A study of excessive daytime sleepiness and its clinical significance in three groups of Parkinson's disease patients taking pramipexole, cabergoline and levodopa mono and combination therapy

Sleepiness in neurological disorders

Sleepiness is a frequent and underrecognized symptom in neurological disorders, that impacts functional outcomes and quality of life. Multiple and potentially additive factors might contribute to sleepiness in neurological disorders, including sleep quality alterations, circadian rhythm disorders, drugs, and sleep disorders including sleep apnea or central disorders of hypersomnolence. Physician awareness of the possible symptoms of hypersomnolence, and associated causes is of crucial importance to allow proper identification and treatment of underlying causes. This review first provides a brief overview on clinical aspects of excessive daytime sleepiness, and diagnosis tools, then examines its frequency and mechanisms in various neurological disorders, including neurodegenerative disorders, multiple sclerosis, autoimmune encephalitis, epilepsy, and stroke.

Factors correlated with excessive daytime sleepiness in patients with Parkinson's disease: A polysomnography study

OBJECTIVE

To explore the factors correlated with excessive daytime sleepiness (EDS) in patients with Parkinson's disease (PD).

METHODS

A total of 239 PD patients were divided into two groups based on the presence of EDS (Epworth Sleepiness Scale score≥10) (PD-EDS vs. PD-non-EDS). Participants underwent an extensive assessment to determine demographic features, disease severity, polysomnography characteristics, and nonmotor symptoms.

RESULTS

Of the 239 patients, 56 patients (23.4%) were classified as having PD combined with EDS. Binary logistic regression analysis showed that fatigue (Fatigue Severity Scale [FSS] score ≥4) (odds ratio [OR] [95% CI] = 4.897 [2.376-10.095], p < .001) and the respiratory-related microarousal index (OR [95% CI] = 2.063 [1.085-3.923], p = .027) were independent risk factors for EDS in PD patients. A priori-determined stratified analysis showed that after adjustment for confounding factors, the association of the respiratory-related microarousal index with EDS was significant (OR = 4.404, 95% CI 1.673-11.592, p trend = .036) in patients with respiratory arousal index scores in the highest quintile compared with those with scores in the lowest quintile.

CONCLUSION

Our data revealed a close association among the respiratory-related microarousal index, FSS scores, and EDS. It can be speculated that fragmented sleep and pathological abnormalities of the central nervous system resulting in changes in arousal are major influencing factors of EDS in PD.

The Park Sleep subtype in Parkinson's disease: from concept to clinic

INTRODUCTION

The heterogeneity of Parkinson's disease (PD) is evident from descriptions of non-motor (NMS) subtypes and Park Sleep, originally identified by Sauerbier et al. 2016, is one such clinical subtype associated with the predominant clinical presentation of sleep dysfunctions including excessive daytime sleepiness (EDS), along with insomnia.

AREAS COVERED

A literature search was conducted using the PubMed, Medline, Embase, and Web of Science databases, accessed between 1 February 2023 and 28 March 2023. In this review, we describe the clinical subtype of Park Sleep and related 'tests' ranging from polysomnography to investigational neuromelanin MRI brain scans and some tissue-based biological markers.

EXPERT OPINION

Cholinergic, noradrenergic, and serotonergic systems are dominantly affected in PD. Park Sleep subtype is hypothesized to be associated primarily with serotonergic deficit, clinically manifesting as somnolence and narcoleptic events (sleep attacks), with or without rapid eye movement behavior disorder (RBD). In clinic, Park Sleep recognition may drive lifestyle changes (e.g. driving) along with therapy adjustments as Park Sleep patients may be sensitive to dopamine D3 active agonists, such as ropinirole and pramipexole. Specific dashboard scores based personalized management options need to be implemented and include pharmacological, non-pharmacological, and lifestyle linked advice.

