Neurophysiological Parameters Research Articles

Utility of the Repetitive Nerve Stimulation Test and Needle EMG in the Trapezius Muscle for the Early Diagnosis of ALS.

To document the utility of decremental responses in the repetitive nerve stimulation test (RNS) and spontaneous activities in needle electromyography (EMG) in the trapezius muscle for the diagnosis of amyotrophic lateral sclerosis. Subjects were retrospectively identified from our EMG database. Cervical spondylosis was represented as a disease control group. We investigated the sensitivity and specificity of RNS and EMG in the trapezius muscle and those of diagnostic criteria including the Gold Coast criteria (GCC). We reviewed 120 patients with amyotrophic lateral sclerosis and 17 patients with cervical spondylosis. "RNS or EMG" achieved the highest sensitivity (85%). The specificity was the highest for RNS (94%). Addition of RNS of the deltoid muscle achieved 98% sensitivity in the upper-limb onset amyotrophic lateral sclerosis. The sensitivity of the GCC was very high (88%). Neurophysiological parameters investigated in this study having close to 100% specificities or sensitivities are useful as complements to the GCC.

Local corticosteroid injection versus surgery for carpal tunnel syndrome.

Carpal tunnel syndrome (CTS) is a very common clinical syndrome manifested by signs and symptoms of irritation of the median nerve at the carpal tunnel in the wrist. Direct and indirect costs of CTS are substantial, with estimated costs of two billion US dollars for CTS surgery in the USA alone. Local corticosteroid injection has been used as a non-surgical treatment for CTS for many years, but its effectiveness is still debated. To evaluate the benefits and harms of corticosteroids injected in or around the carpal tunnel for the treatment of carpal tunnel syndrome (CTS) compared to surgery. We used standard, extensive Cochrane search methods. We searched the Cochrane Neuromuscular Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL, ClinicalTrials.gov, and WHO ICTRP. The latest search was 26 May 2022. We included randomised controlled trials (RCTs) or quasi-randomised trials of adults with CTS that included at least one comparison group of local corticosteroid injection (LCI) into the wrist and one group of any surgical intervention. We used standard Cochrane methods. Our primary outcome was 1. improvement in symptoms at up to three months of follow-up. Our secondary outcomes were 2. functional improvement, 3. improvement in symptoms at greater than three months of follow-up, 4. improvement in neurophysiological parameters, 5. improvement in imaging parameters, 6. improvement in quality of life and 7. We used GRADE to assess the certainty of evidence for each outcome. We included seven studies involving 569 'hands' (although two studies had unusable data for quantitative analyses). All studies used a one-time LCI as a comparator, using several different types and doses of corticosteroids. In every study, for both surgery and LCI groups, all our primary and secondary outcomes showed improvement from pre- to post-treatment. However, evidence from the combined analysis was too uncertain for us to draw reliable conclusions for the comparison of surgical treatment versus LCI with respect to our primary outcome of symptom relief at up to three months' follow-up (standardised mean difference (SMD) 0.63, 95% confidence interval (CI) -0.61 to 1.88; I2 = 95%; 5 trials, 305 participants; very low-certainty evidence). Findings with respect to secondary outcome measures of symptom relief at greater than three months' follow-up (SMD 0.94, 95% CI -0.31 to 2.19; I2 = 93%; 4 trials, 235 participants), functional improvement at up to three months' follow-up (SMD -0.11, 95% CI -0.94 to 0.72; I2 = 84%; 3 trials, 215 participants) and functional improvement at greater than three months' follow-up (SMD 0.19, 95% CI -1.22 to 1.59; I2 = 93%; 3 trials, 185 participants) were also uncertain (very low-certainty evidence) and showed no clear advantage for surgery or LCI. Surgery may improve neurophysiology (median nerve distal motor latency) more than LCI (mean difference (MD) 0.87 ms, 95% CI 0.32 to 1.42; I2 = 72%; 3 trials, 162 participants; low-certainty evidence). Evidence for quality of life and adverse events was also uncertain; quality of life (EuroQol-5D-3L) may be slightly improved after LCI than after surgery (the difference may not be clinically important) (MD 0.07, 95% CI 0.02 to 0.12; 1 trial, 38 participants; very low-certainty evidence) and there may be fewer adverse events with LCI than with surgery (risk ratio (RR) 0.34, 95% CI 0.04 to 3.26; 3 trials, 112 participants; very low-certainty evidence). The evidence comparing LCI to surgery for CTS, either in the short term or up to 12 months' follow-up, is too uncertain for any reliable conclusions to be drawn.

