Motor Amplitude Research Articles

COMBINED FIRST AND SECOND-ORDER SLIDING MODE CONTROL OF INDUCTION MOTOR

This paper uses hybrid sliding mode control to solve an output feedback tracking problem for the induction motor (IM). The main idea of this approach lies in the design of a law that ensures a smooth transition between two sliding regimes based on the choice of two sliding surfaces, one being linked to the other. The control is a combination of first and second-order sliding modes. The proposed approach controls the speed and rotor flux amplitude of the induction motor and guarantees the stability of the decoupled speed and rotor flux by using a Lyapunov method. The hybrid sliding mode algorithm provides robustness despite external disturbances and parameter variations. The controller has been implemented on an experimental setup, and results are presented to confirm the proposed method's effectiveness, robustness, and good performance.

Intravenous lidocaine infusion therapy and intraoperative neurophysiological monitoring in adolescents undergoing idiopathic scoliosis correction: A retrospective study.

Posterior spinal instrumentation and fusion is an established surgical procedure for the correction of adolescent idiopathic scoliosis. Intraoperative neurophysiological monitoring is standard practice for this procedure. Anesthetic agents can have different, but significant, effects on neurophysiological monitoring outcomes. To determine if intravenous lidocaine infusion therapy has an impact on the intraoperative neurophysiological monitoring during posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis. Following ethical approval, we conducted a retrospective review of charts and the archived intraoperative neurophysiological data of adolescents undergoing posterior spinal instrumentation and fusion for adolescent idiopathic scoliosis. Intraoperative neurophysiological monitoring data included the amplitude of motor evoked potentials and the amplitude and latency of somatosensory evoked potentials. A cohort who received intraoperative lidocaine infusion were compared to those who did not. Eighty-one patients were included in this analysis, who had surgery between February 4, 2016 and April 22, 2021: 39 had intraoperative intravenous lidocaine infusion and 42 did not. Based on hourly snapshot data, there was no evidence that lidocaine infusion had a detrimental effect on the measured change from baseline for MEP amplitudes in either lower (mean difference 41.9; 95% confidence interval -304.5 to 388.3; p = .182) or upper limbs (MD -279.0; 95% CI -562.5 to 4.4; p = .054). There was also no evidence of any effect on the measured change from baseline for SSEP amplitudes in either lower (MD 16.4; 95% CI -17.7 to 50.5; p = .345) or upper limbs (MD -2.4; 95% CI -14.5 to 9.8; p = .701). Finally, there was no evidence of a difference in time to first reportable neurophysiological event (hazard ratio 1.13; 95% CI 0.61 to 2.09; p = .680). Data from these two cohorts provide preliminary evidence that intravenous lidocaine infusion has no negative impact on intraoperative neurophysiological monitoring during PSIF for adolescent idiopathic scoliosis.

Game-Based Assessment of Peripheral Neuropathy Combining Sensor-Equipped Insoles, Video Games, and AI: Proof-of-Concept Study.

Detecting peripheral neuropathy (PNP) is crucial in preventing complications such as foot ulceration. Clinical examinations for PNP are infrequently provided to patients at high risk due to restrictions on facilities, care providers, or time. A gamified health assessment approach combining wearable sensors holds the potential to address these challenges and provide individuals with instantaneous feedback on their health status. We aimed to develop and evaluate an application that assesses PNP through video games controlled by pressure sensor-equipped insoles. In the proof-of-concept exploratory cohort study, a complete game-based framework that allowed the study participant to play 4 video games solely by modulating plantar pressure values was established in an outpatient clinic setting. Foot plantar pressures were measured by the sensor-equipped insole and transferred via Bluetooth to an Android tablet for game control in real time. Game results and sensor data were delivered to the study server for visualization and analysis. Each session lasted about 15 minutes. In total, 299 patients with diabetes mellitus and 30 with metabolic syndrome were tested using the game application. Patients' game performance was initially assessed by hypothesis-driven key capabilities that consisted of reaction time, sensation, skillfulness, balance, endurance, and muscle strength. Subsequently, specific game features were extracted from gaming data sets and compared with nerve conduction study findings, neuropathy symptoms, or disability scores. Multiple machine learning algorithms were applied to 70% (n=122) of acquired data to train predictive models for PNP, while the remaining data were held out for final model evaluation. Overall, clinically evident PNP was present in 247 of 329 (75.1%) participants, with 88 (26.7%) individuals showing asymmetric nerve deficits. In a subcohort (n=37) undergoing nerve conduction study as the gold standard, sensory and motor nerve conduction velocities and nerve amplitudes in lower extremities significantly correlated with 79 game features (|R|>0.4, highest R value +0.65; P<.001; adjusted R2=0.36). Within another subcohort (n=173) with normal cognition and matched covariates (age, sex, BMI, etc), hypothesis-driven key capabilities and specific game features were significantly correlated with the presence of PNP. Predictive models using selected game features achieved 76.1% (left) and 81.7% (right foot) accuracy for PNP detection. Multiclass models yielded an area under the receiver operating characteristic curve of 0.76 (left foot) and 0.72 (right foot) for assessing nerve damage patterns (small, large, or mixed nerve fiber damage). The game-based application presents a promising avenue for PNP screening and classification. Evaluation in expanded cohorts may iteratively optimize artificial intelligence model efficacy. The integration of engaging motivational elements and automated data interpretation will support acceptance as a telemedical application.

