Prospective Study of Transcutaneous Parasacral ElectricalStimulation for Overactive Bladder in Children:Long-Term Results
Patrícia Lordêlo, Paulo Vitor Lima Soares, Iza MacIel, Antonio Macedo, Jr. andUbirajara Barroso, Jr.*From the Department of Urology, Section of Pediatric Urology, Bahiana School of Medicine and Public Health, Salvador-Bahia, Brazil
Submitted for publication April 6, 2009.* Correspondence: Av. Juracy Magalhães Jr.,
2096, Sala 306, Salvador-Bahia, Brazil.
Purpose: We evaluated the long-term success of transcutaneous parasacral elec-trical stimulation for overactive bladder in children.Materials and Methods: We prospectively evaluated children who underwenttranscutaneous parasacral electrical stimulation for overactive bladder. All pa-tients had symptoms of overactive bladder, bell curve in uroflowmetry and lowpost-void residual urine. The procedure was performed using a frequency of 10 Hzfor 20-minute sessions 3 times weekly for a maximum of 20 sessions. Initial andlong-term (more than 6 months) success rates were evaluated.Results: Transcutaneous parasacral electrical stimulation was performed in 36girls and 13 boys with a mean age of 10.2 years (range 5 to 17). Mean followupwas 35.3 months (range 6 to 80). Before treatment urgency, daytime incontinenceand urinary tract infection were seen in 100%, 88% and 71% of cases, respec-tively. Initial success (full response) was demonstrated in 79% of patients forurgency, 76% for incontinence and 77% for all symptoms. Continued success wasseen in 84% of patients for urgency, 74% for daytime incontinence and 78% for allsymptoms. If the 30 patients with at least 2 years of followup were considered,treatment was successful in 73%. Recurrence of symptoms after a full responsewas seen in 10% of cases. Two of 33 patients (6%) with urinary tract infectionbefore the procedure still had infection after treatment.Conclusions: Transcutaneous parasacral electrical stimulation is well tolerated,and demonstrates short and long-term effectiveness in treating overactive blad-der in children. Symptoms eventually will recur in 10% of patients.
Key Words: child; electric stimulation therapy; pelvic floor; urinary
bladder, overactive
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LOWER urinary tract dysfunction is acommon problem in children, appear-ing in about 6% of girls and 3.8% ofboys by age 7.1 This entity is classifiedas overactive bladder, dysfunctionalvoiding, postponed voiding and un-deractive bladder. Overactive bladderis characterized clinically by urgencythat may be followed by daytime in-continence, frequency and holding ma-
treated due to the association with in-ternalizing and externalizing psycho-logical problems, as well as urinarytract infection and vesicoureteral re-flux.3–5 Recent studies have revealedthat many adults with lower urinarytract symptoms had bladder dysfunc-tion as children.6,7
Traditionally OAB has been treatedwith anticholinergics. However, their
usage is based on nonrandomized
Vol. 182, 2900-2904, December 2009Printed in U.S.A.
DOI:10.1016/j.juro.2009.08.058
PARASACRAL ELECTRICAL STIMULATION FOR OVERACTIVE BLADDER 2901
clinical trials and they are associated with a low rateof complete resolution of symptoms.8 Additionallydrug treatment has several drawbacks, includingthe need for long-term administration, poor compli-ance and side effects.9,10
Electrotherapy has emerged as an alternative totreat patients with OAB. However, most publishedstudies have used electrotherapy at sites that areuncomfortable for children (penile, anal and percu-taneous sites).11,12 Hoebeke13 and Bower14 et alwere the first to use TCPSE in children with LUTS,reporting a good success rate. Nevertheless, theirresults are confounded by concomitant administra-tion of anticholinergics in many patients. Also, du-ration of treatment was long (several months),which makes diffusion of the method difficult. Re-cently we published a pilot study of children withOAB using ambulatory TCPSE at 10 Hz frequencyfor 20-minute sessions 3 times weekly for a maxi-mum of 20 sessions.15 In that series no patient tookanticholinergics before or during treatment. We ob-served that 63% of patients had complete symptom-atic improvement and 20% had significant improve-ment. The objective of the current study was toevaluate the long-term results of this ambulatoryshort course TCPSE.