Postmovement Beta Rebound in Real and Imagined Movement.

Movement disorders, such as stroke and amyotrophic lateral sclerosis, result in loss of upper limb function and, hence, severe impairments of bimanual coordination. Although motor imagery is increasingly used to enhance neurorehabilitation, cognitive and neurophysiological parameters that inform effective strategies remain elusive. The aim of the present study is to elucidate the neural dynamics that underlie learning during real and imagined movement using both unimanual and bimanual coordination patterns. The post movement beta rebound (PMBR) has been implicated as a biomarker of motor control and therefore was the focus of this study. Healthy adults (n = 21) learned a visuomotor tracking task in a single session using either one or both hands while brainwaves were captured using electroencephalography. Postmovement beta rebound was evident in the sensorimotor cortex for both unimanual and bimanual conditions. Task-related power of the beta band demonstrated that actual unimanual movement requires greater contralateral activity compared with both actual bimanual movement and imagined movement of either condition. Notably, the PMBR was evident even in imagined movement, although to a lesser extent than real movement. Neurophysiological results support a functional role for beta band in movement. Results of these data may inform neurorehabilitation strategies for patients recovering from movement disorders of the upper limbs.

Machine learning allows expert level classification of intraoperative motor evoked potentials during neurosurgical procedures

ObjectiveTo develop and evaluate machine learning (ML) approaches for muscle identification using intraoperative motor evoked potentials (MEPs), and to compare their performance to human experts. BackgroundThere is an unseized opportunity to apply ML analytic techniques to the world of intraoperative neuromonitoring (IOM). MEPs are the ideal candidates given the importance of their correct interpretation during a surgical operation to the brain or the spine. In this work, we develop and test a set of different ML models for muscle identification using intraoperative MEPs and compare their performance to human experts. In addition, we provide a review of the available literature on current ML applications to IOM data in neurosurgery. MethodsWe trained and tested five different ML classifiers on a MEP database developed from six different muscles in patients who underwent brain or spinal cord surgery. MEPs were obtained by both transcranial (TES) and direct cortical stimulation (DCS) protocols. The models were evaluated within a single patient and on previously unseen patients, considering signals from TES and DCS both independently and mixed. Ten expert neurophysiologists classified a set of 50 randomly selected MEPs, and their performance was compared to the best performing model. ResultsA total of 25.423 MEPs were included in the study. Random Forest proved to be the best performing model with 99 % accuracy in the single patient dataset task and a 78 %–94 % accuracy range on previously unseen patients. The model performance was maximized by representing MEPs as a set of features typically employed in signal processing compared to traditional neurophysiological parameters. The classification ability of the Random Forest model between six different muscles and across different MEP acquisition modalities (79 %) significantly exceeded that of human experts (mean 48 %). ConclusionsCarefully selected ML models proved to have reliable capacity of extracting meaningful information to classify intraoperative MEPs using a limited number of features, proving robustness across patients and signal acquisition modalities, outperforming human experts, and with the potential to act as decision support systems to the IOM team. Such encouraging results lay the path to further explore the underlying nature of clinically important signals, with the aim to continue to produce useful applications to make surgeries safer and more efficient.

Clinical and electrophysiological prognostic factors in predicting poor outcomes in patients with idiopathic facial nerve paralysis

ObjectiveThis study was designed to verify whether one or more clinical and neurophysiological parameters could predict a poor prognosis in idiopathic facial paralysis. MethodsSeventy-three outpatients with unilateral idiopathic facial nerve paralysis who visited our hospital within 7 days of onset. All patients received treatment according to a standard therapy protocol and ocular care. Patients’ baseline characteristics were assessed before initiating treatment, including demographic characteristics, facial nerve function assessment and previous medical history. House-Brackmann (H-B) grading system was performed at baseline and six months after the onset. Electroneurography (ENoG) and blink reflex tests were conducted 7–10 days after the onset of paralysis. Sunnybrook Facial Grading System (SFGS) was conducted at baseline, days 7–10 post-onset when the electrophysiological tests were performed, and one month after the onset. ResultsAccording to the H-B grade at 6 months following the onset, 58 patients (79.5 %) had a good prognosis, while 15 patients (20.5 %) had a poor prognosis. The CMAP amplitudes in three facial muscles (frontalis, orbicularis oculi, and orbicularis oris) were decreased, and ENoG values were increased in the poor prognosis group compared with the good prognosis group (all p < 0.01). The results of the blink reflex study showed that the group with a poor prognosis had a longer R1 latency compared to the group with a good prognosis. Additionally, the group with a poor prognosis exhibited a higher rate of R1 absence on the affected side (both p < 0.01). The findings of conditional logistic regression indicated that the absence of R1 on the affected side, frontalis ENoG, orbicularis oculi ENoG, and orbicularis oris ENoG were predictive factors of a poor prognosis for facial nerve palsy. The receiver operating characteristic (ROC) curves showed that the SFGS at 1 month after onset of 55 is considered a critical cutoff value for poor prognosis, with a sensitivity of 86.7 % and specificity of 91.4 %. ConclusionElectroneurography (ENoG) and blink reflex tests acquired within 7–10 days after the onset of paralysis are significant and highly valuable for predicting the prognosis of idiopathic facial nerve paralysis. Higher ENoG values of the muscles innervated by the facial nerve and the absence of R1 on the affected side of the blink reflex are predictive factors for a poor prognosis. The SFGS is a clinical tool that plays an important role in evaluating the prognosis of idiopathic facial paralysis, particularly one month after onset.

