Apomorphine-induced penile erections in Parkinson's disease

Intermittent Apomorphine Use for off Period Rescue in Parkinson's Disease: A Pragmatic Review of over Three Decades of Clinical Experience

Background

Although proven very efficacious as treatment for Parkinson's disease by Schwab as far back as the 1950s, and later confirmed by Cotzias and colleagues in the early 1970s, use of intermittent subcutaneous injections of the dopamine agonist apomorphine remains limited worldwide.

Objectives

To review evidence regarding use of intermittent, on-demand apomorphine as a treatment for off-period disability in Parkinson's disease.

Methods

A PRISMA-compliant structured literature search was carried out with a focus on clinical effect (motor improvement, daily off time decrease; latency, duration), antiemetic prophylaxis, and adverse events.

Results

Fifty-eight studies were evaluated. Apomorphine administration route was subcutaneous in 29 (50%), sublingual in 14 (24.1%), intranasal in 6 (10.3%), inhaled in 5 (8.6%), rectal in 3 (5.2%) and transdermal in 1 (1.7%). Irrespective of the route, motor disability improved 19% to 74% and daily off time decreased 3% to 68%, with subcutaneous having the fastest onset of action ranging from 6 to 24 minutes and lasting 28 to 96 minutes. Antiemetic prophylaxis was used in almost all studies. Systemic side effects like nausea and yawning were mild and well tolerated, but sedation led to discontinuation of subcutaneous apomorphine in 5.5%. Local side effects to subcutaneous administration did not result in discontinuation. Stomatitis with the early sublingual formulations led to discontinuation in nearly half of patients and was reduced to 16.7% with novel film strips.

Conclusions

Intermittent subcutaneous injections remain the most reliable and safest route of apomorphine administration, with an efficacy for off period treatment supported by nearly four decades of clinical experience.

Anatomy, physiology, and evaluation: Bowel, bladder, and sexual disorders

Our present understanding of bowel and bladder control has changed dramatically with the introduction of functional imagining technologies such as PET, SPECT, fMRI scanning, and near-infrared spectroscopy of the brain. Urologists tend to see control of urination and defecation as processes that occurred at or below the level of the pons for the most part. In this chapter, we examine the control of storing and emptying of urine and stool from what will be a more neurocentric perspective, integrating the frontal lobes into the process and moving beyond the pons on which most of the literature has focused in the past. Utilizing this approach gives us a better understanding of why there is an overlapping of neuropsychiatric problems in many patients with voiding dysfunction.

Management strategies of sexual dysfunctions in Parkinson's disease

Sexual dysfunctions (SD) are frequent and highly disabling nonmotor manifestations of Parkinson's disease (PD) but are also potentially treatable. Neurologists should actively discuss, recognize and treat sexual health issues as an integral part of the management of the disease. In this chapter, we provide recommendations for managing and treating both primary and secondary SD in PD. Many sexual problems can be, at least partially, improved by adjusting the treatment of motor, nonmotor symptoms and comorbidities. Although some treatments of primary SD are evidence-based, many therapeutic options have not been yet systematically studied in patients with PD. The development of new treatments and repurposing of existing remedies in patients with PD remain an unmet need.

Erectile dysfunction in common neurological conditions: A narrative review

Neurogenic erectile dysfunction (NED) can be defined as the inability to achieve or maintain an erection due to central or peripheral neurologic disease. Neurologic diseases can also affect the physical ability and psychological status of the patient. All these factors may lead to a primary or secondary NED. Medication history plays an important role since there are many drugs commonly used in neurologic patients that can lead to ED. The assessment of NED in these patients is generally evolving with the application of evoked potentials technology in the test of somatic and autonomic nerves, and functional magnetic resonance imaging. With the electrophysiological examinations, neurogenic causes can be determined. These tools allow to categorize neurologic lesion and assess the patient prognosis. The first-line treatment for NED is phosphodiesterase inhibitors. Second-line treatments include intracavernous and intraurethral vasoactive injections. Third-line treatments are penile prostheses. The efficacy and safety of each treatment modality depend on the specific neurologic condition. This review discusses the physiology, pathophysiology, diagnosis, and treatment of ED in multiple peripheral and central neurologic conditions, as well as for future research.

