Sensory Thresholds Research Articles

Exploring the links between sensory sensitivity, autistic traits and autism-related eating behaviours in a sample of adult women with eating disorders

This study examined the presence of autistic traits in a sample of adult women diagnosed with different Eating Disorders (ED), and explored the concurrent role of autistic traits and sensory sensitivity in influencing both their eating disorder symptomatology and their autism-related eating behaviours. Seventy-five women with different ED (Anorexia Nervosa, Bulimia Nervosa, Binge-Eating Disorder, Other Specified Feeding or Eating Disorder) completed the Eating Attitude Test (EAT-26), the Autism Quotient (AQ), the Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R), the Sensory Perception Quotient - Short Form 35 item (SPQ-SF35) and the Swedish Eating Assessment for Autism Spectrum Disorders (SWEAA). Twelve percent of participants scored above the cut-off on both the AQ and the RAADS-R, while 68% scored above the cut-off on the RAADS-R only. A mediation analysis revealed that the association between sensory sensitivity (SPQ-SFR35) and scores on both the EAT-26 and the SWEAA was significantly mediated by the presence of autistic traits (RAADS-R). These findings, first, confirm the presence of autistic traits in individuals with ED; second, they show that a lower sensory threshold (i.e., a higher sensory sensitivity) is associated with a higher presence of autistic traits which were, in turn, positively associated with dysfunctional eating behaviours typical of ED and ASD. This study ultimately highlights the importance of further research on autistic traits across all diagnostic categories of ED.

Ankle torque variance is a better indicator of balance control performance than plantar perceptual sensitivity threshold.

We explored whether ankle torque variability or plantar perceptual threshold explains human balance control more effectively. We hypothesized that ankle torque variance is a better indicator of center of pressure (COP) velocity variance than plantar perceptual sensitivity. Two conditions were tested: loaded (23-kg vest added) and unloaded, as loading should diminish plantar sensitivity and increase COP velocity variability. We created a linear feedback model to assess the noise change in the sensorimotor loop induced by loading. Plantar sensitivity was quantified using a psychophysical approach while participants stood barefoot. A linear motor applied a force impulse on the participant's heel. A "yes-no" method of limits was selected to identify plantar sole sensory thresholds in both conditions. We observed reduced plantar sensitivity in loaded compared with unloaded conditions. In the loaded condition, participants exhibited greater COP velocity variance, with significant positive Pearson's correlations confirming a substantial association between ankle torque and COP velocity variances for both loaded [variance accounted for (VAF): r2 = 44.56%, P = 0.018] and unloaded conditions (VAF: r2 = 58.83%, P = 0.004). No significant correlation existed between COP velocity variance and plantar sensitivity threshold for both loaded (VAF: r2 = 0.002%, P = 0.99) and unloaded conditions (VAF: r2 = 21.81%, P = 0.35). The model confirmed an ∼88% rise in sensorimotor loop noise in the loaded condition. Ankle torque variance assesses the precision of nonperceptual and perceptual detection mechanisms in evaluating whole body motions and the accuracy in converting sensory cues into ankle torque.NEW & NOTEWORTHY Plantar cutaneous information contributes to balance control by modulating motor commands, but plantar perceptual sensitivity is a suboptimal indicator of balance performance. Multiple sensory cues encode whole body dynamics, guiding sensorimotor mechanisms to minimize body sway variability. Ankle torque variance is proposed as a superior measure for explaining balance control performance and evaluating the sensorimotor loop's functioning in balance control.