Model-predicted brain temperature computational imaging by multimodal noninvasive functional neuromonitoring of cerebral oxygen metabolism and hemodynamics: MRI-derived and clinical validation.

Brain temperature, a crucial yet under-researched neurophysiological parameter, is governed by the equilibrium between cerebral oxygen metabolism and hemodynamics. Therapeutic hypothermia has been demonstrated as an effective intervention for acute brain injuries, enhancing survival rates and prognosis. The success of this treatment hinges on the precise regulation of brain temperature. However, the absence of comprehensive brain temperature monitoring methods during therapy, combined with a limited understanding of human brain heat transmission mechanisms, significantly hampers the advancement of hypothermia-based neuroprotective therapies. Leveraging the principles of bioheat transfer and MRI technology, this study conducted quantitative analyses of brain heat transfer during mild hypothermia therapy. Utilizing MRI, we reconstructed brain structures, estimated cerebral blood flow and oxygen consumption parameters, and developed a brain temperature calculation model founded on bioheat transfer theory. Employing computational cerebral hemodynamic simulation analysis, we established an intracranial arterial fluid dynamics model to predict brain temperature variations across different therapeutic hypothermia modalities. We introduce a noninvasive, spatially resolved, and optimized mathematical bio-heat model that synergizes model-predicted and MRI-derived data for brain temperature prediction and imaging. Our findings reveal that the brain temperature images generated by our model reflect distinct spatial variations across individual participants, aligning with experimentally observed temperatures.

Comparative assessment of MScanFit MUNE and quantitative EMG in amyotrophic lateral sclerosis diagnosis: A prospective study

ObjectiveMotor Unit Number Estimation (MUNE) techniques are crucial in assessing lower motor neuron loss. MScanFit MUNE (MScanFit) is a novel tool which estimates MUNE values from compound muscle action potential (CMAP) scans by considering the probabilistic nature of motor unit firing. We conducted a prospective study to evaluate the diagnostic utility of MScanFit compared to quantitative electromyography (qEMG) in ALS patients. MethodsWe enrolled 35 patients diagnosed with amyotrophic lateral sclerosis (ALS) and 14 healthy controls, assessing qEMG and MScanFit MUNE in abductor pollicis brevis, abductor digiti minimi and tibialis anterior muscles. ResultsWe found higher sensitivity of qEMG in detecting abnormalities compared to MScanFit, with a high concordance rate between the two techniques. Notably, a few muscles exhibited abnormal MUNE but normal qEMG findings, suggesting a potential complementary role for MScanFit in ALS diagnosis. Neurophysiological parameters from MScanFit showed good correlations with qEMG measures. Subclinical neurophysiological involvement was observed in muscles with normal strength, emphasizing the importance of sensitive diagnostic tools. ConclusionMScanFit demonstrated validity in distinguishing ALS patients from healthy subjects and correlated well with qEMG parameters. SignificanceOur study confirmed the diagnostic utility of MScanFit MUNE in ALS, highlighting its role as a supplementary diagnostic tool.

