Bladder and urethral dynamics in multiple sclerosis-like animal model

Management of lower urinary tract dysfunction in multiple sclerosis: a systematic review and Turkish consensus report

AIMS

Since lower urinary tract dysfunction (LUTD) related to multiple sclerosis (MS) has a different behavior pattern than other types of neurogenic voiding dysfunction, we aimed to prepare a national consensus report for the management of LUTD due to multiple sclerosis in light of available literature.

METHODS

A search of available databases yielded an evidence base of 125 articles after the application of inclusion/exclusion criteria. When sufficient evidence existed, recommendations A (high), B (moderate), or C (low) were made according to the strength of evidence; recommendation D was provided when insufficient evidence existed.

RESULTS

Available data did not support the use of invasive urodynamics in the initial evaluation of patients with MS and LUTD. Clinical studies on the safety and efficacy of antimuscarinics and alpha-blockers in these patients were scarce and low quality. Desmopressin could be used in MS-related overactive bladder symptoms owing to its short-term effects as an adjunctive treatment. Intravesical botulinum toxin type A treatment in patients with MS and detrusor overactivity was recommended in cases of medical treatment failure or severe side effects due to antimuscarinics. Pelvic floor rehabilitation together with neuromuscular electrical stimulation was also recommended as it increased symptomatic treatment success. This systematic review was not able to find any evidence-based cut off post-void residual value for the recommendation to start clean intermittent catheterization in MS-related LUTD.

CONCLUSIONS

Patients with MS and LUTD could be best managed through the use of this consensus report.

Smooth muscle of the bladder in the normal and the diseased state: pathophysiology, diagnosis and treatment

The smooth muscle of the normal bladder wall must have some specific properties. It must be very compliant and able to reorganise itself during filling and emptying to accommodate the change in volume without generating any intravesical pressure, but whilst maintaining the normal shape of the bladder. It must be capable of synchronous activation to generate intravesical pressure at any length to allow voiding. The cells achieve this through spontaneous electrical activity combined with poor electrical coupling between cells, and a dense excitatory innervation. In the diseased state, alterations of the smooth muscle may lead to failure to store or failure to empty properly. The diseased states discussed are bladder instability and diabetic neuropathy. Bladder instability is characterised urodynamically by uninhibitable rises in pressure during filling, and is seen idiopathically and in association with bladder outflow obstruction and neuropathy. In diabetic neuropathy, many of the smooth muscle changes are a consequence of diuresis, but there is evidence for alterations in the sensory arm of the micturition reflex. In the unstable bladder, additional alterations of the smooth muscle are seen, which are probably caused by the patchy denervation that occurs. The causes of this denervation are not fully established. Nonsurgical treatment of instability is not yet satisfactory; neuromodulation has some promise, but is expensive, and the mechanisms poorly understood. Pharmacological treatment is largely through muscarinic receptor blockade. Drugs to reduce the excitability of the smooth muscle are being sought, since they may represent a better pharmacological option.

Experimental allergic encephalomyelitis: a neurourological study

To assess the neurourological disturbances produced by the perivascular inflammatory process in the acute phase of experimental allergic encephalomyelitis, we carried out a controlled study. Forty-six New Zealand male rabbits were inoculated with an encephalitogenic preparation. Twenty-seven of them developed neurological deficits in an average of 9.3 days postinoculation. A sample of 19 subjects was used as a control. The subjects were studied within 2 days after the manifestation of the first sign of encephalomyelitis. An average of eight successive cystosphincterograms were recorded. Their entire central nervous system was removed intact and suspended in 10% neutral buffered Formalin solution for 2 weeks, then cut into segments, embedded in paraffin, and finally stained with hematoxylin-eosin and Luxol Fast Blue. The results demonstrated a significant reduction of mean vesical capacity, maximum urethral pressure, and mean urethral pressure in the group with encephalomyelitis. Furthermore, we found a significant negative correlation between the average number of cellular perivascular infiltrates in the spinal sacral segment and urethral pressures. The results showed a significant negative correlation between supreamesencephalic inflammation and mean vesical capacity.

Role of calcium ion antagonists of the bladder detrusor muscle: in vitro and in vivo study

Calcium (Ca2+) ions play an important role in the contractility of the detrusor. Most of the neurotransmitters and modulators act on the detrusor through altering the final intracellular concentration of Ca2+. We studied three commonly used Ca2+ antagonists on their effect of detrusor contractility in vitro: verapamil, nifedipine and segontin. All three inhibited the detrusor-induced contraction in a dose-dependent fashion. Verapamil showed noncompetitive inhibition. Segontin showed a competitive inhibition on both phasic and tonic contractions of the detrusor strips. Nifedipine selectively inhibited the phasic contraction noncompetitively but competitively suppressed the tonic contraction. The in vivo application of verapamil on the bladder of rabbits with multiple-sclerosis-like disease showed a significant increase in bladder capacity. The study shows the possibility of the potential use of Ca2+-antagonist to suppress the problem of bladder instability.