Urodynamic investigations in patients with spinal cord injury: should the ice water test follow or precede the standard filling cystometry?

OBJECTIVES: To evaluate whether the ice water test (IWT) should be performed before or after the standard urodynamic investigation (UDI). PATIENTS AND METHODS: Two cohorts of patients suffering from neurogenic lower urinary tract dysfunction (NLUTD) due to spinal cord injury (SCI) were matched by lesion level and age. The patients of cohort A (n=55, retrospective cohort) underwent the IWT before and the patients of cohort B (n=110, prospective cohort) after standard UDI. The IWT effect on urodynamic parameters has been compared between the two groups using the Mann-Whitney U-test for independent samples. UDI was performed according to good urodynamic practices recommended by the International Continence Society. RESULTS: The mean age of both cohorts was 49 years. Performing the IWT before versus after standard UDI resulted in a significantly lower maximum cystometric bladder capacity (P=0.01), lower incidence of detrusor overactivity (P=0.017) and lower maximum detrusor pressure during IWT (P=0.04). All other urodynamic parameters assessed demonstrated no significant difference (P>0.05). CONCLUSIONS: Our results are in line with findings from animal studies demonstrating a bladder cooling-induced gating effect on the micturition reflex volume threshold on the level of sacral interneurons. Since the IWT is an unphysiological investigation that might significantly bias subsequent urodynamics, we suggest that the IWT should not precede more physiological standard UDI.

[Neuromodulation of lower urinary tract dysfunction]. / Neuromodulation bei Harnblasenfunktionsstörungen.

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.

[Urodynamic phenomena in the aging bladder]. / Urodynamische Phänomene der alternden Blase.

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.

[Chronic pelvic pain syndrome: neurostimulation, neuromodulation and acupuncture]. / Chronisches Schmerzsyndrom des Beckens : Neurostimulation, Neuromodulation und Akupunktur.

Chronic pelvic pain syndrome (CPPS) is defined by the European Association of Urology guidelines as a non-malignant pain perceived in structures related to the pelvis of either women or men for at least 6 months without proven infection or other obvious pathology. It affects the quality of life of millions of people worldwide and has an impact similar to that reported for other chronic diseases, such as diabetes mellitus, Crohn's disease and congestive heart failure. The treatment of CPPS remains a challenge despite several established first line therapies because many patients are therapy refractory. Unconventional treatments, such as neurostimulation, neuromodulation and acupuncture may be highly successful for treating CPPS and have a favorable adverse event profile. Thus, these promising therapeutic alternatives should be considered more often in daily clinical practice.

[Sacral neuromodulation for neurogenic bladder dysfunction]. / Sakrale Neuromodulation bei neurogenen Blasenfunktionsstörungen.

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.

[Unconventional treatment procedures of the bladder in paraplegia and myelomeningocele]. / Behandlungsverfahren der Blase bei Querschnittlähmung und Myelomeningozele.

The established treatment of neurogenic lower urinary tract dysfunction (NLUTD) in patients with spinal cord injury (SCI) or meningomyelocele (MMC) is mainly conservative and is aimed at the lower urinary tract. For example, oral antimuscarinic medication is the standard treatment of neurogenic detrusor overactivity. Recently, however, treatment aiming directly or indirectly at the innervation of the urinary tract has gained increasing attention. Current evidence does not justify the use of nerve rerouting but the existing preliminary data are more promising for MMC patients than for those with SCI. Sacral neuromodulation is already a therapeutic option for incomplete SCI patients. Initial data from a pilot study indicate that in patients with complete SCI implementation in the spinal shock phase may prevent the development of NLUTD. Licensing of onabotulinum toxin A (Botox®) facilitated its clinical use for treating NLUTD but it is limited to the indication of neurogenic detrusor overactivity incontinence with a dosage of 200 IU. The mentioned unconventional treatments, although discussed controversially, are promising future treatment options for NLUTD.