[Neuromodulation of lower urinary tract dysfunction]

Neuromodulative procedures such as transcutaneous electrical nerve stimulation (TENS), transcutaneous/percutaneous tibial nerve stimulation (TTNS/PTNS), and sacral neuromodulation (SNM) are promising second-line treatments for refractory lower urinary tract dysfunction. Using these therapies, both storage and voiding disorders but also bowel dysfunction might be successfully treated. Although the mechanism of action of neuromodulation is not well understood, it seems to involve modulation of spinal cord reflexes and brain networks by peripheral afferents (genital/rectal, tibial and sacral afferents in the case of TENS, TTNS/PTNS, and SNM, respectively). Neuromodulative procedures might also be highly effective in the most desperate situations and further relevant developments are expected so that these innovative techniques will most likely become even more important in urology.

[Sacral neuromodulation for neurogenic bladder dysfunction]

Sacral neuromodulation (SNM) represents a promising option for managing treatment-refractory neurogenic bladder dysfunction. It remains to be seen, however, which types of neurogenic bladder dysfunction and which underlying neurological disorders best respond to SNM. Constant improvements in SNM have been achieved and it is now a minimally invasive approach performed under local anesthesia which should be considered before undertaking larger reconstructive procedures. An electrode is implanted in the S3 or S4 sacral foramen and during a test phase lasting for days to weeks the patient keeps a bladder diary to determine whether SNM has provided a relevant benefit. If the results of the test phase are positive, a neuromodulator is implanted in the gluteal area (or more rarely in the abdominal wall).The mechanism of action of SNM has not been completely clarified, but the afferent nerves most likely play a key role. It appears that SNM produces a modulation of medullary reflexes and brain centers by peripheral afferents. The implanted neuromodulation system does not lead to limitation of the patient's activities. However, it should be noted that high-frequency diathermy and unipolar electrocauterization are contraindicated in patients with neuromodulators, that during extracorporeal shock wave lithotripsy the focal point should not be in the direct vicinity of the neuromodulator or the electrode, that ultrasound and radiotherapy in the region of the implanted components should be avoided, that the neuromodulation should be discontinued in pregnancy, and that MRI examinations should only be conducted when urgently indicated and the neuromodulator is turned off.

[Urodynamic phenomena in the aging bladder]

Lower urinary tract symptoms increase with age in both sexes and are a major problem in the elderly due to the medical and bio-psycho-social consequences involved. Lower urinary tract dysfunctions in the elderly are generally multifactorial in origin and are classifiable to a large extent by age and pathology related changes. Urodynamic findings should never be interpreted without considering the medical history, bladder diary, clinical examination and other findings. Age related changes involve a decrease of voided volume and urinary flow and an increase in overactive bladder symptoms and post void residuals. Consequently, decreased maximum bladder capacity, terminal detrusor overactivity and detrusor overactivity with impaired contractile function are typically found in the elderly. Patients with terminal detrusor overactivity are well treated by bladder training and timed voiding, sometimes combined with anticholinergic drugs, whereas patients with phasic detrusor overactivity are often good candidates for non-invasive electrical neuromodulation.