EEG-based sensorimotor neurofeedback for motor neurorehabilitation in children and adults: a scoping review

ObjectiveTherapeutic interventions for children and young people with dystonia and dystonic/dyskinetic cerebral palsy are limited. EEG-based neurofeedback is emerging as a neurorehabilitation tool. This scoping review maps research investigating EEG-based sensorimotor neurofeedback in adults and children with neurological motor impairments, including augmentative strategies. MethodsMEDLINE, CINAHL and Web of Science databases were searched up to 2023 for relevant studies. Study selection and data extraction were conducted independently by at least two reviewers. ResultsOf 4380 identified studies, 133 were included, only three enrolling children. The most common diagnosis was adult-onset stroke (77%). Paradigms mostly involved upper limb motor imagery or motor attempt. Common neurofeedback modes included visual, haptic and/or electrical stimulation. EEG parameters varied widely and were often incompletely described. Two studies applied augmentative strategies. Outcome measures varied widely and included classification accuracy of the Brain-Computer Interface, degree of enhancement of mu rhythm modulation or other neurophysiological parameters, and clinical/motor outcome scores. Few studies investigated whether functional outcomes related specifically to the EEG-based neurofeedback. ConclusionsThere is limited evidence exploring EEG-based sensorimotor neurofeedback in individuals with movement disorders, especially in children. Further clarity of neurophysiological parameters is required to develop optimal paradigms for evaluating sensorimotor neurofeedback. SignificanceThe expanding field of sensorimotor neurofeedback offers exciting potential as a non-invasive therapy. However, this needs to be balanced by robust study design and detailed methodological reporting to ensure reproducibility and validation that clinical improvements relate to induced neurophysiological changes.

Sex-related differences in corticospinal excitability outcomemeasures of the biceps brachii during a submaximal elbow flexor contraction.

The purpose of this study was to investigate the effects of sex, muscle thickness, and subcutaneous fat thickness (SFT) on corticospinal excitability outcome measures of the biceps brachii. Eighteen participants (10 males and 8 females) completed this study. Ultrasound was used to assess biceps brachii muscle thickness and the overlying SFT. Transcranial magnetic stimulation (TMS) was used to determine corticospinal excitability by inducing motor-evoked potentials (MEPs) at eight different TMS intensities from 90% to 160% of active motor threshold (AMT) from the biceps brachii during an isometric contraction of the elbow flexors at 10% of maximum voluntary contraction (MVC). Biceps brachii maximal compound muscle action potential (Mmax) was also recorded prior to and after TMS. Males had higher (p < 0.001) biceps brachii muscle thickness and lower SFT, produced higher levels of MVC force and had, on average, higher (p < 0.001) MEP amplitudes at lower (p < 0.05) percentages of maximal stimulator output than females during the 10% elbow flexion MVC. Multiple linear regression modeling revealed that sex was not associated with any of the neurophysiological parameters examined, while SFT showed a positive association with the stimulation intensity required at AMT (p = 0.035) and a negative association with biceps brachii pre-stimulus electromyography (EMG) activity (p = 0.021). Additionally, there was a small positive association between muscle thickness and biceps brachii pre-stimulus EMG activity (p = 0.049). Overall, this study suggests that some measures of corticospinal excitability may be different between the sexes and influenced by SFT and muscle thickness.

Predictors of the dynamics of changes in cognitive functions in patients 6 months after carotid endarterectomy

Background. Carotid atherosclerosis is one of the urgent problems due to the high risk of developing ischemic stroke and cognitive impairment. The dynamics of clinical disorders in patients with carotid stenosis is determined by a complex of neurophysiological, angiological, tissue and biomolecular reactions, the characteristics of which can act as predictors of the course of the pathology.The aim of the work. To determine the neurophysiological parameters and predictors of cognitive dysfunction in patients who underwent carotid endarterectomy.Materials and methods. The study included 59 people with carotid atherosclerotic disease. All included patients underwent carotid endarterectomy. We assessed the degree of stenosis of the internal carotid artery and cognitive status using the FAB (Frontal Assessment Battery) scale and MoCA (Montreal Cognitive Assessment) Test and recorded electroencephalogram (EEG), P300 cognitive evoked potentials and heart rate variability in patients at various terms (before surgery, 6 months after the surgery). Patients were divided into groups based on the dynamics of cognitive tests using cluster analysis (k-means) with identification of elements included in the clusters: patients of cluster 1 had a “preserved” profile of cognitive status; patients of cluster 2 – moderate cognitive dysfunction.Results. Patients of cluster 1 had a higher power of beta oscillations in the frontal lead, a higher amplitude of the P3 component of the P300 potential, and a greater variability of R-R intervals in terms of the total indicator and high-frequency power. We proposed a model that allows us to classify patients into groups according to the dynamics of cognitive function scores. According to the data obtained, the most significant predictors of the dynamics of cognitive status were the initial characteristics of the EEG and the P300 cognitive evoked potential.Conclusions. We determined the clinical and neurophysiological correlates of cognitive dysfunction: an association with greater preservation of activating effects on the EEG, processes of recognition and decision-making in the associative zones of the cortex, and less pronounced activity of stress-implementing mechanisms. Indicators of EEG spectral analysis and characteristics of the P300 cognitive evoked potential are predictors of the cognitive status dynamics.

