Bushra A. Fam

Detrusor-Urethral Sphincter Dyssynergia

Inappropriate contraction or failure of relaxation of either the internal (smooth muscle) or external (striated muscle) urethral sphincter or both coincident with detrusor contraction results in a micturitional disorder known as detrusor-urethral sphincter dyssynergia. Based on our clinical experience with more than 200 spinal cord subjects and serial urodynamic observations on some of these individuals from the time of injury, various grades of dyssynergia (1 to 3) were recognized. The duration and completeness of suprasacral cord injury essentially determined the degree of dyssynergia. Internal sphincter dyssynergia was encountered less often in this group. A review in relation to pathophysiology and management of this micturitional dysfunction is presented.

Indication and Results of Semirigid Penile Prostheses in Spinal Cord Injury Patients: Long-Term Followup

During the last 7 years semirigid intracorporeal penile prostheses were inserted in 36 spinal cord injury patients between 21 and 58 years old (average age 38.5 years). An operation was done 1 to 32 years after the initial injury (average 10 years). Surgical intervention was intended to provide an adequate body to the penile shaft so as to hold an external urinary drainage device in 11 patients, for treatment of sexual dysfunction only in 17 and for an external urinary drainage device plus treatment of sexual inadequacy in 8. Although a number of complications causing extrusion or removal of the prosthesis occurred in 6 patients (16.5 per cent), as well as an aborted operation in 1 (19.5 per cent), there were no permanent sequelae. Because of loss of sensation and vasomotor control, and pressure produced by the penile prosthesis spinal cord injury patients represent a higher operative risk than other patients without neurological or vascular impairments. In addition, urinary tract infection should not be overlooked as another major risk factor. Penile prostheses were most successful in maintenance of external urinary appliances in patients with a short or retractile penis. Whenever the prosthesis was intended for sexual intercourse an important prerequisite to a successful surgical outcome was the retention of some reflexogenic or psychogenic erection over and above the rods. Careful individual preoperative assessment is advised if a satisfactory result is to be achieved.

Urethral Striated Sphincter Responses to Electro-Bulbocavernosus Stimulation

Electric stimuli of known strength, duration and frequency were applied to the glans penis, and the cystosphincterometric and electromyographic responses of the urethral striated sphincter were recorded. Studies performed on male subjects, including normal men, patients with a neurologic deficit and patients who had undergone prostatectomy, indicate the usefulness of this technique in evaluating the striated sphincter excitability via the pudendal reflex arc. The intravenous administration of diazepam produced a notable increase in the striated sphincter threshold, indicating the applicability of this technique to evaluate the effect of various neuropharmacologic agents on the striated sphincter activity. In addition, the transit time through the pudendal reflex arc was measured with this method to assess the somatic neural integrity of the lower urinary tract. Also, studies on patients with post-radical prostatectomy incontinence have suggested that our technique of striated sphincter evaluation could be applied to the prediction of postoperative urinary incontinence.

5-microtransducer catheter in evaluation of neurogenic bladder function

Recent use of the multiple microtransducer catheter in the evaluation of neurogenic bladder due to spinal-cord injuries leads us to believe that the use of the inferior edge of the symphysis pubis as the zero point for resting bladder pressure is more accurate than its superior edge, changes in resting bladder pressure at various volumes are influenced more by body position than by intravesical position of the sensor, back-to-back microtransducers indicate significant pressure difference at the external sphincter zone, and detrusor bladder neck dyssynergia during autonomic dysreflexia in patients with spinal cord injury is more likely of skeletal than of smooth muscle origin.

Role of Striated and Smooth Muscle Components in the Urethral Pressure Profile in Traumatic Neurogenic Bladders: A Neuropharmacological and Urodynamic Study. Preliminary Report

