Sensory Thresholds Research Articles

Removal of 4-Ethylphenol and 4-Ethylguaiacol, from Wine-like Model Solutions, by Commercial Modified Activated Carbons Produced from Coconut Shell

When present in high concentrations in red wine, 4-ethylphenol (4-EP) and 4-ethylguaiacol (4-EG) are responsible for the introduction of unpleasant aromas, which causes wine depreciation. The work presented concerns the performance of textural and chemical-modified activated carbons (ACs), produced from coconuts shells, in the treatment of spoiled wines. ACs were submitted to basic and acid treatment, by impregnation into solutions containing NaOH and HNO3, respectively. Modified ACs showed only a small, but noticeable, increase in apparent surface area and micropore volume when compared to the original AC. However, the surface chemistry underwent significant changes. The ability of modified ACs to remove 4-EP and 4-EG, which cause the off-flavor known as “Brett character”, from wine-like solutions has been successfully achieved. On the systems studied, 4-EG was retained in greater extension, but 4-EP was retained more strongly on the surface of the ACs. Ethanol was found to compete with 4-EP and 4-EG for the adsorptive centres. However, when 4-EP and 4-EG were present in the same solution, the addition of ethanol promoted a cooperative effect and favoured the adsorption of both compounds. It should be noted that the modified ACs were able to eliminate 4-EP and 4-EG to levels below their sensory perception thresholds referred for red wine.

Active Tactile Sensibility in Implant Prosthesis vs. Complete Dentures: A Psychophysical Study.

Proprioceptive information from natural dentition and adjacent oral tissues enables correct masticatory function, avoiding damage to the teeth. Periodontium is the main source of this relevant information, and when a tooth is lost, all this proprioceptive sensibility relies on receptors from muscles, the mucous membrane or the temporomandibular joint, and this sensibility gets worse. Active tactile sensibility measures this proprioceptive capability in microns by psychophysical studies consisting of introducing thin metal foils between patients' dental arches during chewing to see if they are able to notice them or not. Osseoperception is a complex phenomenon that seems to improve this sensibility in patients wearing dental implants. The objective of this investigation is to measure this sensibility in different prosthetic situations by performing a psychophysical investigation. We divided 67 patients in three groups depending on their prosthetic situation and performed a psychophysical study by introducing aluminium foils of different thicknesses in order to establish an active tactile sensibility threshold in every group. We also measured variables such as prosthetic wearing time, age or gender to see how they may influence threshold values. We used Student's t-test and Mann-Whitney U tests to analyse these results. Active tactile sensibility threshold values in implants are lower than those from complete dentures but higher than values in natural dentition. However, values in implants are closer to natural dentition than complete denture values. Age, gender or prosthetic wearing time have no influence in active tactile sensibility thresholds. Active tactile sensibility threshold values depend on prosthetic rehabilitations and the mechanoreceptors involved in every situation. Implant prosthesis presents an increased active tactile sensibility thanks to osseoperception phenomenon.

A Study to Compare The Relation of Taste Threshold Between Type 1 and Type 2 Diabetes Mellitus