Neurophysiologic Characteristics of the Anterior Nucleus of the Thalamus during Deep Brain Stimulation Surgery for Epilepsy

Introduction: Anterior nucleus of the thalamus (ANT) deep brain stimulation (DBS) is an increasingly promising treatment option for refractory epilepsy. Optimal therapeutic benefit has been associated with stimulation at the junction of ANT and the mammillothalamic tract (mtt), but electrophysiologic markers of this target are lacking. The present study examined microelectrode recordings (MER) during DBS to identify unique electrophysiologic characteristics of ANT and the ANT-mtt junction. Methods: Ten patients with medically refractory epilepsy underwent MER during ANT-DBS implantation under general anesthesia. MER locations were determined based on coregistration of preoperative MRI, postoperative CT, and a stereotactic atlas of the thalamus (Morel atlas). Several neurophysiological parameters including single unit spiking rate, bursting properties, theta and alpha power and cerebrospinal fluid (CSF)-normalized root mean square (NRMS) of multiunit activity were characterized at recording depths and compared to anatomic boundaries. Results: From sixteen hemispheres, 485 recordings locations were collected from a mean of 30.3 (15.64 ± 5.0 mm) recording spans. Three-hundred and ninety-four of these recording locations were utilized further for analysis of spiking and bursting rates, after excluding recordings that were more than 8 mm above the putative ventral ANT border. The ANT region exhibited discernible features including: (1) mean spiking rate (7.52 Hz ± 6.9 Hz; one-way analysis of variance test, p = 0.014 when compared to mediodorsal nucleus of the thalamus [MD], mtt, and CSF), (2) the presence of bursting activity with 40% of ANT locations (N = 59) exhibited bursting versus 24% the mtt (χ2; p < 0.001), and 32% in the MD (p = 0.38), (3) CSF-NRMS, a proxy for neuronal density, exhibited well demarcated changes near the entry and exit of ANT (linear regression, R = −0.33, p < 0.001). Finally, in the ANT, both theta (4–8 Hz) and alpha band power (9–12 Hz) were negatively correlated with distance to the ventral ANT border (linear regression, p < 0.001 for both). The proportion of recordings with spiking and bursting activity was consistently highest 0–2 mm above the ventral ANT border with the mtt. Conclusion: We observed several electrophysiological markers demarcating the ANT superior and inferior borders including multiple single cell and local field potential features. A local maximum in neural activity just above the ANT-mtt junction was consistent with the previously described optimal target for seizure reduction. These features may be useful for successful targeting of ANT-DBS for epilepsy.

Intraoperative Neurophysiological Monitoring in Tethered Cord Syndrome Surgery: Predictive Values and Clinical Outcome.

"Tethered cord syndrome" (TCS) refers to a congenital abnormality associated with neurological signs and symptoms. The aim of surgery is to prevent or arrest their progression. This study reports a retrospective case series of tethered cord syndrome surgeries, supported by intraoperative neurophysiological monitoring. The case series comprises 50 surgeries for tethered cord syndrome in which multimodal intraoperative neurophysiological monitoring was performed using motor evoked potentials (transcranial motor evoked potentials [TcMEPs]), tibial nerve somatosensory evoked potentials (TNSEPs), and pudendal-anal reflex (PAR). The intraoperative neurophysiological monitoring results are reported and correlated with clinical outcomes. Sensitivity, specificity, and negative predictive value were high for TcMEPs and TNSEPs, while PAR exhibited low sensitivity and positive predictive value but high specificity and negative predictive value. Fisher's exact test revealed a significant correlation between changes in TcMEPs, TNSEPs, and clinical outcome ( P < 0.000 and P = 0.049 respectively), but no correlation was detected between PAR and urinary/anal function ( P = 0.497). While TcMEPs and TNSEPs were found to be reliable intraoperative neurophysiological monitoring parameters during tethered cord syndrome surgery, PAR had low sensitivity and positive predictive value probably because the reflex is not directly related to bladder function and because its multisynaptic pathway may be sensitive to anesthetics. New onset muscle weakness and sensory deficits were related to postoperative changes in TcMEPs and TNSEPs, whereas changes in PAR did not predict bladder/urinary impairment. Urinary deficits may be predicted and prevented with other neurophysiological techniques, such as the bladder-anal reflex.

Distinct effects of long-term Tai Chi Chuan and aerobic exercise interventions on motor and neurocognitive performance in early-stage Parkinson's disease: a randomized controlled trial.

