URGE INCONTINENCE IN THE ELDERLY - SUPRASPINAL REFLEX INCONTINENCE

It is generally accepted that the bladder is controlled by centers in the pens, which determine whether it is in the storage or emptying mod e. The current view is that higher cortical influences on the pontine micturition center are responsible for which mode the bladder is in an d switch on voluntary voiding at an appropriate moment. Moreover, the coordination between detrusor and sphincter is also located in the pon tine area. Age-related degenerative and illness-related changes within the cerebrum should therefore predispose to bladder dysfunction. As t he net effect of the various cerebral structures involved in:micturiti on is an inhibitory one, such processes should cause impaired bladder control associated with the clinical symptoms of frequency, urgency, a nd urge incontinence and with the urodynamic findings of detrusor over activity. Therefore, it is not surprising that epidemiology studies ha ve found a positive association between age and urinary incontinence, predominantly that of the urge type. Urinary incontinence affects 15-3 0% of community-dwelling adults over the age of 65 years; among home-b ound older adults the prevalence of urinary incontinence increases to 43%, and it is even greater in nursing homes [29], ranging up to 70% w ith a variability depending on criteria for admission to nursing homes , definitions used, and country-to-country variability. If the definit ion is extended to include ''dependent continence,'' whereby the patie nt is dry only because of the assistance of staff or care providers, t hen the percentage in nursing homes rises by at least a further 10% [1 0, 23]. Urinary incontinence, especially in the elderly, has a major i mpact on the quality of life as well as far-reaching medical and socio economic implications. Particularly in the elderly, continence depends not only on the integrity of lower urinary tract function but also on the presence of adequate mental and physical function. Nevertheless, impairment of the control of the brain over the bladder is perhaps the most frequent reason for incontinence in this age group. Cerebrovascu lar diseases may damage the neurologic pathways involved in maintainin g continence. It is well known that discrete or diffuse degenerative c hanges within the central nervous system increase with age, as do bett er defined clinical conditions such as cerebrovascular insults, Parkin son's disease and dementia; Nygaard and Lemke [28] have found that peo ple with stroke are nearly twice as often incontinent and, according t o Wetle et al. [34], nearly 3 times as likely to report difficulty in holding urine most, if not all, of the time. Nygaard and Lemke [28] al so found an association between Parkinson's disease and urinary incont inence, as did Brown et al. [3]. Moreover, increased afferentation due to a pathologic sensory input, e.g., caused by chronic urinary tract infections,may lead to decompensation of previously borderline level o f brain control. Recent studies using positron emission tomography (PE T) scanning have revealed new information about areas involved in blad der control and therefore deserve attention.