An overview of the effects of levodopa and dopaminergic agonists on sleep disorders in Parkinson's disease

Sleep disorders are among the most common nonmotor symptoms in Parkinson's disease and are associated with reduced cognition and health-related quality of life. Disturbed sleep can often present in the prodromal or early stages of this neurodegenerative disease, rendering it crucial to manage and treat these symptoms. Levodopa and dopaminergic agonists are frequently prescribed to treat motor symptoms in Parkinson's disease, and there is increasing interest in how these pharmacological agents affect sleep and their effect on concomitant sleep disturbances and disorders. In this review, we discuss the role of dopamine in regulating the sleep-wake state and the impact of neurodegeneration on sleep. We provide an overview of the effects of levodopa and dopaminergic agonists on sleep architecture, insomnia, excessive daytime sleepiness, sleep-disordered breathing, rapid eye movement sleep behavior disorder, and restless legs syndrome in Parkinson's disease. Levodopa and dopaminergic drugs may have different effects, beneficial or adverse, depending on dosing, method of administration, and differential effects on the different dopamine receptors. Future research in this area should focus on elucidating the specific mechanisms by which these drugs affect sleep in order to better understand the pathophysiology of sleep disorders in Parkinson's disease and aid in developing suitable therapies and treatment regimens.

CITATION

Scanga A, Lafontaine A-L, Kaminska M. An overview of the effects of levodopa and dopaminergic agonists on sleep disorders in Parkinson's disease. J Clin Sleep Med. 2023;19(6):1133-1144.

Management of Sleep Disturbances in Parkinson's Disease

Parkinson's disease (PD) is defined by its motor symptoms rigidity, tremor, and akinesia. However, non-motor symptoms, particularly autonomic disorders and sleep disturbances, occur frequently in PD causing equivalent or even greater discomfort than motor symptoms effectively decreasing quality of life in patients and caregivers. Most common sleep disturbances in PD are insomnia, sleep disordered breathing, excessive daytime sleepiness, REM sleep behavior disorder, and sleep-related movement disorders such as restless legs syndrome. Despite their high prevalence, therapeutic options in the in- and outpatient setting are limited, partly due to lack of scientific evidence. The importance of sleep disturbances in neurodegenerative diseases has been further emphasized by recent evidence indicating a bidirectional relationship between neurodegeneration and sleep. A more profound insight into the underlying pathophysiological mechanisms intertwining sleep and neurodegeneration might lead to unique and individually tailored disease modifying or even neuroprotective therapeutic options in the long run. Therefore, current evidence concerning the management of sleep disturbances in PD will be discussed with the aim of providing a substantiated scaffolding for clinical decisions in long-term PD therapy.

Neuroimaging of Sleep Disturbances in Movement Disorders

Sleep dysfunction is recognized as a distinct clinical manifestation in movement disorders, often reported early on in the disease course. Excessive daytime sleepiness, rapid eye movement sleep behavior disorder and restless leg syndrome, amidst several others, are common sleep disturbances that often result in significant morbidity. In this article, we review the spectrum of sleep abnormalities across atypical Parkinsonian disorders including multiple system atrophy (MSA), progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS), as well as Parkinson's disease (PD) and Huntington's disease (HD). We also explore the current concepts on the neurobiological underpinnings of sleep disorders, including the role of dopaminergic and non-dopaminergic pathways, by evaluating the molecular, structural and functional neuroimaging evidence based on several novel techniques including magnetic resonance imaging (MRI), functional magnetic resonance imaging (fMRI), diffusion tensor imaging (DTI), single-photon emission computed tomography (SPECT) and positron emission tomography (PET). Based on the current state of research, we suggest that neuroimaging is an invaluable tool for assessing structural and functional correlates of sleep disturbances, harboring the ability to shed light on the sleep problems attached to the limited treatment options available today. As our understanding of the pathophysiology of sleep and wake disruption heightens, novel therapeutic approaches are certain to transpire.

Sleep disturbances in Taiwanese patients with Parkinson's disease

INTRODUCTION

Sleep disturbance is a common nonmotor symptom of Parkinson's disease (PD) and strongly affects patients' quality of life. The relationship between excessive daytime sleepiness (EDS) and nighttime problems remains uncertain. Arguments persist regarding the risk factors for sleep disturbance among patients with PD. Furthermore, the prevalence of EDS appears to be lower in Asian countries. Herein, we conducted the study to describe the characteristics of sleep problems in a sample of Taiwanese PD patients and delineate the difference with reported sleep disturbances in Caucasian PD patients from the literature.

METHODS

Patients with PD were recruited from the outpatient clinic of a tertiary medical center and were evaluated using standardized assessment protocols, including the Parkinson's Disease Sleep Scale (PDSS), the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS), and 39-Item Parkinson's Disease Questionnaire (PDQ-39).