Parkinson's disease (PD) is a neurodegenerative condition characterized by movement disorders and probable cognitive impairment. Exercise plays an important role in PD management, and recent studies have reported improvement in motor symptoms and cognitive function following aerobic and Tai Chi Chuan exercise. To explore the different effects of Tai Chi Chuan and aerobic exercise on the clinical motor status and neurocognitive performance of patients with early-stage PD. A randomized controlled trial. Parkinson's Disease Center at Kaohsiung Chang Gung Memorial Hospital and National Cheng Kung University Hospital. Patients with idiopathic PD. Fifty-six patients with PD were recruited and divided into three groups: aerobic exercise (AE, N.=14), Tai Chi Chuan exercise (TE, N.=16), and control (CG, N.=13). Before and after a 12-week intervention period, we used unified Parkinson's disease rating scale Part III (UPDRS-III) scores and neuropsychological (e.g., accuracy rates [ARs] and reaction times [RTs]) and neurophysiological (e.g., event-related potential [ERP] N2 and P3 latencies and amplitudes) parameters to respectively assess the patients' clinical motor symptoms and neurocognitive performance when performing a working memory (WM) task. Compared to baseline, UPDRS-III scores were significantly lower in the AE and TE groups after the intervention period, whereas those for the CG group were higher. In terms of the neurocognitive parameters, when performing the WM task after the intervention period, the AE group exhibited significantly faster RTs and larger ERP P3 amplitudes, the TE group exhibited an improvement only in ERP P3 amplitude, and the CG group exhibited a significantly reduced ERP P3 amplitude. However, neither the TE nor the AE group exhibited improved ARs and ERP N2 performance. The present study supported the distinct effectiveness of Tai Chi Chuan and aerobic exercise for improving motor symptoms and providing neurocognitive benefits in PD patients. These results have important implications regarding the use of these exercise interventions for managing PD, particularly in the early stages.

Nursing Interventions in Neurocritical Care.

Highly educated and skilled nursing care is critical to improving patient outcomes in general and in specialties like neurocritical care. Nursing interventions reflect nursing knowledge, critical thinking, and decision-making and is generally rooted in the nursing process. Nursing interventions are also a key focus of research to better understand how nursing care influences patient outcomes. This review describes the literature regarding nursing interventions in key neurocritical diagnoses and contextualizes it within the broader discussion about the nursing process and nursing interventions research. Publications about nursing interventions in neurocritical care emphasize key themes, including managing neurophysiologic parameters, providing psychosocial support, managing the environmental milieu, and interventions to prevent complications. Further study of how to best support nurses in collecting and interpreting data to form nursing interventions is needed, as is understanding the benefits and limitations of the nursing process in low- and middle-income countries.

Longitudinal Exploration of Cortical Brain Activity in Cognitive Fog: An EEG Study in Patients with and without Anosmia.

Long-Covid, characterized by persistent symptoms following acute Covid-19 infection, represents a complex challenge for the scientific community. Among the most common and debilitating manifestations, cognitive fog is a neurological disorder characterized by mental confusion and cognitive difficulties. In this study, we investigated the long-term effects of previous Covid-19 infection on cortical brain activity in patients experiencing cognitive fog symptoms in the medium and long term. A total of 40 subjects (20 females and 20 males) aged between 45 and 70 years (mean age (M) = 59.78, standard deviation (SD) = 12.93) participated in this study. This sample included individuals with symptoms of cognitive fog, both with and without anosmia, and a control group comprised of healthy subjects. All electroencephalography (EEG) data were collected in two sessions, 1 month and 8 months after recovery from Covid-19, to measure the neurophysiological parameters of P300 and beta band rhythms. The results revealed significant differences in the neurophysiological parameters of P300 and beta band rhythms in subjects affected by cognitive fog, and these alterations persist even 8 months after recovery from Covid-19. Interestingly, no significant differences were observed between the participants with anosmia and without anosmia associated with cognitive fog. These findings provide a significant contribution to understanding the long-term effects of Covid-19 on the brain and have important implications for future interventions aimed at managing and treating brain fog symptoms. The longitudinal assessment of cortical brain activity helps highlight the persistent impact of the virus on the neurological health of Long-Covid patients.

LVentral tethering-is the prognosis worse than in dorsal tethering in the dysraphic spine?

