Background Nerve conduction studies ease the understanding of the various pathologies of the peripheral nervous system. It helps physicians to delineate between the two principal types of peripheral etiologies: axonal degeneration and demyelination. An increase in weight in the form of excessive fat deposition or obesity could have a worrisome effect on nerve conduction. So, to find the association of various anthropometric parameters (age, gender, height, weight, waist-hip ratio and body mass index) with motor and sensory median nerve conduction parameters (latency, amplitude and velocity) this cross-sectional study was conducted. Materials and method A total of 87 subjects were taken and their height, weight, waist-hip ratio and body mass index were measured using standard techniques. Motor and sensory nerve conduction parameters were measured on an electromyography machine. Data was stored, tabulated and analyzed. Results The average height of male and female subjects ± SD was 1.699 ± 0.072 m and 1.589 ± 0.067 m respectively. The average weight of male and female subjects ± SD was 64.089 ± 11.497 kg and 52.949 ± 8.404 kg, respectively. The average BMI of normal, underweight and overweight subjects ± SD was 21.668 ± 2.048 kg/m2, 17.074 ± 0.794 kg/m2 and 26.595 ± 0.915 kg/m2 respectively. Weight showed a significant (p = 0.0025) correlation with the latency of motor median nerve conduction. Waist-hip ratio showed a significant (p = 0.042 and p = 0.036) correlation with motor median nerve conduction velocity in both male and female subjects, respectively. BMI in the overweight category showed a significant (p = 0.0156 and p = 0.0290) correlation with latency and amplitude of motor median nerve conduction study, respectively. Conclusions This study exemplifies that an increase in BMI of our body can affect nerve conduction. This could serve as a preliminary study to assess the effect of obesity on peripheral nerve conduction, especially in the Indian population.

Objective: H-reflex recordings of the relaxed flexor carpi ulnaris (FCU) muscle are not frequently performed in clinical or laboratory settings. There are no normative values or reliability standards. This is most likely because of technical difficulties associated with this technique. This study performed surface recordings of the H-reflex of relaxed FCU muscles to establish the normative values and the reliability of these recordings. Methods: The maximum amplitude and latency of the FCU H-reflex were recorded bilaterally in 53 healthy young adults. Normative values and interclass correlation coefficients (ICCs) were calculated. Results: The amplitude of the relaxed FCU H-reflex were recorded in nearly all participants (96 %). The FCU H-reflex average maximum amplitude was 1.35 mV. The average latency was 18.8 ms. H-reflex amplitude and latency were not statistically different among gender or limb sides. Amplitude and latency were recoded reliably both within and between sessions with ICCs ranging from 0.96 to 0.99. Conclusions: Recordings of the relaxed FCU H-reflex were readily available and could be assessed reliably within and between sessions. Significance: This method might be used more frequently in clinical and laboratory settings to examine C7 and C8 spinal segments and upper limb muscle normal function or neuromuscular pathology.

This preliminary study investigates hypoglossal nerve stimulator (HNS) amplitude changes and usage patterns during the initial HNS uptitration period to characterize when patients achieve their therapeutic amplitude. HNS therapy amplitudes, duration, and pause times were examined across the first 4 months of implant use. Average HNS therapy amplitude increased monthly from baseline (0.7 ± 0.3 V) to the first (1.1 ± 0.3 V), second (1.4 ± 0.4 V), third (1.7 ± 0.5 V), and fourth months (1.8 ± 0.5 V) (P < .001). After 4 months, 60% had reached a therapeutic amplitude. Average therapeutic amplitude was greater for patients who did not achieve therapeutic amplitude by month 4 than for those who did (2.6 vs 1.6 V; P < .05). Body mass index, baseline apnea-hypopnea index, respiratory disturbance index, and initial HNS amplitude did not differ between the 2 groups. Predictors for therapeutic amplitude and other usage patterns require further investigation.