Is essential tremor a risk factor for carpal tunnel syndrome? A prospective study excluding the most common comorbid conditions

Aims: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy of the upper extremity, resulting from compression of the median nerve. Tremor, a rhythmic and involuntary movement of any part of the body, is the most common movement disorder, affecting millions of people worldwide. There is limited research on the coexistence of CTS and ET (essential tremor). Methods: This prospective study included patients aged 18-65 who presented to the neurology outpatient clinic and were diagnosed with ET. Participants supplied informed consent, a sociodemographic form, and the Fahn-Tolosa-Marin Clinical Tremor Rating Scale (FTM TRS). Patients were evaluated for the presence and severity of CTS with electromyography (EMG). The EMG data were categorized as normal, mild, moderate, and severe CTS. Results: In the study, the average age of the 50 ET patients was 56.0 (35.0-64.0) years. The gender distribution comprised 22 (44.0%) males and 28 (56.0%) females. The following tremor locations were reported: 41 (82.0%) in both upper extremities, 3 (6.0%) in the right upper extremity, 2 (4.0%) in the left upper extremity, 1 (2.0%) in both upper extremities, head tremor, and voice, and 3 (6.0%) in both upper extremities and head tremor. A high prevalence of CTS was detected in ET patients (46%). Additionally, a positive correlation was found between CTS in ET patients, long disease duration, and female gender. No significant relationship was found between FTM TRS Part A, Part B, Part C, total scores, and median sensory and motor nerve amplitude and velocity values in ETS patients. Conclusion: CTS is more common in patients with ET. This suggests that ET may be a risk factor for CTS, independent of other factors. Early diagnosis and treatment of CTS in patients with ET is important to improve their quality of life.

The long-term impact of rehabilitation in upper limb plexopathies

The main objective of the research consists in providing evidence that a long-term rehabilitation protocol is favorable for the patient. In adult brachial plexus (BP) palsies, after several surgical attempts, the lack of results in the upper limb’s functionality leads to less compliance to rehabilitation therapy. The upper limb’s functionality of 22 patients with posttraumatic operated chronic BP paresis (either on the right or left, regardless the dominant limb) was assessed retrospectively. The patients were evaluated regarding MRC scaling, dynamometric tests and electroneuromyographic examination. All patients have gone through at least one rehabilitation interval (10 days) after an initial evaluation, and were evaluated again, by same methods, at a second session, at least 6 months later, but no more than one year.. Mild and inconstant improvements were obtained in a total of 9 patients, especially in better dynamometric results and improved amplitudes of motor and sensory action potentials. The electrodiagnosis correlates with dynamometric parameters (muscle strength) and slight amelioration of the motor deficit. Given the small sample size as a limitation, as well as no standardized therapeutic protocol, it should be noted that the 9 patients were the only ones who either attended more than one interval or did more procedures as frequency in time (more often meaning 3 times weekly for 6 months, in 6 patients). Although the most frequent procedures were neuromuscular electrical stimulation (NMES) and proprioceptive neuromuscular facilitation (PNF), the results suggest that regardless of the techniques, the more active patients had better results. Proving the need for long-term rehabilitation, even contrary to the less visible results, can be the trigger point for future research and therapy strategies, as the results suggest central mechanisms involved, adding the cortical ongoing plasticity into the equation.

Impact of a mandibular advancement device on corticomotor plasticity in patients with obstructive sleep apnea.

