more than halved in 37% 01' 59 patients with an unstable

bladder. The number 01' leakages also reduced by half in

69% 01' those with urge incontinence. Good symptomatic

results were also reported in a group 01' 55 children aged

6-12 years [32]; 57% and 33% 01' those with daytime

incontinence and bedwetting. respectively. became dry.

while the voiding frequency became normal in 67%.

Site af stimulation. Beneficial resuIts 01' TENS at various

sites have been reported [33]. but few comparative

studies have been undertaken. The possible sites 01'

stimulation are:

. Sacral foramina S2 to S3.

. Sacral dermatomes S2 and S3 (peri-anal region).

. Dorsal penile or elitoral nerve.

. Suprapubic region.

. Thigh museles (quadriceps museles and hamstrings)

[34].

. Common peroneal nerve.

. Posterior tibial nerve.

The published results are conflicting; McGuire et aI.

[35] used traditional acupuncture points for inhibiting

bladder activity over the common peroneal and posterior

tibial nerve in the treatment 01' 15 patients with a

neurogenic bladder dysfunction. and obtained good

symptomatic results in most. However. Hasan et aI.

[29] reported a urodynamic improvement with TENS

over the S2 and S3 dermatomes; but not with TENS over

the posterior tibial nerve and the suprapubic region.

Bower et aI. [30] obtained comparable urodynamic

results with TENS over the suprapubic region and the

sacral foramina.

Lang-term results. The application of TENS is not useful

if the patient is not otTered the opportunity for re-

treatment. either at the elinic or at home. as the

therapeutic etTects outlast the períod 01' treatment only

for a few months. The symptoms 01' 2 5 patients who were

successfully treated by Walsh et aI. [31] returned to

pretreatment levels within 2 weeks in 40% 01' the patients

and within 6 months in ali; other authors obtained

similar results [34.36].

Side-effects. No major complications have been

reported after using TENS. Local skin irritation at

the site 01' the electrodes was seen in a third 01' the

patients by Hasan et aI. [29]. The use 01' hypo-allergic

electrodes and limitation 01' the daily treatment period

was helpful.

Sacra! nerve neuromodulation

Sacra! nerve neuromodulation (sacral nerve stimulation.

SNS. InterStim therapy) has become established within a

relatively short período The method is distinguished from

other types 01' neuromodulation by its continuous

stimulation and elose nerve contact. while the site 01'

stimulation is elosest to the spinal cord. A characteristic

feature is the implantation 01' a pulse generator and an

electrode stimulating one 01' the sacral nerves S3. These

nerves have a higher representation in the bladder

than the nerves S4 and cause less inconvenience to

the legs than the nerves S2. Patients only undergo the

implantation procedure if the preceding so-called PNE

test was successful. i.e. only pre-selected patients are

treated.

Technique. To assess a patient's suitability. a test

electrode is placed percutaneously under local anaes-

thesia. with the patient prone. in one of the S3 foramina

and connected to an external pulse generator (Fig. 3a).

The typical S3 muscle response. a bellows-like inward

movement 01' the levator ani musele and flexion 01' the

great toe. is used to verífy correct positioning 01' the

electrode and proper functioning 01' the nerve. Stimu-

lation is normally felt in the perineal area. After this

acute PNE test the patient enters the subchronic test

phase in which he or she completes a 3-7-day voiding-

incontinence diary. Patients in whom the incontinence is

FIg. 3. a. Acutc PNH tcst wlth a stlmulatlon nccdle Inscrtcd

through the 'Icft 83 foramen and placcd parallcl to the nerve 83.

b. A pulse generator. cxtcnslon cable and 83 foramen clectrode

wlth four stlmulatlon polnts In a patlent.