Taste disorders result from various diseases and drugs. Severe taste dysfunction leads to decreased food intake and poor nutrition. There are five established basic taste modalities, which are altered specifically, or may be affected generally. Diabetes mellitus is one of the diseases that affect taste. It is the most common endocrine-metabolic disorder affecting a large population. Two major type of diabetes are, Type 1 DM in children and adolescents and Type 2 DM in adults. Many studies have been done on alteration of taste sensation in type 1 or type 2 DM separately, mainly on four primary sensations of taste, without considering the umami taste in their study frame. Nevertheless, no comprehensive information is available on alteration of physiological taste threshold for different taste modalities, including umami taste in both type 1 and type 2 DM. Thus, the present study is undertaken with the objectives; to compare the alteration in taste threshold for five primary sensations in type 1 and type 2 DM. Materials and Methods: Investigations were carried out in thirty type 1 diabetic patients, aged between 12 to 35 years and in thirty type 2 diabetics patients aged between 40-70 years and in age and anthropometrically matched control groups of thirty, each for type 1 and type 2 diabetics separately, who were apparently healthy. Their age, health status and other personal data were obtained by comprehensive questionnaire. Statistical analysis was done using ‘Mann Whitney U test’. Results: The taste threshold for Salt and Sweet sensation significantly (p<0.05) increased in type 1 diabetics, compared to their controls. Similarly, the taste threshold for Salt and Sweet were significantly (p <0.05) increased in type 2 diabetics, compare to their controls. Furthermore, in Type 2 diabetics, taste threshold for Salt and Sweet were significantly (p<0.05) higher compared to type 1 diabetics. No difference in threshold was observed for Umami, Sour and Bitter tastes in any one of the diabetic group. Conclusion: Taste dysfunction was evident in both type 1 and type 2 diabetics and more so in type 2 diabetic patients. The increased taste threshold is specific, affecting Salt and Sweet modality mainly. Dysfunction of taste sensation should be detected in diabetics by screening. Measures to improve the food intake and supplementation for nutritional deficiencies can be given priority in diabetics.

A novel, on-demand therapy for premature ejaculation using a miniature trans-perineal electrical stimulator: a randomized-controlled trial

<h3>Objectives</h3> To assess the feasibility, safety, and efficacy of a miniaturized on-demand perineal Transcutaneous Electrical Stimulation (TES) Using the vPatch device, for the treatment of premature ejaculation (PE). <h3>Methods</h3> We designed a bi-center, international, prospective, randomized, double-blind, sham-controlled, clinical study. A total of 59 lifelong PE patients were included. After the screening visit (Visit 1), patients measured their intravaginal ejaculatory latency time (IELT) for a 2-week run-in period and complete the Premature Ejaculation Profile (PEP) questionnaire. At Visit 2, eligible patients tried vPatch to determine the individualized sensory and motor activation thresholds. Patients were randomized into active and sham arms in a 2:1 ratio. At Visit 3, the IELT values and PEP outcomes were recorded again. Clinical Global Impression of Change (CGIC) scores were noted. <h3>Results</h3> Of the patients, 51 completed the study, 34 in the active and 17 in the sham arm. In the active arm the Baseline Geometric Mean IELT (BGMI) was 67 seconds (s) and significantly increased by 56s (standard error (SE) 9s) to 123s (p<.0001). However, in the sham arm the BGMI was 63s and increased insignificantly by 17s (SE 12s) to 80s (p=0.1653). The increase in IELT from base line was 3.22-fold greater in favor of the active arm (p=0.0047). In the active arm 91% (31/34) of the subjects significantly improved their IELT due to treatment compared to baseline. The mean geometric time-fold in IELT, in those positive responders was 2.04 (CI 95% 1.68-2.4). According to the CGIC, patients in the active group were significantly more satisfied with the treatment (74% vs. 41%, p=0.0274). The subjects in the active arm reported significant improvement in all 4 PEP parameters (P<0.05). <h3>Conclusions</h3> IELT values and patient-reported outcome measures can be improved with TES using vPatch. This treatment may become an on-demand, noninvasive, and drug-free therapeutic option for lifelong PE. <h3>Conflicts of Interest</h3> This study was sponsored by Virility Medical Ltd

Type of Rectal Barostat Protocol Affects Classification of Hypersensitivity and Prediction of Symptom Severity in Irritable Bowel Syndrome.

