BLADDER-SPHINCTER DYSFUNCTION IN CHILDHOOD

BLADDER-SPHINCTER DYSFUNCTION IN CHILDHOOD

STEPHEN A. KOFF, M.D.

From the Pediatric Urology Service, C. S. Mott Children’s Hospital,
and the Section of Urology, Department of Surgery, University of
Michigan Medical Center, Ann Arbor, Michigan

ABSTRACT - While it is obvious that the combination of elevated intravesical pressure, urinary
tract infection, and rejux can be devastating to the upper urinary tracts, it has been appreciated
only recently that a single mechanism, obstruction due to disorders of vesicourethral function,
can produce all three pathologic phenomena in neurologically normal children. Advances in pediat-
ric urodynamics now permit these patients to be recognized and their particular pattern of bladder
and sphincter dysfunction to be diagnosed with certainty. Individualized therapy aimed at the un-
derlying functional disturbance is often successful and may make surgical therapy unnecessary.

The idea that urinary tract infection, obstruc- increasing impact on the over-all management
tion, and vesicoureteral reflux can be manifesta- of childhood urinary tract disease. In some
tions of disordered function of the lower urinary cases, unidentified.*‘and untreated voiding dys-
tract in normal children has been slow to function has been shown to be responsible for
evolve. This notion ‘appears to upset traditional failure of surgery to correct reflux while in many
urologic principles which focus on anatomic and instances treatment of underlying vesicourethral
bacteriologic causes for urinary tract dysfunc- disturbance has eliminated recurrent infection
tion. Consequently, in the absence of structural and allowed reflux to disappear spontaneously.
obstruction, the child with urinary tract infec- Consequently, physicians who care for children
tion and reflux has been considered usually to with urinary tract infection and reflux must be
have an idiopathic disease. Recent devel- aware of these pathologic disturbances of blad-
opments in the field of urodynamics, however, der and sphincter function which produce
support this concept by demonstrating that obstruction and must be able to diagnose and
obstructing urinary tract lesions may be caused treat them adequately.
by incoordination between the bladder and the
urinary sphincter and may be as severe and as In the following discussion we will examine
pathophysiologically significant as those pro- the important syndromes of disordered lower
duced by anatomic obstruction. Widespread use urinary tract function occurring in normal chil-
of newer urodynamic techniques has permitted dren after first reviewing the development of
an accurate definition of these functional voiding normal bladder and sphincter control.
disturbances and has documented their frequent
occurrence in neurologically normal children. Development of Normal Urinary Control

The most striking feature of significant void- In the infant, micturition occurs as a simple
ing disturbances is that they begin to develop at spinal cord reflex. When increasing amounts of
about the time of toilet training and appear to bladder urine sufficiently stimulate the afferent
represent aberrant or improperly learned pat- limb of the reflex arc, contraction of the de-
terns of urinary control. Recognition of this rela- trusor occurs. Even in the infant, the periure-
tionship to toilet training and appreciation of the thral striated muscles which comprise the vol-
significance of dysfunctional voiding has had an untary (external) urinary sphincter are fully

UROLOGY / MAY 1982 / VOLUME XIX, NUMBER 5 457

integrated into the voiding reflex. As the bladder bladder and sphincter function. Provided that
fills, the urinary sphincter constricts progres- these are neither sustained nor repetitive they
sively to prevent incontinence. During micturi- do not appear to be of any long-term conse-
tion, reflex relaxation of the sphincter occurs quence. However, those disturbances of
simultaneously to permit low-pressure bladder bladder-sphincter function which are identified
emptying. and persist after attempted toilet training gen-
erally increase in pathologic significance as the
As the child matures, toilet training success child becomes older. For purposes of discussion
and the achievement of urinary control depend these disorders can be subdivided according to
on the outcome of three separate events in the whether the dysfunction occurs during bladder
development of bladder form and function.’ filling or during bladder emptying.
First, the capacity of the bladder must increase
to permit it to function as a reservoir. Second, Detrusor-sphincter dysfunction during bladder
voluntary control over the periurethral striated filling
muscle sphincter must occur to allow decisive
initiation and termination of micturition. As The infantile, unstable, or so-called uninhib-
with other acquired striated muscle skills, ited bladder is a pattern of urinary dysfunction
sphincter control fits into the orderly scheme of which is so common in childhood that often it is
developmental landmarks and usually occurs by not considered an abnormality at all. Indeed,
the age of three years. Third, direct cortical since uncontrolled contractions are the normal
control over the spinal cord micturition reflex mechanism for infant micturition, it is likewise
must develop in order for the child voluntarily unclear how and when they become pathologic.
to initiate or inhibit detrusor contraction. This Considered as an isolated event, the dysfunction
last step in the development of urinary control caused by these contractions will never appear
is probably the most complicated, but once ac- to be more of a problem than enuresis or incon-
complished, the ability voluntarily to void or in- tinence; their pathophysiologic significance,
hibit voiding at any degree of bladder filling sets however, becomes obvious when examined in
the human child apart from all other mammals the context of toilet training and learned voiding
(except the canine).* control.

