Combining different evaluations of sensation to assess the afferent innervation of the lower urinary tract after SCI

Systematic Evaluation of Lower Urinary Tract Sensations to Improve Management of LUTS: ICI-RS 2024

AIMS

Lower urinary tract (LUT) sensations form an essential part of diagnostic criteria for many LUT symptoms, additionally LUT sensations are used to evaluate the effectivity of therapeutic interventions. The accurate measurement of LUT sensations, however, is severely hampered by the subjective nature of these sensations.

METHODS

This paper summarizes the discussions from the 2024 meeting of the International Consultation for Incontinence-Research Society (ICI-RS 2024) regarding systematic evaluations of LUT sensations and the design of more objective tools to measure these.

RESULTS

Here, we discuss factors that influence sensations that are under the control of the caregiver/investigator, the signaling of sensations from the LUT toward the central nervous system, and currently used diagnostic tools to measure LUT sensations. Recent methodological advances to objectively measure factors that correspond with changes in LUT sensations are introduced along with recommendations for future research to optimally enable objective assessment of processes underlying LUT sensations.

CONCLUSIONS

Advancing the objective measurement of LUT sensations will require interdisciplinary collaboration, integrating insights from neuroscience, engineering, and clinical practice. Such efforts hold the potential to transform patient care by enabling more precise diagnostics and personalized therapeutic strategies.

How does the lower urinary tract contribute to bladder sensation? ICI-RS 2023

AIM

Bladder sensation is critical for coordinating voluntary micturition to maintain healthy bladder function. Sensations are initiated by the activation of sensory afferents that innervate throughout the bladder wall. However, the physiological complexity that underlies the initiation of bladder sensory signaling in health and disease remains poorly understood. This review summarises the latest knowledge of the mechanisms underlying the generation of bladder sensation and identifies key areas for future research.

METHODS

Experts in bladder sensory signaling reviewed the literature on how the lower urinary tract contributes to bladder sensation and identified key research areas for discussion at the 10th International Consultation on Incontinence-Research Society.

RESULTS

The importance of bladder sensory signals in maintaining healthy bladder function is well established. However, better therapeutic management of bladder disorders with exaggerated bladder sensation, including overactive bladder syndrome (OAB) and interstitial cystitis/bladder pain syndrome (IC/BPS) is limited by a lack of knowledge in a number of key research areas including; the contribution of different nerves (pudendal, pelvic, hypogastric) to filling sensations in health and disease; the relative contribution of stretch sensitive (muscular) and stretch-insensitive (mucosal) afferents to bladder sensation in health and disease; the direct and indirect contributions of the muscularis mucosae to bladder contraction and sensation; and the impact of manipulating urothelial release factors on bladder sensation.

CONCLUSION

Disturbances in bladder sensory signaling can have severe consequences for bladder sensation and function including the development of OAB and IC/BPS. Advancing therapeutic treatments for OAB and IC/BPS requires a deeper understanding of the mechanisms underlying the generation of bladder sensation, and key areas for future research have been identified.

Developing new ways to assess neural control of pelvic organ function in spinal conditions: ICI-RS 2023

OBJECTIVES

Several central nervous system (CNS) centers affect muscle groups of the lower urinary tract (LUT) and anorectal tract (ART) via autonomic and somatic pathways, working in different modes (storage or expulsion). Hence spinal cord dysfunction can affect the LUT and ART by several possible mechanisms.

METHODS

This review reports the discussions of a workshop at the 2023 meeting of the International Consultation on Incontinence Research Society, which reviewed uncertainties and research priorities of spinal dysfunction.

RESULTS

Discussion focussed on the levator ani nerve, mechanisms underpinning sensory function and sensation, functional imaging, dyssynergia, and experimental models. The following key research questions were identified. (1) Clinically, how can we evaluate the levator ani muscle to support assessment and identify prognosis for effective treatment selection? (2) How can we reliably measure levator ani tone? (3) How can we evaluate sensory information and sensation for the LUT and the ART? (4) What is the role of functional CNS imaging in development of scientific insights and clinical evaluation? (5) What is the relationship of detrusor sphincter dyssynergia to renal failure?

CONCLUSIONS

Spinal cord dysfunction can fundamentally disrupt LUT and ART function, with considerable clinical impact. The evaluation needs to reflect the full scope of potential problems, and new clinical and diagnostic approaches are needed, for prognosis and treatment. The preclinical science evaluating spinal cord function in both LUT and ART storage and elimination remains a major priority, even though it is a challenging experimental context. Without this underpinning evidence, development of new clinical evidence may be held back.

Testing sensation of gently squeezing the testes has diagnostic value in spinal cord injury men

STUDY DESIGN

Retrospective cohort study.

OBJECTIVES

Determine the diagnostic value of testing the sensation of squeezing the testes.

SETTING

Research group run by the University of Antwerp.

METHODS

During the clinical examination, it was evaluated if male spinal cord injury (SCI) patients felt gentle squeezing of the testes. The outcome was related to the type of SCI, to the sensations of the light touch of the dermatomes of the perineum, of bladder filling, of overactive detrusor (DOA) contractions during urodynamics, and of electrosensation elicited in different parts of the lower urinary tract. The neurological pathways elicited by these tests were compared.

RESULTS

Seventy-four patients were included, mean age 46 ± 17 years, a number of weeks post SCI 318 ± 586. Sensation in the testes was present in 72.2%. In patients with AIS A, the sensation was found positive in 41%, while all with AIS B-D felt the sensation. Testes sensation was strongly correlated with the sensation of touch of the perineum and with the filling sensation during cystometry, proving a dorsal column pathway. The sensation of DOA contractions and electrosensation in the bladder, bladder neck/proximal, and distal urethra were not significantly related to the outcome of the testicular examination, showing that anterior and lateral spinothalamic pathways were not involved CONCLUSIONS: Our data show that sensation from gently squeezing the testes informs about the dorsal column from spinal cord level T10-L2 upwards. The test can help refine the neurologic diagnosis after SCI. We advocate to include this easy-to-do test in the neuro-urologic clinical examination.

Sensations Reported During Urodynamic Bladder Filling in Spinal Cord Injury Patients Give Additional Important Information

Purpose

To study sensations reported during filling cystometry in patients with different levels and completeness of spinal cord lesion (SCL).

Methods

A retrospective cohort study. Patient age and sex, cause of SCL, American Spinal Injury Association Impairment Scale (AIS), and lower urinary tract -related sensations in daily life were gathered. Filling cystometry (video-urodynamics) was performed following ICS good urodynamic practice guidelines. Beside bladder filling sensations (first sensation of bladder filling, first desire to void, strong desire to void), other sensations as detrusor overactivity related sensation and pain were noted.

Results

170 patients were included, age 45 ± 17 years, 114 male and 56 female, 92 complete and 78 incomplete SCL. The test was done 6 ± 4 years post SCL. Sensation was reported by 57% of all patients. In complete SCL half (46/92) had sensation, while 36% with incomplete SCL (28/78) reported no sensation. Bladder awareness was not predictable by the AIS. The filling sensations reported were equal to those given in the terminology of ICS. Pain was seldom present 10/170 (6%), Detrusor overactivity contraction was felt by 45/78 ( 58%). Very few patients used sensory information for bladder management at home.

Conclusion

After SCL, most patients retain the ability to be aware of the LUT, assessable and gradable, during urodynamic testing. Filling sensations were not different from those described in healthy, but the number and sequence of the sensations were altered in the minority. Pain and sensation of unstable contractions gave additional important information. As different sensations relate to different spinal afferent pathways, the sensory evaluation during cystometry provided additional important information on the spinal cord's condition.