Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society最新文献

{"title":"Cardiac Rhythm Aberrations in Subacute Sclerosing Panencephalitis: Insights From Heart Rate Variability Analysis.","authors":"L. Viswanathan, Bittanakurike C Nagaraj, R. Mundlamuri, Kandavel Thennarasu, R. Kenchaiah, A. Asranna, M. Nagappa, D. Seshagiri, Jitender Saini, Sanjib Sinha","doi":"10.1097/WNP.0000000000001079","DOIUrl":"https://doi.org/10.1097/WNP.0000000000001079","url":null,"abstract":"PURPOSE\u0000Subacute sclerosing panencephalitis (SSPE) is a fatal neurological disorder resulting from persistent measles virus infection within the brain. Although neurological manifestations have been well-documented, the impact of SSPE on cardiac autonomic function, assessed through heart rate variability (HRV), remains understudied.\u0000\u0000\u0000METHODS\u0000In this prospective single-center study conducted from January 2022 to March 2023 in Southern India, 30 consecutive SSPE patients and age- and sex-matched controls underwent electrocardiogram recordings for HRV analysis. Various HRV parameters were assessed, including time-domain metrics (SD of normal-to-normal intervals, root mean square of successive differences between normal heartbeats, percentage of successive normal interbeat intervals greater than 50 msec), SD1 and SD2 for Poincaré plot analysis, and frequency-domain metrics (low frequency %, high frequency %, low frequency:high frequency ratio).\u0000\u0000\u0000RESULTS\u0000In the study, SSPE patients exhibited markedly reduced HRV. Specifically, SD of normal-to-normal intervals (P = 0.003), percentage of successive normal interbeat intervals greater than 50 msec (P = 0.03), and SD2 (P = 0.0016) were significantly lower compared with controls. Frequency-domain analysis did not reveal significant distinctions. Correlation analysis demonstrated a negative relationship between percentage of successive normal interbeat intervals greater than 50 msec and SSPE severity (r = -0.37, P = 0.042). Heart rate variability did not significantly differ between SSPE stages or with clinical variables. The interbeat interval range showed a narrower distribution in SSPE subjects.\u0000\u0000\u0000CONCLUSIONS\u0000Our study highlights the clinical relevance of HRV analysis in SSPE and autonomic dysfunction throughout the disease course underscoring its importance in SSPE. This investigation provides valuable insights into cardiac autonomic dysfunction probably because of affliction of the central autonomic networks caused by the disease process and may be a contributing factor to mortality in SSPE.","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":"1151 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140748942","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":"Neurophysiological Findings in Critical COVID-19 Patients With Peripheral Nervous System Manifestations.","authors":"Susana Santiago-Pérez,&nbsp;Sandra Espinosa-García,&nbsp;Almudena Martínez-Pérez,&nbsp;Erika Herráez-Sánchez,&nbsp;Cristian Rizea,&nbsp;Lilia Alejandrina Ruiz-Ávila","doi":"10.1097/WNP.0000000000000823","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000823","url":null,"abstract":"<p><strong>Introduction: </strong>Coronavirus disease 2019 patients hospitalized in intensive care units develop neuromuscular manifestations. However, to our knowledge, a study describing the neurophysiological findings in these patients has not been reported. The objective of this study was to diagnose the cause of neuromuscular deficit in severe coronavirus disease 2019 patients, through neurophysiological examination.</p><p><strong>Methods: </strong>This is a retrospective, observational case series. Data were collected from April 13, 2020, to May 31, 2020. Twenty-two coronavirus disease 2019 patients with generalized neuromuscular deficit during intensive care unit hospitalization were studied. Neurophysiological examinations included motor and sensory peripheral nerve conductions, needle electromyography, F waves, and repetitive nerve stimulation.</p><p><strong>Results: </strong>The subjects were 14 men (63.6%) and eight women, ranged from 35 to 74 years old (58.0, interquartile ranges 50.7-66.2). Intensive care unit hospitalization time ranged from 14 to 82 days (median 37.5, interquartile ranges 22.7-55.0). Through neurophysiological examination, myopathy was diagnosed in 17 patients (77.3%) and polyneuropathy in four (18.2%). Focal neuropathies were diagnosed in 12 patients (54.6%), with a total of 19 affected nerves. Common peroneal nerve lesions at the fibular head (68.4%) and ulnar nerve lesions at the elbow level (21.1%) were the most frequent locations. No significant differences were established between neurophysiological findings and clinical or analytical data.