Recent advances in neuroimaging of bladder, bowel and sexual function

PURPOSE OF REVIEW: In this review, we summarize recent advances in the understanding of the neural control of the bladder, bowel and sexual function, in both men and women. RECENT FINDINGS: Evidence of supraspinal areas controlling the storage of urine and micturition in animals, such as the pontine micturition centre, emerged in the early 20th century. Neurological stimulation and lesion studies in humans provided additional indirect evidence for additional bladder-related brain areas. Thereafter, functional neuroimaging in humans with PET and fMRI provided more direct evidence of the involvement of these brain areas. The areas involved in the storage and expulsion of urine also seem to be involved in the central control of storage and expulsion of feces. Furthermore, most knowledge on the brain control of sexual function is obtained from dynamic imaging in human volunteers. Relatively little is known about the dysfunctional central circuits in patients with pelvic organ dysfunction. SUMMARY: fMRI has been the most widely used functional neuroimaging technique in the last decade to study the central control of bladder function, anorectal function and sexual function. The studies described in this review show which sensory and motor areas are involved, including cortical and subcortical areas. We propose the existence of a switch-like phenomenon located in the pons controlling micturition, defecation and orgasm

A systematic review and activation likelihood estimation meta-Analysis of the central innervation of the lower urinary tract: Pelvic floor motor control and micturition

Purpose Functional neuroimaging is a powerful and versatile tool to investigate central lower urinary tract (LUT) control. Despite the increasing body of literature there is a lack of comprehensive overviews on LUT control. Thus, we aimed to execute a coordinate based meta-Analysis of all PET and fMRI evidence on descending central LUT control, i.e. pelvic floor muscle contraction (PFMC) and micturition. Materials and methods A systematic literature search of all relevant libraries was performed in August 2020. Coordinates of activity were extracted from eligible studies to perform an activation likelihood estimation (ALE) using a threshold of uncorrected p 0.001. Results 20 of 6858 identified studies, published between 1997 and 2020, were included. Twelve studies investigated PFMC (1xPET, 11xfMRI) and eight micturition (3xPET, 5xfMRI). The PFMC ALE analysis (n = 181, 133 foci) showed clusters in the primary motor cortex, supplementary motor cortex, cingulate gyrus, frontal gyrus, thalamus, supramarginal gyrus, and cerebellum. The micturition ALE analysis (n = 107, 98 foci) showed active clusters in the dorsal pons, including the pontine micturition center, the periaqueductal gray, cingulate gyrus, frontal gyrus, insula and ventral pons. Overlap of PFMC and micturition was found in the cingulate gyrus and thalamus. Conclusions For the first time the involved core brain areas of LUT motor control were determined using ALE. Furthermore, the involved brain areas for PFMC and micturition are partially distinct. Further neuroimaging studies are required to extend this ALE analysis and determine the differences between a healthy and a dysfunctional LUT. This requires standardization of protocols and task-execution

Bladder Dysfunction in the Context of the Bladder-Brain Connection

The aim of the thesis "Bladder dysfunction in the context of the bladder-brain connection" written by Ilse Groenendijk, was to investigate potential diagnostic tools in the field of functional urology. The first aim was to define the brain areas involved in LUT control in healthy individuals and to investigate the clinical applicability of dynamic brain imaging as a diagnostic tool of functional bladder disorders in individuals. The second aim was to evaluate and improve traditional and patient reported outcome measurements in the field of functional urology

Investigating white matter changes underlying overactive bladder in multiple sclerosis with diffusion MRI