Small Fiber Neuropathy in Burning Mouth Syndrome: A Systematic Review

Burning mouth syndrome (BMS) is a chronic idiopathic orofacial pain disorder, characterized by persistent burning sensations and pain without clear pathological causes. Recent research suggests that small fiber neuropathy (SFN) may play a significant role in the neuropathic pain and sensory disturbances associated with BMS. Following PRISMA guidelines, this systematic review aims to evaluate and synthesize current evidence supporting SFN’s involvement in BMS. The protocol is registered in PROSPERO (CRD42024555839). The results show eight studies reported reductions in nerve fiber density in tongue biopsies (ranging from 30% to 60%), along with morphological changes indicative of small fiber damage. Additionally, an increase in TRPV1-positive, NGF-positive, and P2X3-positive fibers, overexpression of Nav1.7, and slight underexpression of Nav1.9 mRNA were observed in BMS patients. Quantitative Sensory Testing in seven studies revealed sensory abnormalities such as reduced cool detection and cold pain thresholds. Blink reflex and corneal confocal microscopy also indicated peripheral and central small fiber damage, along with increased artemin mRNA expression. The evidence strongly supports SFN as a key factor in the pathophysiology of BMS, particularly due to reductions in nerve fiber density and altered sensory thresholds. However, variability across studies highlights the need for larger, standardized research to establish causal relationships and guide therapeutic strategies.

Comparative analysis of the characteristics of high-resolution anorectal manometry in children with outlet obstructive constipation of different age groups

Objective: To compare the characteristics of high-resolution anorectal manometry (HR-ARM) in children with outlet obstructive constipation (OOC) in different age groups. Methods: Retrospective inclusion of clinical data of functional constipation (FC) patients who underwent HR-ARM examination in the Department of Gastroenterology of Children's Hospital Affiliated of Zhengzhou University from January 2019 to September 2023 was conducted. The patients were divided into low age group (4 years old≤age<6 years) and high age group (6 years old≤age≤15 years old) according to age. They were divided into OOC group (the pediatric patients with uncoordinated pelvic floor muscle contractions, insufficient rectal thrust during defecation, or insufficient relaxation of anal sphincter muscles during contraction) and non-OOC group based on HR-ARM results. The rectal motility [rectal resting pressure, maximum squeeze pressure (MSP), rectal pressure during force delivery, residual anal pressure, rectal anal pressure gradient], rectal sensory function (initial rectal sensory capacity threshold, initial fecal sensory capacity threshold, defecation distress capacity threshold, and maximum tolerance capacity threshold) and other indicators were compared between OOC group and non-OOC group in 2 age groups, respectively. Results: A total of 228 children with FC were included, including 146 males and 82 females, with an age [M (Q1, Q3)] of 7.5 (6.0, 9.7) years, including 54 in the low age group and 174 in the high age group. There were 131 cases in the OOC group and 97 cases in the non-OOC group. Compared with non OOC children (24 cases), there were no statistically significant differences in rectal resting pressure, anal sphincter resting pressure, MSP, rectal pressure during force delivery, initial rectal sensory capacity threshold, initial fecal sensory capacity threshold, defecation distress capacity threshold, and maximum tolerance capacity threshold among OOC children (30 cases) in the low age group (all P>0.05). In the high age group, the residual anal pressure of the OOC children (101 cases) was higher than that of the non-OOC children (73 cases) [102 (70, 113) vs 41 (24, 58) mmHg (1 mmHg=0.133 kPa), P<0.001], and the rectal anal pressure gradient was lower than that of the non-OOC children [-43 (-55, -23) vs 16 (9, 29) mmHg, P<0.001];The initial fecal sensory capacity threshold of the OOC children was higher than that of the non-OOC children [90 (54, 110) vs 60 (50, 91) ml, P=0.024]. Conclusions: Compared with non-OOC children in the same age group, OOC children aged 6 years and above have higher residual anal pressure and initial fecal sensory capacity threshold, and lower rectal anal pressure gradient. There is no statistically significant differences in the rectal sensory function in children under 6 years old with OOC.

A Prospective Feasibility Study to Differentiate Sacral Neuromodulation Lead Electrode Configurations Using Motor and Sensory Thresholds and Locations of Sensation.

Background Accurate positioning and effective programming of sacral neuromodulation (SNM) relies upon the use of several acute stimulation measurements. While the clinical utility of these acute measurements including pelvic floor motor thresholds (PFMT), toe/leg motor thresholds (TMT), and sensory thresholds (ST), are widely accepted, their usefulness in quantitative research remains unclear. The purpose of this prospective study was to test these measurements and gauge their utility in future research. Methods Eight participants received Axonics SNM, 6 Medtronic Interstim II, and 2 Medtronic Micro SNM. PFMT was measured after implantation. ST and the location of sensation (LOS) were measured immediately postoperatively (PO), at pre-release from the surgery center (PR), and during a follow-up clinic visit (FU). Thresholds were compared across contact and time using linear mixed-effects models. Results Significant differences in PFMT were found across electrode configurations, with stimulation through proximal contacts exhibiting lower PFMT than distal configurations. ST displayed no significant differences across electrodes and showed minimal changes over time. LOS exhibited substantial variability across patients and periods. Conclusions Results suggest that PFMT were able to differentiate differences across electrode configurations that may be useful for future quantitative research. The lack of differences in ST and LOS across electrode configurations was interesting given the focus on these measurements clinically. Future testing is to confirm these limitations.

