The Vesical Sphincter Electromyogram in Children With Normal and Abnormal Voiding Patterns

0022-534 7/83/1291-0092$02.00/0 Vol. 129, January

THE JOURNAL OF UROLOGY

Printed in U.S. A.

Copyright© 1983 by The Williams & Wilkins Co.

THE VESICAL SPHINCTER ELECTROMYOGRAM IN CHILDREN WITH NORMAL AND ABNORMAL VOIDING PATTERNS MAX MAIZELS, WILLIAM E. KAPLAN, LOWELL R. KING AND CASIMIR F. FIRLIT From the Division of Urology, Children's Memorial Hospital and Department of Urology, Northwestern University Medical School, Chicago, Illinois, and Department of Urology, Duke University Medical Center, Durham, North Carolina

ABSTRACT

Recording the vesical sphincter electromyogram clarifies abnormal patterns of voiding in children. Since the electromyogram patterns in children with normal voiding patterns have not yet been evaluated, we recorded the sphincter electromyograms during voiding of 39 children with normal voiding patterns. These normal electromyograms were compared to those recorded in 86 children with abnormal voiding patterns. Each of the 39 children with a normal voiding pattern demonstrated synergy of the vesical sphincter during voiding. Of the 86 children with an abnormal voiding pattern 69 per cent demonstrated synergy and 31 per cent demonstrated dyssynergia of the vesical sphincter during voiding. Of the children with dyssynergia 89 per cent were girls and only 11 per cent were boys. Sphincter dyssynergia was demonstrated only by children with an abnormal pattern of voiding and those with a history of a normal pattern of voiding demonstrated only sphincter synergy (p less than 0.005). The electromyographic diagnoses ofvesical sphincter synergy and dyssynergia obtained by surface electrode recordings correlated with the clinical voiding patterns of the children. Children who are incontinent of urine constitute a major group seeking urologic care. When physical examination or diagnostic x-rays do not disclose a responsible anatomic abnormality, the incontinence is labeled as a functional disorder of voiding. Disorders of voiding may be evaluated by monitoring the vesical sphincter electromyogram. 1· 2 Previously, monitoring the electromyogram had been restricted to children with recognized voiding abnormalities because the insertion of wire electrodes was painful or required general anesthesia. Electromyograms have not yet been recorded in a series of children with normal voiding patterns. Recently, the application of surface electrodes to the perianal skin allowed the electromyogram to be detected in a noninvasive manner. 2 This technique of surface recording enabled us to monitor the vesical sphincter electromyogram patterns of children with clinically normal voiding patterns, and we herein present our results. We have found that children with normal voiding patterns demonstrate only sphincter synergy, while children with abnormal voiding patterns may demonstrate either sphincter synergy or dyssynergia.

the vesical sphincter and pelvic floor musculature during voiding. Vesical sphincter dyssynergia was diagnosed when there was a sustained increase in the amplitude of the electromyogram activity recorded during voiding. This electromyogram pattern was viewed to reflect contraction of the vesical sphincter and pelvic floor musculature during voiding. When children are apprehensive bursts of electromyogram artifact may be recorded. In these instances testing was repeated after the children were reassured to eliminate artifacts. Statistical analysis was performed using the chi-square test, which included Yates correction factor. 3 RESULTS

Sphincter electromyogram patterns. The study included 125 children between 3 and 22 years old. There were 27 boys and 12 girls judged to have clinically normal patterns of voiding and urologic diagnoses unassociated with a voiding dysfunction. Each of these 39 children demonstrated synergy during voiding (fig. 1). There were 37 boys and 49 girls judged to have clinically abnormal patterns of voiding. Of these 86 children 59 demonstrated synergy (table 1) (fig. 2, A), while 27 demonstrated dyssynergia (table 2) (fig. 2, Band C). Dyssynergia was the only abnormality in 19 children with voiding pattern abnormalities and a history of urine infection (table 2). Of the 27 children with dyssynergia 24 (89 per cent) were girls and only 3 (11 per cent) were boys (p <0.005). Dyssynergia was demonstrated only in children with clinically abnormal patterns of voiding and those with clinically normal patterns of voiding demonstrated only synergy (p <0.005). Sphincter dyssynergia and urine infection. Of the 61 girls in the study 45 had a history of urine infection. Of these 45 girls 19 (42 per cent) demonstrated dyssynergia. Of the 16 girls without a history of urine infection 5 (31 per cent) demonstrated dyssynergia. It appears that dyssynergia is as common in girls with and without a history of infection. Voiding abnormality and urine infection. Of the 45 girls with a history of urine infection 35 (78 per cent) had abnormal patterns of voiding when the urine was sterile. Of the 16 girls without a history of infection 14 (88 per cent) also had abnormal voiding patterns. It appears that abnormal voiding patterns are as common in girls with and without a history of urine infection. Of the 35 girls with clinically abnormal patterns of voiding