RESULTS

A total of 225 patients with PD were recruited. The mean age of patients with PD was 65.7 years old and the mean disease duration was 8.18 years. Among the patients, 53.8% were defined as poor sleepers (PSQI > 5) and 26.3% had EDS. Seventy-one percent of the poor sleepers used hypnotic medications. The poor sleepers were worse in the scores of Unified Parkinson's Disease Rating Scale (UPDRS), PDSS, and the PDQ-39, and received higher levodopa daily dosage. A PDSS score of <126 indicate that a patient with PD was a poor sleeper. EDS was positively correlated with advanced Hoehn and Yahr stages and use of dopamine agonists but not with levodopa daily dosage and levodopa equivalent daily dosage.

CONCLUSIONS

Taiwanese patients with PD had a lower prevalence of EDS compared with the literatures reported in Caucasian patients. We identify and suggest that PDSS total score, rather than subcategory items, should be used to predict poor sleep among patients with PD.

Hypersomnia in Neurodegenerative Diseases

Hypersomnia is a common complaint in many patients with neurodegenerative diseases and a major cause of decreased quality of life. This article discusses the prevalence and factors associated with hypersomnia in patients with a variety of neurodegenerative diseases affecting the central nervous system, including tauopathies, synucleinopathies, and other conditions. Common nocturnal sleep problems that may result in daytime hypersomnia are delineated. A clinical approach to hypersomnia in patients with neurodegenerative diseases, recommended diagnostic testing, and available treatment options are also discussed.

A review of adverse events linked to dopamine agonists in the treatment of Parkinson's disease

INTRODUCTION

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 less than 65-70 years old since 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.

AREAS COVERED

This article presents an overview of the efficacy and the potential negative effects related to the use of dopamine agonists in the treatment of Parkinson's disease.

EXPERT OPINION

Beyond the new generation non ergot dopamine agonists, no strong evidences allow the choice of a specific dopamine agonists for Parkinson 's disease treatment and by now dopamine agonists treatment should be tailored on specific adverse events profile.

Multimodal imaging evaluation of excessive daytime sleepiness in Parkinson's disease

PURPOSE OF THE STUDY

The multimodal imaging investigation of excessive daytime sleepiness (EDS) in Parkinson's disease (PD). The role of dopaminergic treatment and other clinical parameters was also evaluated.

MATERIALS AND METHODS

Seventeen non-demented PD patients with EDS (PD-EDS) and 17 PD patients without EDS were enrolled. Clinical, treatment and MRI data were acquired. Gray matter (GM) volume was examined with voxel-based morphometry, while white matter (WM) integrity was assessed with diffusion tensor imaging by means of fractional anisotropy, mean diffusivity, axial diffusivity (AD) and radial diffusivity measures.

RESULTS

Increased regional GM volume was found in the PD-EDS group bilaterally in the hippocampus and parahippocampal gyri. Increased AD values were also shown in the PD-EDS group, in the left anterior thalamic radiation and the corticospinal tract and bilaterally in the superior corona radiata and the superior longitudinal fasciculus. Levodopa equivalent dose differed significantly between the groups and was the only predictor of EDS, while the only predictor of the Epworth sleepiness scale score in the PD-EDS group was the dopamine-agonist dose. Increased frequency of gamblers was also observed in the PD-EDS group.

CONCLUSIONS

Regional GM increases and increased AD values in certain WM tracts were found in the PD-EDS group. The changes could result from disinhibited signaling pathways or represent compensatory changes in response to anatomical or functional deficits elsewhere. The study findings support also the contribution of the total dopaminergic load in the development of EDS, while the dose of dopamine agonists was found to predict the severity of the disorder.

Sleep Attacks in Patients With Parkinson's Disease on Dopaminergic Medications: A Systematic Review