MATERIALS AND METHODS
We prospectively evaluated children with OAB symptomswho underwent TCPSE with a minimum followup of 6months. OAB was defined as presence of urgency with orwithout urge incontinence, an associated bell curve inuroflowmetry, post-void residual urine less than 10% ofexpected bladder capacity on ultrasound and more than 3voids daily recorded in the voiding diary. Post-void resid-ual urine was less than 5 ml in 44 patients, 5 to 20 ml in3 and not recorded in 2. No child presented with post-voidresidual urine greater than 20 ml. A rigorous voidinghistory was taken using a structured nonvalidated ques-tionnaire. The severity of daytime incontinence and noc-turnal enuresis was divided into the 4 categories of 5 to 7episodes, 3 to 4 episodes, 1 to 2 episodes and less than 1episode weekly.
Speech, motor coordination, limb sensitivity, bulbocav-ernosus and ischiocavernosus reflex, and tonicity of theanal sphincter were routinely examined. The lumbosacralarea was evaluated for signs of spina bifida. All childrenwith a suspected neurological disorder were evaluated bya neurologist and excluded from the study, as were thosewith anatomical anomalies of the lower urinary tract orless than 6 months of followup.
TCPSE was performed at the office using 2 superficial3.5 cm electrodes placed on each side of S3 (see figure),with electrical energy produced by a generator (DualpexUro 961, Quark®). A frequency of 10 Hz was used with agenerated pulse of 700 �s. Frequency was increased to themaximum level tolerated by the child. TCPSE was per-
formed 3 times weekly for 20-minute sessions. Number of
sessions varied according to outcome, with a maximumof 20.
One month before TCPSE and during followup we rec-ommended behavioral training consisting of voiding every3 hours or at onset of desire to void and avoidance of tea,coffee, sodas and chocolate. The training is described in abooklet with illustrations indicating the need to void be-fore sleeping, increase daily volume of ingested liquid, eatfoods rich in fiber and avoid postponing voiding whensymptoms of urgency are present. Girls are asked to pri-oritize voiding comfort by avoiding sitting on a toilet seatwith an overly large opening. The booklet suggests optionsof toilet seat adapters and foot supports to adjust forheight issues. Only patients who do not improve signifi-cantly with this approach progress to TCPSE.
To evaluate the effectiveness of the method, caregiverswere asked about the presence of OAB symptoms accord-ing to ICCS definition, as follows.2 Initial outcome wasdefined as nonresponse (0% to 49%), partial response (50%to 89%), significant response (90% or greater) or full re-sponse (100%) in decreasing symptoms. Long-term out-come was defined as relapse (symptom recurrence morethan monthly), continued success (no relapse at 6 monthsafter treatment) and complete success (no relapse at 2years after treatment).
Outcome concerned only daytime symptom resolution.Persistence of nocturnal enuresis as the only symptomwas not considered a failure because it may have a differ-ent physiopathological process. Children were asked toreturn for evaluation 1 month after the last treatmentsession. Parents were asked to rate symptom improve-ment as “complete,” “significant,” “mild” or “no improve-ment.” Also, parents were asked to rate the percentage ofimprovement on a scale of 0% to 100%. Return visits werescheduled at 3-month intervals during the first 2 yearsand 6-month intervals thereafter. Patients who did not
Parasacral superficial electrode placement for electricalstimulation.
return were contacted by telephone.
PARASACRAL ELECTRICAL STIMULATION FOR OVERACTIVE BLADDER2902
RESULTS
TCPSE was performed in 36 girls and 13 boys withan average age of 10.2 years (range 5 to 17). Fol-lowup ranged from 6 to 80 months (average 35.3).Before treatment all patients presented with symp-toms of urgency and holding maneuvers to avoidurinary loss. Of the patients 43 (88%) also had day-time incontinence. Distribution of patients accord-ing to daytime incontinence and nocturnal enuresisseverity is outlined in table 1. UTI was detected in35 patients (71%), of whom 54% had 3 or moreepisodes.
Initial Success
Two patients did not have outcome registered imme-diately after treatment. The majority of patientsreported a full response for urgency, incontinenceand all symptoms. When we asked parents aboutpercentage of symptom improvement 25 reported100%, 6 reported 90% to 99%, 2 reported 80% to89%, 3 reported 50% to 59% and 1 reported less than50% improvement. Data for 12 patients were miss-ing.