Neuroplasticity induced by mandibular advancement appliance (MAD) in patients with obstructive sleep apnoea (OSA) is poorly documented. This randomised placebo-controlled crossover mechanistic study assessed the effects of short-term use of a MAD on corticomotor excitability of the masseter and tongue in patients with OSA. Adults (n = 28) with mild or moderate OSA were randomly allocated to sleep with a MAD for 2-weeks with 40% of the maximal protrusion (MAD active position) and without any jaw protrusion (MAD placebo position). The outcomes were assessed at baseline, and after 2 and 6 weeks, with a 2-week washout period. The primary outcome was the amplitude of motor evoked potential (MEP) assessed on the right masseter, right side of tongue and right first dorsal interosseous with transcranial magnetic stimulation. Corticomotor map volume of the same muscles was also assessed. Repeated-measures ANOVAs followed by Tukey test were applied to the data (p < .050). There was a significant increase in the MEP amplitude of the masseter and tongue following the MAD active position compared with the baseline and MAD placebo (Tukey: p < .001). There were no significant MEP amplitude differences between the baseline and placebo positions (p > .050). Moreover, there was a significant increase in corticomotor map volume for the masseter and tongue muscles following the MAD active position compared with baseline and MAD placebo (Tukey: p < .003). Excitability of the masseter and tongue motor pathways is, at least transiently, increased in patients with OSA following a short-term use of MAD. This novel finding of MAD-induced neuroplasticity in corticomotor pathways may contribute to a further understanding of the mechanisms of oral appliances for treating OSA.

Normative data of upper limb nerve conduction in North Kerala population

Objectives: The objective of this study was to detect the normal motor amplitude, distal latency, conduction velocity, sensory amplitude, sensory latency and F-wave latency of upper limb nerves (Median nerve, ulnar nerve and radial nerve). Materials and Methods: It was a cross-sectional study conducted in the Department of Neurology, Government Medical College, Kozhikode, between 1 January 2022 and 31 December 2022. Nerve conduction studies (NCSs) were performed prospectively in the upper limbs of 311 carefully screened, healthy individuals of either sex, who were between the ages of 13 and 60 years, belonging to the North Kerala population, using the standardised technique. Results: The study population consisted of 54% males and 46% females. The mean age, height, weight and body mass index (BMI) of the study population were 39 ± 15 years, 163 ± 12 cm, 58 ± 11 Kgs and 22 ± 2.7 Kg/m2, respectively. The motor, sensory parameters and F-wave latency of median ulnar and radial nerves were established. We obtained a significant positive correlation between motor distal latency, sensory distal latency and F-wave latency of median and ulnar and radial nerves with age, height and weight. We obtained a significant negative correlation between motor distal amplitude, sensory distal amplitude and conduction velocity of median, ulnar, and radial nerves with age, height and weight. In our study, females had faster conduction velocity, shorter F-wave latency, motor distal latency, sensory latency and higher motor amplitude and sensory amplitude than males. BMI did not have a significant correlation with nerve conduction parameters in our study. Conclusion: Normative conduction parameters of commonly tested peripheral nerves of the upper limb were established for our electrophysiology laboratory. While performing NCS, it is essential to adapt values based on physiological factors such as age, gender, height, weight and BMI, which enhance the diagnostic sensitivity of the procedure and, thus, avoid misdiagnosis and mistreatment of various demyelinating and axonal disorders.

Epidural magnetic stimulation of the motor cortex using an implantable coil

BackgroundMagnetic stimulation, represented by transcranial magnetic stimulation (TMS), is used to treat neurological diseases. Various strategies have been explored to improve the spatial resolution of magnetic stimulation. While reducing the coil size is the most impactful approach for increasing the spatial resolution, it decreases the stimulation intensity and increases heat generation. ObjectiveWe aim to demonstrate the feasibility of magnetic stimulation using an epidurally implanted millimeter-sized coil and that it does not damage the cortical tissue via heating even when a repetitive stimulation protocol is used. MethodsA coil with dimensions of 3.5 × 3.5 × 2.6 mm3 was epidurally implanted on the left motor cortex of rat, corresponding to the right hindlimb. Before and after epidural magnetic stimulation using a quadripulse stimulation (QPS) protocol, changes in the amplitude of motor evoked potentials (MEPs) elicited by a TMS coil were compared. ResultsThe experimental group showed an average increase of 88 % in MEP amplitude in the right hindlimb after QPS, whereas the MEP amplitude in the left hindlimb increased by 18 % on average. The control group showed no significant change in MEP amplitude after QPS in either hindlimb. The temperature changes at the coil surface remained <2 °C during repetitive stimulation, meeting the thermal safety limit for implantable medical devices. ConclusionThese results demonstrate the feasibility of epidural magnetic stimulation using an implantable coil to induce neuromodulation effects. This novel method is expected to be a promising alternative for focal magnetic stimulation with an improved spatial resolution and lowered stimulus current than previous magnetic stimulation methods.

Whether coagulation dysfunction influences the onset and progression of diabetic peripheral neuropathy: A multicenter study in middle-aged and aged patients with type 2 diabetes.

