Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes

Bibliographic Details
Main Author: Mariano, Timothy Yu
Language:English
Published: Case Western Reserve University School of Graduate Studies / OhioLINK 2009
Subjects:
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=case1246392300
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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-case12463923002021-08-03T05:33:15Z Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes Mariano, Timothy Yu Biomedical Research Rehabilitation URETHRAL bladder Voiding Sacral REFLEXES Dermatome STIMULATION <p>Aberrant urethral reflexes following neurological injury or disease are a major component of voiding dysfunction, preventing micturition and leading to serious medical complications. Current neuroprostheses—-such as the Brindley implant—-require irreversible transection of the dorsal sacral roots (dorsal rhizotomy), permanently eliminating remaining sensation and desirable reflexes. These side effects greatly reduce the number of people choosing the approach. This project therefore addresses an unmet clinical need for rhizotomy-free suppression of aberrant urethral reflexes by employing electrical stimulation of afferent neural pathways to interrupt the unwanted responses. This afferent-based approach will improve bladder control neuroprostheses for human use.</p><p>In experiments with spinal-intact canines (Aim 1)-—designed to demonstrate a fully implanted system—-afferent stimulation was applied to the intradural dorsal roots. Although there was evidence of increased voiding, evoked bladder pressures were generally inadequate. Exhaustive troubleshooting suggested the need for an improved animal preparation.</p><p>A novel feline preparation with good neuroanatomical homology to the human was developed (Aim 2a). It exhibited aberrant post-spinalization urethral responses that were quantified with clinical urodynamic measures (Aim 2b). The results were consistent with these responses being reflexive and mediated by urethral stretch or flow receptors (Aim 2c). These acute reflexes were functionally similar to those occurring chronically in humans with spinal cord injury, making the experimental preparation a useful tool for developing future pharmacological or neuroprosthetic therapies.</p><p>We demonstrated reflex suppression with rhizotomy-free and surgically non-invasive afferent stimulation of sacral skin dermatomes, providing a novel proof-of-concept with significant clinical potential. Some cats exhibited reflex exacerbation. Subsequent investigation of the reflex modulation suggested parameters—-such as electrode location and stimulation amplitude—-that governed surface stimulation efficacy (Aim 2c). The most effective suppression occurred with sacral dermatomes stimulated at sufficiently high current amplitudes.</p><p>These results provide the key data for motivating future chronic animal and human studies, in which further optimization of the stimulation pattern will improve the suppression effect. The low cost of this innovative modality of surgically non-invasive and rhizotomy-free reflex suppression make it an attractive clinical alternative for treating voiding dysfunction that has distinct advantages over the present state of the art.</p> 2009 English text Case Western Reserve University School of Graduate Studies / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=case1246392300 http://rave.ohiolink.edu/etdc/view?acc_num=case1246392300 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Biomedical Research
Rehabilitation
URETHRAL
bladder
Voiding
Sacral
REFLEXES
Dermatome
STIMULATION
spellingShingle Biomedical Research
Rehabilitation
URETHRAL
bladder
Voiding
Sacral
REFLEXES
Dermatome
STIMULATION
Mariano, Timothy Yu
Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes
author Mariano, Timothy Yu
author_facet Mariano, Timothy Yu
author_sort Mariano, Timothy Yu
title Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes
title_short Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes
title_full Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes
title_fullStr Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes
title_full_unstemmed Electrical Stimulation of Afferent Neural Pathways for Suppression of Urethral Reflexes
title_sort electrical stimulation of afferent neural pathways for suppression of urethral reflexes
publisher Case Western Reserve University School of Graduate Studies / OhioLINK
publishDate 2009
url http://rave.ohiolink.edu/etdc/view?acc_num=case1246392300
work_keys_str_mv AT marianotimothyyu electricalstimulationofafferentneuralpathwaysforsuppressionofurethralreflexes
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