Dopaminergic medications are used as first-line treatment for Parkinson's disease (PD). In 1999, a case series was published describing 9 patients who took dopamine agonists (pramipexole or ropinirole) and experienced sudden irresistible sleep attacks. Sleep attacks have subsequently been reported with other dopaminergic medications, including levodopa. Because these symptoms might not be rare and can affect health-related quality of life, we set out to review the prevalence and clinical characteristics of sleep attacks in patients with PD on dopaminergic medications. We conducted a systematic literature review using the terms parkinson* AND dopamine* AND narcolep* OR sleep attack in multiple databases (PubMed, Embase, and PsycINFO). The systematic literature review yielded 23 relevant articles, including nine case reports or case series and 14 original studies. According to the pooled data from the five studies reporting prevalence figures (n = 10,084), sleep attacks occur in 13.0% of patients with PD on dopaminergic medications. Our analysis failed to show significant differences in the Epworth Sleepiness scores between patients with and without sleep attacks (mean difference: 2.92; 95% confidence interval: -0.47-6.31). The I² value of 76% indicated high heterogeneity among the studies. Sleep attacks are not a rare occurrence in patients with PD on dopamine agonist treatment. We found conflicting results on whether sleep attacks in PD resemble narcolepsy. The pathophysiology of these symptoms might be related to dopamine D2 and D4 receptor gene polymorphisms. The most effective management strategies were dose reduction and discontinuation of the offending drugs.

Drug treatment of Parkinson's disease

Parkinson's disease (PD) is a common neurodegenerative disease. While its cause remains elusive, much progress has been made regarding its treatment. Available drugs have a good symptomatic effect, but none has yet been shown to slow the progression of the disease in humans. The most efficacious drug is levodopa, but it remains unclear whether the symptomatic benefit is associated with neurotoxic effects and long-term deterioration. The long-term problem associated with levodopa is the appearance of dyskinesias, which is significantly delayed among patients treated with dopamine agonists as initial therapy. Less clear is the role of other drugs in PD, such as monoamine oxidase inhibitors (MAOIs), including selegiline and rasagiline, the putative N-meihyl-o-aspartaie (NMDA) receptor antagonists amantadine and memantine, and the muscarinic receptor blockers. All these may be used as initial therapy and delay the use of dopaminergic drugs, or can be added later to reduce specific symptoms (tremor or dyskinesias). Advanced PD is frequently associated with cognitive decline. To some extent, this can be helped by treatment with cholinesterase inhibitors such as rivastigmine. Similarly, hallucinations and delusions affect PD patients in the advanced stages of their disease. The use of classical neuroleptic drugs in these patients is contraindicated because of their extrapyramidal effects, but atypical drugs, and particularly clozapine, are very helpful. The big void in the therapy of PD lies in the more advanced stages. Several motor symptoms, like postural instability, dysphagia, and dysphonia, as well as dyskinesias, are poorly controlled by existing drugs. New therapies should also be developed against autonomic symptoms, particularly constipation.

Excessive daytime sleepiness in patients with Parkinson's disease

Excessive daytime sleepiness (EDS) is described as inappropriate and undesirable sleepiness during waking hours and is a common non-motor symptom in Parkinson's disease, affecting up to 50% of patients. EDS has a large impact on the quality of life of Parkinson's disease patients as well as of their caregivers, in some cases even more than the motor symptoms of the disease. Drug-induced EDS is a particular problem as many dopamine agonists used for the treatment of Parkinson's disease have EDS as an adverse effect. Dopaminergic treatment may also render a subset of Parkinson's disease patients at risk for sudden-onset sleep attacks that occur without warning and can be particularly hazardous if the patient is driving. This demonstrates the need for early recognition and management not only to increase health-related quality of life but also to ensure patient safety. There are many assessment tools for EDS, including the Epworth Sleepiness Scale (ESS) and the Multiple Sleep Latency Test (MSLT), although only the Parkinson's Disease Sleep Scale (PDSS) and the SCales for Outcomes in PArkinson's Disease-Sleep (SCOPA-S) are specifically validated for Parkinson's disease. Polysomnography can be used when necessary. Management comprises non-pharmacological and pharmacological approaches. Non-pharmacological approaches can be the mainstay of treatment for mild to moderate EDS. Advice on good sleep hygiene is instrumental, as pharmacological approaches have yet to provide consistent and reliable results without significant adverse effects. The efficacy of pharmacological treatment of EDS in Parkinson's disease using wakefulness-promoting drugs such as modafinil remains controversial. Further areas of research are now also focusing on adenosine A(2A) receptor antagonists, sodium oxybate and caffeine to promote wakefulness. A definitive treatment for the highly prevalent drug-induced EDS has not yet been found.

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.

Antiparkinsonian drug-induced sleepiness: a double-blind placebo-controlled study of L-dopa, bromocriptine and pramipexole in healthy subjects

AIMS

To assess the sleepiness induced by pramipexole, a D2/D3-dopamine receptor agonist commonly used in Parkinson's disease and restless legs syndrome, without the problem of the confounding factors related to the disease.

