In the case of a flaccid bladder typical of spinal lesions in the sacral levels of the cord, loss of detrusor muscle tone prevents bladder emptying and leads to bladder wall damage from over-filling, urine reflux and an increase in infection risk due to urine stasis. The external sphincter tone also tends to be flaccid and that can cause incontinence with maneuvers contributing to increased intraabdominal pressure (e.g., “Valsalva” maneuvers) including external pressure, straining during transfers, coughing and sneezing. Internal sphincter tone may, however, be intact due to the higher origin of sympathetic innervation and this may contribute to incomplete emptying, even with externally applied suprapubic pressure.
Compared to DESD, patients with detrusor areflexia comprise a much smaller proportion of the SCI population. Thus, there is very little literature examining the effectiveness of interventions for this latter patient subpopulation (e.g., individuals with detrusor areflexia). The paucity of literature on detrusor areflexia is represented by some individual studies that address both types of bladder dysfunction. Conversely, the current literature more commonly addresses DESD and therefore management and treatment of individuals with DESD appears to be the focus of the review below.