The term of detrusor-sphincter dyssynergia, which has appeared in many literatures on neurogenic bladder dysfunction, means the dysfunction of cooperative working of the detrusor and external urethral sphincter. This dyssyneriga contains the following conditions.
1. The external sphincter stays flaccid during the filling phase of the urinary bladder.
2. The external sphincter can not relax when the detrusor begins to contract.
3. When it is impossible to produce a detrusor contraction due to pelvic nerve lesion, voiding action in straining or Credé maneuver leads to contraction of the external sphincter.
The first condition causes urinary incontinence and the latter two conditions lead to the difficulty of micturition.
Clinically, persistent difficulty of micturition causes urinary infection and/or dilatation of the upper urinary tract.
In this paper we described the detrusor-sphincter dyssynergia with difficulty of micturition.
The most common causes of this dyssynergia are the upper spinal cord lesions (upper motor neurone lesions). When these patients have severe spastic paralysis of lower extremities, spasm of the external sphincter leads to acute urinary retention. When the pelvic nerve was injured by intrapelvic surgery and the pudendal nerve was intact, the dyssynergia occurs in consequence of the disturbance of the so-called vesico-urethral reflex arch.
The other common causes are Parkinsonism, disc hernia and myelodysplasia. Inflammatory changes of the bladder and urethra also cause the temporary dyssynergic condition. In some cases of distal urethral stenosis, the dyssynergia is found by precise urodynamic examinations.
As mentioned above, the detrusor-sphincter dyssynergia is not a restricted rare pathological condition, but can be found relatively often, if precise urodynamic examinations are carried out.
A sign of sphincter spasm on voiding cysto-urethrogram suggests the dyssynergia, but for definitive diagnosis electromyographic examination of the external urethral sphincter or perineal muscles is indispensable. To find out the dyssynergic condition, we routinely carried out electromyographic examination of perineal muscles with simultaneous cystometry during micturition.
When the condition is caused by inflammation or distal urethral stenosis therapies to original disease may cure the dyssynergia. But, if the dyssynergia are caused by neurological disorders, it is not so easy to cure the dyssynergia.
Today, many therapeutic procedures are carried out, that is, pudendal neurotomy, sphincterotomy, alcohol block of cauda equina and so on. But these procedures need admission and particulary alcohol block may predispose to complications, paralysis of the lower estxremities.
We have made a new simple pudendal nerve block under the guide of direct nerve stimulation using 5 or 10% phenolglycerin to dissolve the detrusor-sphincter dyssynergia and have been getting good results.
We presented here two typical cases, 34 year-old man with dyssynergia due to vertebral and sacral dysgenesis, and 27 year-old man with spinal cord lesion. After simple phenol block of the pudendal nerve, remarkable improvement of urination has been observed in these two cases.
The technique of this nerve block was described here in detail.
The only problem of this procedure is that the effect of this phenol block disappears within one to three months. But this problem is settled by repeated nerve block which causes degeneration of the pudendal nerve.