On the Emergence of Tremor in Prodromal Parkinson's Disease

Clinical, neuropathological and neuroimaging research suggests that pathological changes in Parkinson's disease (PD) start many years before the emergence of motor signs. Since disease-modifying treatments are likely to be most effective when initiated early in the disease process, there has been significant interest in characterizing prodromal PD. Some people with PD describe autonomic symptoms at the time of diagnosis suggesting that autonomic dysfunction is a common feature of prodromal PD. Furthermore, subtle motor signs may be present and emerge prior to the time of diagnosis. We present a series of patients who, in the prodromal phase of PD, experienced the emergence of tremor initially only while yawning or straining at stool and discuss how early involvement of autonomic brainstem nuclei could lead to these previously unreported phenomena. The hypothalamic paraventricular nucleus (PVN) plays a central role in autonomic control including bowel/bladder function, cardiovascular homeostasis and yawning and innervates multiple brainstem nuclei involved in autonomic functions (including brainstem reticular formation, locus ceruleus, dorsal raphe nucleus and motor nucleus of the vagus). The PVN is affected in PD and evidence from related phenomena suggest that the PVN could increase tremor either by increasing downstream cholinergic activity on brainstem nuclei such as the reticular formation or by stimulating the locus ceruleus to activate the cerebellothalamocortical network via the ventrolateral nucleus of the thalamus. Aberrant cholinergic/noradrenergic transmission between these brainstem nuclei early in PD couldlead to tremor before the emergence of other parkinsonian signs, representing an early clinical clue to prodromal PD.

Update on treatments for nonmotor symptoms of Parkinson's disease-an evidence-based medicine review

OBJECTIVE

To update evidence-based medicine recommendations for treating nonmotor symptoms in Parkinson's disease (PD).

BACKGROUND

The International Parkinson and Movement Disorder Society Evidence-Based Medicine Committee's recommendations for treatments of PD were first published in 2002, updated in 2011, and now updated again through December 31, 2016.

METHODS

Level I studies testing pharmacological, surgical, or nonpharmacological interventions for the treatment of nonmotor symptoms in PD were reviewed. Criteria for inclusion and quality scoring were as previously reported. The disorders covered were a range of neuropsychiatric symptoms, autonomic dysfunction, disorders of sleep and wakefulness, pain, fatigue, impaired olfaction, and ophthalmologic dysfunction. Clinical efficacy, implications for clinical practice, and safety conclusions are reported.

RESULTS

A total of 37 new studies qualified for review. There were no randomized controlled trials that met inclusion criteria for the treatment of anxiety disorders, rapid eye movement sleep behavior disorder, excessive sweating, impaired olfaction, or ophthalmologic dysfunction. We identified clinically useful or possibly useful interventions for the treatment of depression, apathy, impulse control and related disorders, dementia, psychosis, insomnia, daytime sleepiness, drooling, orthostatic hypotension, gastrointestinal dysfunction, urinary dysfunction, erectile dysfunction, fatigue, and pain. There were no clinically useful interventions identified to treat non-dementia-level cognitive impairment.

CONCLUSIONS

The evidence base for treating a range of nonmotor symptoms in PD has grown substantially in recent years. However, treatment options overall remain limited given the high prevalence and adverse impact of these disorders, so the development and testing of new treatments for nonmotor symptoms in PD remains a top priority. © 2019 International Parkinson and Movement Disorder Society.

New tricks for an old dog: A repurposing approach of apomorphine

Apomorphine is a 150-year old nonspecific dopaminergic agonist, currently indicated for treating motor fluctuations in Parkinson's disease. At the era of drug repurposing, its pleiotropic biological functions suggest other possible uses. To further explore new therapeutic and diagnostic applications, the available literature up to July 2018 was reviewed using the PubMed and Google Scholar databases. As many of the retrieved articles consisted of case reports and preclinical studies, we adopted a descriptive approach, tackling each area of research in turn, to give a broad overview of the potential of apomorphine. Apomorphine may play a role in neurological diseases like restless legs syndrome, Huntington's chorea, amyotrophic lateral sclerosis, Alzheimer's disease and disorders of consciousness, but also in sexual disorders, neuroleptic malignant(-like) syndrome and cancer. Further work is needed in both basic and clinical research; current developments in novel delivery strategies and apomorphine derivatives are expected to open the way.

Treatment of autonomic dysfunction in Parkinson disease and other synucleinopathies

Dysfunction of the autonomic nervous system afflicts most patients with Parkinson disease and other synucleinopathies such as dementia with Lewy bodies, multiple system atrophy, and pure autonomic failure, reducing quality of life and increasing mortality. For example, gastrointestinal dysfunction can lead to impaired drug pharmacodynamics causing a worsening in motor symptoms, and neurogenic orthostatic hypotension can cause syncope, falls, and fractures. When recognized, autonomic problems can be treated, sometimes successfully. Discontinuation of potentially causative/aggravating drugs, patient education, and nonpharmacological approaches are useful and should be tried first. Pathophysiology-based pharmacological treatments that have shown efficacy in controlled trials of patients with synucleinopathies have been approved in many countries and are key to an effective management. Here, we review the treatment of autonomic dysfunction in patients with Parkinson disease and other synucleinopathies, summarize the nonpharmacological and current pharmacological therapeutic strategies including recently approved drugs, and provide practical advice and management algorithms for clinicians, with focus on neurogenic orthostatic hypotension, supine hypertension, dysphagia, sialorrhea, gastroparesis, constipation, neurogenic overactive bladder, underactive bladder, and sexual dysfunction. © 2018 International Parkinson and Movement Disorder Society.