Background/AimsVisceral hypersensitivity is an important pathophysiologic mechanism in irritable bowel syndrome (IBS). We compared 2 barostat distension protocols and their ability to distinguish between IBS patients and healthy controls, identify subjects with rectal hypersensitivity, and their associations with gastrointestinal symptom severity.MethodsWe retrospectively reviewed all patients at our unit that had undergone barostat investigations 2002-2014. Protocol 1 (n = 369) used phasic isobaric distensions with stepwise increments in pressure and protocol 2 (n = 153) used pressure controlled ramp inflations. Both protocols terminated when subjects reported pain or maximum pressure was reached. Thresholds for first sensation, urgency, discomfort and pain were established. Age- and gender-matched controls were used for comparison. The gastrointestinal symptom rating scale–IBS, and the hospital anxiety and depression scale were used for symptom reports.ResultsA significantly higher proportion of patients was classified as having hypersensitivity in protocol 1 vs protocol 2 for all thresholds (P < 0.001). Patients with visceral hypersensitivity, defined based on rectal pain thresholds in protocol 1 had more severe gastrointestinal symptoms overall as well as anxiety, whereas these associations were weaker or in most cases absent when visceral hypersensitivity was defined based on rectal pain thresholds in protocol 2.ConclusionOur study indicates that a rectal barostat protocol using phasic isobaric distensions with stepwise pressure increments is more sensitive in IBS patients with respect to identifying subjects with rectal hypersensitivity and a link with IBS symptoms.

Vibrotactile mapping of the upper extremity: Absolute perceived intensity is location-dependent; perception of relative changes is not.

Vibrotactile sensation is an essential part of the sense of touch. In this study, the localized vibrotactile sensation of the arm-shoulder region was quantified in 10 able-bodied subjects. For this analysis, the six relevant dermatomes (C3-T2) and three segments-the lower arm, the upper arm, and the shoulder region were studied. For psychometric evaluation, tasks resulting in the quantification of sensation threshold, just noticeable difference, Weber fraction, and perception of dynamically changing vibrotactile stimuli were performed. We found that healthy subjects could reliably detect vibration in all tested regions at low amplitude (2-6% of the maximal amplitude of commonly used vibrotactors). The detection threshold was significantly lower in the lower arm than that in the shoulder, as well as ventral in comparison with the dorsal. There were no significant differences in Weber fraction (20%) detectable between the studied locations. A compensatory tracking task resulted in a significantly higher average rectified error in the shoulder than that in the upper arm, while delay and correlation coefficient showed no difference between the regions. Here, we presented a conclusive map of the vibrotactile sense of the healthy upper limb. These data give an overview of the sensory bandwidth that can be achieved with vibrotactile stimulation at the arm and may help in the design of vibrotactile feedback interfaces (displays) for the hand/arm/shoulder-region.

Continuous administration of leuprolide acetate improves urinary function in male rats with severe thoracic spinal cord injury

AimsTo determine if a continuous administration of leuprolide acetate (LA), a synthetic agonist for the gonadotrophin-releasing hormone receptor, facilitates the recovery of urinary function in spinal cord injured male rats. Main methodsMale Wistar rats were randomized into spinal cord injury (SCI; n = 7), SCI with continuous administration of LA for two weeks via implantation of a subcutaneous osmotic pump (SCI + LA; n = 7), Sham SCI (SH-SCI; n = 6) or no surgery (Intact; n = 6) groups. Micturition, hind-limb nociception and locomotor behaviors were analyzed before and after surgical procedures on days 7, 14, 21 and 28. After behavioral studies, electromyography of the external urethral sphincter (EUS-EMG) and cystometric (CMG) studies were performed in all groups. Key findingsSCI significantly decreased frequency of voids and CMG parameters (p < 0.001), abolished the bursting activity of the EUS during CMG, significantly increased hind limb sensory threshold and decreased locomotor performance in comparison to the other groups (p < 0.001). Continuous LA treatment significantly increased the frequency of voids and improved CMG parameters (p < 0.001), exhibiting bursting EUS activity during CMGs, and enhanced locomotor performance in comparison to SCI rats (p < 0.001). SignificanceSCI severely affected behavioral and functional micturition processes, including sensory and locomotor functions. Systemic and uninterrupted treatment with LA improves the recovery of micturition behavior and the synergistic function of the EUS. Furthermore, sensory and locomotor responses were also improved in SCI rats. This procedure may have a therapeutic potential to facilitate urinary function recovery in patients with SCI.