The role of environmental sensitivity, traumatic experiences, defense mechanisms and mental pain on central sensitivity: testing a path analysis model in chronic headache on quality of life.

Central pain sensitivity (CS) is defined as an increased responsiveness of nociceptive neurons in the central nervous system to normal or subthreshold inputs. The main aim of this paper is to investigate if and how specific psychological constructs are related with CS burden in patients with chronic headache (CH). Specifically, research question 1 explores the association of temperament, personality, childhood adversities, defense mechanisms and mental pain with CS burden. Research question 2 aims to test the role of the best predictors of CS burden in affecting the quality of life (QoL) using path analysis. A total of 508 women with CH completed a psycho-diagnostic survey. Results showed that higher levels of low sensory threshold (β = 0.200), bodily threat traumatic experiences (β = 0.156), neurotic defenses (β = 0.109) and mental pain (β = 0.343) emerged as the best predictors of higher CS burden. The model presented demonstrated a satisfactory fit (GFI = 0.984; NFI = 0.966; CFI = 0.979; RMSEA = 0.056 [95% CI 0.028-0.085]) with large and medium effect sizes on physical (-0.654) and psychological QoL (-0.246). The study showed a key role of psychological dimensions in CS burden levels and their relationships with QoL in CH patients. From a clinical perspective, these results suggest the importance of evaluating the level of CS burden during the clinical assessment for chronic pain conditions such as CH, since it may contribute to guide patients to tailored psychological and medical treatments, thereby saving time and costs on diagnostic procedures for chronic pain.

The effects of subsensory electrical noise stimulation on the reactive control of balance during support surface perturbations

BackgroundThe ability to respond effectively to balance perturbations is crucial for fall prevention. Subsensory electrical stimulation (SES) applied to the skin leads to improved proactive balance control but there is limited evidence on the SES effect on reactive balance control. Research QuestionsTo test the efficiency of SES in improving reactive balance control against unpredictable support surface perturbations and to compare the effects of SES applied to the trunk and the lower legs. MethodsTwenty-three young adults stood on a treadmill while recovering from 15 forward and 15 backward surface translations of increasing magnitude to determine the backward and forward stepping thresholds (BSTh and FSTh). Then, they recovered from three repetitions of forward and backward perturbations of fixed magnitude to determine the characteristic of the compensatory step (i.e., step time, step length, step delay and Margin of Stability - MOS). Each test was conducted with no stimulation (NS), leg stimulation (LS), or trunk stimulation (TS) equal to 90% of the sensory threshold. Repeated-measures ANOVA and Tukey post-hoc tests were used to analyze the main and interaction effects of stimulation and repetition. ResultsTS and LS increased the BSTh by 31.5% (p=0.002) and 16.4% (p=0.028), respectively, with greater effects of TS; (ii) during backward perturbations, TS reduced compensatory step time by 9.0%, step length by 17.1%, and MOS at compensatory heel strike by 17.7% (p<0.016); and (iii) during forward perturbations, LS and TS reduced the step time by 4.5% and 3.5% (p<0.017), and increased the minimum MOS by 7.8% and 4.5%, respectively (p<0.048). SignificanceThis is the first study that showed how the application of SES affects reactive balance control during support surface perturbations. TS was more effective than LS during backward perturbations. TS may be an effective strategy to enhance balance control during reactive postural tasks, thus potentially reducing fall risk.

Cadherin 16 promotes sensory gating via the endocrine corpuscles of Stannius.

