Authors: *A. N. HERRITY1,4, C. A. ANGELI1,2,4, E. REJC1,2, S. J. HARKEMA1,2,4, C. H. HUBSCHER1,3;
1Kentucky Spinal Cord Injury Res. Ctr., 2Dept. of Neurolog. Surgery, 3Dept. of Anatom. Sci. and Neurobio., Univ. of Louisville, Louisville, KY; 4Frazier Rehab Inst., Louisville, KY
Spinal cord injury (SCI) results in profound changes to sensorimotor as well as autonomic systems. Deficits in urogenital and bowel function after spinal cord injury profoundly impact quality of life and are ranked as top priority issues in the SCI population. Bladder dysfunction may manifest as a failure to store, characterized by uninhibited bladder contractions and an areflexic outlet or as a failure to empty with an areflexic bladder and a sphincter that is unable to relax. Urinary retention and an inability of the bladder to store urine under appropriately low pressures can lead to infection and ultimately impact renal health. Bowel issues such as frequent constipation can trigger blood pressure increases associated with autonomic dysreflexia. The impact of injury on sexual function includes impairments in genital responses in both male and females. While standard pharmacological therapy aims to manage the prevalent urogenital and bowel issues, therapies addressing recovery of function are still needed. Thus, the objective of this study is to describe the effects of spinal cord epidural stimulation as an alternative approach to improve bladder, bowel and sexual function after SCI. This study included AIS grade A and B subjects (n=8) receiving spinal cord epidural stimulation at L1-S1 spinal levels in combination with activity-based therapy: locomotor and/or stand training, cardiovascular and voluntary motor training by our research team. Urodynamic assessments, with and without the use of spinal cord epidural stimulation, at pre- and post-training time-points and the Spinal Cord Injury Data Set questionnaires for bladder, bowel and sexual function management accompanied each urodynamic procedure. We identified specific configurations and stimulation parameters optimal for continence and micturition in several subjects during filling cystometry. While activity-based therapies have resulted in improvements in bladder capacity and voiding efficiency, this study provides evidence that the use of spinal cord epidural stimulation can further enhance these parameters and in a frequency-dependent manner. Importantly, as capacity increased in these participants, bladder pressures continued to remain low, indicating better compliance. Several participants reported reductions in the time required for defecation post-training as well as enhanced ejaculatory ability. Spinal cord epidural stimulation, along with activity-based training, may help provide an appropriate level of excitation to the spinal cord, targeting the neural circuitry involved in urogenital and bowel function.
A.N. Herrity: None. C.A. Angeli: None. E. Rejc: None. S.J. Harkema: None. C.H. Hubscher: None.
LINK: Society for Neuroscience
Science News Article LINK
PLOS One Article LINK