The Role of Sex Therapy in the Management of Patients with Parkinson's Disease

Background

Patients with Parkinson disease (PD) and their partners report deterioration in their sexual life. Sexual dysfunction (SD), an important and often ignored aspect, is common in PD. Motor and nonmotor symptoms are involved in limiting pleasure and disturbing function. Sexual dissatisfaction is more common in men that in women. Frequently, both patients and partners have SD associated with PD, and both need suitable treatment. These issues need to be evaluated by neurologists or PD nurses and by specialized sex therapists. The objectives of this study were to describe the complexity and multidimensional nature of sexual problems in PD, enable practitioners to assess and treat sexual difficulties of their patients, and increase awareness of the role of sex therapy in the therapeutic process of PD.

Methods

Based on clinical experience of over 30 years in movement disorder clinics and a review of the literature, the authors suggest practical approaches, including an "Open Sexual Communication" module, prescribing medications, and/or referring to specialists.

Results and Discussion

The longitudinal nature of treating neurologic patients puts physicians in an important position to introduce sexual issues and to assess and plan the interventions and follow-up needed to ensure that sexual difficulties are resolved. The management of hypersexuality requires a thoughtful distinction between lack of opportunities for sexual expression, limited ability to perform, and true hypersexuality. Sex therapists have a major role in the assessment and treatment of the multiple factors that may underlie sexual dissatisfaction in PD, differentiating between hypersexual behaviors and other sexual preoccupation behaviors, and training the professional team.

Dopaminergic Therapies for Non-motor Symptoms in Parkinson's Disease

Apart from the typical motor symptoms, Parkinson's disease is characterized by a wide range of different non-motor symptoms, which are highly prevalent in all stages of the disease and have an incisive influence on quality of life. Moreover, their treatment continues to be challenging. In this review, we critically summarize the evidence for the impact of dopaminergic therapies on non-motor symptoms in Parkinson's disease. We performed a PubMed search to identify relevant clinical studies that investigated the response of non-motor symptoms to dopaminergic therapy. In the domain of neuropsychiatric disturbances, there is increasing evidence that dopamine agonists can ameliorate depression or anxiety. Other neuropsychiatric symptoms such as psychosis or impulse control disorders can also be worsened or even be induced by dopaminergic agents. For the treatment of sleep disturbances, it is essential to identify different subtypes of sleep pathologies. While there is for example profound evidence for the effectiveness of dopaminergic medication for the treatment of restless legs syndrome and sleep fragmentation, evidence for an improvement of rapid eye movement sleep behavior disorder is lacking. With regard to the broad spectrum of autonomic disturbances, response to dopaminergic treatment seems to differ largely, with on the one hand, some evidence for an improvement of sexual function or sweating with dopaminergic treatment, while on the other hand, constipation can be worsened. Finally, the analysis of sensory deficits reveals that some forms of pain, in particular fluctuation-dependent dystonic pain, can be well addressed by adapting the dopaminergic therapy, while no effect has been seen so far for hyposmia or visual deficits. Moreover, the occurrence of non-motor fluctuations is gaining increased attention, as they can be specifically addressed by a more continuous dopaminergic intake. Taken together, there is evidence of a good response of some (but not all) non-motor symptoms to dopaminergic therapy, which must be individually adapted to the special spectrum of symptoms.

Practical management of adverse events related to apomorphine therapy

The potential for adverse events is often cited as a barrier to the use of subcutaneous apomorphine therapy (intermittent injections and continuous infusion) in the management of Parkinson's disease. However, with proactive management most adverse effects are manageable if reported and tackled early enough. As such, proper clinician and patient awareness of the potential adverse effects is important to minimize their impact on the overall clinical utility of this efficacious antiparkinsonian agent. In this paper, we review the key local and systemic adverse effects reported during apomorphine titration, initiation and long-term treatment, and discuss practical management strategies.

The treatment of erectile dysfunction in patients with neurogenic disease

Erectile dysfunction (ED) related to compromise of the nervous system is an increasingly common occurrence. This may be due to the multifactorial nature of ED, the myriad of disorders affecting the neurotransmission of erectogenic signals, and improved awareness and diagnosis of ED. Nevertheless, neurogenic ED remains poorly understood and characterized. Disease related factors such as depression, decreased physical and mental function, the burden of chronic illness, and loss of independence may preclude sexual intimacy and lead to ED as well. The amount of data regarding treatment options in subpopulations of differing neurologic disorders remains scarce except for men with spinal cord injury. The treatment options including phosphodiesterase inhibitors, intracavernosal or intraurethral vasoactive agents, vacuum erection devices (VED) and penile prosthetic implantation remain constant. This review discusses the options in specific neurologic conditions, and briefly provides insight into new and future developments that may reshape the management of neurogenic ED.