Urodynamic investigations with urethral pressure profile, and vesical, intrarectal and anal pressure recordings were performed in 37 patients with spinal cord lesions. The recordings were done before and after phentolamine injections and/or pudendal nerve blocks to evaluate the respective contribution of sympathetic and somatic innervation to the maximum urethral closure pressure in the mid and distal portions of the membranous urethra. A pressure gradient was demonstrated in the membranous urethra with higher values in the distal than in the mid portion. These results emphasize that the interrupted withdrawal technique is superior to the continuous technique in patients with upper motor neuron bladders. Mid urethral striated and smooth muscle components were shown to represent approximately 60 and 30 per cent of the maximum urethral closure pressure, respectively. In the distal urethra striated and smooth components are more abundant than in the mid portion and contribute in equal proportion to the maximum urethral closure pressure. No substantial role was found for the vascular bed in the maximum urethral closure pressure. The greatest pressure decrease in the mid and distal urethra of patients with lower motor neuron bladders was believed to be an effect of denervation supersensitivity. The results of pudendal blocks showed sphincter dyssynergia to be mediated through pudendal nerves via spinal reflex arcs. Phentolamine effects on bladder activity suggest that blockade of alpha-adrenergic receptors inhibits primarily the transmission in vesical and/or pelvic parasympathetic ganglia and acts secondarily through direct depression of the vesical smooth muscle. Our neuropharmacological results raise strong doubts as to the existence of a sympathetic innervation of the striated urethral muscle in humans.

Functional contribution of autonomic innervation to urethral striated sphincter: studies with parasympathomimetic, parasympatholytic and alpha-adrenergic blocking agents in spinal cord injury and control male subjects.

Mechanisms underlying urethral pressure changes at the external sphincter region after administration of neuropharmacologic agents were investigated with cystosphincterometric studies and electromyography of the external urethral sphincter in adult patients with spinal cord injury and control male subjects. Bethanechol chloride, propantheline or phentolamine were administered to 37 spinal cord injury men and 3 normal controls. After cystectomy 3 additional spinal cord injury patients were subjected to bethanechol studies. The results of these studies suggested that the pressure changes in the external sphincter zone were caused predominantly by the concurrent changes produced in the detrusor and/or the smooth muscle components of the proximal urethra and of the external sphincter zone.

Urodynamics in spinal shock patients.

We investigated 17 spinal shock patients with traumatic complete cord lesions with cystometry, urethral pressure profile, anal and rectal pressure recordings, and electromyography 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 electromyographic activity. These results indicate an increased sympathetic activity in the smooth muscle component of the entire urethra. In the majority of patients the continuous withdrawal pressure profile had higher values in the membranous urethra than the interrupted 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 somewhat decreased electromyographic 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 sphincters escape spinal shock, the primary characteristic of which is areflexia.

Functional striated sphincter component at the bladder neck: clinical implications.

Anatomical proximal extension of the striated urethral sphincter muscle towards the bladder neck was assessed functionally in normal male subjects and in patients with upper motor neuron lesions. Synchronous cystosphincterometric studies were performed and urethral pressure responses were studied (contraction complexes) at the vesicourethral junction, the supramontane prostatic urethra and the membranous urethra to repeated bulbocavernosus stimuli. All subjects demonstrated positive responses at the membranous urethra. Contraction complexes with amplitudes of less magnitude were elicited at the vesicourethral junction and at the supramontane prostatic urethra in 48 and 71 per cent of the total number of subjects, respectively. The functional significance of the striated muscle component at the bladder neck in patients with detrusor-striated sphincter dyssynergia is described.

Striated Sphincter Participation in Distal Passive Urinary Continence Mechanisms: Studies in Male Subjects Deprived of Proximal Sphincter Mechanism

Striated urethral sphincter function was studied in passive incontinent and continenet male subjects who were deprived of the proximal sphincter mechanism. Functional assessment of striated urethral sphincter include electromyography and electrostimulation. Varying degrees of diminished striated sphincter excitability and reflex activity were observed in passive incontinent male subjects who also had varying degrees of somatomotor neuron lesions. The studies indicate that the participating role of periurethral striated musculature in distal passive continence mechanisms cannot be ignored.

Management of neurogenic bladder in female spinal cord injury patients.

Twenty-two female spinal cord injury patients were admitted to the Spinal Cord Injury Service at the West Roxbury VAMC during a period of 17 years (1965-1982). Bladder status and means of drainage were evaluated. Twelve patients (55%) required no means of drainage, nine of them were dry all the time, while the other three needed pamper support to counteract occasional wetness. Seven were on constant indwelling catheters, two were on self-catheterization, while one had an intestinal loop diversion. It appears that female spinal cord injury patients depend more on constant indwelling catheters than their male counterparts. In some instances, female paraplegics do well on self-catheterization. Catheter complications in female spinal cord injury patients appear to be less than in males.