Nearly half of patients with diabetes experience diabetic peripheral neuropathy (DPN), resulting in a mere 53% survival rate within 3 years. Aberrations in coagulation function have been implicated in the pathogenesis of microvascular complications, prompting the need for a thorough investigation into its role as a contributing factor in the development and progression of DPN. Data were gathered from 1211 type 2 diabetes patients admitted to five centers from September 2018 to October 2022 in China. DPN was evaluated by symptoms and electromyography. Motor and sensory nerve conduction velocity (NCV) was appraised and the NCV sum score was calculated for the median, ulnar, and peroneal motor or sensory nerves. Patients with DPN exhibited alterations in coagulation function. (i) Specifically, they exhibited prolonged thrombin time (p = 0.012), elevated fibrinogen (p < 0.001), and shortened activated partial thromboplastin time (APTT; p = 0.026) when compared to the control group. (ii) After accounting for potential confounders in linear regression, fibrinogen, and D-dimer were negatively related to the motor NCV, motor amplitude values, and mean velocity and amplitude. Also, fibrinogen was associated with higher Michigan neuropathy screening instrument (MNSI) scores (β 0.140; p = 0.001). This result of fibrinogen can be validated in the validation cohort with 317 diabetic patients. (iii) Fibrinogen was independently associated with the risk of DPN (OR 1.172; p = 0.035). In the total age group, DPN occurred at a slower rate until the predicted fibrinogen level reached around 3.75 g/L, after which the risk sharply escalated. Coagulation function is warranted to be concerned in patients with type 2 diabetes to predict and prevent the occurrence of DPN in clinical practice.

Pilot study of using transcranial temporal interfering theta-burst stimulation for modulating motor excitability in rat

Transcranial temporal interference stimulation (tTIS) is a promising brain stimulation method that can target deep brain regions by delivering an interfering current from surface electrodes. Most instances of tTIS stimulate the brain with a single-frequency sinusoidal waveform generated by wave interference. Theta burst stimulation is an effective stimulation scheme that can modulate neuroplasticity by generating long-term potentiation- or depression-like effects. To broaden tTIS application, we developed a theta burst protocol using tTIS technique to modulate neuroplasticity in rats. Two cannula electrodes were unilaterally implanted into the intact skull over the primary motor cortex. Electrical field of temporal interference envelopes generated by tTIS through cannula electrodes were recorded from primary motor cortex. Theta burst schemes were characterized, and motor activation induced by the stimulation was also evaluated simultaneously by observing electromyographic signals from the corresponding brachioradialis muscle. After validating the stimulation scheme, we further tested the modulatory effects of theta burst stimulation delivered by tTIS and by conventional transcranial electrical stimulation on primary motor cortex excitability. Changes in the amplitude of motor evoked potentials, elicited when the primary motor cortex was activated by electrical pulses, were measured before and after theta burst stimulation by both techniques. Significant potentiation and suppression were found at 15 to 30 min after the intermittent and continuous theta burst stimulation delivered using tTIS, respectively. However, comparing to theta burst stimulations delivered using conventional form of transcranial electrical stimulation, using tTIS expressed no significant difference in modulating motor evoked potential amplitudes. Sham treatment from both methods had no effect on changing the motor evoked potential amplitude. The present study demonstrated the feasibility of using tTIS to achieve a theta burst stimulation scheme for motor cortical neuromodulation. These findings also indicated the future potential of using tTIS to carry out theta burst stimulation protocols in deep-brain networks for modulating neuroplasticity.

Effect of propofol infusion vs ketamine plus dexmedetomidine infusion on the amplitude of motor evoked potential in pediatric patients undergoing tethered spinal cord surgeries; a randomized, double blind controlled study