Current Concepts in the Treatment of Multiple System Atrophy

MSA is a progressive neurodegenerative disorder characterized by autonomic failure and a variable combination of poor levodopa-responsive parkinsonism and cerebellar ataxia (CA). Current therapeutic management is based on symptomatic treatment. Almost one third of MSA patients may benefit from l-dopa for the symptomatic treatment of parkinsonism, whereas physiotherapy remains the best therapeutic option for CA. Only midodrine and droxidopa were found to be efficient for neurogenic hypotension in double-blind, controlled studies, whereas other symptoms of autonomic failure may be managed with off-label treatments. To date, no curative treatment is available for MSA. Recent results of neuroprotective and -restorative trials have provided some hope for future advances. Considerations for future clinical trials are also discussed in this review.

Sexuality in patients with Parkinson's disease, Alzheimer's disease, and other dementias

Sexual dysfunction (SD) is common among patients with Parkinson's disease (PD), Alzheimer's disease (AD), and other dementias. Sexual functioning and well-being of patients with PD and their partners are affected by many factors, including motor disabilities, non-motor symptoms (e.g., autonomic dysfunction, sleep disturbances, mood disorders, cognitive abnormalities, pain, and sensory disorders), medication effects, and relationship issues. The common sexual problems are decreased desire, erectile dysfunction, difficulties in reaching orgasm, and sexual dissatisfaction. Hypersexuality is one of a broad range of impulse control disorders reported in PD, attributed to antiparkinsonian therapy, mainly dopamine agonists. Involvement of a multidisciplinary team may enable a significant management of hypersexuality. Data on SD in demented patients are scarce, mainly reporting reduced frequency of sex and erectile dysfunction. Treatment of SD is advised at an early stage. Behavioral problems, including inappropriate sexual behavior (ISB), are distressing for patients and their caregivers and may reflect the prevailing behavior accompanying dementia (disinhibition or apathy associated with hyposexuality). The neurobiologic basis of ISB is still only vaguely understood but assessment and intervention are recommended as soon as ISB is suspected. Management of ISB in dementia demands a thorough evaluation and understanding of the behavior, and can be treated by non-pharmacologic and pharmacologic interventions.

Bupropion: pharmacology and therapeutic applications

A total of 17 years after its introduction, bupropion remains a safe and effective antidepressant, suitable for first-line use. Bupropion undergoes metabolic transformation to an active metabolite, 4-hydroxybupropion, through hepatic cytochrome P450-2B6 (CYP2B6) and has inhibitory effects on cytochrome P450-2D6 (CYP2D6), thus raising concern for clinically-relevant drug interactions. Common side effects are nervousness and insomnia. Nausea appears slightly less common than with the SSRI drugs and sexual dysfunction is probably the least of any antidepressant. Bupropion is relatively safe in overdose with seizures being the predominant concern. The mechanism of action of bupropion is still uncertain but may be related to inhibition of presynaptic dopamine and norepinephrine reuptake transporters. The activity of vesicular monoamine transporter-2, the transporter pumping dopamine, norepinephrine and serotonin from the cytosol into presynaptic vesicles, is increased by bupropion and may be a component of its mechanism of action. Bupropion is approved for use in major depression and seasonal affective disorder and has demonstrated comparable efficacy to other antidepressants in clinical trials. Bupropion is also useful in augmenting a partial response to selective serotonin reuptake inhibitor antidepressants, although bupropion should not be combined with monoamine oxidase inhibitors. It may be less likely to provoke mania than antidepressants with prominent serotonergic effects. Bupropion is effective in helping people quit tobacco smoking. Anecdotal reports indicate bupropion may lower inflammatory mediators such as tumor necrosis factor-alpha, may lower fatigue in cancer and may help reduce concentration problems.

Summary of the recommendations of the EFNS/MDS-ES review on therapeutic management of Parkinson's disease

OBJECTIVE

To summarize the 2010 EFNS/MDS-ES evidence-based treatment recommendations for the management of Parkinson's disease (PD). This summary includes the treatment recommendations for early and late PD.

METHODS

For the 2010 publication, a literature search was undertaken for articles published up to September 2009. For this summary, an additional literature search was undertaken up to December 2010. Classification of scientific evidence and the rating of recommendations were made according to the EFNS guidance. In cases where there was insufficient scientific evidence, a consensus statement ('good practice point') is made.

RESULTS AND CONCLUSIONS

For each clinical indication, a list of therapeutic interventions is provided, including classification of evidence.

Management of sexual dysfunction in Parkinson's disease

Nonmotor symptoms, among them sexual dysfunction, are common and underrecognized in patients with Parkinson disease; they play a major role in the deterioration of quality of life of patients and their partners. Loss of desire and dissatisfaction with their sexual life is encountered in both genders. Hypersexuality (HS), erectile dysfunction and problems with ejaculation are found in male patients, and loss of lubrication and involuntary urination during sex are found in female patients. Tremor, hypomimia, muscle rigidity, bradykinesia, 'clumsiness' in fine motor control, dyskinesias, hypersalivation and sweating may interfere with sexual function. Optimal dopaminergic treatment should facilitate sexual encounters of the couple. Appropriate counselling diminishes some of the problems (reluctance to engage in sex, problems with ejaculation, lubrication and urinary incontinence). Treatment of erectile dysfunction with sildenafil and apomorphine is evidence based. HS or compulsive sexual behaviour are side effects of dopaminergic therapy, particularly by dopaminergic agonists, and should be treated primarily by diminishing their dose. Neurologists should actively investigate sexual dysfunction in their Parkinsonian patients and offer treatment, optimally within a multidisciplinary team, where a dedicated professional would deal with sexual counselling.

