Intermediate detrusor

For prognostic and therapeutic reasons, only functional classifications based on the reflex activity of the different muscle groups involved in storing and evacuating urine should be used. One commonly used classification is based primarily on the reflex activity of the detrusor muscle, defining three types contractile detrusor (detrusor hyperreflexia), acontractile detrusor (detrusor areflexia), and intermediate detrusor (mixed type). 

Einally, external urethral sphincter (voluntary sphincter, or rhabdosphincter) is a striated circumscribing structure emanating from the bladder neck and bladder base detrusor through the mid-urethra in the female and intermediate prostatic urethra in the male. While also surrounding Cowper s glands in the male, these rhabdosphincter subunits contract, most likely, only with ejaculation (Hutch, 1972 Elbadawi, 1980), along with simultaneous anal rhabdosphincter, bulbo-cavernosus muscle, and cremaster muscle contractions. 

Based on the reflex activity of the detrusor muscle and the fact that most children with myelodysplasia do not fit into the classical anatomical and neurological categories, a classification system with three types of bladder dysfunction (contractile, acontrac-tile, and intermediate) is in use (Rickwood et al. 1982). 

The bladder neck is usually competent in infants and children with contractile detrusors, whereas it is mostly nonobstructive and incompetent in children with intermediate or acontractile bladders at their usual bladder volumes. 

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