Lower urinary tract symptoms (LUTS) are presented in more than 80% of multiple sclerosis (MS) patients. Current understanding of LUT control is based on studies exploring activities in grey matter (GM) and investigating functional correlations with LUTS. The relationship between white matter (WM) changes and overactive bladder (OAB) symptoms are limited to findings in small vessel disease, and the nature of the association between WM changes and OAB symptoms is poorly understood. Advanced diffusion-weighted magnetic resonance imaging (MRI) techniques provide non-invasive techniques to study WM abnormalities and correlates to clinical observations. The overarching objectives of this work are to explore WM abnormalities subtending OAB symptoms in MS, and to reconstruct the structural network underpinning the working model of lower urinary tract (LUT) control. Using Tract-Based Spatial Statistics (TBSS), OAB symptoms related WM abnormalities in MS can be identified, and a structural network subtending OAB symptoms in MS can be subsequently created. The findings of this work illustrate the correlation between OAB symptoms severity and WM abnormalities in MS. These were observed in regions in frontal lobes and non-dominant hemisphere, including corpus callosum, anterior corona radiata bilaterally, right anterior thalamic radiation, superior longitudinal fasciculus bilaterally, and right inferior longitudinal fasciculus. The structural network created for OAB symptoms in MS connected regions known to be involved in the working model of LUT control, and the network identified connectivity between insula and frontal lobe, which is the key circuit for perception of bladder fullness. Moreover, structural connectivity between insula-temporal lobe and insula-occipital lobe were observed, which may underpin changes seen in functional MRI (fMRI) studies. The novel findings of this study present WM abnormalities and structural connectivity subtending LUTS in MS with diffusion-weighted imaging (DWI). The techniques used in this work can be applied to other patterns of LUTS and other neurological diseases

A multimodal approach to investigate brain reorganization after spinal cord injury using functional magnetic resonance imaging and functional near-infrared spectroscopy

Traumatic Spinal Cord Injury (SCI) results in structural and functional neurological changes at both the brain and the level of the spinal cord. Anatomical studies indicate decreased grey matter volume in sensorimotor and non-sensorimotor regions of the cortex following SCI; whereas, neurophysiological findings mostly report altered functional activity in the sensorimotor nodes of the cortex, subcortex, and cerebellum. Therefore, it is currently unknown whether tissue atrophy observed in non-motor related areas has any concomitant functional consequences. Furthermore, the neural underpinnings of adaptive neuroplasticity after SCI is not well-defined in the current literature. Hence, this dissertation is a pioneer study investigating the structural and functional changes in the whole brain after SCI, with particular focus on subcortical regions, using a multimodal approach employing magnetic resonance imaging (MRI), resting-state functional MRI (fMRI) and functional near-infrared spectroscopy (fNIRS), that may take best advantage of each of these three tools. MRI scans from 23 healthy controls (HC) and 36 individuals with complete SCI within two years of injury were used to demonstrate that both injury level and duration since injury are important factors contributing to recovery. Specifically, cervical level injury when compared to thoracolumbar level injury exhibits a greater loss of cortical grey matter volume in the orbitofrontal cortex, insula, and anterior cingulate cortex. Next, using the fMRI scans of the same participants during a resting-state scan, the intrinsic functional connectivity of the mediodorsal, pulvinar and ventrolateral nuclei of the thalamus to the regions of salient network and the fronto-parietal network is observed to be dynamic and altered in the SCI group. Lastly, a continuous-wave fNIRS is used to reliably measure brain function in individuals with SCI during both dynamic and static tasks while accounting for cerebrovascular reactivity. Five min of resting-state data and 26 min of motor data including finger tapping, finger tapping imagery and ankle tapping were acquired to identify the spatial activation pattern unique to each of the movement type. A breath-hold paradigm is also used to quantify cerebrovascular reactivity as a means to calibrate task activity from neurovascular constraints. Sixteen HC were scanned at two separate visits to determine the sensitivity and test-retest reliability of fNIRS data from the sensorimotor cortex. Following validation, the same procedure was repeated in 13 individuals with paraplegia resulting from SCI and 13 HC to quantify alterations in the cortical activity of the motor cortex and cerebrovascular reactivity between the two groups. Results indicate that SCI group exhibit altered cerebrovascular reactivity with greater delay in response and greater pre-stimulus undershoot. As hypothesized, the hemodynamic response to ankle movement resulted in only a small change in oxyhemoglobin concentration in the sensorimotor cortex of SCI group when compared to HC. The application of fNIRS to assess cortical reorganization following SCI is unique and expands our understanding of the neurophysiology after SCI. It paves the groundwork for extending the implementation of fNIRS to rehabilitation research and other clinical populations with vascular dysfunction. This dissertation is one of the first studies to comprehensively examine both the structural and functional alterations of the brain in humans with complete SCI and opens promising avenues for SCI research using fNIRS modality

The effect of exercise-induced pain on endurance performance, and strategies to mitigate its impact