Sensory thresholds enable animals to regulate their behavioral responses to environmental threats. Despite the importance of sensory thresholds for animal behavior and human health, we do not yet have a full appreciation of the underlying molecular-genetic and circuit mechanisms. The larval zebrafish acoustic startle response provides a powerful system to identify molecular mechanisms underlying establishment of sensory thresholds and plasticity of thresholds through mechanisms like habituation. Using this system, we identify Cadherin 16 as a previously undescribed regulator of sensory gating. We demonstrate that Cadherin 16 regulates sensory thresholds via an endocrine organ, the corpuscle of Stannius (CS), which is essential in zebrafish for regulating Ca 2+ homeostasis. We further show that Cadherin 16 regulates whole-body calcium and ultimately behavior through the hormone Stanniocalcin 1L, and the IGF-regulatory metalloprotease, Papp-aa. Finally, we demonstrate the importance of the CS through ablation experiments that reveal its role in promoting normal acoustic sensory gating. Together, our results uncover a previously undescribed brain non-autonomous pathway for the regulation of behavior and establish Ca 2+ homeostasis as a critical process underlying sensory gating in vivo .

Sensory thresholds and the sense of bodily identity in schizophrenia

Aim of the studyThe aim of the study was to investigate: 1) whether schizophrenia is associated with disturbances in bodily identity (BI) and in sensation thresholds (STs) assessed by a questionnaire and experimental methods (pain and proprioception thresholds); 2) whether disturbances in STs are related to BI in the schizophrenia group.Subject or material and methodsFifty-four outpatients with schizophrenia in remission and 54 controls completed: Bodily Identity Scale, Heightened Thresholds Scale, and Lowered Thresholds Scale. Their pain and proprioception thresholds were estimated using the TempTest Apparatus and the Discrimination Weights Test, respectively.ResultsCompared to the control group, patients with schizophrenia: reported more disturbances in BI and in the STs examined by questionnaire, displayed increased proprioception, but a lower pain threshold. In the schizophrenia group disturbances in BI were only associated with distortions in STs examined by questionnaires.DiscussionDisturbances in stimulus processing in the experimental setting did not explain disruptions in BI in schizophrenia, which may be due to the study's methodology and the weak (pain threshold) or moderate (proprioception threshold) manifestation of STs disturbances in the experimental setting in the clinical group.ConclusionsIn schizophrenia remission no coherent pattern of sensitivity to experimental stimuli is observed. The increased sensitivity to experimental pain in patients in remission is consistent with the results of previous studies, and undermines the popular thesis of pain indifference in schizophrenia. Patients with schizophrenia struggle throughout their lives with disturbances of bodily identity and states of both over- and under-sensitivity to environmental stimuli.

Intergenerational Pathways Linking Mothers’ Childhood Traumatic Experiences and Preschoolers’ Prosocial Behaviors

ABSTRACT Research Findings: The present study investigated the potential mediating role of maternal parenting in the intergenerational effects of maternal childhood traumatic experiences (CTEs) on prosocial behaviors of their offspring and examined whether the offspring’s sensory processing sensitivity (SPS) moderates this association using a 1-year longitudinal design. A total of 203 preschoolers (M age = 4.84, SD = 0.64, 96 girls, at T1) and their mothers participated in this study. Mothers completed questionnaires assessing their own CTEs and parenting toward their offspring, and offspring’s SPS and prosocial behaviors. Results indicated that maternal neglect experiences could intergenerationally directly influence their offspring’s prosocial behaviors in early childhood (β = −0.20, p = .012), as well as having an indirect influence through the mediating role of maternal authoritative parenting (indirect effect = −0.09, p = .009). Moreover, aesthetic sensitivity (AES) and low sensory threshold (LST), two subdimensions of SPS, moderated the predictive influence of authoritative parenting on preschoolers’ prosocial behaviors (AES: β = 0.17, p = .005; LST: β = 0.17, p = .006). Practice or Policy: The findings provide new evidence for understanding the intergenerational influence of different maternal CTEs on prosocial behaviors among children with different SPS and have implications for alleviating the intergenerational negative effects on children’s prosocial behaviors.

The Anaesthetic Efficacy of Tetracaine and Oxymetazoline Compared With Co-Phenylcaine in Healthy Individuals.

