sleep related behaviors, perceptions, emotions, dreams, and autonomic nervous system activity.</p><p>Rapid eye movement (REM) parasomnias include REM sleep behavior disorder (RBD), isolated recurrent sleep paralysis and nightmare disorder. Neurophysiology is key for diagnosing these disorders and provides insights into their pathophysiology.</p><p>RBD is very well characterized from a neurophysiological point of view, also thank to the fact that polysomnography is needed for the diagnosis. Diagnostic criteria are provided by the American Academy of Sleep Medicine and video-polysomnography guidelines for the diagnosis by the International REM Sleep Behavior Disorder Study Group. Differences between the two sets of criteria are presented and discussed. Availability of polysomnography in RBD provides data on sleep electroencephalography (EEG), electrooculography (EOG) and electromyography (EMG). Sleep EEG in RBD shows e.g. changes in delta and theta power, in sleep spindles and K complexes. EMG during REM sleep is essential for RBD diagnosis and is an important neurodegeneration biomarker. RBD patients present alterations also in wake EEG, autonomic function, evoked potentials, and transcranial magnetic stimulation.</p><p>Clinical neurophysiological data on recurrent isolated sleep paralysis and nightmare disorder are scant. The few available data provide insights into the pathophysiology of these disorders, demonstrating a state dissociation in recurrent isolated sleep paralysis and suggesting alterations in sleep macro- and microstructure as well as autonomic changes in nightmare disorder.</p></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"9 ","pages":"Pages 53-62"},"PeriodicalIF":1.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467981X24000027/pdfft?md5=284f181c314e115bc2779fb68c7c51dd&pid=1-s2.0-S2467981X24000027-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139455170","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":"Sensory nerve conduction studies in infants, children and teenagers – An update","authors":"Tom Frenzel ,&nbsp;Anne-Katrin Baum ,&nbsp;Hardy Krause ,&nbsp;Christoph Arens ,&nbsp;Aiden Haghikia ,&nbsp;Imke Galazky","doi":"10.1016/j.cnp.2024.01.001","DOIUrl":"10.1016/j.cnp.2024.01.001","url":null,"abstract":"<div><h3>Objective</h3><p>Nerve conduction studies (NCS) in children remain technically challenging and depend on the cooperation of the child. Motor NCS are not compromised by analgosedation but data for sensory NCS are lacking. Here, we ask whether sensory NCS is influenced by analgosedation. We also compare the present data with NCS studies from the 1990s regarding anthropometric acceleration of the contemporary paediatric population.</p></div><div><h3>Methods</h3><p>Sensory NCS of the median nerve and sural nerve were performed in 182 healthy subjects aged 1 to 18 years during general anaesthesia and in 47 of them without analgosedation.</p></div><div><h3>Results</h3><p>Sensory NCS was not influenced by midazolam or propofol. The sensory nerve action potential (SNAP) amplitude and the nerve conduction velocity (NCV) of the sural nerve as well as the SNAP of the median nerve show no significant age dependence in age range 1–18 years. The sensory NCV of the median nerve increased age-dependent.</p></div><div><h3>Conclusions</h3><p>In clinical practice, analgosedation can be used for diagnostic NCS. Sensory NCS data show no relevant secular trend over the last 30 years. Differences due to technical inconsistency predominate.</p></div><div><h3>Significance</h3><p>Analgosedation can improve diagnostic quality of sensory NCS in children. Additionally, we provide sensory NCS values from a large pediatric cohort.</p></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"9 ","pages":"Pages 63-68"},"PeriodicalIF":1.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467981X24000015/pdfft?md5=61bf88b20b03d7d1f52c1913018a1aab&pid=1-s2.0-S2467981X24000015-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139457901","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":"Decreased diaphragm moving distance measured by ultrasound speckle tracking reflects poor prognosis in amyotrophic lateral sclerosis","authors":"Shunsuke Watanabe ,&nbsp;Kenji Sekiguchi ,&nbsp;Hirotomo Suehiro ,&nbsp;Masaaki Yoshikawa ,&nbsp;Yoshikatsu Noda ,&nbsp;Naohisa Kamiyama ,&nbsp;Riki Matsumoto","doi":"10.1016/j.cnp.2024.10.002","DOIUrl":"10.1016/j.cnp.2024.10.002","url":null,"abstract":"<div><h3>Objective</h3><div>Decreased cephalocaudal diaphragm movement may indicate respiratory dysfunction in amyotrophic lateral sclerosis (ALS). We aimed to evaluate diaphragm function in ALS using ultrasound speckle tracking, an image-analysis technology that follows similar pixel patterns.</div></div><div><h3>Methods</h3><div>We developed an offline application that tracks pixel patterns of recorded ultrasound video images using speckle-tracking methods. Ultrasonography of the diaphragm movement during spontaneous quiet respiration was performed on 19 ALS patients and 21 controls to measure the diaphragm moving distance (DMD) in the cephalocaudal direction during a single respiration. We compared respiratory function measures and analyzed the relationship between the clinical profiles and DMD.</div></div><div><h3>Results</h3><div>DMD was significantly lower in ALS patients than in the control group (0.6 ± 1.4 mm vs 2.2 ± 2.2 mm, <em>p</em> &lt; 0.01) and positively correlated with phrenic nerve compound motor action potential amplitude (R = 0.63, <em>p</em> = 0.01). DMD was negatively correlated with the change in the ALS Functional Rating Scale-Revised scores per month after the exam (R = −0.61, <em>p</em> = 0.02), and those with a larger rate of decline had a significantly lower DMD (<em>p</em> = 0.03).