Background &amp; objective: The use of intraoperative neurophysiologic monitoring (IOM) has increased over the past two decades for the detection and prevention of iatrogenic neurologic injuries. Motor evoked potentials (MEP) are extremely sensitive to changes in physiological variables and inhalational agents reduce MEPs in a dose dependent manner. So IV anesthetics (propofol or ketamine) and opioids (fentanyl or remifentanil), are frequently used in spinal surgeries under MEPs monitoring. We compared the effects of propofol and fentanyl to those of ketamine, dexmedetomidine, and fentanyl in terms of minimizing their effects on MEP amplitude and hemodynamic stability during surgery Methodology: This double blind, randomized, prospective study was conducted on 46 children, who were randomly allocated into 2 groups Ketamine–dexmedetomidine group: (n = 23) Maintenance throughout the procedure, by infusing Dexmedetomidine (0.4 -0.6 μg/.kg /.hr) ketamine, (1 -2m/.kg/.hr.) and giving bolus of fentanyl, (1-2μg/.kg/ ). Propofol-group:(n = 23) Maintenance throughout the procedure, By infusing propofol (100 ug L/kg/min) and giving bolus of fentanyl, (1-2μg/.kg/ ), with keeping mean arterial blood pressure changes within 25% of the baseline in both groups. Results: Right and left quadriceps muscle measurements were insignificantly different between both groups at base line and were significantly higher in Group KD than Group P at skin incision, surgical manipulation and surgical closure. Right and left adductor hallucis muscle measurements were insignificantly different between both groups at base line and were significantly higher in Group KD than Group P at 5 mins, 10 mins, 15 mins, skin incision, surgical manipulation and surgical closure (P value &lt;0.001). Intraoperative fentanyl consumption was significantly lower in Group KD than Group P. Conclusion: The combination of dexmedetomidine and ketamine infusion is efficacious, safe, and has minimal effect on evoked potentials compared with the propofol-based TIVA group during spine pediatrics surgery. In addition, this combination increases the reliability and accuracy of MEP monitoring with hemodynamic stability and adequate post-operative pain relief. Using dexmedetomidine and ketamine infusions during pediatric spine surgery might successfully replace the typical propofol-based TIVA, although more studies are required . Registration: ClinicalTrials.gov registration number NCT05591001. Keywords: Motor evoked potential, dexmedetomidine, ketamine, propofol. Citation: Saleh AH, Hammad SH, Hassan PF. Effect of propofol infusion vs ketamine plus dexmedetomidine infusion on the amplitude of motor evoked potential in pediatric patients undergoing tethered spinal cord surgeries; a randomized, double blind controlled study. Anaesth. pain intensive care 2024;28(4):692−699; DOI: 10.35975/apic.v28i4.2218 Received: May 08, 2023; Reviewed: February 02, 2024; Accepted: July 03, 2924

Exploring the Feasibility of Bidirectional Control of Beta Oscillatory Power in Healthy Controls as a Potential Intervention for Parkinson's Disease Movement Impairment.

Neurofeedback (NF) is a promising intervention for improvements in motor performance in Parkinson's disease. This NF pilot study in healthy participants aimed to achieve the following: (1) determine participants' ability to bi-directionally modulate sensorimotor beta power and (2) determine the effect of NF on movement performance. A real-time EEG-NF protocol was used to train participants to increase and decrease their individual motor cortex beta power amplitude, using a within-subject double-blind sham-controlled approach. Movement was assessed using a Go/No-go task. Participants completed the NASA Task Load Index and provided verbal feedback of the NF task difficulty. All 17 participants (median age = 38 (19-65); 10 females) reliably reduced sensorimotor beta power. No participant could reliably increase their beta activity. Participants reported that the NF task was challenging, particularly increasing beta. A modest but significant increase in reaction time correlated with a reduction in beta power only in the real condition. Findings suggest that beta power control difficulty varies by modulation direction, affecting participant perceptions. A correlation between beta power reduction and reaction times only in the real condition suggests that intentional beta power reduction may shorten reaction times. Future research should examine the minimum beta threshold for meaningful motor improvements, and the relationship between EEG mechanisms and NF learning to optimise NF outcomes.

Detection of Sub-Clinical Tarsal Tunnel Syndrome in Rheumatoid Arthritis Patients