Exercise-induced pain (EIP) is a natural consequence of exercising intensely, and results due to an accumulation of endogenous algesic substances, an increase in muscular pressure and muscular distortion or tissue damage. However, the presence of EIP may have negative consequences for exercise and endurance performance, brought about by the physiological and/or psychological effect of pain. EIP has not been widely addressed in sport and exercise science research, and much of the contemporary literature has ignored its potential role in endurance exercise performance, despite the wide acknowledgement it gains in interviews with athletes, coaches, exercise scientists and health and fitness practitioners. Therefore, more empirical research needs to be completed that explores the role of EIP in endurance performance, and the physiological and/or psychological contribution it may make to fatigue and work rate regulation. Therefore, the main purpose of this thesis was to examine the effect of EIP on endurance exercise performance, and identify strategies to mitigate its impact in various endurance exercise tasks. Consequently, this thesis consists of 5 experimental studies, as outlined below. The 1st experimental study (Chapter 3) assessed the relationship between traditional experimental measures of pain (the cold pressor test (CPT) and algometry), EIP tolerance and participants' performance of a 10 mile (16.1 km) cycling time trial. The primary finding was that no correlation was found between experimental pain measures and TT performance (mean pain in CPT; R = 0.222; time lasted in the CPT; R = -0.292; PPT; R = -0.016). However, there was a significant correlation between EIP tolerance and TT performance (R = -0.83, P 0.05). The ANOVA also revealed a significant main effect of condition for exercise-induced pain during the TTE test (P = 0.035). No significant changes in rating of perceived exertion (RPE) were found between the three conditions (P > 0.05). A 3 x 8 (condition x iso-time) ANOVA revealed a significant interaction effect for exercise-induced pain over time between conditions during the TTE test with lower pain intensity in the TENS and IFC conditions (F (3.4, 58.4) = 3.671, P = 0.013). No interaction and main effects for RPE were found between the three conditions (P > 0.05). For the MVC, paired-sample t-tests demonstrated that MVC was significantly reduced following the TTE in the Sham (t (17) = 9.069, P 0.05). No significant differences in mean RPE were found between conditions during the TT (P > 0.05). Interestingly, this study also showed that TENS elicits an analgesic effect on EIP and improves the TT performance, whereas IFC technique does not elicit any reduction of EIP and consequently has no effect on whole-body endurance performance. This experiment demonstrated the first time that TENS intervention significantly improved completion time of the cycling TT, and that this was attained by the cyclists sustaining a greater power output (PO), heart rate (HR) and blood lactate (B[La]). Regardless of the increased physiological stress and metabolic rate induced by the higher PO, participants perceived EIP in the TENS strategy alongside in the absence of a difference in RPE between conditions. The improvement in dynamic endurance was probably the result of reduction in EIP for a given load. This is the first experiment showing that a TENS intervention can be used to elicit this analgesia to EIP, and suggests that there may be scope for TENS to be used during exercise in those where EIP negatively effects their engagement in physical activity. The final experiment in this thesis (Chapter 7) examined the effect of mood and emotional state on EIP and endurance performance. The use of painful images prior to endurance cycling performance was used to negatively affect mood, which was hypothesised to increase EIP. The primary finding was that the ANOVA revealed a significant difference in completion time between conditions (F (2, 40) = 8.480, P = 0.001). Pairwise comparisons revealed that participants performed a significantly faster TT (P = 0.003) in the pleasant condition (29 min 38 s ± 4 min 35 s) and the neutral condition (29 min 39 s ± 3 min 34 s) compared to the painful condition (30 min 19 s ± 5 min 7 s). There were no significant differences between the neutral condition and the pleasant (P = 1.000). The ANOVA also revealed a significant difference in PO (F (2, 40) = 6.318, P = 0.004), mean HR ((F (2, 40) = 4.502, P = 0.017) and mean B[La] (F (2, 40) = 5.724, P = 0.007) between conditions during ?the TT cycling performance, but no significant effect of condition for mean RPE or EIP (P > 0.05). In the FP, a ?significant main effect of condition for EIP (F (2, 40) = 4.363, P = 0.019), but no difference for RPE, HR or B[La]. This experiment demonstrated the first time that painful images negatively affect mood and elicit a compassionate hyperalgesia response to exercise. The results demonstrate that an increased pain sensation during exercise (induced via compassional hyperalgesia) can decrease TT performance, and highlights there is an emotional element to the processing of EIP that can be influenced by compassional hyperalgesia. This is probably the consequence of 'top-down' processing increasing the pain sensation elicited by a given 'bottom-up' stimulus. These results highlight the importance of maintaining a positive mood and emotional state prior to and during exercise. The experimental studies performed as part of this thesis provides unique empirical evidence to advance scientific knowledge and understanding of the phenomenon of EIP. This thesis provides further new insights into how different interventions both alleviate and exacerbate EIP, which subsequently influences endurance exercise performance. Furthermore, considering the lack of knowledge regarding the testing and role of EIP in exercise, this thesis contributes to and enhances scientific understanding for how to test for and control these variables