</p><p><strong>Conclusions: </strong>In critical coronavirus disease 2019 patients with neuromuscular complaints, neurophysiological examination provides an accurate diagnosis-useful to select treatment measures and establish the prognosis of recovery. Neurophysiological findings are similar to those described for critical illness neuromuscular disease, with myopathy being the most frequent diagnosis.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"583-591"},"PeriodicalIF":2.4,"publicationDate":"2022-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40454274","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":"Tongue as a Wire? Glossokinetic Artifact and Insights From Intracranial EEG.","authors":"Ayşe Kaçar Bayram,&nbsp;Dennis D Spencer,&nbsp;Rafeed Alkawadri","doi":"10.1097/WNP.0000000000000814","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000814","url":null,"abstract":"<p><strong>Background: </strong>Glossokinetic artifact (GKA) is a well-known scalp EEG artifact characterized by deflections within the delta to low-theta frequency bands and dynamic polarity typically attributed to the direction of tongue movement. This study aims to investigate intracranial EEG correlations of scalp-GKA. If the tongue is a dipole, per the conventional view, then volume-conducted deflections are expected in the nearest frontal intracranial EEG contacts.</p><p><strong>Materials and methods: </strong>Simultaneous scalp and intracranial EEG recordings were evaluated in five consecutive medically resistant epilepsy patients at Yale Epilepsy Center in 2017 and 2018, who had classic GKA deflections on scalp EEG. The EEG was sampled at 2,048 to 4,096 Hz and analyzed visually, using a reference placed in the diploic space or over the convexity, and confirmed quantitatively by a statistical framework. Ten GKA deflections were analyzed per case.</p><p><strong>Results: </strong>The medians of age at the time of recording, contacts per case, and amplitude of scalp GKA deflections were 35 years (range: 20-41 years), 171 contacts (range: 165-241 contacts), and 56 μV (range: 51-72 μV), respectively. There were no slow discharges in the frontal intracranial EEG contacts synchronized with the scalp GKA, either in the delta (1-3 Hz) or in the sub-delta (0.1-1 Hz) bands. However, the expected physiologic attenuation of alpha and beta rhythms and the emergence of high-gamma activity were observed over the peri-Rolandic regions in the invasive recordings.</p><p><strong>Conclusions: </strong>The traditional view of the tongue as a dipole generator of scalp GKA is simplistic and does not account for the findings reported herein. The tongue most probably shunts other scalp and soft-tissue currents. Knowledge of tongue potentials is of interest in the education and the design of tongue-computer interfaces.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"481-485"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39326582","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":"Non-neurophysiologist Physicians and Nurses Can Detect Subclinical Seizures in Children Using a Panel of Quantitative EEG Trends and a Seizure Detection Algorithm.","authors":"Eroshini S Swarnalingam,&nbsp;Rajesh RamachandranNair,&nbsp;Karen L M Choong,&nbsp;Kevin C Jones","doi":"10.1097/WNP.0000000000000812","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000812","url":null,"abstract":"<p><strong>Purpose: </strong>This study evaluated the sensitivity of nonconvulsive seizure detection by non-neurophysiologist physicians and nurses using a panel of quantitative EEG (QEEG) trends in the setting of a pediatric intensive care unit.</p><p><strong>Methods: </strong>Forty-five 1-hour QEEG epochs were obtained retrospectively from 10 patients admitted to the McMaster Children's Hospital pediatric intensive care unit, which included 184 electrographic seizures. Each epoch constituted 4 QEEG trends, a seizure probability marker, automated seizure detector, rhythmicity spectrograms, and amplitude-integrated EEG. Six pediatric residents and 5 pediatric intensive care unit nurses analyzed the epochs for possible seizures after a 15-minute power point presentation. This was compared with the gold standard of a board-certified epileptologist interpreting the conventional EEG data for seizures.</p><p><strong>Results: </strong>Sensitivity of seizure detection for pediatric residents and intensive care unit nurses were 0.90. The specificity was 0.87 and 0.89, respectively. The interrater agreement among the pediatric residents was moderate with a kappa (κ) value of 0.45 (confidence interval: 0.41-0.49), and among the nurses were moderate with a κ value of 0.59 (confidence interval: 0.54-0.63). A post hoc analysis involving 2 neurophysiologists demonstrated a sensitivity of 0.90 and a specificity of 0.93 (confidence interval: 0.90-0.96) for seizure detection and a substantial interrater agreement of κ = 0.76 (confidence interval: 0.61-0.91).