Nonmotor disorders and their correlation with dopamine: can they be treated by currently available methods?

Many of the nonmotor symptoms in Parkinson disease have a dopaminergic basis, whether the result of dopaminergic degeneration or as a result of dopaminergic treatment. In the latter case, the symptoms may be genuine side effects of drugs (hypotension, pathologic gambling, etc.) or they may be secondary either to the pathoplastic effect they have on the natural course of the disease (nonmotor fluctuations) or to the lack of dopamine (apathy, depression, dopamine withdrawal syndrome, etc.). In all these cases, dopaminergic treatment can be helpful. However, many other nonmotor (and motor) symptoms will have no correlation with dopamine; therefore, they require different treatments, very often with little efficacy, as in apathy or cognitive decline.

Multiple system atrophy: current and future approaches to management

Multiple system atrophy (MSA) is a rare neurodegenerative disorder without any effective treatment in slowing or stopping disease progression. It is characterized by poor levodopa responsive Parkinsonism, cerebellar ataxia, pyramidal signs and autonomic failure in any combination. Current therapeutic strategies are primarily based on dopamine replacement and improvement of autonomic failure. However, symptomatic management remains disappointing and no curative treatment is yet available. Recent experimental evidence has confirmed the key role of alpha-synuclein aggregation in the pathogenesis of MSA. Referring to this hypothesis, transgenic and toxic animal models have been developed to assess candidate drugs for MSA. The standardization of diagnosis criteria and assessment procedures will allow large multicentre clinical trials to be conducted. In this article we review the available symptomatic treatment, recent results of studies investigating potential neuroprotective drugs, and future approaches for the management in MSA.

The use of monoamine pharmacological agents in the treatment of sexual dysfunction: evidence in the literature

INTRODUCTION

The monoamine neurotransmitters serotonin, dopamine, and norepinephrine play an important role in many medical and psychological conditions, including sexual responsiveness and behavior. Pharmacological agents that modulate monoamines may help alleviate sexual dysfunction.

AIMS

To provide an overview of pharmacological agents that modulate monoamines and their use in the treatment of sexual dysfunction.

METHODS

EMBASE and PubMed search for articles published between 1950 and 2010 using key words "sexual dysfunction,""monoamines,""monoaminergic receptors," and "generic names for pharmacological agents."

MAIN OUTCOME MEASURES

To assess the literature evaluating the efficacy of monoamine pharmacologic agents used in the treatment of sexual dysfunction.

RESULTS

The literature primarily cites the use of monoaminergic agents to treat sexual side effects from serotonergic reuptake inhibitors (SSRIs), with bupropion, buspirone and ropinirole providing the most convincing evidence. Controlled trials have shown that bupropion improves overall sexual dysfunction, but not frequency of sexual activity in depressed and nondepressed patients. Nefazodone and apomorphine have been used to treat sexual dysfunction, but their use is limited by significant side effect and safety profiles. New research on pharmacologic agents with subtype selectivity at dopaminergic and serotonergic receptors and those that possess dual mechanisms of action are being investigated.

CONCLUSION

There has been tremendous progress over the past 50 years in understanding the role of monoamines in sexual function and the effect of pharmacologic agents which stimulate or antagonize monoaminergic receptors on sexual dysfunction. Nevertheless, large, double-blind, placebo-controlled studies evaluating the efficacy of currently available agents in populations without comorbid disorders are limited, preventing adequate interpretation of data. Continued research on sexual function and specific receptor subtypes will result in the development of more selective pharmacologic agents with the goal of increasing efficacy without the dose-limiting side effects of nonselective agents.

Impulse control disorders in Parkinson's disease: definition, epidemiology, risk factors, neurobiology and management

There is increasing awareness that impulse control disorders (ICDs), including pathological gambling, hyper-sexuality, compulsive eating and buying, can occur as a complication of Parkinson's disease (PD). In addition, other impulsive or compulsive disorders have been reported to occur, including dopamine dysregulation syndrome (DDS) and punding. Case reports and prospective studies have reported an association between ICDs and the use of dopamine receptor agonists at higher doses, and DDS has been associated with L-dopa at higher doses or short-acting dopamine receptor agonists. Risk factors for ICDs include male sex, younger age or younger age at PD onset, a pre-PD history of ICD symptoms, history of substance use or bipolar disorder, and a personality profile characterized by impulsiveness. The management of clinically significant ICD symptoms should consist of modifications to dopamine replacement therapy, particularly dopamine receptor agonists, which is usually associated with an improvement of ICDs. There is no empirical evidence supporting the use of psychiatric drugs for ICDs in PD. Functional neuroimaging studies such as functional MRI and PET can investigate in vivo the neurobiological basis of these pathological behaviours.

