Urodynamics in Spinal Shock Patients

Abstract

Spinal shock patients (17) with traumatic complete cord lesions were investigated with cystometry, urethral pressure profile, anal and rectal pressure recordings and electromyography [EMG] of the pelvic floor sphincters. Bladder filling was accompanied by an elevation of resistance in the bladder neck area with a concomitant increase of pressure in the external sphincter zone but without a simultaneous increase of the EMG activity. An increased sympathetic activity in the smooth muscle component of the entire urethra is indicated. In the majority of patients the continuous withdrawal pressure profile had higher values in the membranous urethra than the interrupted withdrawal pressure profile, revealing the importance of sensory afferents from the urethral mucosal receptors in producing artifactual reflex activity in the pelvic floor muscles. In the majority of interrupted withdrawal urethral pressure profiles higher pressures were recorded in the juxtabulbous region than in the mid part of the membranous urethra. A decreased EMG activity was found in the anal and urethral sphincters at rest; it did not often relate to the amount of resistance recorded in either sphincter. High urethral sphincter pressures and somatic activity of the conus medullaris reflexes show that external urethral and anal spincters escape spinal shock, the primary characteristic of which is areflexia.