</p><p><strong>Conclusions: </strong>A panel of QEEG trends can be used by non-neurophysiologists in a pediatric critical care setting to detect nonconvulsive seizures with a reasonable accuracy, which may expedite subclinical seizure identification and timely intervention.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"453-458"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38796715","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":"Source Analysis of Triphasic Waves Using Quantitative Neuroimaging.","authors":"Alex Tiburtino Meira,&nbsp;Karen Fernanda Alves,&nbsp;Thais O P Rezende,&nbsp;Arthur Oscar Schelp,&nbsp;Luiz Eduardo Betting","doi":"10.1097/WNP.0000000000000804","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000804","url":null,"abstract":"<p><strong>Purpose: </strong>Triphasic waves (TWs), a common EEG pattern, are considered a subtype of generalized periodic discharges. Most patients with TWs present with an altered level of consciousness, and the TW pattern is believed to represent thalamocortical dysfunction. However, the exact meaning and mechanism of TWs remain unclear. The objective of the current study was to evaluate the source of TWs using EEG source imaging and computerized tomography.</p><p><strong>Methods: </strong>Twenty-eight patients with TWs were investigated. Source analysis was performed on the averaged TWs for each individual, and source maps were extracted. Normalization and automatic segmentation of gray matter were performed on computerized tomography scans before analysis. Finally, voxelwise correlation analyses were conducted between EEG source maps and gray matter volumes.</p><p><strong>Results: </strong>Source analyses showed that the anterior cingulate cortex was mainly involved in TWs (16/28 patients, 57%). Correlation analyses showed moderate positive and negative correlations between source location and gray matter volumes for the posterior cingulate ( T = 2.85; volume = 6,533 mm 3 ; r = 0.53; P = 0.002) and the superior frontal gyrus ( T = 2.54; volume = 18,167 mm 3 ; r = -0.48; P < 0.0001), respectively.</p><p><strong>Conclusions: </strong>The results suggest that the anterior cingulate is involved in the origin of TWs. Furthermore, the volumes of posterior brain regions were positively correlated with TWs, indicating a possible preservation of these structures. Conversely, the volumes of anterior regions were negatively correlated with TWs. These findings may indicate a structural pattern necessary for the generation of the abnormal network responsible for TWs.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"466-473"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"39126480","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":"Success Rate of Obtaining Baseline Somatosensory and Motor Evoked Potentials in 695 Consecutive Cranial and Spine Surgeries.","authors":"Andres A Gonzalez,&nbsp;Brian S Droker,&nbsp;Eric S Kim,&nbsp;Pooja Parikh","doi":"10.1097/WNP.0000000000000796","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000796","url":null,"abstract":"<p><strong>Purpose: </strong>Intraoperative neurophysiological monitoring has been well documented as an adjunctive technique that significantly decreases the risk of developing inadvertent sensory and motor deficits during cranial and spine surgeries. The ability to detect neurologic problems intraoperatively depends largely on accurately identifying changes that occur in somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) during each procedure. Therefore, obtaining accurate and reproducible SSEP and MEP data during the initial setup is paramount for intraoperative monitoring. In 2007, Chen et al. found the overall success rate for establishing reliable MEP responses to be 94.8% in the upper extremities and 66.6% in the lower extremities. Since then, the success rate of obtaining baseline sensory and motor evoked potential responses has not been specifically reevaluated. The main goal of this study was to evaluate the current success rates of obtaining adequate SSEP and MEP baseline data in the current era, as well as take a closer look into some of the factors that can reduce the success rates.</p><p><strong>Methods: </strong>Somatosensory evoked potential and MEP monitoring was attempted in a total of 695 consecutive brain and spine surgeries performed by neurosurgeons and orthopedic surgeons between January 2010 and July 2011. Somatosensory evoked potential and MEP baseline data were obtained after initiation of general anesthesia and before skin incision. The primary measure is the ability to obtain adequate SSEP and MEP baseline in each extremity. A secondary measure was to stratify the success rate based on preoperative diagnosis.