New approaches to the study of neurorehabilitation protocols in dogs and cats with acute or chronic spinal cord injury with or without deep pain sensation and possible spinal shock signs

Tese de Doutoramento em Ciências Veterinárias na especialidade Clínica, área científica de ClínicaABSTRACT - Intensive neurorehabilitation protocols (INRP) with rehabilitation modalities and weight supported treadmill training (BWSTT), are suggested as treatment to obtain ambulation in dogs and cats with complete (DPP-), discomplete and incomplete (DPP+) compressive or non-compressive spinal cord injury (SCI), similarly to what is performed in human medicine.The first study is a cohort, prospective, controlled and blinded study that was performed in 22 dogs with T11-L3 Hansen type I, revealing ambulation in 100% of the BWSTT group, within a mean of 4.6 weeks. One other study, a retrospective controlled clinical study, was developed in 367 acute post-surgical dogs, with T10-L3 Hansen type I. A new functional neurorehabilitation scale (FNRS-DPP-) was performed to evaluate the DPP- or discomplete dogs, that were able to achieve spinal reflex locomotion (SRL). A strong significance between groups was verified in the DPP+ (p<0.001), with 99.4% of ambulation. The same difference was seen in the DPP- (p=0.007) with 58,5% of ambulation and a tendency (p=0.058) was observed in regard to DPP recovery, with 37.2% achieving SRL, within a maximum of 3 months. INRP was demonstrated to be safe and ambulation recovery achieved earlier. The same population was included in another study, on 16 dogs with incomplete recovery 3 months after surgery. DPP- were under INRP associated with 4-aminopyridine administration, achieving 78% of SRL at day 45 and automatic micturition within a mean of 62 days. Also, 100% of ambulation in the DPP+ within a mean of 47 days and positive follow-up evolution. Ambulatory status was achieved in 88%, establishing this INRP as a therapeutic option to reduce euthanasia. Non-compressive myelopathies with contusive patterns were also referred in a prospective study of 9 cats that revealed 56% (n=5) of ambulation and 44% (n=4) of SRL, showing that INRP should be considered to improve quality of life and the well-being of our patients. Some dogs may develop spinal shock following SCI, including in acute noncompressive nucleus pulposus extrusion. Thus, a cohort prospective study applied a spinal shock scale as a monitoring tool, suggesting spinal shock as a negative factor for a quick recovery. INRP was shown to be safe, tolerable and feasible, allowing 32% of ambulation within 7 days and 94% within 60 days. Follow-ups until 4 years revealed a positive evolution. These studies should be continued, considering each limitationRESUMO - Nova abordagem aos protocolos de neuroreabilitação em cães e gatos com lesão medular aguda ou crónica, com/sem sensibilidade à dor profunda e choque espinhal. - Os protocolos de neuroreabilitação intensiva (INRP), com as modalidades de reabilitação e o treino locomotor em tapete rolante com suporte de peso (BWSTT), são sugeridos como terapêutica para obter a ambulação em cães e gatos de lesão medular compressiva / não compressiva, completa (DPP-), “discompleta” e incompleta (DPP+), tal como na medicina humana. Assim, apresenta-se o primeiro artigo, estudo de coorte, prospetivo, controlado e cego, em 22 cães com lesão T11-L3 Hansen tipo I, que demonstrou 100% de ambulação no grupo BWSTT, em média de 4.6 semanas. O segundo artigo refere-se ao estudo controlado e retrospetivo de 367 cães pós-cirúrgicos com lesão aguda T10-L3 de Hansen tipo I. A escala de neuroreabilitação funcional (FNRS-DPP-) foi elaborada e aplicada nestes cães, DPP- ou incompletos, capazes de atingir a locomoção espinhal por reflexos (SRL). Verificaram-se diferenças significativas entre grupos, nos DPP+ (p<0,001) com 99,4% de ambulação, e nos DPP- (p=0,007) com 58,5%. Em relação à recuperação da sensibilidade profunda (p=0,058), ocorreu 37.3% de SRL, no máximo em 3 meses. O INRP demonstrou-se seguro e a recuperação foi atingida de forma mais precoce. O mesmo foi estudado em 16 cães com recuperação incompleta 3 meses após cirurgia, sendo associada a administração de 4- aminopiridina nos DPP- com 78% de SRL até 45 dias e micção automática em ~62 dias. Obteve-se 100% de ambulação nos cães DPP+, em ~47 dias, com evolução positiva nas consultas de seguimento. A ambulação total foi de 88%, estabelecendo este INRP como opção terapêutica, reduzindo o número de eutanásias em âmbito clínico. As mielopatias não compressivas foram, também, estudadas. Assim sendo, estudo propectivo em 9 gatos revelou 56% de ambulação e 44% de SRL, demostrando que o INRP poderá ser considerado, no sentido de melhorar a qualidade de vida e bem-estar destes doentes. Após a lesão medular, alguns cães podem desenvolver o choque espinhal, principalmente na extrusão aguda não compressiva do núcleo pulposo. Assim, foi desenvolvido estudo propectivo coorte que elaborou e aplicou escala de choque espinhal para monitorização, sugerindo o choque espinhal como fator negativo para a rápida recuperação. Este INRP revelou-se seguro, tolerável e viável, com 32% de ambulação em 7 dias e 94% em 60 dias. Consultas de seguimento até 4 anos revelaram evolução positiva. Estes estudos devem ser continuados considerando as suas limitações.N/