To compare cases of dysraphism with ventral tethering of cord with those with dorsal tethering and to find out any differences in the outcome of surgery in them. We collected the data of 188 consecutively operated tethered cord patients at our institute in the past 7years and divided them into ventral tethering and dorsal tethering groups. Those that we felt had both dorsal and ventral tethering were excluded. Their preoperative clinical, radiological, and baseline neurophysiological parameters as well as postoperative clinical and radiological parameters were analyzed in a retrospective study. Among the 188 tethered cord patients, 52 (28%) had ventral tethering and 136 (72%) had posterior tethering. Preoperative neurodeficit and cord signal changes as well as absent baseline MEP (of any one muscle) were significantly more associated with ventral tethered cord than the dorsal tethered cord. The neurological deterioration after surgery occurred significantly in the ventral tethered cord group than in the dorsal tethered cord group. Also, the postoperative MRI had more incomplete detethering cases in the ventral group than in the dorsal tethered cord group. Ventral tethered cord is more likely to present with preoperatively neurological deficits. It should be carefully identified in the preoperative MRI, so that the intraoperative difficulties in complete detethering and postoperative deterioration can be anticipated.

Clinical Neurophysiological Methods Verify Improvement in the Motor Neural Transmission in Patients with Surgically Treated Idiopathic Scoliosis in Long-Term Follow-up

The evaluation of patients after the surgical correction of idiopathic scoliosis in a long-term follow-up with clinical neurophysiological methods has not been presented in detail. This study aimed to compare the results of neurophysiological studies in 45 girls with scoliosis of Lenke types 1–3 performed pre- (T0) and postoperatively, 1 week after surgery (T1) and 6 months after surgery (T2). The parameter values of the surface electromyography while attempting maximal contraction (mcsEMG) and the transcranial motor-evoked potentials (MEPs) recorded in the anterior tibial muscles, as well as the electroneurography (ENG) of the peripheral transmission in the peroneal nerve motor fibers, were compared. The results indicate that efferent neural conduction function both centrally and peripherally, and TA muscle function slightly improved immediately after the surgical correction of scoliosis, and further normalization appeared after six months in the long-term follow-up (at p = 0.03). The sEMG recordings indicate that half a year after surgical treatment in IS patients, the TA muscle motor unit recruitment function, as well as the muscle strength evaluated with Lovett’s scale, was comparable to the normal condition. The ENG recording results indicated a gradual reduction in the motor fiber injury symptoms, mainly of the axonal type, in the peroneal nerves. The surgeries also improved the lumbar ventral roots’ neural transmission to a normal functional status. The MEP amplitude parameter values recorded after the surgical scoliosis corrections in T1 indicated a slight improvement in the efferent transmission of neural impulses within the fibers of the spinal tracts; in the long-term T2 observation period, they reached values comparable to those recorded in healthy volunteers, bilaterally. Preoperatively (T0), the results of all the neurophysiological study parameters in the IS patients were asymmetrical at p = 0.036–0.05 and recorded as worse on the concave side, suggesting the lateralization of neurological motor deficits. One week postoperatively (T1), this asymmetry was recorded as gradually reduced, showing almost no difference between the right and left sides six months later (T2). The presented algorithm for the neurophysiological assessments performed in the pre-, intra-, and long-term postoperative periods using the mcsEMG, MEP, and ENG neurophysiological examinations, together with the clinical studies, may help in the comprehensive functional evaluation of the spinal cord tracts and ventral root neural conduction, which allows the detection of the subclinical neurological changes related to scoliosis itself and the consequences of the corrective surgery. Such an evaluation can also be significant in making final decisions regarding IS surgeries and their personalization after attempting conservative treatments with bracing and kinesiotherapy. Neurophysiological studies, as a sensitive biomarker, allowed us to predict and ascertain the final result of IS treatment in the long-term follow-up, which showed the health status of patients as being comparable to that of healthy volunteers.

Open-label observational study of effectiveness and tolerability of ipidacrine in treatment of patients with diabetic polyneuropathy (DIAMANT study)