Abstract Background Asymptomatic or subclinical entrapments are common and frequent specially in patients with rheumatoid arthritis. Objectives Detection of sub clinical tarsal tunnel syndrome in rheumatoid arthritis patients and detect its correlation with disease activity and severity. Patient and Methods This case control was carried out on 16 patients with rheumatoid arthritis (RA) diagnosed according to American College of Rheumatology (ACR) and European League Against Rheumatism (EULAR) criteria of 2010 and 16 healthy controls matched for age and sex. Assessment of disease activity was done by Disease Activity Score in 28 joints (DAS28) and Rheumatoid Arthritis Severity Scale (RASS). Electrophysiological studies were conducted on a two channel EMG machine, for each patient on both legs. Results No significant differences were noted between study groups regarding basal demographic and clinical manifestations. In rheumatoid patient, mean ± SD for disease activity score (DAS) was 4.11±0.51 versus 2.51 ± 0.66 in control patient with p &amp;lt; 0.0001. Regarding RASS, in rheumatoid patient, mean ± SD for disease activity was 28.94 ± 5.78; mean ± SD for functional impairment was 28.44 ± 5.46 and mean ± SD for physical damage was 31.75 ± 5.58 versus 11.44 ± 4.91, 13.88 ± 5.88 and 12.69 ± 4.24 in control group with statistically significant difference between both groups (p &amp;lt; 0.0001). In rheumatoid cases, all patients (100%) were affected on medial plantar nerve “sensory latency and amplitude” of right and left sides, also, all patients (100%) were affected on lateral plantar nerve “sensory latency” of right and left sides, while for amplitude right and left; 31.25% of patients were affected. Medial plantar nerves (motor latency) in both sides weren‟t affected in any patients, while for amplitude and nerve conduction velocity the percentage of patients in right and left was 100%. Lateral plantar nerve (motor latency and amplitude) weren‟t affected in any patients in both sides, while for nerve conduction velocity the percentage of patients in right and left was 100%. Posterior tibial nerves (motor latency and nerve conduction velocity) weren‟t affected in any patients in both sides, while for amplitude the percentage of patients in right and left was 6.25%. No correlation was detected between DAS and RASS as regard clinical, laboratory data and electrophysiological study in rheumatoid cases. This was clearly demonstrated by sensitivity and specificity test that medial and lateral plantar nerved (sensory and motor) were of highly significant value and posterior tibial nerve (motor) was of insignificant value in detection of sub clinical tarsal tunnel syndrome in rheumatoid arthritis patients. Conclusion Subclinical entrapments and sub clinical tarsal tunnel syndrome were detected in all rheumatoid arthritis patients using electrophysiological study and they were positively correlated with disease activity and severity. Also, most of joint complaints of rheumatoid arthritis patients as oedema and pain were due undiagnosed subclinical entrapments and sub clinical tarsal tunnel syndrome.

Differential Responses to Low- and High-Frequency Subthalamic Nucleus Deep Brain Stimulation on Sensor-Measured Components of Bradykinesia in Parkinson's Disease.

The current approach to assessing bradykinesia in Parkinson's Disease relies on the Unified Parkinson's Disease Rating Scale (UPDRS), which is a numeric scale. Inertial sensors offer the ability to probe subcomponents of bradykinesia: motor speed, amplitude, and rhythm. Thus, we sought to investigate the differential effects of high-frequency compared to low-frequency subthalamic nucleus (STN) deep brain stimulation (DBS) on these quantified facets of bradykinesia. We recruited advanced Parkinson's Disease subjects with a chronic bilateral subthalamic nucleus (STN) DBS implantation to a single-blind stimulation trial where each combination of medication state (OFF/ON), electrode contacts, and stimulation frequency (60 Hz/180 Hz) was assessed. The Kinesia One sensor system was used to measure upper limb bradykinesia. For each stimulation trial, subjects performed extremity motor tasks. Sensor data were recorded continuously. We identified STN DBS parameters that were associated with improved upper extremity bradykinesia symptoms using a mixed linear regression model. We recruited 22 subjects (6 females) for this study. The 180 Hz STN DBS (compared to the 60 Hz STN DBS) and dopaminergic medications improved all subcomponents of upper extremity bradykinesia (motor speed, amplitude, and rhythm). For the motor rhythm subcomponent of bradykinesia, ventral contacts yielded improved symptom improvement compared to dorsal contacts. The differential impact of high- and low-frequency STN DBS on the symptoms of bradykinesia may advise programming for these patients but warrants further investigation. Wearable sensors represent a valuable addition to the armamentarium that furthers our ability to conduct objective, quantitative clinical assessments.

Sex differences in spontaneous respiratory recovery following chronic C2 hemisection.

Respiratory deficits after C2 hemisection (C2Hx) have been well documented through single-sex investigations. Although ovarian sex hormones enable enhanced respiratory recovery observed in females 2 wk post-C2Hx, it remains unknown if sex impacts spontaneous respiratory recovery at chronic time points. We conducted a longitudinal study to provide a comprehensive sex-based characterization of respiratory neuromuscular recovery for 8 wk after C2Hx. We recorded ventilation and chronic diaphragm electromyography (EMG) output in awake, behaving animals, phrenic motor output in anesthetized animals, and performed diaphragm muscle histology in chronically injured male and female rodents. Our results show that females expressed a greater recovery of tidal volume and minute ventilation compared with males during subacute and chronic time points. Eupneic diaphragm EMG amplitude during wakefulness and phrenic motor amplitude are similar between sexes at all time points after injury. Our data also suggest that females have a greater reduction in ipsilateral diaphragm EMG amplitude during spontaneous deep breaths (e.g., sighs) compared with males. Finally, we show evidence for atrophy and remodeling of the fast, fatigable fibers ipsilateral to injury in females, but not in males. To our knowledge, the data presented here represent the first study to report sex-dependent differences in spontaneous respiratory recovery and diaphragm muscle morphology following chronic C2Hx. These data highlight the need to study both sexes to inform evidence-based therapeutic interventions in respiratory recovery after spinal cord injury (SCI).NEW & NOTEWORTHY In response to chronic C2 hemisection, female rodents display increased tidal volume during eupneic breathing compared with males. Females show a greater reduction in diaphragm electromyography (EMG) amplitude during spontaneous deep breaths (e.g., sighs) and atrophy and remodeling of fast, fatigable diaphragm fibers. Given that most rehabilitative interventions occur in the subacute to chronic stages of injury, these results highlight the importance of considering sex when developing and evaluating therapeutics after spinal cord injury.

