An electromyographic study of detrusor sphincter dyssynergia in neurogenic vesical dysfunction. Part 2. Changes after radical transurethral resection of prostate and response to alpha-adrenergic stimulation

Abstract

The relevance of the type of detrusor sphincter dyssynergia (DSD) and motor unit analysis as examined by simultaneous recordings of electromyography (EMG) of the external urethral sphincter (EUS) and bladder pressure was discussed in the first report. In this report, they were analysed similarly before and after radical transurethral resection of the prostate (TUR-P) to see how it was effective in relieving DSD. Furthermore, the response of the EUS to alpha-adrenergic stimulation was examined by analyzing its motor unit activity. Radical TUR-P was performed in 18 cases. After radical TUR-P, there was an improvement in the type of DSD (3 cases) or in its sub-types (8 cases), associated with decrease in residual urine rate in 16 cases. EUS responded to alpha-adrenergic stimulation with an increase in the frequency of pre-existing motor units and recruitment of new motor units. After radical TUR-P,EUS was similarly activated when stimulated with alpha-adrenergics. These data indicated that radical TUR-P was effective in relieving DSD by suppressing or abolishing abnormal continence reflex. Moreover, alpha-adrenergic activation of EUS also seemed to suggest a possible sympathetic role in the genesis of DSD, although exact mode of its involvement in the somatomotor innervation of the EUS remains to be settled.