Cutaneous C-polymodal fibers lacking TRPV1 are sensitized to heat following inflammation, but fail to drive heat hyperalgesia in the absence of TPV1 containing C-heat fibers

<p>Abstract</p> <p>Background</p> <p>Previous studies have shown that the TRPV1 ion channel plays a critical role in the development of heat hyperalgesia after inflammation, as inflamed TRPV1-/- mice develop mechanical allodynia but fail to develop thermal hyperalgesia. In order to further investigate the role of TRPV1, we have used an ex vivo skin/nerve/DRG preparation to examine the effects of CFA-induced-inflammation on the response properties of TRPV1-positive and TRPV1-negative cutaneous nociceptors.</p> <p>Results</p> <p>In wildtype mice we found that polymodal C-fibers (CPMs) lacking TRPV1 were sensitized to heat within a day after CFA injection. This sensitization included both a drop in average heat threshold and an increase in firing rate to a heat ramp applied to the skin. No changes were observed in the mechanical response properties of these cells. Conversely, TRPV1-positive mechanically insensitive, heat sensitive fibers (CHs) were not sensitized following inflammation. However, results suggested that some of these fibers may have gained mechanical sensitivity and that some previous silent fibers gained heat sensitivity. In mice lacking TRPV1, inflammation only decreased heat threshold of CPMs but did not sensitize their responses to the heat ramp. No CH-fibers could be identified in naïve nor inflamed TRPV1-/- mice.</p> <p>Conclusions</p> <p>Results obtained here suggest that increased heat sensitivity in TRPV1-negative CPM fibers alone following inflammation is insufficient for the induction of heat hyperalgesia. On the other hand, TRPV1-positive CH fibers appear to play an essential role in this process that may include both afferent and efferent functions.</p

Urological Management at Discharge from Acute Spinal Cord Injury Rehabilitation: A Descriptive Analysis from a Population-based Prospective Cohort.

Background There is limited epidemiological evidence describing contemporary neuro-urological management of persons with acute spinal cord injury (SCI). Objective To describe neurogenic lower urinary tract dysfunction (NLUTD) management at discharge from SCI rehabilitation. Design setting and participants The population-based Swiss Spinal Cord Injury (SwiSCI) cohort study prospectively collected data from 602 adults undergoing specialized postacute SCI rehabilitation from 2013 to 2020. The management strategy was based on the European Association of Urology (EAU) Guidelines on Neuro-Urology. Outcome measurements and statistical analysis Data were collected at discharge using the International SCI Lower Urinary Tract Function Basic Data Set. Multivariable logistic regression adjusting for demographics, SCI characteristics, and center, with inverse probability weighting accounting for sampling bias, was used to produce prevalence estimates and identify predictors of lower urinary tract symptoms (LUTS) and NLUTD management outcomes. Results and limitations At discharge (median time after SCI: 5.0 mo [Q1-Q3: 3.0-7.2]), the prevalence of LUTS or managed NLUTD was 82% (95% confidence interval [CI]: 79-85%). SCI completeness was the main predictor of LUTS and managed NLUTD. The risk of urinary incontinence was elevated in females (odds ratio 1.98 [95% CI: 1.18-3.32]) and with complete lesions (odds ratio 4.71 [95% CI: 2.52-8.81]). Voiding dysfunction was most commonly managed with intermittent catheterization (prevalence 39% [95% CI: 35-42%]), followed by indwelling catheterization (prevalence 22% [95% CI: 18-25%]). The prevalence of antimuscarinic or mirabegron use was 29% (95% CI: 26-33%). Urodynamic and renal function data were not collected. Conclusions Our population-based description of urological management in Swiss SCI centers utilizing the EAU Guidelines on Neuro-Urology may be used as a reference for evaluation in other settings. Data further indicate a need for sex-specific neuro-urological management research. Patient summary At discharge from spinal cord injury (SCI) rehabilitation, a majority of patients have lower urinary tract problems, especially those with complete SCI. Women have a higher risk of urinary incontinence

Development of a Sham Protocol to Investigate Transcutaneous Tibial Nerve Stimulation in Randomised, Sham-Controlled, Double-Blind Clinical Trials