O081 / #805 MECHANISMS OF LOW FREQUENCY SUB PERCEPTION SPINAL CORD STIMULATION: TRACK 1: MECHANISMS OF ACTION, MAPPING AND SPINAL CORD STIMULATION

Spinal cord stimulation (SCS) was developed as a treatment for chronic pain based on the gate-control theory, which posits that activation of large diameter afferent fibers leads to inhibition of dorsal horn (DH) pain projection neurons. Conventional SCS uses low stimulation frequencies (<200 Hz) at amplitudes above sensory threshold to activate dorsal column (DC) axons and inhibit pain. SCS above sensory threshold generates paresthesias that some patients find undesirable, and recent subperception modalities of SCS demonstrated equivalent or superior pain relief without evoking paresthesias.

Efeito da estimulação elétrica transcutânea do nervo vago na inflamação, modulação autonômica cardíaca e evolução clínica dos pacientes com COVID-19: estudo de protocolo para um ensaio clínico, controlado, randomizado e cego

ABSTRACT This study aims to evaluate the effect of transcutaneous auricular vagus nerve stimulation (taVNS) on inflammation, cardiac autonomic modulation, and clinical evolution of patients with COVID-19. This is a clinical, sham-controlled, randomized, and blind trial, in which 52 hospitalized individuals diagnosed with COVID-19 will participate. They will be randomized into: experimental group (usual medical treatment associated with active taVNS) and control group (usual medical treatment associated with sham taVNS). The taVNS will be performed by a neuromuscular electric stimulator (Dualpex model 071 of Quark Medical Products), with the stimulation electrode positioned on the left tragus, with alternating current, at a 30Hz frequency with 50% variation. Intensity will be adjusted to the patient’s sensory threshold, with 90-minutes-long stimulation sessions, happening twice per day for seven consecutive days, totaling 14 sessions. Interleukin-6 (IL-6) and interleukin-10 (IL-10), cortisol and C-reactive protein (CRP), blood pressure, heart rate variability (HRV) by low frequency (LF), high frequency (HF) and low and high frequency ratio (LF/HF) parameters will be evaluated before and after the intervention, as well as patients’ clinical evolution-including anxiety and depression levels-whose data will be obtained through medical records and questionnaires. A follow-up will also be performed seven and 14 days after the end of the interventions to verify the clinical evolution, including anxiety and depression levels. Memory and attention levels will be evaluated for six months.

Functional and Psychosocial Outcomes following Innervated Breast Reconstruction: A Systematic Review.

Background:With the incidence of breast cancer, breast cancer survival rates, and prophylactic mastectomies all increasing, efforts to optimize breast reconstruction and improve quality of life are becoming increasingly important. Nerve coaptation has been investigated for its potential to remedy the clinical and psychosocial deficits in newly reconstructed breasts. The purpose of this review is to gauge the efficacy of nerve coaptation during breast reconstruction in creating worthwhile benefits in both objective and subjective dimensions of sensation.Methods:A Prospero registered systematic review was conducted. Databases including PubMed, SCOPUS, and ScienceDirect were screened using search terms “innervation," “breast reconstruction," and “neurotization” and relevant inclusion criteria.Results:Twenty-three studies were found that met parameters for inclusion. We identified studies that assessed DIEP-based reconstruction (7), TRAM-based reconstruction (9), implant-based reconstruction (2), and five studies that looked at a variety of reconstructive modalities. Monofilament testing was the most common modality used to assess sensation, while pain, temperature, and pressure thresholds were assessed more infrequently. Various tools were used to measure psychosocial impacts, including the BREAST-Q. While the methods for evaluation of both aspects of sensation were heterogenous, there was a trend towards improved outcomes with neurotization.Conclusions:The results of this review show promising improvements in clinical and psychosocial outcomes in innervated breasts compared to non-innervated breasts. However, the heterogeneity of studies in the literature indicates that more multi-center studies with standardized methodology including the BREAST-Q, sensory testing and complication analysis are needed to adequately demonstrate the value of neurotization in breast reconstruction.