Eventually, by the age of four years, most Uninhibited bladder contractions are involun-
children are toilet trained and have developed tary and unsuppressible detrusor contractions
the adult pattern of urinary control. During which occur in children who have failed to gain
filling of the bladder, this pattern is char- complete voluntary control over the micturition
acterized by an absence of uninhibited or infan- reIlex.4*7-‘0 Their causation is unknown. They
tile detrusor contractions. Urodynamic studies appear to represent either a delay in central
confirm that even at bladder capacity, when the nervous system maturation or a developmental
desire to void is strong, no detrusor contraction regression with persistence of the infantile pat-
will occur unless initiated voluntarily. With tern of spontaneous bladder emptying.’ Al-
reflex constriction of the urinary sphincter mus- though the uncontrolled contractions do not
cles occurring progressively during bladder normally occur after the age of toilet training,
filling, their contraction will become maximal at they do not represent a neuropathy, and
bladder capacity. When detrusor contraction is neurologic disease is rarely identified. Were it
voluntarily started, simultaneous reflex relaxa- not for the fact that toilet-trained children have
tion of the sphincter permits low-pressure blad- become physiologically able to constrict the uri-
der emptying and normal urinary flow ratesa nary sphincter and have learned the social vir-
tues of being continent, the uninhibited bladder
Syndromes of Detrusor-Sphincter Dysfunction would probably be of no clinical or pathologic
significance.
In neurologically normal children the dis-
orders of vesicourethral function which are sig- The pathologic significance of uninhibited
nificant enough to cause urinary tract infection, contractions depends entirely on the child’s vol-
reflux, and urologic disease appear to represent untary response to them which can be assessed
abnormalities of toilet training and aberrations using modern urodynamic techniques. Because
in the development of normal urinary control.4-7 uninhibited contractions are involuntary and
It is likely that all children in making the transi- unsuppressible, the child attempting to main-
tion from infantile to adult patterns of urinary tain continence during such contractions must
control transiently display abnormalities of voluntarily and tightly constrict the urinary

B3 UROLOGY / MAY 1982 1 VOLUME SIX. NUMBER 5

sphincter to stay dry. This results in a simul- travesical anatomic distortions in children with
uninhibited contractions. Trabeculation, sac-
taneous and unphysiologic contraction of both cules, diverticula, and abnormalities of the ure-
teral orifices have been regularly observed in
bladder and sphincter which has been termed the absence of anatomic obstruction, and once
acquired these changes tend to persist long after
detrusor-sphincter dyssynergia. During the in- the symptoms of bladder dysfunction are eradi-
cated. The occurrence of vesicoureteric reflux
voluntary detrusor contraction, high intravesical in up to 50 per cent of children with uninhibited
bladders indicates the magnitude of the in-
pressures develop and persist until either the travesical disturbance. 4,g The development and
perpetuation of intravesical structural alterations
bladder relaxes or empties. If, on the other and reflux in children with uninhibited bladders
is analogous to the situation which occurs in
hand, the child wishes to void during the unin- true neuropathic bladder disease, the only dif-
ference being that sphincter uncoordination in
hibited contraction, micturition will proceed the uninhibited bladder is induced voluntarily.

normally but at low pressures to completion, The basic approach to treating the uninhib-
ited bladder in childhood is predicated on the
because the urinary sphincter will reflexly relax observation that with maturation children will
outgrow the tendency toward uncontrolled con-
during bladder contraction without volitional in- tractions and will develop the adult pattern of
urinary control. 4~16Until such occurs, the goal of
terference. therapy is elimination of the uninhibited con-
tractions without interfering with normal mictu-
Voluntary constriction of the urinary sphinc- rition. Anticholinergic drugs are the mainstay of
treatment and are used to reduce detrusor
ter during uninhibited bladder contractions has hyperactivity, to increase the threshold volume
at which uninhibited contractions occur, and to
been shown to produce urinary obstruction and enlarge the functional capacity of the bladder.
Our own preference is oxybutynin, which be-
high intravesical pressure which is cause of its long time of activity (six to eight
hours) tends to provide smoother bladder con-
pathophysiologically identical to anatomic trol. High doses are often required (5 mg. tid)
and must be titrated against anticholinergic
obstruction and to the bladder-sphincter in- drug side effects (flushing, dry mouth).” In ad-
dition fluid restriction and frequent voidings are
coordination seen in true neurogenic bladder helpful therapeutic adjuncts to keep bladder
volumes low.
disease.4,11The signs and symptoms in each pa-
The program combining anticholinergic
tient will vary and depend on the frequency and drugs, fluid restriction, and frequent bladder
emptyings has been shown effective in treating
forcefulness of the contractions and on the effec- patients with uninhibited bladder contractions.
Symptoms can usually be eliminated in over 80
tiveness of sphincteric constriction. Reports in- per cent of children. 4,7,gOf interest in support-
ing the etiologic relationship between functional
dicate that the typical features of bladder obstruction and organic urinary tract disease are
reports which have demonstrated that nearly 60
hyperactivity (urgency, frequency, and precipi- per cent of children with uninhibited bladders
and recurrent urinary tract infection can be
tate micturition) occur in about 60 to 70 per maintained free of infection without antimi-
crobials by successful treatment of the uninhib-
cent of patients. 4~’Interestingly, up to one third ited contractions alone. 4,gIn contrast, the struc-
tural abnormalities such as diverticula and
of children have no incontinence, apparently ureteral orifice changes with reflux do not