Diminished levels of insulin-like growth factor-1 may be a risk factor for peripheral neuropathy in type 2 diabetes patients.

To investigate risk factors for diabetic peripheral neuropathy (DPN) and to explore the connection between insulin-like growth factor-1 (IGF-1) and DPN in individuals with type 2 diabetes. A total of 790 patients with type 2 diabetes participated in a cross-sectional study, divided into two groups: those with DPN (DPN) and those without DPN (non-DPN). Blood samples were taken to measure IGF-1 levels and other biochemical markers. Participants underwent nerve conduction studies and quantitative sensory testing. Patients with DPN exhibited significantly lower levels of IGF-1 compared with non-DPN patients (P < 0.001). IGF-1 was positively correlated with the average amplitude of both motor (P < 0.05) and sensory nerves (P < 0.05), but negatively correlated with the vibration perception threshold (P < 0.05). No significant difference was observed between IGF-1 and nerve conduction velocity (P > 0.05), or the temperature detection threshold (P > 0.05). Multivariate regression analysis identified diabetes duration, HbA1c, and the low levels of IGF-1 as independent risk factors (P < 0.001). Receiver operating characteristic analysis determined that at 8 years duration of diabetes, 8.5% (69.4 mmol/mol) HbA1c and 120 ng/mL IGF-1, the optimal cut-off points, indicated DPN (P < 0.001). A reduction of IGF-1 in patients with DPN suggests a potential protective role against axon injury in large fiber nerves of type 2 diabetes patients.

The Scratch-Collapse Test: Are Electrodiagnostic Changes Measurable?

Carpal tunnel syndrome is commonly managed by hand and upper extremity surgeons. Though electrodiagnostics are considered the gold standard diagnosis, the scratch collapse test (SCT) was introduced to address uncertainty, despite remains controversial. To address this, we sought to identify if the SCT can correlate with EDS studies if the SCT can identify actual changes in measures of nerves. We reviewed patients who underwent electrodiagnostic studies (EDX) and SCT for carpal tunnel syndrome (CTS). Demographic data as well as sensorimotor amplitudes, latencies, and velocities on nerve conduction and electromyography were collected. Analogous values based on SCT findings were analyzed for statistical significance. Three hundred fifty patients with CTS were included. Sensory and motor velocities and amplitudes were significantly lower in patients with a positive SCT. Motor values were independent of age, though younger patients had larger measured changes. Obese patients did not show any motor EDX changes with the scratch collapse test, though thinner patients did. All changes were seen in nerve conduction only. Carpal tunnel can be a difficult problem to diagnose as one study does not singularly determine the condition. The SCT was introduced to facilitate easier diagnosis. We demonstrate that the SCT correlates with changes on nerve conduction studies, especially in relation to decreased amplitudes and velocities, suggesting that it does identify changes in nerve with compression, specifically axonal, and myelin damage. These findings support the use of the SCT maneuver to evaluate and diagnose in appropriate patients.

Electrophysiological Assessment of Paresthesia in Patients Following Radial Angiography: AProspective Study.

Radial angiography, preferred for its safety and comfort in percutaneous coronary interventions, occasionally leads to paresthesia-a tingling or numbing sensation in the hand. This study aimed to investigate the presence of nerve damage in patients experiencing paresthesia post-radial angiography through electrophysiological examination. This prospective study involved 77 patients who developed hand paresthesia following radial angiography. Excluded were those with malignancy, pregnancy, pace-makers, or recent angiography. Nerve conduction studies were performed using the Neuropack MEB 9102K EMG device, assessing sensory and motor amplitudes, latencies, and velocities of median, ulnar, and radial nerves. The study included 77 patients (23 females, 54 males; average age 58.39 ± 10.44 years). In 11 diabetic patients, polyneuropathy was detected. For the remaining 66 patients, electrophysiological evaluations showed no significant pathological findings. Comparative analysis of both upper extremities revealed no significant differences in nerve conduction parameters between the side where angiography was performed and the other side. Despite paresthesia complaints, no electrophysiological evidence of nerve damage was found, suggesting that symptoms might be due to local irritation rather than direct nerve injury. This aligns with the safety profile of radial angiography and underscores the importance of distinguishing between transient paresthesia and serious nerve complications. Paresthesia post-radial angiography, while clinically notable, is not typically associated with nerve damage. This study is significant as it is the first in the literature to demonstrate that radial angiography does not cause nerve damage.