Non-motor symptoms of Parkinson's disease: dopaminergic pathophysiology and treatment

Several studies, including work from the Parkinson's disease (PD) non-motor group and others, have established that the non-motor symptoms of PD are common, occur across all stages of PD, are under-reported, and are a key determinant of quality of life. Research suggests that the non-motor symptoms of the disease are frequently unrecognised by clinicians and remain untreated. Even when identified, there is a common perception that many of these symptoms are untreatable. The role of dopaminergic drugs in treating the various non-motor problems of PD, although clinically recognised, has received little attention. In this Review, we investigate the dopaminergic basis of the range of non-motor symptoms that occur in PD such as depression, apathy, sleep disorders (including rapid-eye movement sleep behaviour disorder), and erectile dysfunction. We discuss the evidence that these symptoms are treatable, at least in part, with various dopaminergic strategies and, where relevant, we also refer to the use of deep-brain stimulation of appropriate targets in the brain. This Review provides a comprehensive overview of the management of this challenging aspect of PD.

[Intermittent apomorphine injections as rescue therapy for advanced Parkinson's disease. Consensus statement]

Intermittent subcutaneous apomorphine therapy should be considered in patients with advanced Parkinson's disease who experience recurrent off periods despite optimised oral treatment (according to guidelines), for reliable and quick reversal of these otherwise refractory periods. Such treatment is also called rescue therapy. At present, apomorphine injections with the apomorphine pen are underutilised, considering its current indications and contraindications. In the present consensus statement, concepts for the use of apomorphine are presented and discussed based on existing study results, indications, and contraindications. Recommendations for a practical approach are also provided.

The safety of dopamine agonists in the treatment of Parkinson's disease

Dopamine agonists are highly effective as adjunctive therapy to levodopa in advanced Parkinson's disease. These drugs have rapidly gained popularity as a monotherapy in the early stages of Parkinson's disease for patients < 65-70 years old, because they are about as effective as levodopa, but patients demonstrate a lower tendency to develop motor complications. However, dopamine agonists could have peripheral and central side effects, which are often the reason for the discontinuation of the treatment. This review focuses on the potential negative effects related to the use of dopamine agonists in the treatment of Parkinson's disease.

Ginkgo biloba extract enhances male copulatory behavior and reduces serum prolactin levels in rats

The aim of this study was to investigate the effects of Ginkgo biloba extract (EGb 761) on male copulatory behavior in rats. EGb 761 (1 mg/ml) induced significant production of testosterone (T) in rat Leydig cells in vitro. Its effects on sexual behavior were then tested in Long-Evans male rats after 7, 14, 21, or 28 days of oral gavage of vehicle (distilled water) or EGb 761 at doses of 10, 50, or 100 mg/kg. Administration of 50 mg/kg of EGb 761 for 28 days and of 100 mg/kg for 14 or 21 days significantly increased intromission frequency compared to controls on the same day. An increase in ejaculation frequency was seen after treatment with 50 mg/kg of EGb 761 for 14, 21, or 28 days when compared to either the control group on the same day or the same group on day 0. A reduction in ejaculation latency was only seen after administration of 50 mg/kg of EGb 761 for 14 days compared to the vehicle-treated group. After treatment for 28 days, no significant difference was seen in mount latency, intromission latency, serum T levels, reproductive organ weight, sperm number, or levels of the metabolite of dopamine, 3,4-dihydroxyphenylacetic acid in the brain with any dose of EGb 761, but significantly reduced serum prolactin levels and increased dopamine levels in the medial preoptic area and arcuate nucleus were seen at the dose of 50 mg/kg. These findings show that EGb 761 (especially at the dose of 50 mg/kg) enhances the copulatory behavior of male rats and suggest that the dopaminergic system, which regulates prolactin secretion, may be involved in the facilitatory effect of EGb 761.

The effects of dopamine receptor agonists on BK Ca channels and signal transduction mechanism in corpus cavernosal smooth muscle cells

In this study, we investigated the effect of dopamine receptor agonists on potassium channels' activity and their signal transduction pathway in corporal smooth muscle cells. We used cultured human corporal smooth muscle cells. The whole cell and cell-attached configuration of the patch-clamp technique were used for electrophysiological recordings, and enzyme immunoassay was used for measuring cyclic AMP (cAMP) and cyclic GMP levels. Extracellular application of 10 microM dopamine and apomorphine significantly increased whole-cell K(+) currents by 283.5+/-55.7% (at +60 mV; n=12, P<0.001), 292.4+/-58.8.0% (at +60 mV; n=9, P<0.005), respectively. We confirmed that the increase in whole-cell currents was mainly due to activation of the tetraethylammonium-sensitive large conductance Ca(2+)-activated K(+) channels (BK(Ca) channels). Enzyme immunoassay indicated that dopamine and apomorphine stimulates cAMP levels in corporal smooth muscle cells in a concentration-dependent fashion. The activation of BK(Ca) channels by dopamine receptor agonists in corporal smooth muscle cells might be one of the mechanisms in inducing penile erection.