MATERIALS AND METHODS

The study was performed at the Children's Memorial Hospital from June 1980 to March 1981. All children >3 years old who were evaluated in the Division of Urology were eligible for study. Children with a neurologic deficit were excluded from study. History was elicited. If the child exhibited incontinence, urgency, infrequent voiding, dysuria or straining to void when the urine was sterile, a voiding pattern abnormality was diagnosed. If these symptoms were not elicited the voiding pattern was considered normal. The vesical sphincter electromyogram was detected in all children studied using skin surface electrodes.1 Testing was performed only when the urine was sterile. Girls sat and boys stood to void. V esical sphincter synergy was diagnosed when the amplitude of the electromyogram activity recorded was not increased or decreased during voiding. These electromyogram patterns were viewed to reflect relaxation of Accepted for publication March 12, 1982. Read at annual meeting of American Urological Association, Boston, Massachusetts, May 10-14, 1981. Supported in part by Grant RR-05370, United States Public Health Service, National Institutes of Health and Basil O'Conor Starter Research Grant 11770 March of Dimes. 92

VE.SICAL SPJ-IIi...JCTER ELRCTR,OIV1YOGRA1V1

CHILDREbT

B

FIG. 1. A, sphincter synergy in 9-year-old girl with recurrent urine infection. Voiding pattern is normal. Excretory urogram (IVP), voiding cystourethrogram and cystoscopy were normal. Amplitude of electromyogram activity decreases with voiding (volume voided 250 ml.). B, sphincter synergy in 8-year-old boy with recurrent balanitis and phimosis. Voiding pattern is There is no increase or decrease of amplitude of electromyogram activity during voiding (volume voided llO ml.). 1. Results of urologic evaluation of children with a clinically abnormal voiding pattern who demonstrate sphincter synergy

TABLE

Fin.ding Priina:ry diurnal/nocturnal enuresis Urge incontinence with urinary tract infection Infrequent voiding Ectopic ureter i,i Posterior urethral Rule out urethral stricture Strains to void Frequency and abdominal pain, spontaneously resolved Dysuria, no cause found Total

2. Results of urologic evaluation of children with a clinically abnormal voiding pattern who demonstrate sphincter dyssynergia

TABLE

No. Pts. 40 5

5

1 3

2

Findings

No. Pts.

IVP and voiding cystoutre\:hr<)l(r:am normal:

Incontinence Incontinence and urinary tract infection ~--···e-····· voiding and urinary tract infection voiding cystou,re1:hT<)gr:am abnormal: Ureteral reflux, mcon1t1rn,nc:e, urinary tract infection Urethral valves, incontinence, urinary tract infection

7 6

27

Total 59

and a history of urine infection 19 (54 per cent) also demonstrated dyssynergia. Only 5 (36 per cent) of the 14 girls vvith abnormal voiding patterns but no history of infection also demonstrated dyssynergia. It appears that dyssynergia tends to be more common in girls with voiding pattern abnormalities and a history of urine infection than in girls with a voiding pattern abnormality only (p <0.25). Treatment of sphincter dyssynergia. Of the 19 girls with dyssynergia and a history of infection 10 were treated with diazepam, 3 biofeedback, 1 phenoxybenzamine, 2 anticholinergics and 3 observation. Voiding symptoms were resolved in 5 and improved in 5 girls treated with diazepam, resolved in l girl treated with phenoxybenzamine, resolved in 3 girls treated

with biofeedback and improved in 2 girls treated with anticholinergics. Voiding symptoms persisted in all 3 girls treated with observation. DISCUSSION

The electromyographic diagnoses of vesical sphincter synergy and dyssynergia recorded using surface electrodes correlate well with the clinical voiding history of the child. All children with clinically normal voiding patterns demonstrated synergy. Of the children with abnormal voiding patterns 69 per cent demonstrated synergy and their voiding abnormalities were attributed to diagnoses unrelated to a sphincter disturbance (table 1). Dyssynergia was noted only in children with abnormal