</p><p><strong>Results: </strong>Six hundred ninety-five consecutive cranial and spinal cases that required intraoperative monitoring were reviewed. Baseline upper extremity SSEPs were successfully obtained in 679 cases (98.1%), and baseline lower extremity SSEPs were successfully obtained in 626 cases (90.1%). However, if the preoperative diagnosis was in the category spine trauma or spine infection, the success rate of obtaining adequate baseline in the lower extremities dropped to around 60% for both SSEPs and MEPs.</p><p><strong>Conclusions: </strong>The success rates of obtaining adequate baseline SSEP and MEP data are overall higher than previously reported. Preoperative diagnosis like spinal infection or trauma may predict lower success rates for acquiring adequate baseline SSEPs and MEPs.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"513-518"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38672637","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":"Minimum Technical Requirements for Performing Ambulatory EEG.","authors":"William O Tatum,&nbsp;Jonathan J Halford,&nbsp;Piotr Olejniczak,&nbsp;Olga Selioutski,&nbsp;Madeleine M Grigg-Damberger,&nbsp;David Gloss,&nbsp;Jayant Acharya,&nbsp;Stephan Schuele,&nbsp;Saurabh R Sinha,&nbsp;Tammy Tsuchida,&nbsp;Frank W Drislane","doi":"10.1097/WNP.0000000000000950","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000950","url":null,"abstract":"<p><strong>Summary: </strong>Ambulatory EEG (AEEG) devices offer portable, multichannel, digital EEG recording with or without video in the patient's natural environment. The technology applied for AEEG recording is like the technology for routine EEG and inpatient long-term video-EEG monitoring but designed to be compact and wearable. Computer-based AEEG technology is well-suited to digital recording, signal processing, and visual display. However, acquiring interpretable EEG outside of the hospital setting presents its own technical challenges. Published guidelines have established technical standards for performing routine EEG and inpatient video-EEG monitoring, but technical standards for AEEG are lacking. Therefore, this guideline provides minimal technical standards for the performance of AEEG which are essential to ensure the quality of studies for clinical and research practice. We expect these minimum standards to evolve over time with improved performance and advances in the technology.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"435-440"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40685974","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":"Multimodal Evoked Potential Profiles in Woodhouse-Sakati Syndrome.","authors":"Ali Abusrair,&nbsp;Iftetah AlHamoud,&nbsp;Saeed Bohlega","doi":"10.1097/WNP.0000000000000811","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000811","url":null,"abstract":"<p><strong>Purpose: </strong>Woodhouse-Sakati syndrome is a rare autosomal recessive syndrome caused by homozygous mutations in the DCAF17 gene, characterized by marked neurologic and endocrine manifestations in the setting of brain iron accumulation and white matter lesions on neuroimaging. Here, we report electrophysiologic profiles in Woodhouse-Sakati syndrome and their possible value in understanding disease pathophysiology and phenotypic variability.</p><p><strong>Methods: </strong>Thirteen genetically confirmed Woodhouse-Sakati syndrome patients were evaluated via different evoked potential (EP) modalities, including brainstem auditory EPs, pattern reversal visual EPs, and somatosensory EPs to tibial and/or median nerves.</p><p><strong>Results: </strong>All EP modalities showed variable abnormalities. Pattern reversal visual EPs were recorded in all patients, with nine patients exhibiting abnormal results. From those, seven patients showed prolonged P100 latencies after stimulation of right and left eyes for each in turn. Two patients showed P100 latency abnormality after single eye stimulation recorded from midoccipital electrode. Median somatosensory EPs were recorded in 10 patients, with 6 patients having a prolonged cortical N19 response. Tibial somatosensory EP was performed for 11 patients, and 8 patients showed abnormal results where P37 cortical response was absent or prolonged, whereas peripheral potentials at the popliteal fossa were normal. Brainstem auditory EPs were abnormal only in two patients, with prolonged wave III and V latencies. Five patients with hearing impairment presented with normal brainstem auditory EP results.</p><p><strong>Conclusions: </strong>Multiple EP abnormalities are observed in Woodhouse-Sakati syndrome patients, mainly in pattern reversal visual EPs and somatosensory EPs. These findings indicate potential myelin dysfunction that has a role in the underlying pathophysiology, disease course, and phenotypic variability.