Alison Williams’ MSc Thesis Proposal

Title: “Exploring pelvic floor muscle sparing in individuals with spinal cord injury using transcranial magnetic stimulation and pelvic floor training exercises”

Supervisor: Dr. Tania Lam (Kinesiology)
Committee Members: Dr. Lynn Stothers (Urologic Sciences), Dr. Mark Carpenter (Kinesiology)

Background: The pelvic floor muscles (PFM) are incredibly important in maintaining urinary continence. Damage and denervation to this muscle group is associated with urine leakage, especially during instances of high intraabdominal pressure. In able-bodied individuals, exercise programs intended to strengthen the core and PFM muscles are considered the first line of treatment against urinary incontinence. However, despite the success of this treatment in the able-bodied population, limited research has explored applying these exercises to those with neurological impairments. One such population includes those with spinal cord injury (SCI), with more than 80% of individuals experiencing bladder dysfunction. PFM training programs may not have been attempted in people with SCI may be because of assumptions about remaining PFM function post-injury. Further, for those with high-thoracic motor-complete SCI, it is often incorrectly assumed that they are unable to engage muscles of the core based on standard neurological assessment. Evidence from previous work has already shown that sparing in abdominal function can be detected using manual palpation, surface electromyography, and with the use of transcranial magnetic stimulation. It remains unknown to what extent the PFM muscles may be similarly spared in this population.

Objectives: To a) evaluate corticospinal excitability to the pelvic floor via transcranial magnetic stimulation and b) characterize and compare activation patterns of pelvic floor, abdominal, and gluteal muscles during validated PFM training exercises among in individuals with motor-complete SCI.

Methods: This study will use a two-part cross-sectional design. In both parts, EMG recordings will be taken bilaterally from rectus abdominis, external obliques, erector spinae, levator ani, and gluteus maximus. In Part 1, participants will receive transcranial magnetic stimulation in supine and supported standing conditions. In Part 2, participants will attempt a variety of validated maneuvers to attempt to elicit PFM activity.

Preliminary Results: Our preliminary results suggest that motor-evoked potentials can be elicited using TMS in able-bodied individuals. Voluntary PFM contractions have been seen in able-bodied subjects, but no voluntary activation has been noted in those with SCI.