Association between systemic omega-3 polyunsaturated fatty acid levels, and corneal nerve structure and function

BackgroundOmega-3 polyunsaturated fatty acids (PUFAs), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), have anti-inflammatory and neuroprotective properties. This study sought to determine the relationship between corneal parameters and systemic omega-3 fatty acid levels.MethodsForty-seven participants with no/mild peripheral neuropathy (26 with diabetes and 21 without) underwent comprehensive ocular surface and systemic PUFA assessments. Corneal anatomical parameters were assessed using in vivo confocal microscopy. Corneal sensitivity was measured using non-contact esthesiometry. Relationships between systemic PUFA levels and corneal parameters were evaluated with multiple linear regression, adjusted for age, sex, neuropathy symptom score, and presence of diabetes and dry eye disease. The relationship between corneal nerve fibre length (CNFL) and corneal sensitivity threshold was evaluated.ResultsThe median Omega-3 Index, a measure of erythrocyte EPA and DHA, was 5.21% (interquartile range: 4.44–5.94%) in the study population. Mean ( ± SD) CNFL was 13.53 ± 3.37 mm/mm2. Multiple linear regression showed that Omega-3 Index (β = 0.33; p = 0.02), age (β = −0.46; p = 0.001) and diabetes (β = −0.30; p = 0.03) were independently associated with CNFL (R2 = 0.39, p = 0.002). In a separate model, DHA (β = 0.32; p = 0.027) and age (β = −0.41; p = 0.003) were associated with CNFL (R2 = 0.37, p = 0.003). Neither systemic EPA nor omega-6 fatty acid levels correlated with CNFL. There was no association between PUFA levels and corneal sensitivity or corneal immune cell density. A negative correlation was found between CNFL and corneal sensation thresholds to a cooled stimulus in diabetes participants, in the central (ρ = −0.50; p = 0.009) and peripheral (ρ = −0.50; p = 0.01) cornea.ConclusionsA positive relationship between the systemic Omega-3 Index and corneal nerve parameters suggests omega-3 PUFA intake may influence corneal nerve architecture.

Antioxidant Effect of Ocimum basilicum Essential Oil and Its Effect on Cooking Qualities of Supplemented Chicken Nuggets.

A commonly observed chicken meat issue is its lipid oxidation that leads to deterioration of its organoleptic and nutritional properties and its further-processed products. Basil (Ocimum basilicum L.) is one of the traditional culinary herbs exhibiting food preservation properties. The current study investigated the essential oil composition, antioxidant activity and in vitro cytotoxic capacity of the essential oil of basil indigenous to Pakistan. GC–MS analysis of the essential oil revealed the presence of 59 compounds that constituted 98.6% of the essential oil. O. basilicum essential oil (OB-EO) exhibited excellent antioxidant activity, i.e., IC50 5.92 ± 0.15 µg/mL as assayed by the DPPH assay, 23.4 ± 0.02 µmoL Fe/g by FRAP, and 14.6 ± 0.59% inhibition by H2O2. The brine shrimp lethality assay identified an average mortality of ~18% with OB-EO at 10–1000 µg/mL, while that of the same concentration range of the standard drug (etoposide) was 72%. OB-EO was found to be non-toxic to HeLa and PC-3 cell lines. TBARS contents were significantly decreased with increase of OB-EO in chicken nuggets. The lowest TBARS contents were recorded in nuggets supplemented with 0.3% OB-EO, whereas the highest overall acceptability score was marked to the treatments carrying 0.2% OB-EO. The results suggest OB-EO as a promising carrier of bioactive compounds with a broad range of food preservation properties, and which has a sensory acceptability threshold level for chicken nuggets falling between 0.2-0.3% supplementation. Future research must investigate the antibacterial impact of OB-EO on meat products preserved with natural rather than synthetic preservatives.