Nasal anaesthetic-decongestant sprays are commonly used prior to nasal instrumentation, such as flexible and rigid nasal endoscopy. Co-phenylcaine (lignocaine 5%, phenylephrine 0.5%, ENT Technologies Pty Ltd., Melbourne, VIC, Australia) is a combination spray commonly used for this purpose. However, lignocaine is less potent than other local anaesthetics, and both active constituents of Co-phenylcaine have a bitter taste. It was hypothesised that a combination spray containing tetracaine and oxymetazoline would both offer more potent topical anaesthesia and have a better taste. Four anaesthetic-decongestant nasal sprays were tested in 10 healthy participants (Co-phenylcaine, and tetracaine 0.5%, 1% and 2% with oxymetazoline 0.05%). Sensory thresholds were sequentially measured at the head of the inferior turbinate using Semmes-Weinstein monofilaments over the following hour. Participants also rated taste on a Likert-style scale, and reported whether they experienced subjective numbness of the maxillary teeth. A median peak sensory threshold of 60 g (the maximum tested) was observed with Co-phenylcaine, but this threshold was exceeded by all the tetracaine-based sprays. Tetracaine 2% with oxymetazoline 0.05% had a significantly more rapid onset than Co-phenylcaine (4 min vs. 6 min, p < 0.05) and a longer duration of action. Eight participants reported dental numbness after administration of tetracaine 2% with oxymetazoline 0.05%, but only one participant after Co-phenylcaine. Tetracaine-based sprays were generally perceived to taste less unpleasant than Co-phenylcaine. Tetracaine 2% with oxymetazoline 0.05% is a more potent and rapidly acting anaesthetic-decongestant spray than Co-phenylcaine, with a longer duration of action.

Presence of neuropathy in children and adolescents with type 1 diabetes evaluated with bedside modalities

AimsTo investigate the prevalence of diabetic polyneuropathy (DPN), cardiac autonomic neuropathy (CAN) and sudomotor dysfunction in children and adolescents with type 1 diabetes using bedside modalities. Secondly, to evaluate the co-existence of these types of diabetes neuropathies. MethodsCross-sectional study including 221 children and adolescents with type 1 diabetes. DPN was assessed by vibration sensation threshold and sural nerve conductance, CAN by cardiac reflex tests and sudomotor function by electrochemical skin conductance. ResultsMedian (interquartile range) age was 14.2 (11.9, 16.5) years, diabetes duration 4.8 (2.7, 7.7) years and Hba1c 7.1 (6.6, 7.9) %, (54: 49, 63 mmol/mol). Three had retinopathy; all had normal albuminuria. DPN was present in 40 %, early CAN in 17 %, established CAN in 3 % and sudomotor dysfunction in the feet in 5 %. Of these, 60 % had one type of neuropathy, while 35 % had two types. Only 1 participant manifested all three types of neuropathies. ConclusionsBedside modalities demonstrated a high prevalence of neuropathy in children and adolescents with type 1 diabetes, despite good glycemic outcome, short diabetes duration and absence of complications. A lack of co-existing neuropathies was shown, underscoring the need for multiple screening modalities.

Integrated volatolomics and lipidomics analysis reveal the characteristic flavor formation mechanism in steamed large yellow croaker (Pseudosciaena crocea)

The internal relationship between lipid composition and characteristic flavor in the steamed large yellow croaker (LYC) was investigated using volatolomics, lipidomics, and electronic sensory systems. Compared to fresh LYC, the concentrations of five key volatile flavor compounds detected after steaming exceeded human sensory thresholds. Notably, nonanal, hexanal, and 1-octen-3-ol significantly influenced the flavor of the cooked meat. Steaming at 70 °C enhanced the LYC flavor profile, with the strongest flavor observed at 80 °C. The content of three key volatile flavor compounds peaked, especially hexanal, which reached 54.55 μg/kg. Phosphatidylcholines, triacylglycerols, and fatty acids were closely associated with the volatile flavor profile of steamed LYC. The oxidation of FA 22:6 was identified as a crucial source of flavor in LYC. This study aimed to improve consumer experience by exploring the nutritional quality and flavor formation mechanisms in the thermal processing of LYC.

The value of electrophysiological testing in the adjunctive diagnosis of premature ejaculation.

