The overactive bladder: review of current pharmacotherapy in adults. Part 2: treatment options in cases refractory to anticholinergics

Nonmotor symptoms in Parkinson’s disease: the dark side of the moon

Nonmotor symptoms may appear during the course of Parkinson’s disease, complicating the advanced phase in particular, but are also common in the premotor phase of Parkinson’s disease. The appearance of nonmotor manifestations represents a milestone, determining a worse prognosis and lower quality of life; however, they are often misdiagnosed and untreated. The spectrum of nonmotor symptoms encompasses mood disorders, psychosis, dementia, sleep disorders, impulse-control disorders and autonomic dysfunctions. This article describes these nonmotor symptoms and their management.

Non-motor symptoms in Parkinson's disease

Parkinson's disease is a hypokinetic movement disorder with cardinal motor features of bradykinesia, resting tremor and rigidity. However, non-motor symptoms, such as cognitive, neuropsychiatric, sleep, autonomic and sensory disturbances are gaining increasing attention. These non-motor symptoms may be intrinsic to the disease pathology or may be results of treatment with dopaminergic agents. Given that most, if not all, patients with Parkinson's disease will experience non-motor symptoms, it is important to be sensitive to these phenomena, especially since some non-motor signs may precede motor impairment. Treatment may include interventions independent of traditional, dopaminergic anti-Parkinson therapy or may be tailored to increase or reduce dopamine responsiveness of the symptom.

Medical treatment of Parkinson disease

The cardinal characteristics of Parkinson disease (PD) include resting tremor, rigidity, and bradykinesia. Patients may also develop autonomic dysfunction, cognitive changes, psychiatric symptoms, sensory complaints, and sleep disturbances. The treatment of motor and non-motor symptoms of Parkinson disease is addressed in this article.

Excitatory and inhibitory urinary bladder reflexes induced by stimulation of cervicovaginal capsaicin-sensitive sensory fibers in rats

We have investigated the effect of intravaginal application of capsaicin on micturition reflex in female rats. Urinary bladder contractility was measured by transurethral pressure recording at isovolumetric and subthreshold conditions in anaesthetized rats. The intravaginal application of capsaicin (15 microg/50 microl rat) induced reproducible bladder phasic contractions, without desensitization upon repeated applications, that were blocked by intravenous atropine (1 mg/kg) or hexamethonium (5 mg/kg) and prevented by removal of paracervical ganglia or systemic capsaicin pretreatment (125 mg/kg, s.c.). The inhibition of sympathetic transmission by guanethidine (30 mg/kg, s.c.) produced significant increase of the bladder reflex contractions activated by intravaginal capsaicin. Intravenous administration of the TRPV1 antagonist, capsazepine (3 mg/kg), significantly reduced the excitatory reflex response to capsaicin. Intravaginal administration of capsaicin (15 microg/50 microl), during distension-induced reflex bladder contractions, produced a transient block of reflexes, unaffected by guanethidine pretreatment. In conclusion, the stimulation of capsaicin-sensitive sensory nerve endings in the rat cervix-vagina induced a dual excitatory or inhibitory bladder response in anaesthetized female rats depending on the degree of bladder distension.

PDE5 inhibitors beyond erectile dysfunction

The phosphodiesterase type-5 (PDE5) inhibitors sildenafil, vardenafil and tadalafil are widely used first-line therapy for erectile dysfunction (ED). Since the advent of sildenafil in 1998, more than 40 million men worldwide have been successfully treated with these compounds. The safety and high tolerability of PDE5 inhibitors make them an attractive tool to investigate further physiological functions of PDE5, for example the modulation of intracellular cyclic GMP (cGMP) pools. As cGMP is a key component of intracellular signaling this may provide novel therapeutic opportunities beyond ED even for indications in which chronic administration is necessary. The approval of sildenafil for the treatment of pulmonary hypertension in 2005 was a notable success in this area of research. A number of other potential new indications are currently in various phases of preclinical research and development. In recent years, extensive but very heterogeneous information has been published in this field. The aim of this review is to summarize existing preclinical and clinical knowledge and critically discuss the evidence to support potential future indications for PDE5 inhibitors.

Changing concepts of bladder regeneration

During the last decade, there has been a dramatic increase in studies aimed at regeneration of the urinary bladder. Many studies employed animal-derived or synthetic materials as grafts for experimental bladder augmentation models, with or without additional measures to promote regeneration, such as autologous cell transplantation or growth factor loading. However, in spite of encouraging results in several reports, few methodologies have shown proven definitive clinical utility. One major problem in these studies is the lack of a clear distinction between native and regenerated bladder in total bladder function after augmentation. Another crucial problem is the absorption and shrinkage of larger grafts, which may result from insufficient vascular supply and smooth muscle regeneration. In contrast, researchers have recently attempted to establish alternative regenerative strategies for treating bladder diseases, and have employed far more diverse approaches according to the various pathological conditions to be treated. For total replacement of the bladder after cystectomy for invasive bladder cancer, urothelium-covered neobladder with non-urinary tract backbone remains a viable choice. In addition, functional bladder diseases such as urinary incontinence, weak detrusor, or non-compliant fibrotic bladder have also been major targets for many leading research groups in this field. These conditions are studied much more from different therapeutic standpoints, aiming at the prevention or reversal of pathological conditions in muscle remodeling or neural control. Such altered research direction would inevitably lead to less surgically based basic biological research, and also would include a far wider spectrum of adult and pediatric bladder diseases, from overactive bladder to dysfunctional voiding.