Bladder Neck Dysynergia in Spinal Cord Injury1

Abstract

Urodynamic evaluations were performed in 43 male patients with spinal cord injuries, before any therapeutic decisions, and a minimum of 5 mo following the injury. Results were subdivided according to level of injury. Mean detrusor contraction pressures, incidence of detrusor-sphincter dysynergia (DSD), and incidence of detrusor-bladder neck dysynergia (DBND) were calculated. The incidence pattern of DBND was found to follow closely the incidence pattern of DSD, with the highest incidence among the upper thoracic injuries, considerably more than among the cervical injuries. A significantly higher resting detrusor pressure differential was found among the patients with DBND. This was felt to represent sympathetic dysfunction and poor accommodation and is proposed to be secondary to adrenergic detrusor neoinnervation.

Bladder Neck Dysfunction in Spinal Cord Injury

“…2). This finding is comparable with that of a previous study, in which patients with thoracic SCI, although they displayed the highest overall incidence of dyssynergia, also displayed the lowest detrusor pressure [20]. Patients with high thoracic or cervical SCI typically have a hyperreflexic detrusor contraction during cystometry.…”

“…Bladder neck dyssynergia can also be diagnosed when the bladder neck is noted to be incompletely or intermittently open during voiding, and a voiding urethral pressure profile discloses a pressure difference of 10 cm H 2 O across the bladder neck. A significantly higher resting detrusor pressure differential was found among the patients with bladder neck dyssynergia, suggesting sympathetic dysfunction and poor accommodation secondary to adrenergic detrusor neoinnervation [20].…”

“…Incidence of bladder neck dysfunction is also highest in high thoracic SCI (27%), second highest in low thoracic SCI (22%), and followed by cervical SCI (7%). No bladder neck dysfunction is seen in lumbar SCI [20]. The influence of sympathetic and pudendal nerve hyperactivity on the detrusor nucleus in sacral cords may be enhanced after SCI, thereby inducing bladder dysfunction and DSD.…”

“…In SCI patients with a lesion above T9, the sympathetic activity abnormally increases, resulting in a strong inhibition of detrusor contractility. Previous studies also demonstrated patients with high thoracic SCI may have low detrusor pressure or underactive detrusor [20]. The recovery period is also prolonged [29•].…”

“…However, normal detrusor contractility is necessary to yield a therapeutic effect after TUI-BN. Patients with areflexic detrusor have been reported to be unable to void spontaneously after TUI-BN [20]. Lockhart et al [38] investigated 15 SCI patients who failed with external urethral sphincterotomy.…”