Although the four-class system of classifying premature ejaculation (PE), including lifelong PE (LPE), acquired PE (APE), natural variable PE (NPE), and subjective PE (SPE), has existed for many years, objective classification standards in clinical practice are lacking. In this study, we sought to investigate the use of electrophysiologic parameters to assist in the classification of PE, thereby guiding subsequent treatment. From July 2023 to April 2024, 187 study participants were enrolled. For each participant, the biological sensory threshold (BST), penile sympathetic skin response (PSSR), and dorsal nerve somatosensory evoked potential (DNSEP) were recorded. The differences in the PSSR latencies (PL) and DNSEP latencies (DL), the PSSR amplitudes (PA) and DNSEP amplitudes (DA), and the BST were compared among the LPE, APE, SPE, NPE, and healthy control (HC) groups. The participants were divided into the LPE (46 cases), APE (53 cases), SPE (20 cases), NPE (33 cases), and HC (35 cases) groups. The results showed shorter latencies of the PSSR (PL) and DNSEP (DL), larger amplitudes of the PSSR (PA) and DNSEP (DL), and smaller BST in the LPE group than in the NPE, SPE, APE, and HC groups (P < .05). In addition, the larger PA and shorter PL in the APE group than in the NPE and HC groups (P < .05). However, the electrophysiological parameters were not significantly different among the NPE, SPE, and HC groups (P > .05). In addition, PL <1262.0milliseconds and DL <41.85 milliseconds were strong predictors of LPE, 1262.0milliseconds < PL <1430.0milliseconds was a predictor of APE, and PL >1430.0milliseconds suggested possible SPE or NPE. Analysis of the electrophysiological parameters of PE may be helpful for classification and treatment. No previous study, to our knowledge, has analyzed the electrophysiological parameters of the four types of PE. The main limitation is the small sample size. APE is characterized by increased sympathetic excitability, whereas LPE is characterized by increased penile sensitivity and increased sympathetic excitability. However, penile sensitivity and sympathetic excitability in SPE and NPE patients may not differ significantly from normal.

Somatosensory Mapping Using a Novel Sensory Discrimination Task: Technical Note.

Although diffuse gliomas in the primary somatosensory cortex (S1) are often considered resectable, gliomas in the primary motor cortex require motor mapping to preserve motor function. Recent evidence indicates that some somatosensory cortex neurons may trigger motor responses, necessitating refined somatosensory mapping techniques. Using piezoelectric tactile stimulators on patients' faces and hands, we delivered 25 Hz vibrations and prompted patients to discriminate between dermatomes. Testing included areas contralateral to tumor-infiltrated and to non-tumor-infiltrated cortical regions. Sensory thresholds were determined by reducing stimulus intensity based on performance. Intraoperatively, electrocorticography electrode arrays were used to map sensory responses, and postoperative assessments evaluated sensory outcomes. The high-grade glioma case involved a 61-year-old man with right-sided weakness and numbness with a left parietal mass on MRI. Preoperative testing showed that the average vibratory detection threshold of the hand contralateral to the suspected tumor site was significantly higher than that of the hand contralateral to healthy cortex (P < .001). Intraoperative mapping confirmed the absence of functional involvement in cortical structures overlying the tumor. Postoperative imaging confirmed gross total resection, and sensory vibratory thresholds were normalized (P = .51). The low-grade glioma case included a 54-year-old man with a left parietal nonenhancing mass on MRI. No baseline sensory impairments were found on preoperative testing. Intraoperative mapping identified motor and sensory cortices, guiding tumor resection while preserving motor function. Postoperative MRI confirmed near-total resection, but new sensory impairments were noted in the hand and face contralateral to the resection site (P < .001). These deficits resolved by postoperative day 11, with no evidence of tumor progression on follow-up imaging. The sensory discrimination task provides a quantifiable method for assessing sensory changes and functional outcomes related to glioma. This technique enhances our understanding of how glioma infiltration remodels sensory systems and affects clinical outcomes in patients.

Sensory dysfunction in SMA type 2 and 3 - adaptive mechanism or concomitant target of damage?