due to their ability to overcome bladder con-

traction by tight sphincter constriction - unfor-

tunately, at the expense of raised intravesical

pressure. Characteristically, children with unin-

hibited bladders empty to completion without

residue, and the occurrence of large residual

urine volumes should make the diagnosis sus-

pect. One sign which has been observed so fre-

quently in little girls that it is almost pathog-

nomonic of the condition is the Vincent curtsy,

so named because the child squats and with the

heel of one foot compresses the perineum and

urethra to prevent urinary leakage. l2

Although the precise incidence is unknown,

urinary tract infections occur frequently in chil-

dren with uninhibited bladders and are believed

to be due to the repeatedly high intravesical

pressure elevations. 4,811 The distress in these

patients may be heightened by the sensitizing

effect of infection on bladder mucosal sensory

neurons which increases bladder hyperactivity,

produces pain, and may lead to spasm of the

striated muscle sphincter. 11,13-15

In addition to causing infection, repetitive

obstruction and raised bladder pressures have

been reported to produce a spectrum of in-

UROLOGY / MAY1982 / VOLUMEXIX.NUMBER5 459

appear to respond immediately to improved blad- pected obstruction in patients with unrecog-
der control, although their precise resolution
rates are unknown, nized and untreated detrusor-sphincter dys-

Detrusor-sphincter dysfunction during bladder synergia. 18s25Unfortunately, in the past the
emptying
diagnosis was made too often only after opera-
If obstruction to urinary outflow occurs dur-
ing voiding as a result of disordered bladder and tive failure. Treatment of the sequelae of this
sphincter function, urinary tract infection and
intravesical structural abnormalities can occur. disordered voiding state depends first on an ac-
Collectively these functional disturbances have
been called detrusor-sphincter dyssynergia, curate urodynamic diagnosis, and then on re-
recognizing the pathologic state of simultaneous
bladder and sphincter contraction during at- storing and normalizing bladder and sphincter
tempted micturition. This phenomenon is
common and well recognized in patients with activities. Success has been reported using a
neurogenic bladder disease in whom altered
neural transmissions cause the sphincter to con- wide variety of conventional urologic techniques
strict involuntarily during bladder contraction.
In neurologically normal children, detrusor- and unconventional methods’8-25 which include:
sphincter dyssynergia has been described in
cases in which the incoordination or misuse of intermittent catheterization, timed voidings,
sphincter constriction was voluntary, as a con-
sequence of inproperly learned patterns of uri- bladder retraining, pharmacotherapy, biofeed-
nary control.
back techniques, and hypnosis. The ultimate
The syndrome of the non-neurogenic,
neurogenic bladder, or occult neuropathic blad- goal with any of these techniques is an individu-
der represents the severest form of dysfunc-
tional voiding in childhood. leVz2The obstructive ally tailored program aimed at the patient’s
uropathy often seen in these patients has been
interpreted by some investigators to indicate a specific voiding disturbances.
true but undiagnosable bladder neuropathy.23
Although genuine controversy exists as to pre- Pathophysiologically severe detrusor-
cise origin, Hinman18*1g*21and Allen5~22~24*h2a5ve
demonstrated that many patients appear to have sphincter dyssynergia as occurs in the syndrome
acquired or learned abnormal voiding habits
manifested as detrusor-sphincter dyssynergia. of non-neurogenic, neurogenic bladder is fortu-
That this can be corrected or improved by
noninvasive measures such as bladder retraining nately an uncommon entity, and even at large
is convincing evidence for a functional rather
than a neurologic origin. centers with a particular interest in the prob-