94

MAIZELS AND ASSOCIATES

20

FLOW

(cc/sec) 10

FIG. 2. A, sphincter synergy in 5-year-old girl with day and night enuresis. Ectopic ureter drained on vaginal introitus. Electromyograrn demonstrates sphincter synergy (volume voided 100 ml.). lpsilateral ureteroureterostomy resulted in immediate urinary continence. B, sphincter dyssynergia in 12-year-old girl with failed ureteral reimplantation for ureteral reflux. Progressive hydronephrosis and recurrent urine infections followed transureteroureterostomy. She voids with slow, weak stream and is incontinent every day and night. Peak flow rate is 7 ml. per second and there is sustained increase in amplitude of electromyogram activity during voiding (volume voided 100 ml.). C, sphincter dyssynergia in 5year-old girl with urine incontinence each afternoon and night. Urine infections recur. IVP and voiding cystourethrogram are normal. At cystoscopy distal urethral meatal ring was ruptured. Peak flow rate is 13 ml. per second and there is sustained increase in amplitude of electromyogram activity during voiding (volume voided 170 ml.).

voiding patterns and was 8 times more common in girls than boys. A careful history that discloses a normal voiding pattern excludes the possibility of dyssynergia. Since these children were neurologically intact sphincter dyssynergia recorded was probably not a manifestation of a neurologic lesion. Sphincter dyssynergia during voiding appears to result from unintentional, habitual contraction of the muscles of the perianal sphincter/ urogenital diaphragm during voiding. This dyssynergia appears

to be demonstrated only by children, especially girls, with an abnormal voiding pattern. Children with normal voiding patterns demonstrated only sphincter synergy. Therefore, when a child with an abnormal voiding pattern demonstrates sphincter synergy the voiding abnormality must relate to an abnormality of the detrusor, such as the unstable bladder of an enuretic child, the urethra, such as a urethral stricture or the ureter, such as an ectopic ureter on the vaginal introitus. When a child with an abnormal voiding

VESICAL S?IIINCTEft ELECTROivIYOGR.AIVI Il-.J CHILJ)ILEN

pattern demonstrates ,,,-,,1-..,.,,~1,t, v~,,v,CJionn the abnoris related at least part to the sphincter. Further evaluation may disclose other abnormalities. In this series 30 per cent of the children with sphincter dyssynergia had another abnormality that contributed to the abnormality (table 2). A history of urine infection only is not associated with an increased incidence of a voiding abnormality or dyssynergia. Girls with a clinically abnormal voiding pattern and a history of urine infection are likely to demonstrate dyssynergia. The diagnosis of vesical sphincter dyssynergia should be reserved for children who demonstrate dyssynergia on repeated examinations. "Strain dyssynergia" may relate to artifactual bursts of electromyogrnm activity during voiding. 4 These artifacts may be due to poor patient cooperation, poorly applied surface electrodes, movement of the child during voiding when urinary urgency is severe or voiding only small volumes of unne. Technical assistance was provided

Mr. R. Bashoor.

4.

Reading, ]V[assachusetts: Addison-Wesley Publishing Co., chapt. 1980. and Kass, E. J.: Abdominal wall electromyography: a 11oninvasive technique to improve pediatric urodynamic accuracy. J. Urol., 127: 736, 1982.

EDITORIAL COMMENT These authors have contributed significantly to the organization and simplification of the evaluation and treatment of voiding abnormalities in children. This report continues their accomplishments in this area. However, certain questions are bound to occur to the more than casual reader. What is the pathophysiology of the incontinence in the children with the clinically abnormal voiding pattern and sphincter dyssynergia? Is it simply a form of overflow incontinence, or is it related to detrusor hyperreflexia or a form of uncontrollable relaxation of some portion of the bladder outlet? Finally, can the incontinence, assuming that infection is treated in those cases in which it is present, be corrected in all instances simply by correcting the sphincter dyssynergia? If so, then it would seem that a noninvasive attempt at the correction of the sphincter dyssynergia would be the first step in the treatment of these patients and that, until this were done, further sophisticated and invasive u:rodynamic studies should be kept to a minimum. A.J. W.

REFERENCES

1. Sundin, T. and Petersen, I.: Cystometry and simultaneous electro-

myography from the striated urethral and anal sphincters and from levator ani. Invest. Urol., 13: 40, 1975. 2. Iviaizels, M. and Firlit, C. F.: Pediatric urodynamics: a clinical comparison of surface versus needle pelvic floor/ external sphincter electromyography. J. Urol., lilil: 518, 1979. 3. Schaeffer, W. C.: Enumeration data-chi-square and poisson distributions. In: Statistics for the Biological Sciences, 2nd ed.

REPLY BY AUTHORS We agree that more than a casual reading of almost any article that addresses a urodynamic topic suggests further investigations. Since the sphincter electromyogram patterns in normal children had not been examined it appeared appropriate to document these patterns. We also agree that a noninvasive attempt to correct urodynamic disorders is of primary importance. The remaining questions and thoughts posed are appropriate and merit investigation.