METHODS

Placebo, bromocriptine (2.5 mg), L-dopa (100 mg) and pramipexole (0.5 mg) were administered in a single oral dose on four separate days, with at least a 2-week wash-out period in a randomized cross-over design. Induced somnolence was assessed using Multiple Sleep Latency Test (MSLT) and subjective scaling of vigilance. Twelve male subjects (26.3 +/- 5.5 years old) without anxiety, mood, sleep or sedation disorders were enrolled.

RESULTS

Pramipexole significantly reduced mean sleep latency compared with placebo 3 h 30 min [-6.1 min (-9.8, -2.4), P = 0.002] and 5 h 30 min [-5.6 min (-7.7, -3.5), P = 0.003] after administration. In addition, the total duration of sleep during the tests was higher with pramipexole than with placebo [+6.0 min (2.3, 9.7), P < 0.001]. These differences were not observed with L-dopa and bromocriptine in comparison with placebo. The induced sleepiness was not associated with an increase in subjective somnolence scaling, indicating that this adverse event may occur without prior warning.

CONCLUSIONS

These results show that a single oral dose of pramipexole induces sleepiness as assessed by MSLT in healthy young subjects, independent of disease-related sleep dysfunction.

Restless legs syndrome: pathophysiology, diagnosis and treatment

Restless legs syndrome (RLS) is clinically defined by the presence of (i) an urge to move the legs with or without an actual paraesthesia; (ii) a worsening of symptoms with inactivity; (iii) improvement with activity; and (iv) a worsening of symptoms in the evening and at night. Patients may use a variety of semantic phrases to describe their symptoms but all must have an urge to move. Most people with RLS also have periodic limb movements during sleep, although this is not part of the clinical diagnostic criteria. RLS is very common. About 10% of all Caucasian populations have RLS, although it may be mild in the majority of cases. Women generally outnumber men by about 2:1. As a general rule, RLS severity worsens through the first seven to eight decades of life, but may actually lessen in old age. The aetiology of RLS is only partly understood. There is a strong genetic component, and several genetic linkages and three causative genes have been identified worldwide. Several medical conditions, including renal failure, systemic iron deficiency and pregnancy, and possibly neuropathy, essential tremor and some genetic ataxias, are also associated with high rates of RLS. In all cases to date, the actual CNS pathology of RLS demonstrates reduced iron stores, in a pattern that suggests that the homeostatic control of iron is altered, not just that there is not enough iron entering the brain. The relationship between reduced CNS iron levels and the clinical phenotype or treatment response to dopaminergics is not known but generates promising speculation. Treatment of RLS is usually rewarding. Most patients respond robustly to dopamine receptor agonists. Over time, response may lessen, or the patients may develop 'augmentation', whereby they have a worsening of symptoms, usually in the form of an earlier onset. Other treatment options include gabapentin, or similar antiepileptic drugs, and opioids. High-dose intravenous iron is a promising but still experimental approach.

Sleep deprivation decreases binding of [11C]raclopride to dopamine D2/D3 receptors in the human brain

Sleep deprivation did not affect dopamine transporters (target for most wake-promoting medications) and thus dopamine increases are likely to reflect increases in dopamine cell firing and/or release rather than decreases in dopamine reuptake. Because dopamine-enhancing drugs increase wakefulness, we postulate that dopamine increases after sleep deprivation is a mechanism by which the brain maintains arousal as the drive to sleep increases but one that is insufficient to counteract behavioral and cognitive impairment. Sleep deprivation can markedly impair human performance contributing to accidents and poor productivity. The mechanisms underlying this impairment are not well understood, but brain dopamine systems have been implicated. Here, we test whether one night of sleep deprivation changes dopamine brain activity. We studied 15 healthy subjects using positron emission tomography and [11C]raclopride (dopamine D2/D3 receptor radioligand) and [11C]cocaine (dopamine transporter radioligand). Subjects were tested twice: after one night of rested sleep and after one night of sleep deprivation. The specific binding of [11C]raclopride in the striatum and thalamus were significantly reduced after sleep deprivation and the magnitude of this reduction correlated with increases in fatigue (tiredness and sleepiness) and with deterioration in cognitive performance (visual attention and working memory). In contrast, sleep deprivation did not affect the specific binding of [11C]cocaine in the striatum. Because [11C]raclopride competes with endogenous dopamine for binding to D2/D3 receptors, we interpret the decreases in binding to reflect dopamine increases with sleep deprivation. However, we cannot rule out the possibility that decreased [11C]raclopride binding reflects decreases in receptor levels or affinity. Sleep deprivation did not affect dopamine transporters (target for most wake-promoting medications) and thus dopamine increases are likely to reflect increases in dopamine cell firing and/or release rather than decreases in dopamine reuptake. Because dopamine-enhancing drugs increase wakefulness, we postulate that dopamine increases after sleep deprivation is a mechanism by which the brain maintains arousal as the drive to sleep increases but one that is insufficient to counteract behavioral and cognitive impairment.