Diabetic polyneuropathy (DPN) is one of the most common complications of diabetes mellitus, leading to the development of flaccid paresis, neuropathic pain syndrome, sensitive ataxia, as well as trophic disorders in the distal parts of the lower extremities.The purpose of the randomized, open-label, comparative, prospective study was to evaluate the effectiveness and tolerability of ipidacrine in the complex treatment of patients with DPN.Materials and methods. Patients with DPN (n = 60) were randomized into 2 groups. Both groups received basic therapy (alpha-lipoic acid, B vitamins, gabapentin); in the treatment of patients of the main group (n = 30), in addition, ipidacrine was used (Ipidacrine-SZ, North Star Co., Russia). We have analyzed the intensity of pain syndrome (VAS-P), the average daily dosage of gabapentin, and the results of the neuropathic dysfunctional scale (modified version, NDSm), Pittsburgh Sleep Quality Index, PSQI), Global Rating of Change Scale (GROC), the results of electroneuromyography (ENMG). The total duration of the observation and treatment period was 2 months.Results. After 2 months of therapy in the main group of patients, compared with the control group, there was significantly more complete pain control (VAS-P: 3.0 ± 0.9 vs 3.6 ± 0.8), a decrease in the average daily dosage of gabapentin (390 vs 500 mg/day), reduction in the severity of clinical manifestations of polyneuropathic syndrome (NDSm: 4.4 ± 1.0 vs 4.9 ± 1.0 points) and improvement in sleep quality (PSQI: 6.8 ± 1.3 vs 7.9 ± 1.7). According to ENMG data, patients in the main group showed a significant improvement in the neurophysiological parameters of both motor and sensory fibers, which was significantly more pronounced compared to the control group. A significantly larger proportion of patients in the main group assessed the improvement from the therapy as ‘pronounced’ (GROC: 10/33.3 % vs 6/20.0 %).Conclusions. The use of ipidacrine in complex therapy of patients with DPN can significantly reduce the clinical manifestations of disease and improve the neurophysiological parameters of the peripheral nerves of the lower extremities. Ipidacrine can be considered as a basic drug for the treatment of patients with neurological complications of diabetes mellitus.

Diaphragm weakness in late-onset Pompe disease: A complex interplay between lower motor neuron and muscle fibre degeneration

BackgroundLate-onset Pompe disease (LOPD) patients may still need ventilation support at some point of their disease course, despite regular recombinant human alglucosidase alfa treatment. This suggest that other pathophysiological mechanisms than muscle fibre lesion can contribute to the respiratory failure process. We investigate through neurophysiology whether spinal phrenic motor neuron dysfunction could contribute to diaphragm weakness in LOPD patients. Material and methodsA group of symptomatic LOPD patients were prospectively studied in our centre from January 2022 to April 2023. We collected both demographic and clinical data, as well as neurophysiological parameters. Phrenic nerve conduction studies and needle EMG sampling of the diaphragm were perfomed. ResultsEight treated LOPD patients (3 males, 37.5%) were investigated. Three patients (37.5%) with no respiratory involvement had normal phrenic nerve motor responses [median phrenic compound muscle action potential (CMAP) amplitude of 0.49 mV; 1st-3rd interquartile range (IQR), 0.48–0.65]. Those with respiratory failure (under nocturnal non-invasive ventilation) had abnormal phrenic nerve motor responses (median phrenic CMAP amplitude of 0 mV; 1st-3rd IQR, 0–0.15), and were then investigated with EMG. Diaphragm needle EMG revealed both myopathic and neurogenic changes in 3 (60%) and myopathic potentials in 1 patient. In the last one, no motor unit potentials could be recruited. ConclusionsOur study provide new insights regarding respiratory mechanisms in LOPD, suggesting a contribution of spinal phrenic motor neuron dysfunction for diaphragm weakness. If confirmed in further studies, our results recommend the need of new drugs crossing the blood-brain barrier.

The main directions of research of physical development in the context of psychology, psychophysiology, genetics and sports anthropology: а review based on the articles published in «Lomonosov Journal of Anthropology» for the last 15 years

Introduction. This work continues the series of articles devoted to the assessment of the main directions of auxology development in Russian anthropology. This part presents and describes the work of the staff of the Research Institute and Museum of Anthropology of Lomonosov Moscow State University, the Department of Anthropology of the Faculty of Biology of Lomonosov Moscow State University, as well as the Russian University Sport (SCOLIPE) and the Federal Science Center of Physical Culture and Sport (VNIIFK). Materials and methods. In this part of the work, articles devoted to the comprehensive assessment of the research of physical development in the context of psychology, psychophysiology, genetics and sports anthropology, which were published in the «Lomonosov Journal of Anthropology (Moscow University Anthropology Bulletin)» from 2009 to 2022 were used as a source of information. Results and discussion. The described works evaluate, firstly, the psychosomatic connections of self-esteem and soma parameters that determine it, as well as the specifics of the processes of growth and adaptation in biological and psychological aspects. Secondly, the intra-group variability of neurophysiological parameters (EEG parameters) and the analysis of their correlations with somatic indicators are considered. Thirdly, the contribution of genetic factors to the development of morphological trait systems, primarily associated with increased body weight and obesity, is evaluated. In addition, the results of studies devoted to the search for predictors of sports success and the analysis of the physical status of athletes of various specializations are presented. Conclusion. The number of works similar to those described in this review is steadily growing every year, which suggests an increasing integrative nature of anthropological research.