Transcutaneous tibial nerve stimulation (TTNS) is a promising treatment for neurogenic lower urinary tract symptoms. However, the evidence is limited due to a general lack of randomised controlled trials (RCTs) and, also, inconsistency in the sham and blinding conditions. In the context of much-needed RCTs, we aimed to develop a suitable sham-control protocol for a clinical setting to maintain blinding but avoid meaningful stimulation of the tibial nerve. Three potential electrode positions (lateral malleolus/5th metatarsal/plantar calcaneus) and two electrode sizes (diameter: 2.5 cm/3.2 cm) were tested to determine which combination provided the optimal sham configuration for a TTNS approach, based on a visible motor response. Sixteen healthy volunteers underwent sensory and motor assessments for each sham configuration. Eight out of them came back for an extra TTNS visit. Sensory thresholds were present for all sham configurations, with linear regression models revealing a significant effect regarding electrode position (highest at plantar calcaneus) but not size. In addition, motor thresholds varied with the position-lowest for the 5th metatarsal. Only using this position and 3.2 cm electrodes attained a 100% response rate. Compared to TTNS, sensory and motor thresholds were generally higher for the sham configurations; meanwhile, perceived pain was only higher at the lateral malleolus. In conclusion, using the 5th metatarsal position and 3.2 cm electrodes proved to be the most suitable sham configuration. Implemented as a four-electrode setup with standardized procedures, this appears to be a suitable RCT protocol for maintaining blinding and controlling for nonspecific TTNS effects in a clinical setting

Indwelling catheter vs intermittent catheterization: is there a difference in UTI susceptibility?

BACKGROUND Patients with neurogenic lower urinary tract dysfunction (NLUTD) often rely on some type of catheterization for bladder emptying. Intermittent catheterization (IC) is considered the gold standard and is preferred over continuous catheterization, since it is considered to cause fewer urinary tract infections (UTIs) than indwelling catheterization. The main objective of our study was to describe UTI prevalence (at visit) and incidence (within the last 12 months) and urine culture characteristics between patients using an indwelling catheter versus (vs) those performing IC. METHODS In this cross-sectional study, we prospectively evaluated from 02/2020 to 01/2021 patients with NLUTD undergoing urine cultures for prophylactic reasons or due to UTI symptoms. At visit, all patients underwent a standardized interview on current UTI symptoms as well as UTI history and antibiotic consumption within the past year. Patients using an indwelling catheter (n = 206) or IC (n = 299) were included in the analysis. The main outcome was between-group differences regarding UTI characteristics. RESULTS Patients using an indwelling catheter were older (indwelling catheter vs IC: median 66 (Q1-Q3: 55-77) vs 55 (42-67) years of age) and showed a higher Charlson comorbidity index (indwelling catheter vs IC: median 4 (Q1-Q3: 2-6) vs 2 (1-4) (both p < 0·001). A total of 40 patients from both groups were diagnosed with a UTI at visit (indwelling catheters vs IC: 8% (16/206) vs 8% (24/299); p = 0·782), and the number of UTIs within the past 12 months was not significantly different between groups. Overall, Escherichia coli (21%), Enterococcus faecalis (17%), and Klebsiella spp. (12%) were the most frequently detected bacteria. CONCLUSIONS In this cohort of patients with NLUTD, we did not find relevant differences in UTI frequency between groups. These results suggest that UTI-related concerns should not be given undue emphasis when counseling patients for catheter-related bladder emptying methods

Urodynamics Are Essential to Predict the Risk for Upper Urinary Tract Damage after Acute Spinal Cord Injury