To determine the value of iMAX, a new electrodiagnostic method, and its application in the evaluation of peripheral motor nerve excitability

Objective: To test the new method of iMAX (the minimum stimulus current that elicits the maximum compound muscle action potential amplitude) electrodiagnosis, verify the feasibility of this method in evaluating the excitability of peripheral motor axons, and preliminarily explore the clinical application value. Methods: This study was a cross-sectional study. A total of 50 healthy subjects were recruited from the outpatient department of Peking University Third Hospital from June 2022 to March 2023, including 25 males and 25 females, aged 25-68 (48±8) years. Eleven patients with Charcot-Marie-Pain-1A (CMT1A), 7 males and 4 females, aged 19-55 (41±13) years and 21 patients with diabetic peripheral neuropathy (DPN), 10 males and 11 females, aged 28-79 (53±16) years were enrolled in this study. iMAX of bilateral median nerves, ulnar nerves and peroneal nerves were detected in all patients. Repeatable motor responses with minimum motor threshold and amplitude of at least 0.1 mV and the minimum stimulus current intensity, at which the maximum compound muscle action potential amplitude is elicited, were measured respectively [1 mA increment is called (iUP) and, 0.1 mA adjustment is called (iMAX)].Comparison of the parameters: the parameters of threshold, iUP and iMAX were compared among different age groups, genders and sides, body mass index(BMI) values and detection time , as well as between CMT1A patients, DPN patients and healthy subjects. Results: In healthy subjects, the threshold, iUP value and iMAX value were (1.8±0.7) mA, (4.4±1.2) mA, and (4.2±1.3) mA respectively; ulnar nerve (3.1±1.6) mA, (6.8±3.2) mA, (6.4±3.2) mA; peroneal nerve (3.7±2.0) mA, (7.8±2.8) mA, (7.4±2.9) mA. There were statistically significant differences in threshold, iUP value and iMAX value among different age groups (all P<0.001).With the increase of age, there was a trend of increasing threshold, iUP, and iMAX values in different nerves, and the differences are statistically significant (all P<0.001). There were no significant differences in gender, side and detection time threshold, iUP value and iMAX value (all P>0.05). The parameters of healthy subjects with high BMI value were higher than those of healthy subjects with low BMI value(all P<0.05). Compared with the healthy subjects, the parameters of 11 CMT1A patients were significantly increased (all P<0.05), and the parameters of 21 DPN patients were slightly increased (P<0.05). Conclusion: The new iMAX method reflects the excitability of motor axons and early axonal dysfunction, which is an important supplement to the traditional nerve conduction, and can be used to monitor motor axon excitability disorders.

Transcranial magnetic stimulation in the assessment of acupuncture effect on exercise-induced fatigue.

Acupuncture as a traditional Chinese medicine therapy relies on unique theories to alleviate fatigue. The aim of this study is to evaluate the effect of acupuncture on exercise-induced fatigue utilizing transcranial magnetic stimulation (TMS). A total of 20 participants with regular exercise habits were recruited for this study. All participants were randomly assigned to receive either acupuncture or sham acupuncture intervention for exercise-induced fatigue. TMS and a heart rate monitor were used to measure the amplitude and latency of motor evoked potential (MEP) as well as heart rate every 5min over a 30-min period. The blood lactic acid (BLA) levels were measured using Lactate Scout+ at baseline, 0min, and 30min after fatigue. Two-way repeated measures analysis of variance was utilized to compare the differences between the effects of acupuncture method and time. Bonferroni post hoc tests were conducted to compare specific differences. Statistical significance was set at p<.05. Interaction effect was observed between acupuncture method and time effect in terms of amplitude (F(1, 38)=5.40, p<.001, η2=0.12) and latency (F(1, 38)=3.78, p=.008, η2=.09) of MEP. The application of acupuncture can promote the recovery of heart rate especially at 30min (p<.05), but which seem insufficient to generate significant difference in BLA (F(1, 38)=0.067, p=.797, η2=0.002). Acupuncture can promote the increase of MEP amplitude, shorten MEP latency, and restore heart rate. Preliminary findings provide novel insights for individuals with exercise habits to alleviate fatigue and enhance sports performance.