Long-Term Success
Table 2 outlines long-term success of TCPSE. Forurgency 41 cases had continued success, 3 had per-sistent symptoms and 5 improved only after anticho-linergics. For daytime incontinence 32 cases hadcontinued success, 3 had significant improvement, 4had persistent symptoms and 4 had resolution afteranticholinergics. Continued resolution of all symp-toms was reported in the majority of patients. Asmall percentage of patients with UTI before TCPSEstill had infection after treatment. Nocturnal enure-sis was present in 32 patients (65%) before treat-ment, with 5 to 7 episodes in 21, 3 to 4 episodes in 5,1 to 2 episodes in 3 and less than 1 episode weekly in3. Of these patients 24 (75%) had resolution of symp-toms and 8 (25%) had persistent symptoms.
A total of 30 patients had 2 years or more offollowup available. Complete success was reportedin 22 patients (73%), while 8 (16%) had relapses.After a full response to TCPSE 3 patients (10%) hadsymptoms recur soon after the procedure.
This prospective study demonstrates the long-termefficacy of TCPSE in treating OAB symptoms. Anti-cholinergics were used only when treatment failed.Results of long-term studies of children with LUTDmay be criticized because patients may show markedspontaneous improvement of symptoms. Also, contin-uation of bladder training (urotherapy) in followupsessions could have a positive influence on successrates. However, these results confirm our previousdata, in which TCPSE was effective even shortlyafter the procedure.15
According to our data, in the first month aftertreatment the majority of children had a full re-sponse for daytime incontinence and urgency. Theseresults were maintained through time. Consideringonly cases with at least 2 years of followup, 73% hadcomplete success and 27% relapsed. Global rate ofUTI after treatment was only 4%. To our knowledgethis study of electrical stimulation for children withOAB has the longest reported followup.
Caldwell was the first to describe the results ofelectrical therapy for LUTD in children.16 However,despite the initial success, invasive techniques ofelectrical stimulation preclude its widespread use inchildren.11,12
Hoebeke13 and Bower14 et al reported the first 2series of TCPSE over S3 for children with OAB.Hoebeke et al evaluated 15 girls and 26 boys. Thesessions used a frequency of 2 Hz and were per-formed daily for 2 hours each for a period of 6months. The patients studied had not achieved ini-tial significant improvement with other types oftreatment for daytime incontinence. Of the patients13 did not respond to treatment. At 1 year the rate ofcomplete resolution of daytime incontinence was51.2%. Bower et al applied home TCPSE in 17 chil-dren, using 1 or 2 sessions daily with a frequency of10 to 150 Hz. Of children with daytime urinaryincontinence 47% had the symptom resolve.
Our series differs from these studies due to thedecreased number and duration of sessions (3 timesweekly, 20 minutes each), decreased frequency (10
PARASACRAL ELECTRICAL STIMULATION FOR OVERACTIVE BLADDER 2903
neously with the procedure. Use of a high frequencyof energy (more than 20 Hz) may be hazardous be-cause it excites the neuromotor system, which in-creases pelvic floor muscle tension. Gladh et al dem-onstrated in cats that a frequency of 5 to 10 Hzbetter inhibited bladder function.11 Our success rateis similar to some series of electrical stimulation andbetter than others.11–14 Possible reasons for this dis-crepancy include differences in study populations(some prior series had less rigid restrictions andincluded dysfunctional voiding cases, and some in-cluded only refractory OAB) and difference in treat-ment method.
As ICCS recommends, our series stratifies type ofLUTD and standardizes final measurements.2 Onlypatients with OAB were included in the study. Allpatients exhibited urgency, the hallmark symptomof OAB, and also had a coordinating void. The out-come was also evaluated using the ICCS recommen-dation, which allows comparison with other series.
No side effects were detected in our study, andcompliance with treatment was good. Usually chil-dren experience a tolerable “pins and needles” sen-sation in the sacral area. When a child reports anyuncomfortable sensation the intensity of the stimu-lus is reduced.