Applications of EMG in Clinical and Sports Medicine

This second of two volumes on EMG (Electromyography) covers a wide range of clinical applications, as a complement to the methods discussed in volume 1. Topics range from gait and vibration analysis, through posture and falls prevention, to biofeedback in the treatment of neurologic swallowing impairment. The volume includes sections on back care, sports and performance medicine, gynecology/urology and orofacial function. Authors describe the procedures for their experimental studies with detailed and clear illustrations and references to the literature. The limitations of SEMG measures and methods for careful analysis are discussed. This broad compilation of articles discussing the use of EMG in both clinical and research applications demonstrates the utility of the method as a tool in a wide variety of disciplines and clinical fields

Facteurs psychophysiologiques qui influencent les mécanismes endogènes de la douleur

La douleur se divise en composantes sensorielles, cognitives et affectives qui s’inter-influencent. La composante affective semble jouer un rôle dominant dans certaines douleurs chroniques, mais aussi dans le recrutement des mécanismes endogènes de contrôle de la douleur (conditioned pain modulation; CPM) et des réponses du système nerveux autonome (SNA). De plus, des études récentes supportent que les réponses du SNA semblent être liées avec l’efficacité des CPM. Il va de soi que la composante affective soit grandement impliquée dans des douleurs qui affectent les relations interpersonnelles et même les relations intimes, comme la vestibulodynie provoquée (VP), une douleur à l’entrée du vagin au moment d’une pénétration ou de l’insertion d’un tampon. Un des facteurs affectifs important dans la douleur est justement relationnel, soit l’empathie. En effet, l’observation d’une personne en douleur, principalement si elle nous est significative, est douloureuse pour l’observateur et s’accompagne de réponses physiologiques similaires à la douleur vécue. Dans cette étude, nous avons vérifié si l’observation d’étrangers en douleur provoque l’activation d’une réponse inhibitrice s’apparentant aux CPM, comme c’est le cas pour l’observation du conjoint. Nous avons aussi vérifié si le fait de souffrir de VP influence l’efficacité inhibitrice par la douleur expérimentale (situation contrôle) et par l’observation d’une femme et d’un homme inconnus dans la même situation de douleur expérimentale (situation d’observation). Les résultats ont démontré que l’observation d’étrangers en douleur n’était pas suffisant pour activer une inhibition descendante de la douleur, et ce, indépendamment de la condition de l’observateur. De plus, l’évaluation de la douleur perçue ne différait pas entre les deux groupes. Finalement, le portrait clinique des femmes souffrant de VP montre la présence de trois sous-groupes de patientes présentant des dysfonctions des CPM différentes. En somme, ces données permettent de mieux cerner l’effet de la composante affective chez des sujets sains et chez des patientes qui souffrent de VP. Les résultats permettent de faire évoluer nos connaissances des facteurs qui modulent ces douleurs ainsi que l’observation de la douleur d’autrui