Sexual function in men and women with neurological disorders

The advent of non-invasive functional brain imaging has clarified which regions of the brain are recruited during sexual arousal. Injuries to those regions, and to the spinal cord and peripheral nerves that link genitalia to limbic and cognitive centres, can profoundly influence sexual wellbeing. In epilepsy, expressions of hypersexuality and hyposexuality interact with the location of epileptogenic foci in the temporolimbic circuitry, and are tempered by the sexual effects of drug treatments. We outline the sexual consequences of epilepsy, stroke, multiple sclerosis, Parkinson's disease, and other common neurological disorders. Management of sexual dysfunction from both disease and treatment is discussed. Nerve-sparing techniques could mitigate the substantial sexual dysfunction in both men and women through surgical disruption of the autonomic nerves during radical pelvic surgery.

The supraspinal network in the control of erection

Penile erection is a complex event controlled by vascular, hormonal and neuronal systems. The neuronal system involved in erection is often divided into spinal and supraspinal networks. It is generally accepted that the spinal system directly controls erection and that the supraspinal network modulates this control mechanism through different ascending and descending pathways. In contrast to the spinal control of erection, relatively little is known about the supraspinal network. In the present review, the authors outline the supraspinal network involved in the control of penile erection. Firstly, the brain regions reported to be involved in erection are described and the brain circuit of erection is outlined. Subsequently, the neuromediators involved in erection are summarised. Finally, these data are discussed in the light of therapeutic possibilities in the management of erectile dysfunction by targeting the supraspinal system.

Urinary and erectile dysfunction in multiple system atrophy (MSA)

Multiple system atrophy (MSA) is a neurodegenerative disease of undetermined etiology that occurs sporadically and manifests itself as a combination of parkinsonian, autonomic, cerebellar, and pyramidal signs. Despite the lack of effective therapies, some of the symptoms may be, at least temporarily, improved with adequate symptomatic therapies. Urinary and erectile dysfunction (ED) symptoms are prominent early features in male MSA patients. Lower urinary tract infections (UTIs) are a major cause of morbidity and mortality in this disorder. More than 50% of MSA patients suffer from recurrent lower UTIs and a significant number (approximately 25%) die of complications related to them. Urogenital symptoms in MSA are usually due to a complex mixture of central and peripheral nervous abnormalities, sometimes superimposed on previous local pathological conditions such as benign prostatic hyperplasia and perineal laxity. There have been instances were MSA-related urological symptoms were confused with symptoms of benign prostatic hyperplasia, leading to unnecessary urological surgery. In this review, we present the phenotypic range and therapeutic approaches for common storage and voiding urological symptoms and ED, in patients with MSA.

Review of the therapeutic management of Parkinson's disease. Report of a joint task force of the European Federation of Neurological Societies (EFNS) and the Movement Disorder Society-European Section (MDS-ES). Part II: late (complicated) Parkinson's disease

To provide evidence-based recommendations for the management of late (complicated) Parkinson's disease (PD), based on a review of the literature. Complicated PD refers to patients suffering from the classical motor syndrome of PD along with other motor or non-motor complications, either disease-related (e.g. freezing) or treatment-related (e.g. dyskinesias or hallucinations). MEDLINE, Cochrane Library and INAHTA database literature searches were conducted. National guidelines were requested from all EFNS societies. Non-European guidelines were searched for using MEDLINE. Part II of the guidelines deals with treatment of motor and neuropsychiatric complications and autonomic disturbances. For each topic, a list of therapeutic interventions is provided, including classification of evidence. Following this, recommendations for management are given, alongside ratings of efficacy. Classifications of evidence and ratings of efficacy are made according to EFNS guidance. In cases where there is insufficient scientific evidence, a consensus statement ('good practice point') is made.

Role of the brain in the control of erection

In contrast to the spinal control of erection, relatively little is known about the brain control. In the present review, we have outlined the role of brain structures involved in penile erection and provided a synopsis on the brain circuit of erection. Findings from both animal and human studies are discussed. Evidence suggests that the most important structures are the frontal lobe, cingulate gyrus, amygdala, thalamus and hypothalamus. Within the brain circuit of erection, the thalamus serves as a gate-controller in which all relevant information is evaluated and further processed to higher and lower centres.