The effects of low intensity focused ultrasound on neuronal activity in pain processing regions in a rodent model of common peroneal nerve injury

BackgroundNon-invasive, external low intensity focused ultrasound (liFUS) offers promise for treating neuropathic pain when applied to the dorsal root ganglion (DRG). ObjectiveWe examine how external liFUS treatment applied to the L5 DRG affects neuronal changes in single-unit activity from the primary somatosensory cortex (SI) and anterior cingulate cortex (ACC) in a common peroneal nerve injury (CPNI) rodent model. MethodsMale Sprague Dawley rats were divided into two cohorts: CPNI liFUS and CPNI sham liFUS. Baseline single-unit activity (SUA) recordings were taken 20 min prior to treatment and for 4 h post treatment in 20 min intervals, then analyzed for frequency and compared to baseline. Recordings from the SI and ACC were separated into pyramidal and interneurons based on waveform and principal component analysis. ResultsFollowing CPNI surgery, all rats (n = 30) displayed a significant increase in mechanical sensitivity. In CPNI liFUS rats, there was a significant increase in pyramidal neuron spike frequency in the SI region compared to the CPNI sham liFUS animals beginning at 120 min following liFUS treatment (p < 0.05). In the ACC, liFUS significantly attenuated interneuron firing beginning at 80 min after liFUS treatment (p < 0.05). ConclusionWe demonstrate that liFUS changed neuronal spiking in the SI and ACC regions 80 and 120 min after treatment, respectively, which may in part correlate with improved sensory thresholds. This may represent a mechanism of action how liFUS attenuates neuropathic pain. Understanding the impact of liFUS on pain circuits will help advance the use of liFUS as a non-invasive neuromodulation option.

Trigeminal‐mediated headshaking: A diagnostic challenge

Trigeminal‐mediated headshaking: A diagnostic challenge

Novel electrode design reduces sensory threshold current drift during peripheral nerve evaluation in patients considered for sacral nerve stimulation

Objective: To retrospectively compare the efficacy and technical performance of a novel lead used for percutaneous nerve evaluation (PNE) during the testing phase for sacral nerve neuromodulation with the existing lead currently used. Materials and methods: Sixty-three PNE leads were inserted in 45 consecutive patients who underwent PNE with the novel helical electrodes, and the intra-operative and return clinic sensory threshold currents were recorded. This resulted in current measurements for 63 individual electrodes. Measurements were compared with 46 consecutive patients who previously underwent PNE using the standard lead with measurements for 63 individual electrodes. Current difference distributions for the two leads were compared using a Wilcoxon signed-rank test. Results: There was a statistically significant difference observed between the two types of PNE electrode. The new PNE lead demonstrated less drift in sensory threshold current during a 12-day test period in comparison to the old lead. Conclusion: The novel helical PNE electrodes demonstrate a significant improvement in current drift compared with the old style leads over a 12-day test period. Level of evidence: Level III

Continuum of sensory profiles in diabetes mellitus patients with and without neuropathy and pain.

