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.