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"504-509"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38796714","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":"Evoked Potentials in Patients With Wilson Disease.","authors":"Violeta M Mihaylova,&nbsp;Olga R Kosseva,&nbsp;Iskren A Kotzev,&nbsp;Georgi Georgiev,&nbsp;Ivo M Kremensky,&nbsp;Teodor N Todorov,&nbsp;Ivaylo L Tournev","doi":"10.1097/WNP.0000000000000797","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000797","url":null,"abstract":"<p><strong>Introduction: </strong>Wilson disease (WD) is an inherited disorder of copper metabolism presenting with a variety of symptoms but commonly as a liver or neuropsychiatric disease. Abnormal evoked responses are constantly found among patients with neurologic manifestations and sometimes in patients with hepatic presentation or in presymptomatic siblings. The aim of our study was to assess visual and brainstem auditory evoked potentials (BAEP) in patients with various presentation of WD.</p><p><strong>Methods: </strong>Visual evoked potentials (VEP) were performed in 36 WD patients and BAEP were done in 37 WD patients.</p><p><strong>Results: </strong>Brainstem auditory evoked potentials were normal in patients with isolated hepatic presentation, whereas they were abnormal in 93.5% of patients with neurologic symptoms. There was significant prolongation of the latencies of the III and V waves and of the interpeak III-V and I-V latencies in comparison with the healthy controls (T-test P = 0). Abnormal VEP were observed in 81% of the patients including six of seven neurologically asymptomatic patients. The values of N75, P100, and N145 latencies were significantly longer in all patients than in healthy controls (T-test).</p><p><strong>Conclusions: </strong>The data showed that VEP and BAEP are more frequently abnormal in WD than previously reported. The abnormal VEP and BAEP even without clinical signs and brain MRI abnormalities point to subclinical involvement of visual and auditory pathways caused by copper toxicity. Because VEP and BAEP are noninvasive and widely available, they should be performed in all patents with WD.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"510-512"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38595915","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":"Does Essential Tremor Alter the Axonal Excitability Properties of Lower Motor Neurons?","authors":"Yerim Kim,&nbsp;Young Eun Kim,&nbsp;Joo Young Lee,&nbsp;Hyeo-Il Ma,&nbsp;Soon Kyung Shim,&nbsp;Sun Min Yoon,&nbsp;Jong Seok Bae","doi":"10.1097/WNP.0000000000000799","DOIUrl":"https://doi.org/10.1097/WNP.0000000000000799","url":null,"abstract":"<p><strong>Purpose: </strong>Automated nerve excitability testing has identified that the altered excitability of lower motor neuron (LMN) axons in central diseases is because of trans-synaptic plasticity. Essential tremor (ET) is considered a central disorder caused by an altered cerebellar circuit. This study aimed to identify alterations in the excitability of distal motor axons in subjects with ET, with the intention of clarifying whether a trans-synaptic mechanism or LMN adaptation for tremor affects the LMNs of subjects with ET.</p><p><strong>Methods: </strong>Twenty-one consecutive patients diagnosed with ET underwent a clinical and electrophysiological evaluation. For the enrolled cases and 45 age- and gender-matched healthy controls, automated nerve excitability testing with threshold tracking techniques (QTRACS software with TRONDF multiple-excitability protocol) was used to evaluate multiple nerve excitability indices in distal median nerve motor axons.</p><p><strong>Results: </strong>The automated protocol calculated the strength-duration time constant, parameters of threshold electrotonus and current-threshold relationship, and the recovery cycle of excitability. Comparisons of the automated nerve excitability testing parameters revealed no significant differences between the ET and control groups in any of strength-duration time constant, threshold electrotonus, current-threshold relationship, and recovery cycle, whereas the rheobase was higher in the ET group (3.4 ± 1.1 vs. 2.3 ± 1.1, mean ± standard error mean; P < 0.01).</p><p><strong>Conclusions: </strong>With the exception of an increased rheobase in ET subjects, no significant differences were observed in LMN excitability between the ET subjects and their controls. The extent of plasticity or adaptation in LMNs may be limited to a major change in central processes that exert marked effects on the pool of LMNs.</p>","PeriodicalId":117726,"journal":{"name":"Journal of clinical neurophysiology : official publication of the American Electroencephalographic Society","volume":" ","pages":"492-496"},"PeriodicalIF":2.4,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38758202","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}