The long-lasting improvement of sexual dysfunction in patients with advanced, fluctuating Parkinson's disease induced by pergolide: evidence from the results of an open, prospective, one-year trial

Fourteen male patients suffering from Parkinson's disease, each of whom had been treated with L-DOPA, and in whom additional treatment with oral dopamine agonist (DA) was needed, were followed for a period of one year. Pergolide mesylate (Permax) was given to each patient, and titrated to a total daily dose of 3 mg. All of the patients were taking L-DOPA. The assessments performed before the start of pergolide treatment consisted of neurological examination, unified Parkinson's disease rating scale (UPDRS) III and IV subscales scoring, mini mental state examination (MMSE) scoring, the neuropsychological examination including Zung scale scoring, biochemical and hematological examinations including prolactine serum levels; and a sexological examination during which the patients filled-in the international index of erectile function (IIEF) questionnaire. These examinations were repeated during the control assessments at months 1, 3, 6 and 12. ANOVA, non-parametric Friedmann's ANOVA and Tukey post hoc tests were used for the statistical analysis. There were statistically significant differences between the values of UPDRS III motor subscale and all subscales of IIEF when months 0 and 1 were compared with the results obtained at months 3, 6 and 12. Pergolide mesylate, when added to L-DOPA, significantly improved all sexual functions in younger male Parkinsonian patients who were still interested in sexual activities. The treatment with pergolide in these cases might be more beneficial than with short-acting PDE-5 inhibitor sildenafile. Nevertheless, the relationship between pergolide treatment and incidence of restrictive valvular heart disease must be considered.

The neuropsychiatry of Parkinson's disease and related disorders

Parkinson's disease is associated with classical Parkinsonian features that respond to dopaminergic therapy. Neuropsychiatric sequelae include dementia, major depression, dysthymia, anxiety disorders, sleep disorders, and sexual disorders. Panic attacks are particularly common. With treatment, visual hallucinations, paranoid delusions, mania, or delirium may evolve. Psychosis is a key factor in nursing home placement, and depression is the most significant predictor of quality of life. Clozapine may be the safest treatment for psychotic features, but more research is needed to establish the efficacy of antidepressant treatments. Dementia with Lewy bodies, the second most common dementia in the elderly, may present in association with systematized delusions, depression, or RBD. Early evidence suggests the utility of rivastigmine, donepezil, low-dose olanzapine, and quetiapine in treating DLB. Parkinson-plus syndromes generally lack a good response to dopaminergic treatment and evidence additional features, including dysautonomia, cerebellar and pontine features, eye signs, and other movement disorders. MSA is associated with dysautonomia and RBD. SND (MSA-P) is associated with frontal cognitive impairments, but dementia, psychosis, and mood disorders have not been strikingly apparent unless additional pathological findings are present. In SDS (MSA-A), impotence is almost ubiquitous; urinary incontinence is frequent; depression is occasional, and sleep apnea should be treated to avoid sudden death during sleep. OPCA neuropsychiatric correlates await further definition. Progressive supranuclear palsy neuropsychiatric features include apathy, subcortical dementia, pathological emotionality, mild depression and anxiety, and lack of appreciable response to donepezil. CBD usually is recognized by early frontal dementia with ideomotor apraxia, often in the right upper extremity, attended later by poorly responsive unilateral Parkinsonism, with additional signs including cortical reflex myoclonus, limb dystonia, alien limb, oculomotor apraxia when asked to look horizontally, depression, personality changes, and, occasionally, Kluver-Bucy syndrome. The neuropsychiatry of FTDP-17 involves apraxia, executive impairment, personality changes, hyperorality, and occasional psychosis. Future research in these Parkinsonian disorders should target the characterization of neuropsychiatric sequelae and their treatment.

Neural control of erection

Penile erection is a vascular event controlled by the autonomic nervous system. The spinal cord contains the autonomic preganglionic neurons that innervate the penile erectile tissue and the pudendal motoneurons that innervate the perineal striated muscles. Sympathetic pathways are anti-erectile, sacral parasympathetic pathways are pro-erectile, and contraction of the perineal striated muscles upon activity of the pudendal nerves improves penile rigidity. Spinal neurons controlling erection are activated by information from peripheral and supraspinal origin. Both peripheral and supraspinal information is capable of either eliciting erection or modulating or inhibiting an erection already present. Sensory information from the genitals is a potent activator of pro-erectile spinal neurons and elicits reflexive erections. Some pre-motor neurons of the medulla, pons and diencephalon project directly onto spinal sympathetic, parasympathetic and pudendal motoneurons. They receive in turn sensory information from the genitals. These spinal projecting pathways release a variety of neurotransmitters, including biogenic amines (serotonin, dopamine, noradrenaline, and adrenaline) and peptides that, through interactions with many receptor subtypes, exert complex effects on the spinal network that controls penile erection. Some supraspinal structures (e.g. the paraventricular nucleus and the medial preoptic area of the hypothalamus, the medial amygdala), whose roles in erection have been demonstrated in animal models, may not project directly onto spinal pro-erectile neurons. They are nevertheless prone to regulate penile erection in more integrated and coordinated responses of the body, as those occurring during sexual behavior. The application of basic and clinical research data to treatment options for erectile dysfunction has recently proved successful. Pro-erectile effects of phosphodiesterase type 5 inhibitors, acting in the penis, and of melanocortin agonists, acting in the brain, illustrate these recent developments.