We used clinical parameters to develop a prediction model for the occurrence of urodynamic risk factors for upper urinary tract (UUT) damage during the first year after acute spinal cord injury (SCI). A total of 97 patients underwent urodynamic investigation at 1, 3, 6, and 12 months after acute SCI, within the framework of a population-based longitudinal study at a single university SCI center. Candidate predictors included demographic characteristics and neurological and functional statuses 1 month after SCI. Outcomes included urodynamic risk factors for UUT damage: detrusor overactivity combined with detrusor sphincter dyssynergia, maximum storage detrusor pressure (pDetmax) ≥ 40 cmH$_{2}$O, bladder compliance < 20 mL/cmH$_{2}$O, and vesicoureteral reflux. Multivariable logistic regression was used for the prediction model development and internal validation, using the area under the receiver operating curve (aROC) to assess model discrimination. Two models showed fair discrimination for pDetmax ≥ 40 cmH$_{2}$O: (i) upper extremity motor score and sex, aROC 0.79 (95% CI: 0.69-0.89), C-statistic 0.78 (95% CI: 0.69-0.87), and (ii) neurological level, American Spinal Injury Association Impairment Scale grade, and sex, aROC 0.78 (95% CI: 0.68-0.89), C-statistic 0.76 (95% CI: 0.68-0.85). We identified two models that provided fair predictive values for urodynamic risk factors of UUT damage during the first year after SCI. Pending external validation, these models may be useful for clinical trial planning, although less so for individual-level patient management. Therefore, urodynamics remains essential for reliably identifying patients at risk of UUT damage

Temporal development of unfavourable urodynamic parameters during the first year after spinal cord injury

Objectives: To describe the temporal development of and risk factors for the occurrence of unfavourable urodynamic parameters during the first year after spinal cord injury (SCI). Patients and methods: This population-based longitudinal study used data from 97 adult patients with a single-event traumatic or ischaemic SCI who underwent video-urodynamic investigation (UDI) at a university SCI centre. The first occurrences of unfavourable urodynamic parameters (detrusor overactivity combined with detrusor sphincter dyssynergia [DO-DSD], maximum storage detrusor pressure ≥40 cmH2 O, bladder compliance <20 mL/cmH2 O, vesico-ureteric reflux [VUR] and any unfavourable parameter [composite outcome]) were evaluated using time-to-event analysis. Results: The majority of the population (87/97 [90%]) had at least one unfavourable urodynamic parameter. Most unfavourable urodynamic parameters were initially identified during the 1- or 3-month UDI, including 92% of the DO-DSD (78/85), 82% of the maximum storage pressure ≥40 cmH2 O (31/38), and 100% of the VUR (seven of seven) observations. No low bladder compliance was observed. The risk of DO-DSD was elevated in patients with thoracic SCI compared to those with lumbar SCI (adjusted hazard ratio [aHR] 2.38, 95% confidence interval [CI] 1.16-4.89). Risk of maximum storage detrusor pressure ≥40 cmH2 O was higher in males than females (aHR 8.33, 95% CI 2.51-27.66), in patients with a cervical SCI compared to those with lumbar SCI (aHR 14.89, 95% CI 3.28-67.55), and in patients with AIS Grade B or C compared to AIS Grade D SCI (aHR 6.17, 95% CI 1.78-21.39). No risk factors were identified for the composite outcome of any unfavourable urodynamic parameter. Conclusions: The first UDI should take place within 3 months after SCI as to facilitate early diagnosis of unfavourable urodynamic parameters and timely treatment. Neuro-urological guidelines and individualised management strategies for patients with SCI may be strengthened by considering sex and SCI characteristics in the scheduling of UDIs. Keywords: #Urology; longitudinal studies; spinal cord injuries; survival analysis; urinary bladder, neurogenic; urinary bladder, overactive; urodynamic

bTUNED: transcutaneous tibial nerve stimulation for neurogenic lower urinary tract dysfunction

OBJECTIVE To present the protocol for a randomized controlled trial (RCT) evaluating the efficacy and safety of transcutaneous tibial nerve stimulation (TTNS) for refractory neurogenic lower urinary tract dysfunction (NLUTD). STUDY DESIGN AND RESULTS bTUNED (bladder and TranscUtaneous tibial Nerve stimulation for nEurogenic lower urinary tract Dysfunction) is an international multicentre, sham-controlled, double-blind RCT investigating the efficacy and safety of TTNS. The primary outcome is success of TTNS, defined as improvements in key bladder diary variables at study end compared to baseline values. The focus of the treatment is defined by the Self-Assessment Goal Achievement (SAGA) questionnaire. Secondary outcomes are the effect of TTNS on urodynamic, neurophysiological, and bowel function outcome measures, as well as the safety of TTNS. CONCLUSIONS A total of 240 patients with refractory NLUTD will be included and randomized 1:1 into the verum or sham TTNS group from March 2020 until August 2026. TTNS will be performed twice a week for 30 min during 6 weeks. The patients will attend baseline assessments, 12 treatment visits and follow-up assessments at the study end