OBJECTIVE: This study analyzes the stimulation parameters implemented during two successful trials that used non-invasive transcutaneous spinal cord stimulation (tSCS) to effectively improve upper extremity function after chronic spinal cord injury (SCI). It proposes a framework to guide stimulation programming decisions for the successful translation of these techniques into the clinic.
METHODS: Programming data from 60 participants who completed the Up-LIFT trial and from 17 participants who subsequently completed the LIFT Home trial were analyzed. All observations of stimulation amplitudes, frequencies, waveforms, and electrode configurations were examined. The incidence of adverse events and relatedness to stimulation parameters is reported. A comparison of parameter usage across the American Spinal Injury Association Impairment Scale (AIS) subgroups was conducted to evaluate stimulation strategies across participants with varying degrees of sensorimotor preservation.
RESULTS: Active (cathodal) electrodes were typically placed between the C3/C4 and C6/C7 spinous processes. Most sessions featured return (anodal) electrodes positioned bilaterally over the anterior superior iliac spine, although clavicular placement was frequently used by 12 participants. Stimulation was delivered with a 10-kHz carrier frequency and typically a 30-Hz burst frequency. Biphasic waveforms were used in 83% of sessions. Average stimulation amplitudes were higher for biphasic waveforms. The AIS B subgroup required significantly higher amplitudes than did the AIS C and D subgroups. Device-related adverse events were infrequent, and not correlated with specific waveforms or amplitudes. Within the home setting, participants maintained their current amplitudes within 1% of the preset values. The suggested stimulation programming framework dictates the following hierarchical order of parameter adjustments: current amplitude, waveform type, active/return electrode positioning, and burst frequency, guided by clinical observations as required.
CONCLUSIONS: This analysis summarizes effective stimulation parameters from the trials and provides a decision-making framework for clinical implementation of tSCS for upper extremity functional restoration after SCI. The parameters are aligned with existing literature and proved safe and well tolerated by participants.

The single macroscopic flow on the boundary of a closed curve equals the sum of the countless microscopic flows in the enclosed area. According to the dictates of the Green\'s theorem, the counterclockwise movements on the border of a two-dimensional shape must equal all the counterclockwise movements taking place inside the shape. This mathematical approach might be useful to analyse neuroscientific data sets for its potential capability to describe the whole cortical activity in terms of electric flows occurring in peripheral brain areas. Given a map of raw EEG data to coloured ovals in which different colours stand for different amplitudes, the theorem suggests that the sum of the electric amplitudes measured inside every oval equals the amplitudes measured just on the oval\'s edge. This means that the collection of the vector fields detected from the scalp can be described by a novel, single parameter summarizing the counterclockwise electric flow detected in the outer electrodes. To evaluate the predictive power of this parameter, in a pilot study we investigated EEG traces from ten young females performing Raven\'s intelligence tests of various complexity, from easy tasks (n = 5) to increasingly complex tasks (n = 5). Despite the seemingly unpredictable behavior of EEG electric amplitudes, the novel parameter proved to be a valuable tool to to discriminate between the two groups and detect hidden, statistically significant differences. We conclude that the application of this promising parameter could be expanded to assess also data sets extracted from neurotechniques other than EEG.

The NMDAR is a heterotetramer composed of two GluN1 subunits and two GluN2 and/or GluN3 subunits, with the GluN2 subunits exhibiting significant diversity in their structure and function. Recent studies have highlighted the importance of characterizing the specific roles of each GluN2 subunit across central nervous system regions and developmental stages, as well as their unique contributions to NMDAR-mediated signaling and plasticity. Understanding the distinct functions of GluN2 subunits is critical for the development of targeted therapeutic strategies for NMDAR-related disorders. However, measuring the functional contribution of individual GluN2 subtypes in ex vivo slices is challenging. Conventionally, pharmacological or genetic approaches are used, but, in many cases, this is not possible or is restricted to population-level NMDAR responses. Here, we describe a technique for using biophysical properties of miniature synaptic NMDAR responses as a proxy to measure the functional contribution of specific GluN2-NMDAR subunits to individual synapses within a neuron.

OBJECTIVE: The laryngeal adductor reflex (LAR) is vital for airway protection and can be electrophysiologically obtained under intravenous general anesthesia (IGA). This makes the electrophysiologic LAR (eLAR) an important tool for monitoring of the vagus nerves and relevant brainstem circuitry during high-risk surgeries. We investigated the intra-class variability of normal and expected abnormal eLAR.
METHODS: Repeated measures of contralateral R1 (cR1) were performed under IGA in 58 patients. Data on presence/absence of cR2 and potential confounders were also collected. Review of neuroimaging, pathology and clinical exam, allowed classification into normal and expected abnormal eLAR groups. Using univariate and multivariate analysis we studied the variability of cR1 parameters and their differences between the two groups.
RESULTS: In both groups, cR1 latencies had coefficients of variation of <2%. In the abnormal group, cR1 had longer latencies, required higher activation currents and was more frequently desynchronized and unsustained; cR2 was more frequently absent.
CONCLUSIONS: cR1 latencies show high analytical precision for measurements. Delayed onset, difficult to elicit, desynchronized and unsustained cR1, and absence of cR2 signal an abnormal eLAR.
CONCLUSIONS: Understanding the variability and behavior of normal and abnormal eLAR under IGA can aid in the interpretation of its changes during monitoring.