Quantitative sensory testing (QST) assesses the functional integrity of small and large nerve fibre afferents and central somatosensory pathways; QST was assumed to provide insight into the mechanisms of neuropathy. We analysed QST profiles and phenotypes in patients with diabetes mellitus to study whether these could differentiate patients with and without pain and neuropathy. A standardized QST protocol was performed and 'loss and gain of function' abnormalities were analysed in four groups of subjects: diabetic patients with painful (pDSPN; n=220) and non-painful distal symmetric polyneuropathy (nDSPN; n=219), diabetic patients without neuropathy (DM; n=23) and healthy non-diabetic subjects (n=37). Based on the QST findings, diabetic subjects were further stratified into four predefined prototypic phenotypes: sensory loss (SL), thermal hyperalgesia (TH), mechanical hyperalgesia (MH) and healthy individuals. Patients in the pDSPN group showed the greatest hyposensitivity ('loss of function'), and DM patients showed the lowest, with statistically significant increases in thermal, thermal pain, mechanical and mechanical pain sensory thresholds. Accordingly, the frequency of the SL phenotype was significantly higher in the pDSPN subgroup (41.8%), than expected (p &lt; 0.0042). The proportion of 'gain of function' abnormalities was low in both pDSPN and nDSPN patients without significant differences. There is a continuum in the sensory profiles of diabetic patients, with a more pronounced sensory loss in pDSPN group probably reflecting somatosensory nerve fibre degeneration. An analysis of 'gain of function' abnormalities (allodynia, hyperalgesia) did not offer a key to understanding the pathophysiology of spontaneous diabetic peripheral neuropathic pain. This article, using quantitative sensory testing profiles in large cohorts of diabetic patients with and without polyneuropathy and pain, presents a continuum in the sensory profiles of diabetic patients, with more pronounced 'loss of function' abnormalities in painful polyneuropathy patients. Painful diabetic polyneuropathy probably represents a 'more progressed' type of neuropathy with more pronounced somatosensory nerve fibre degeneration. The proportion of 'gain of function' sensory abnormalities was low, and these offer limited understanding of pathophysiological mechanisms of spontaneous neuropathic pain.

Comparison of the Response to Pulpal Sensibility Tests in Well-Controlled and Uncontrolled Type II Diabetes Mellitus Patients: A Cross-Sectional Study.

Introduction Diabetes mellitus is a metabolic disorder in which impairment of sensory fibers would be anticipated. The present study would assess the dental pulp response to cold and EPT sensibility tests in patients with type 2 diabetes, both well-controlled and uncontrolled. Materials and Methods One hundred two maxillary central incisors, belonging to participants aged 35–67 years, were included in this survey. At last, 51 diabetic patients were allocated to each group of well-controlled (HbA1C < 7) and uncontrolled (HbA1C ≥ 7). Electric and cold pulpal vitality tests were conducted for all teeth. Statistical analysis was performed with Student's t-test, the chi-square test, and the multiple linear regression model. A P value less than 0.05 was considered significant. Results Based on the results of this study, the mean value of response to EPT was 4.51 ± 2.06 and 4.41 ± 1.85 in well-controlled and uncontrolled diabetic patients, respectively. Also, the pulpal responses to cold and EPT tests had no significant differences between the two groups (P > 0.05). Conclusion Tooth responses to the cold and EPT sensibility tests were not different in well-controlled and uncontrolled diabetic patients. Despite no statistically significant correlation, male diabetic patients in the uncontrolled group showed a lower sensory response threshold to EPT compared to a well-controlled group.

Age-related decrease in motor contribution to multisensory reaction times in primary school children.

Traditional measurement of multisensory facilitation in tasks such as speeded motor reaction tasks (MRT) consistently show age-related improvement during early childhood. However, the extent to which motor function increases with age and hence contribute to multisensory motor reaction times in young children has seldom been examined. Thus, we aimed to investigate the contribution of motor development to measures of multisensory (auditory, visual, and audiovisual) and visuomotor processing tasks in three young school age groups of children (n = 69) aged (5−6, n = 21; 7−8, n = 25.; 9−10 n = 18 years). We also aimed to determine whether age-related sensory threshold times for purely visual inspection time (IT) tasks improved significantly with age. Bayesian results showed decisive evidence for age-group differences in multisensory MRT and visuo-motor processing tasks, though the evidence showed that threshold time for visual identification IT performance was only slower in the youngest age group children (5−6) compared to older groups. Bayesian correlations between performance on the multisensory MRT and visuo-motor processing tasks indicated moderate to decisive evidence in favor of the alternative hypothesis (BF10 = 4.71 to 91.346), though not with the threshold IT (BF10 < 1.35). This suggests that visual sensory system development in children older than 6 years makes a less significant contribution to the measure of multisensory facilitation, compared to motor development. In addition to this main finding, multisensory facilitation of MRT within race-model predictions was only found in the oldest group of children (9−10), supporting previous suggestions that multisensory integration is likely to continue into late childhood/early adolescence at least.