The clinical features of this syndrome include lem, relatively few of these cases have been col-
incontinence that is often chronic and diurnal,
fecal retention and soiling, emotional disturb- lected. More common are the many neurologi-
ances with family psychosocial problems, no
evidence for anatomic or neuropathic bladder tally normal children with less severe symptoms
disease, and a spectrum of structural uropathol-
ogy with bladder trabeculation, diverticula, of voiding dysfunction and minimal or absent
reflux, and hydronephrosis. Urodynamic inves-
tigation typically reveals a large postvoid re- structural pathology. In most instances, these
sidual urine volume and individualized patterns
of bladder-sphincter incoordination during void- lesser disturbances do not require treatment, do
ing.
not tend to progress, and are usually transient,
Attention has been called to the hazards of at-
tempting surgical correction of reflux and sus- reflecting the peculiar but probably normal

ways in which children eventually develop uri-

nary control.

University of Michigan Medical Center

University Hospital, Box 03
Ann Arbor, Michigan 48109

References

1. Nash DFE: The development of micturition control with
special reference to enuresis, Ann. R. COIL Surg. Engl. 5: 318
(1949).

2. Muellner SR: Development of urinary control in children,
JAMA 173: 1256 (1960).

3. Diokno AC, KotT SA, and Bender LF: Perturethral striated
muscle activity in neurogenic bladder dysftmction, J. Urd. 114:
743 (1974).

4. K& SA, Laoides J, and Piazza DH: The uninhibited bladder
in children: a cause for urinary obstruction, infection and reflux,
in. Hodson 1. and Kincaid-Smith P (Ed.+ Refhrx Nep”hropa. thy,
Nkw York, Masson, 1979, p. 161.

5. Allen TD, and Bright TC: Urodynamic patterns in children
with dysfunctional voiding probIems, J. Urol. lH?r 247 (1978).

6. Hinman F Jr: Syndromes of vesical incoordination, Ural.
Clin. North Am. 7: 311 (1980).

7. Bauer SB, et al: The unstable bladder of childhood, ibid. 7:
321 (1980).

8. Johnston JH, Koff SA, and Glassberg Ki: The pseudo-
obstructed bladder in enuretic children, Br. J. Ural. Jo: 505
(19’78).
’ 9. ‘KoE SA, Lapides J, and Piazza DH: Association of urinary

460 UROLOGY / MAY 1982 / VOLUME XIX, NUMBER 5

tract infection and reflux with uninhibited bladder contractions 17. Diokno AC, and Lapides J: Oxybutynin: a new drug with

and voluntary sphincteric obstruction, J. Urol. 122: 373 (1979). analgesic and antichohnergic properties, ibid. 108: 367 (1972).

10. Lapides J, and Diokno AC: Persistence of the infant blad- ” 18. Hinman F Jr, and Bauman FW: Complications of ves-

der as a cause for urinary infection in girls, Trans. Am. Assoc. icoureteral operations from incoordination of micturition, ibid.

Cenitourin. Surg. 61: 51 (1969). 116: 638 (1976).

11. Van Cool JD: Bladder infection and pressure, p. 181, op cit.” 19. IDEM: Vesical and uretera) damage from voiding dysfunc-

12. Vincent Sk Postural control of urinary incontinence. The tion in boys without neurologic or obstructive disease, ibid. 169:

curtsey sign, Lancet 2: 631 (1966). 727 (1973).

13. Tanagho EA, Miller ER, Lyon RP, and Fisher R: Spastic 20. Mix LW: Occult neuropathic bladder, Urology 10: l(1977).

striated external sphincter and urinary infection in girls, Br. J. 21. Hinman F: Urinary tract damage in children who wet,

Ural. 43: 69 (1971). Pediatrics 54: 142 (1974).

14. Tanagho EA, and Miller ER: Abnormal voiding and urinary 22. Allen TD: The non-neurogenic, neurogenic bladder, J.

tract infection. Int. Ural. Nenhrol. 4: 165 (1972). Urol. 117: 232 (1977).

15. Van C&l J, and Tan&o EA: External’sphincter activity 23. Dorfman LE, Bailey J, and Smith JP: Subclinical

and recurrent urinary tract infection in girls, Urology 10: 348 neurogenic bladder in children, ibid. 101: 48 (1969).

0-W. 24. Allen TD: Commentarv on dvsfunctional abnormalities of
16. Lapides J, and Costello RT Jr: Uninhibited neurogenic the urinary tract, Ural. Qin. North Am. 7: 357 (1980).

bladder: a common cause for recurrent urinary tract infection in 25. IDEM: Vesicoureteral reflux as a manifestation of dysfunc-
normal women, J. Ural. 101: 539 (1969).
tional voiding, p. 171, op cik4

UROLOGY I MAY 1982 / VOLUME XIX, NUMBER 5 461