Injury, tumors, ischemia, and lesions in the cerebellum show the involvement of this region in human speech. The association of the cerebellum with learned birdsong has only been identified recently. Cerebellar dysfunction in young songbirds causes learning disabilities, but its role in adult songbirds has not been established. The aim of this study was to investigate the role of the deep cerebellar nuclei (DCN) in adult birdsong. We created bilateral excitotoxic lesions in the DCN of adult male zebra finches (Taeniopygia guttata) and recorded their songs for up to 4 months. Using magnetic resonance imaging (MRI) and immunohistochemistry, we validated the lesion efficacy. We found that the song duration significantly increased from 14 weeks post-op; the increase in duration was caused by a greater number of introductory notes as well as a greater number of syllables sung after the introductory notes. On the other hand, the motif duration decreased from 8 weeks after DCN lesions were induced, which was due to faster singing of syllables, not changes in inter-syllable interval length. DCN lesions also caused a decrease in the fundamental frequency of syllables. In summary, we showed that DCN lesions influence the temporal and acoustic features of birdsong. These results suggest that the cerebellum influences singing in adult songbirds.

Reciprocating motion expands the lifetime of endodontic instruments during the preparation of severely curved root canals. This study aimed to investigate the time to fracture (TTF) and number of cycles to failure (NCF) of different reciprocating instruments (n = 20 in each group) at body temperature using a dynamic testing model (amplitude = 3 mm). Reciproc Blue (RPB), size 25/.08, WaveOne Gold (WOG) 25/.07, Procodile (Proc) 25/.06, R-Motion (RM_06) 25/.06 and R-Motion (RM_04) 30/.04 instruments were tested in their specific reciprocating motion in artificial matching root canals (size of the instrument ± 0.02 mm; angle of curvature 60°, radius 5.0 mm, and centre of curvature 5.0 mm from apical endpoint). The number of fractured instruments, TTF, NCF, the and lengths of the fractured instruments were recorded and statistically analysed using the Chi-Square or Kruskal-Wallis test. Both TTF (median 720, 643, 562, 406, 254 s) and the NCF (3600, 3215, 2810, 2032, 1482 cycles) decreased in the following order RM_06 > RPB > RM_04 > Proc > WOG with partially significant differences. During testing, only six RM_06 instruments fractured, whereas 16/20 (RPB), 18/20 (Proc), and 20/20 (RM_04, WOG) fractures were recorded (p < 0.05). Within the limitations of the present study, blue-coloured RPB and RM instruments exhibited a significantly superior cyclic fatigue resistance compared to SE-NiTi and Gold-wire instruments. Heat treatment, cross-sectional design and core mass significantly influenced the longevity of reciprocating instruments in cyclic dynamic testing.

BACKGROUND: Current liver magnetic resonance elastography (MRE) scans often require adjustments to driver amplitude to produce acceptable images. This could lead to time wastage and the potential loss of an opportunity to capture a high-quality image.
OBJECTIVE: To construct a linear regression model of individualized driver amplitude to improve liver MRE image quality.
METHODS: Data from 95 liver MRE scans of 61 participants, including abdominal missing volume ratio (AMVR), breath-holding status, the distance from the passive driver on the skin surface to the liver edge (Dd-l), body mass index (BMI), and lateral deflection of the passive driver with respect to the human sagittal plane (Angle α), were continuously collected. The Spearman correlation analysis and lasso regression were conducted to screen the independent variables. Multiple linear regression equations were developed to determine the optimal amplitude prediction model.
RESULTS: The optimal formula for linear regression models: driver amplitude (%) = -16.80 + 78.59 × AMVR - 11.12 × breath-holding (end of expiration = 1, end of inspiration = 0) + 3.16 × Dd-l + 1.94 × BMI + 0.34 × angle α, with the model passing the F test (F = 22.455, P <0.001) and R2 value of 0.558.
CONCLUSIONS: The individualized amplitude prediction model based on AMVR, breath-holding status, Dd-l, BMI, and angle α is a valuable tool in liver MRE examination.