BackgroundThe motor neuron survival protein performs numerous cellular functions; hence, spinal muscular atrophy (SMA) is considered to be a multi-organ disease with possible sensory system damage. The controversy surrounding the presence of sensory disturbances, prompted us to conduct standard electrophysiological studies and assess the sensory thresholds for different modalities in adults with SMA types 2 and 3. The study group consisted of 44 adult SMA patients (types 2 and 3). All patients underwent neurological examination using the Hammersmith Functional Motor Scale – Expanded (HFMSE). Standard sensory electrophysiological studies in the ulnar nerve and the estimation of vibratory, temperature, and warm- and cold-induced pain thresholds with temperature dispersion assessment were performed using quantitative sensory testing (QST).ResultsThe most repeatable result was the high amplitude of the sensory nerve action potentials (SNAP) in SMA patients compared to controls. This was higher in type 2 patients compared to type 3a and 3b patients and patients with low HFSME scores. Patients with SMA, especially type 3b presented a longer sensory latency and slower conduction velocity than did controls. Cold pain threshold was higher and warm dispersion larger in SMA. The vibratory limit was higher in patients with high HFSME scores.ConclusionsA high SNAP amplitude suggests sensory fibre hyperactivity, which may be based on overactivation of metabolic pathways as an adaptive mechanism in response to SMN protein deficiency with additionally coexisting small C- and A-delta fibre damage. SMA patients seem to have a concomitant, mild demyelinating process present at the early SMA stage.

Corneal hypersensitivity to cold stimuli in symptomatic computer users.

Prolonged computer use may result in repeated stimulation of the ocular surface due to ocular dryness, potentially leading to alterations in its sensitivity. This study aimed to evaluate the relationship between ocular symptoms and corneal sensitivity to cold and mechanical stimuli in computer users. Fifty-two young (31 ± 6 years), frequent computer users, including symptomatic and asymptomatic users, participated in this study. Mechanical and cold sensation thresholds were determined at the central cornea of one randomly selected eye of each participant using the UNSW Liquid Jet Aesthesiometer. Ocular surface symptoms and digital eye strain were assessed using the Ocular Surface Disease Index, Ocular Comfort Index, Instant Ocular Symptom Survey, and Computer Vision Syndrome Questionnaire (CVS-Q). Associations between central corneal sensation thresholds and demographic variables, patterns of digital device use, and symptom scores were analyzed using Pearson (r) or Spearman (ρ) correlations and linear regression models. Age (ρ = 0.24), CVS-Q score (ρ = -0.33), CVS-Q dry eye score (ρ = -0.28), and mechanical sensation threshold (ρ = 0.63) were significantly associated with cold sensation threshold (p≤0.04). Conversely, there were no significant relationships with Ocular Surface Disease Index, Ocular Comfort Index, or Instant Ocular Symptom Survey or with other demographic variables (p≥0.34). In multiple linear regression models, age and mechanical sensation threshold were significant predictors of cold sensitivity (p=0.04 and p<0.001, respectively) (adjusted R2 = 0.459). There were no significant correlations between mechanical sensitivity and symptom scores (p≥0.09). Symptoms of digital eye strain, particularly those related to dry eye, were associated with higher corneal cold sensitivity. Corneal hypersensitivity to cold stimuli as a marker of ocular discomfort during computer use requires further investigation.

CD34 distribution in C-fiber low threshold mechanoreceptors in the mouse dorsal root ganglion and spinal cord

CD34 is a well-known cell marker of hematopoietic stem/ progenitor cells, endothelial cells, and fibrocytes. In the peripheral nervous system, a certain type of primary sensory neuron C-fiber low threshold mechanoreceptors (C-LTMRs) are reported to express CD34 mRNA. Here, we investigated the distribution of CD34 protein among putative C-LTMRs (pC-LTMR) using pC-LTMR markers such as VGLUT3 and TH in the dorsal root ganglion (DRG) and spinal cord. CD34 was frequently observed in DRG neurons double-positive for VGLUT3 and TH and single-positive for VGLUT3 in C8 and L4 levels, however, in C4 and L1 levels most of CD34-positive DRG neurons were demonstrated to be double-positive for VGLUT3 and TH. As for the termination, CD34-positive DRG neurons terminated in the ventral part of inner lamina II (lamina IIiv). At C4 and L1 levels of the dorsal horn, CD34 was observed in the entire region of lamina IIiv, however, in C8 and L4 levels of the dorsal horn CD34 was not detected in the medial part of lamina IIiv, which receives neural inputs from DRG neurons that innervate palm or sole skin. These results indicate that CD34 is expressed in pC-LTMRs and suggest that CD34 may play a role in providing C-LTMRs with a specific sensation by maintaining neural circuits

"Effect Of Electroacupuncture On Sensory Peripheral Nerve Function In Diabetic Peripheral Neuropathy: A Randomized Controlled Trial Protocol."

