There are two reflex control mechanisms of the bladder, opening (micturition) and closure (continence). These reflexes concern, in particular, urge incontinence. Both of these reflexes are controlled by CNS feedback systems. Afferent signals from stretch receptors are conveyed to the brain. These are processed. Depending on circumstances, the brain sends out efferent signals to activate directional muscle forces to retain or expel the urine. These forces act against suspensory ligaments. If the ligaments are loose, the muscle forces weaken, so both modalities, closure (continence) and micturition opening (evacuation) may become dysfunctional to cause the appropriate symptoms. All bladder symptoms reflect inability to close (incontinence) or open (evacuation difficulties) or the afferent signals themselves (urgency). In this context, ‘Overactive bladder’ (OAB) symptoms (urge, frequency, nocturia) and ‘Detrusor Overactivity’ (DO) are consistent with a prematurely activated, but normal micturition reflex. The wave pattern characteristic of DO is a function of the two partly activated control mechanisms struggling for dominance, with the time delay expressed as a wave pattern. When the micturition finally dominates, the detrusor spasms and expels the urine.
Corresponding Author: PETROS P.|