</div></div><div><h3>Conclusions</h3><div>Diaphragm ultrasound speckle tracking enabled the detection of diaphragm dysfunction in ALS.</div></div><div><h3>Significance</h3><div>Diaphragm ultrasound speckle tracking may be useful for predicting prognosis.</div></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"9 ","pages":"Pages 252-260"},"PeriodicalIF":2.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561077","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":"Effects of sleep deprivation on cortical excitability: A threshold-tracking TMS study and review of the literature","authors":"Magdalena Mroczek ,&nbsp;Amedeo de Grado ,&nbsp;Hossain Pia ,&nbsp;Zahra Nochi ,&nbsp;Hatice Tankisi","doi":"10.1016/j.cnp.2023.12.001","DOIUrl":"10.1016/j.cnp.2023.12.001","url":null,"abstract":"<div><h3>Objective</h3><p>Insufficient sleep is linked to several health problems. Previous studies on the effects of sleep deprivation on cortical excitability using conventional transcranial magnetic stimulation (TMS) included a limited number of modalities, and few inter-stimulus intervals (ISIs) and showed conflicting results. This study aimed to investigate the effects of sleep deprivation on cortical excitability through threshold-tracking TMS, using a wide range of protocols at multiple ISIs.</p></div><div><h3>Methods</h3><p>Fifteen healthy subjects (mean age ± SD: 36 ± 3.34 years) were included. The following tests were performed before and after 24 h of sleep deprivation using semi-automated threshold-tacking TMS protocols: short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF) at 11 ISIs between 1 and 30 ms, short interval intracortical facilitation (SICF) at 14 ISIs between 1 and 4.9 ms, long interval intracortical inhibition (LICI) at 6 ISIs between 50 and 300 ms, and short-latency afferent inhibition (SAI) at 12 ISIs between 16 and 30 ms.</p></div><div><h3>Results</h3><p>No significant differences were observed between pre- and post-sleep deprivation measurements for SICI, ICF, SICF, or LICI at any ISIs (p &lt; 0.05). As for SAI, we found a difference at 28 ms (p = 0.007) and 30 ms (p = 0.04) but not at other ISIs.</p></div><div><h3>Conclusions</h3><p>Sleep deprivation does not affect cortical excitability except for SAI.</p></div><div><h3>Significance</h3><p>This study confirms some of the previous studies while contradicting others.</p></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"9 ","pages":"Pages 13-20"},"PeriodicalIF":1.7,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467981X23000318/pdfft?md5=e67a80b5f9c36abe3de95d1e36740be1&pid=1-s2.0-S2467981X23000318-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138992566","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":"The speed of completion of the decremental responses on repetitive nerve stimulation","authors":"Yuki Ueta ,&nbsp;Takamichi Kanbayashi ,&nbsp;Yosuke Miyaji ,&nbsp;Yuki Hatanaka ,&nbsp;Keisuke Tachiyama ,&nbsp;Kazusa Takahashi ,&nbsp;Hiroo Terashi ,&nbsp;Hitoshi Aizawa ,&nbsp;Masahiro Sonoo","doi":"10.1016/j.cnp.2024.06.003","DOIUrl":"10.1016/j.cnp.2024.06.003","url":null,"abstract":"<div><h3>Objective</h3><p>It is generally believed that the decremental response in repetitive nerve stimulation (RNS) stabilizes at the fourth or fifth response. We have a preliminary impression that the decremental response approaches a plateau earlier in proximal muscles than in distal muscles. We investigated the speed of the completion of the decremental response in different muscles.</p></div><div><h3>Methods</h3><p>The “decrement completion ratio (DCR)” in the second or third response (DCR2 or DCR3) was defined as the ratio of the decremental percentage of the second or third response to that of the fourth response. Patients showing more than 10% decremental response both in the abductor pollicis (APB) and deltoid muscles were retrospectively extracted from our EMG database. The DCR2 and DCR3 were compared between two muscles in patients with myasthenia gravis (MG) and amyotrophic lateral sclerosis (ALS).</p></div><div><h3>Results</h3><p>Identified subjects consisted of 11patients with MG and 11 patients with ALS. Multiple regression analysis revealed that only the difference of muscle influenced on DCR2 and DCR3, with no contribution from the different disorder (MG or ALS) or the initial amplitude of the compound muscle action potential (CMAP). Both DCR2 and DCR3 were significantly higher in deltoid than in APB. In ALS, the normalized CMAP amplitude was not different between APB and deltoid whereas the decremental percentage was significantly higher in deltoid, suggesting a lower safety factor of the neuromuscular transmission in proximal muscles.</p></div><div><h3>Conclusions</h3><p>The decremental response completed more rapidly in deltoid than in APB which may be related to the lower safety factor also documented by this study.</p></div><div><h3>Significance</h3><p>Unexpected early completion of the decrement such as at the second response in RNS is not a technical error but may be an extreme of the rapid completion in deltoid, a proximal muscle.</p></div>","PeriodicalId":45697,"journal":{"name":"Clinical Neurophysiology Practice","volume":"9 ","pages":"Pages 211-216"},"PeriodicalIF":2.0,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S2467981X24000192/pdfft?md5=0179049e31ad5c3015c4fdbd0d282190&pid=1-s2.0-S2467981X24000192-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141623880","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}