Surround Inhibition Mediates Pain Relief by Low Amplitude Spinal Cord Stimulation: Modeling and Measurement.

Low-frequency (<200 Hz), subperception spinal cord stimulation (SCS) is a novel modality demonstrating therapeutic efficacy for treating chronic neuropathic pain. When stimulation parameters were carefully titrated, patients experienced rapid onset (seconds–minutes) pain relief without paresthesia, but the mechanisms of action are unknown. Using an integrated computational model and in vivo measurements in urethane-anesthetized rats, we quantified how stimulation parameters (placement, pulse width, frequency, and amplitude) influenced dorsal column (DC) axon activation and neural responses in the dorsal horn (DH). Both modeled and recorded DC axons responded with irregular spiking patterns in response to low-amplitude SCS. Maximum inhibition of DH neurons occurred at ∼80% of the predicted sensory threshold in both modeled and recorded neurons, and responses were strongly dependent on spatially targeting of stimulation, i.e., the complement of DC axons activated, and on stimulation parameters. Intrathecal administration of bicuculline shifted neural responses to low-amplitude stimulation in both the model and experiment, suggesting that analgesia is dependent on segmental GABAergic mechanisms. Our results support the hypothesis that low-frequency subperception SCS generates rapid analgesia by activating a small number of DC axons which inhibit DH neuron activity via surround inhibition.

427.9: Total Bilateral Arm Transplantation: Functional Recovery and Psychosocial Outcomes at One Year

Introduction: Although arm loss causes severe disability and compromission of body image, functional recovery after allotransplantation still presents many challenges. Objective: A bilateral arm transplantation including reconstruction of the left shoulder was performed on January 13, 2021 in Lyon (France). Functional recovery and psychosocial outcomes are reported one year after the transplantation. Materials and Methods: The recipient was a 48-year old patient with bilateral amputation at proximal arm level after electric shock in January 1998, who underwent liver transplantation in 2002. The patient used mechanic prostheses with poor satisfaction. The surgical procedure consisted in a total arm transplantation on the left side with reconstruction of the gleno-humeral joint. The maintenance immunosuppressive therapy included tacrolimus, mycophenolate mofetil and prednisone. Rehabilitation therapy started on day one. It progressively included manual lymphatic drainage, passive motion of all joints in a total range except limitations for the shoulders during the first 6 weeks. Then, electrostimulation on denervated muscles was performed. After 6 weeks the protocol included hand therapy, psychomotricity, physical activities, occupational therapy and sensory-motor simulation training approaches (motor imagery, virtual mirror therapy, virtual reality). Results: Motor recovery was already appreciated 8 months after the transplantation. At one year, passive ranges of motion of upper limbs are subnormal. According to MRC scale, muscular strength at shoulder level is from 3 to 4/5 on the right side and from 1 to 2/5 on the left side; from 3 to 4/5 for elbow flexors and from 1 to 2 for elbow extensors on both sides; 3/5 for wrist flexors on the right side and 0/5 on the left side; 1 to 2/5 for wrist extensors on both sides; 3/5 for pronators and supinators on the right side and 1/5 on the left side. Slight contraction and movements of the extrinsic flexors and extensor muscles of the fingers have been evidenced on both sides, and the first prehension movements started on the right hand. The Semmes-Weinstein monofilament test for sensory threshold was 6.65 in the right palm and below the left elbow; deep pressure sensation is recovered in both hands. Functional Independence Measure is 96/126 and the DASH score 75.8. The patient is able to perform the same daily activities as with the prostheses before the transplantation.The patient was psychologically tested during the follow-up using a specific questionnaire for upper extremity allotransplantation and MADRS, Hamilton and Rosenberg tests. The results (Table 1) show the difficulties, the patient’s strong motivation and capacity to cope, and his satisfaction reached at the first year of follow-up. Conclusions: The patient is very satisfied of his grafts and of his restored body image, which was his main expectation.