Urological Management at Discharge from Acute Spinal Cord Injury Rehabilitation: A Descriptive Analysis from a Population-based Prospective Cohort

Background There is limited epidemiological evidence describing contemporary neuro-urological management of persons with acute spinal cord injury (SCI). Objective To describe neurogenic lower urinary tract dysfunction (NLUTD) management at discharge from SCI rehabilitation. Design setting and participants The population-based Swiss Spinal Cord Injury (SwiSCI) cohort study prospectively collected data from 602 adults undergoing specialized postacute SCI rehabilitation from 2013 to 2020. The management strategy was based on the European Association of Urology (EAU) Guidelines on Neuro-Urology. Outcome measurements and statistical analysis Data were collected at discharge using the International SCI Lower Urinary Tract Function Basic Data Set. Multivariable logistic regression adjusting for demographics, SCI characteristics, and center, with inverse probability weighting accounting for sampling bias, was used to produce prevalence estimates and identify predictors of lower urinary tract symptoms (LUTS) and NLUTD management outcomes. Results and limitations At discharge (median time after SCI: 5.0 mo [Q1-Q3: 3.0-7.2]), the prevalence of LUTS or managed NLUTD was 82% (95% confidence interval [CI]: 79-85%). SCI completeness was the main predictor of LUTS and managed NLUTD. The risk of urinary incontinence was elevated in females (odds ratio 1.98 [95% CI: 1.18-3.32]) and with complete lesions (odds ratio 4.71 [95% CI: 2.52-8.81]). Voiding dysfunction was most commonly managed with intermittent catheterization (prevalence 39% [95% CI: 35-42%]), followed by indwelling catheterization (prevalence 22% [95% CI: 18-25%]). The prevalence of antimuscarinic or mirabegron use was 29% (95% CI: 26-33%). Urodynamic and renal function data were not collected. Conclusions Our population-based description of urological management in Swiss SCI centers utilizing the EAU Guidelines on Neuro-Urology may be used as a reference for evaluation in other settings. Data further indicate a need for sex-specific neuro-urological management research. Patient summary At discharge from spinal cord injury (SCI) rehabilitation, a majority of patients have lower urinary tract problems, especially those with complete SCI. Women have a higher risk of urinary incontinence

Sex differences in urological management during spinal cord injury rehabilitation: results from a prospective multicenter longitudinal cohort study.

STUDY DESIGN Prospective, multicenter, longitudinal cohort study. OBJECTIVES To describe female-male differences in first-line urological management during spinal cord injury (SCI) rehabilitation. SETTING Inpatient specialized post-acute SCI rehabilitation in Switzerland. METHODS Data on bladder storage medication (antimuscarinic and beta-3 agonist) use, suprapubic catheter placement, demographic and SCI characteristics was collected within 40 days of SCI and at rehabilitation discharge from May 2013-September 2021. Prevalence and indicators of bladder storage medication and suprapubic catheter use at discharge were investigated with sex-stratified descriptive and logistic regression analyses. RESULTS In 748 patients (219 females, 29%), bladder storage medication use at discharge had a prevalence of 24% (95% CI: 18-29%) for females and 30% (95% CI: 26-34%) for males and was indicated by cervical AIS grade A, B, C and traumatic SCI in both sexes. Thoracic AIS grade A, B, C SCI (males), and lumbar/sacral AIS grade A, B, C SCI (females) predicted higher odds of bladder storage medication use (SCI characteristic*sex interaction, p 60 in both sexes. Females with thoracic grade A, B, C SCI tended to have higher odds of suprapubic catheter use (SCI characteristic*sex interaction, p = 0.013). CONCLUSIONS We identified sex differences in urological management especially in persons with AIS grade C or higher sub-cervical SCI. There is scope for well-powered, female-specific research in SCI in order to understand the underlying mechanisms and support patient-tailored management