A limitation of our study is the lack of a controlgroup. However, we performed a randomized clinicaltrial comparing children with OAB who underwentTCPSE (test group) with a sham group (controlgroup) who underwent scapular stimulation.17 Allpatients underwent 20 sessions of 20 minutes each,3 times weekly. A total of 33 patients completedtreatment (test group 19, sham group 14). In the testgroup 63.2% and 37.8% of parents, respectively, re-ported complete resolution and significant improve-ment of symptoms. In the sham group complete res-
olution and significant improvement were reported
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The mechanism of action of electrical stimulationfor OAB has not been established, but we know thatit acts directly on the muscle fibers as well as thereflexes.18 One theory is that electrical stimulationwould inhibit the detrusor contraction by activatingthe sympathetic plexus or inhibiting the parasym-pathetic neurons.19 The reflexogenic mechanism ofaction of intracavitary electrical stimulation hasbeen observed in animals.20–22 However, recentstudies have revealed a supraspinal action of elec-trical stimulation.
Liao et al investigated whether brain reorganiza-tion occurred along with clinical improvement aftersacral root stimulation.23 Six patients 33 to 68 yearsold with idiopathic OAB were included in the study.All exhibited clinical improvement after sacral rootstimulation. Transcranial magnetic stimulation wasapplied to study motor cortex excitability and thebrain mapping of the muscle. Motor cortex excitabil-ity and area of representation for the flexor hallucisbrevis muscle increased for at least 30 minutes aftersacral root stimulation was terminated. These re-sults show that sustained sacral root stimulationmay reorganize the human brain and its ability toexcite the motor cortex, modulating lower urinarytract function.
CONCLUSIONS
TCPSE is a well tolerated and effective method fortreating OAB in children in short and long-termfollowup. Rate of complete response with this treat-ment is about 73%. Only 6% of patients with a his-tory of UTI still had infection after the procedure.We expect that 10% of the patients will have recur-
rence of OAB symptoms after TCPSE with time.
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EDITORIAL COMMENTS
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I congratulate the authors on a nice study with goodlong-term followup. There are several issues thatcould have been addressed but were lacking. Theexplanation regarding how this treatment modalityworks is interesting but the references cited dateback to the early 1970s. Much has been learnedsince then, especially with newer neuroimagingtechniques in humans.
One wonders whether the authors would havehad the same success rate as other studies cited ifthey had treated the same class of patients (refer-ences 12 to 14 in article). Does the 26% incontinencerate at 2 years apply to the same class of patientsthe other authors were dealing with when they be-gan treatment? This is an important question that
appealing and intriguing is that a large number ofpatients responded to this treatment and remainedsymptom-free without medications. If we see thismodality as modifying supraspinal pathways or inthe simplest form, it may just be leading to a reduc-tion of urgency during the treatment period. It maybe that elimination of the urgency (guarding reflex)leads to normalization of voiding without the pres-ence of abnormally increased outlet resistance, andthe eventual return of normal detrusor and/or pos-sibly up-regulated receptors and/or neurotransmit-ters in the bladder or spinal cord.
Israel Franco
Department of UrologyNew York Medical College
will need to be answered in future studies. What is Valhalla, New York
This report concerns the prospective study of trans-cutaneous parasacral electrical stimulation to treatsymptoms of overactive bladder in children. The sig-nificance of the article is that it is a long-term studyfrom a series first published in 2006. The parasacralcutaneous pads and use of transcutaneous electricalnerve stimulation at 10 Hz 3 times weekly for 20minutes for a maximum of 20 sessions is signifi-cantly less onerous than previously published stud-ies.
The authors report success rates for the symp-toms of overactive bladder in the 70% or betterrange, which is an improvement over recently pub-lished studies. The results are based on reportedpercentile improvements in symptoms of overactivebladder rather than strict urodynamic criteria. Theyrecognize the lack of strict science that might havebeen derived from followup urodynamics but sug-
this group. Additionally although there is no specificplacebo group in this series, the authors interest-ingly compared the parasacral group to a group ofpatients who underwent scapular stimulation, andobserved a clear benefit in the former.
A possible weakness of the study was that caseswith successful stimulation were continued on con-servative management (bladder training). One won-ders whether the positive effects seen in the longterm were due to conservative urotherapy in addi-tion to stimulation.
The 2-year followup and excellent results achievedwith this therapy are noteworthy. This technique maybe helpful in patients with failed conservative uro-therapy for overactive bladder.
William E. Kaplan
Division of Pediatric UrologyNorthwestern University Feinberg School of Medicine