Background: Diabetes, a chronic metabolic disorder, affects millions globally, with Type 2 diabetes being the most prevalent. Diabetic Peripheral Neuropathy (DPN) is a common complication, characterized by symptoms such as pain, tingling, and numbness due to peripheral nerve damage. The global burden of diabetes has been rising, particularly in low- and middle-income countries. In India, the number of diabetes cases is projected to reach over 134 million by 2045. Traditional treatments for DPN often have limited efficacy and adverse longterm effects, highlighting the need for alternative therapies. Objective: This study aims to investigate the efficacy of electroacupuncture in improving sensory nerve functions in patients with DPN. Specific acupuncture points will be targeted to assess their impact on vibration perception, hot and cold perception, touch sensitivity, and skin temperature. Methods: A randomized controlled trial will be conducted with 80 participants divided equally into an interventional group and a control group. The interventional group will receive electroacupuncture at specific points (ST44, ST36, ST43, K2, K3, BL60, SP9, and GB41) three times a week for 8 weeks. The control group will continue their usual routine and receive the treatment post-study. Primary outcomes will be measured using the NEURO TOUCH instrument to assess sensory thresholds and skin temperature. Secondary outcomes will include pain assessment using the Visual Analog Scale (VAS). Data will be analyzed using SPSS version 16. Results: The study will evaluate the degree of sensory improvement in peripheral nerves and the effectiveness of electroacupuncture in reducing neuropathic pain. This research seeks to bridge the gap in understanding the mechanisms and efficacy of electroacupuncture in DPN treatment. Conclusion: This study will provide significant insights into the potential benefits of electroacupuncture for DPN, offering an alternative approach to improve the management of this debilitating condition. The findings could inform future clinical practices and guidelines for DPN treatment

"Effect Of Electroacupuncture On Sensory Peripheral Nerve Function In Diabetic Peripheral Neuropathy: A Randomized Controlled Trial Protocol."

Background: Diabetes, a chronic metabolic disorder, affects millions globally, with Type 2 diabetes being the most prevalent. Diabetic Peripheral Neuropathy (DPN) is a common complication, characterized by symptoms such as pain, tingling, and numbness due to peripheral nerve damage. The global burden of diabetes has been rising, particularly in low- and middle-income countries. In India, the number of diabetes cases is projected to reach over 134 million by 2045. Traditional treatments for DPN often have limited efficacy and adverse longterm effects, highlighting the need for alternative therapies. Objective: This study aims to investigate the efficacy of electroacupuncture in improving sensory nerve functions in patients with DPN. Specific acupuncture points will be targeted to assess their impact on vibration perception, hot and cold perception, touch sensitivity, and skin temperature. Methods: A randomized controlled trial will be conducted with 80 participants divided equally into an interventional group and a control group. The interventional group will receive electroacupuncture at specific points (ST44, ST36, ST43, K2, K3, BL60, SP9, and GB41) three times a week for 8 weeks. The control group will continue their usual routine and receive the treatment post-study. Primary outcomes will be measured using the NEURO TOUCH instrument to assess sensory thresholds and skin temperature. Secondary outcomes will include pain assessment using the Visual Analog Scale (VAS). Data will be analyzed using SPSS version 16. Results: The study will evaluate the degree of sensory improvement in peripheral nerves and the effectiveness of electroacupuncture in reducing neuropathic pain. This research seeks to bridge the gap in understanding the mechanisms and efficacy of electroacupuncture in DPN treatment. Conclusion: This study will provide significant insights into the potential benefits of electroacupuncture for DPN, offering an alternative approach to improve the management of this debilitating condition. The findings could inform future clinical practices and guidelines for DPN treatment.