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.

Association of daytime sleepiness with nigrostriatal dopaminergic degeneration in early Parkinson's disease

INTRODUCTION

Many patients with Parkinson's disease (PD) report daytime sleepiness. Its etiology, however, is still not fully understood. The aim of this study was to examine if the amount of nigrostriatal dopaminergic degeneration is associated with subjective daytime sleepiness in patients with PD.

PATIENTS AND METHODS

We investigated 21 patients with PD clinically and by means of [(123)I] FP-CIT-SPECT (DaTSCAN(R)). Each patient filled in the Epworth sleepiness scale (ESS), the Parkinson's Disease Sleep Scale (PDSS), and the self-rating depression scale according to Zung (SDS) to assess sleepiness, sleep quality, and depressive symptoms.

RESULTS

The mean specific dopamine transporter binding in the 21 PD patients (60.8 +/- 10.4 years, nine females, median Hoehn and Yahr stage 2.0) was decreased. Nine patients were in Hoehn and Yahr stage 1 (58.7 +/- 6.6 years, four females; ESS score 7.4 +/- 4.5; PDSS score 105.1 +/- 30.9), the other 12 patients were in Hoehn and Yahr stage 2 (62.4 +/- 12.6 years, five females; ESS score 6.7 +/- 4.7, PDSS score 97.1 +/- 25.6). Age, gender, ESS, and PDSS scores were not significantly different in both groups. However, ESS scores showed an inverse correlation with mean DAT binding in the striatum (r = -0.627, p = 0.03), the caudate nucleus (r = -0.708, p = 0.01), and the putamen (r = -0.599, p = 0.04) in patients with Hoehn and Yahr stage 2. There was no correlation of the ESS score with age, disease duration, UPDRS motor score, PDSS score, or depression score.

CONCLUSION

Subjective daytime sleepiness seems to be associated with dopaminergic nigrostriatal degeneration in early PD.

A nationwide survey of excessive daytime sleepiness in Parkinson's disease in France

To determine the prevalence of excessive daytime sleepiness (EDS) and that of dozing and sudden onset of sleep episodes (SOS) while driving in ambulatory patients with Parkinson's disease (PD) in France, a national sample of private and public neurologists was asked to recruit the first 10 consecutive nondemented PD patients. Each patient completed a questionnaire including the Epworth Sleepiness Scale (ESS) and the likelihood of dozing off and experiencing SOS episodes behind the wheel. Clinical and demographic data were collected. One thousand six hundred and twenty-five patients with PD were included in the survey. Twenty-nine percent of the patients suffered from EDS (ESS score>or=10) but only 0.8% declared a high chance of dozing while driving and 0.5% reported totally unpredictable SOS episodes while driving. Risk factors for EDS were male gender, reduced activity of daily living, and a high daily levodopa equivalent dosage. Risk factors for SOS episodes while driving were an ESS score>or=10, male gender, and low Hoehn and Yahr staging. EDS is common in ambulatory patients with PD and is a major risk factor for dozing and for SOS episodes behind the wheel in patients who drive.

Ropinirole for the treatment of restless legs syndrome

Dopaminergic agents, anticonvulsants, benzodiazepines, opiates, and iron supplementation comprise the classes of medications commonly used to treat restless legs syndrome (RLS), which is a disorder that is estimated to affect about 1 in 10 individuals worldwide and impacts an affected patient's sleep, mood, daytime function, and quality of life. RLS is characterized by an urge to move the legs that is worse at bedtime and at rest; the symptoms are temporarily relieved by leg movement. It is frequently accompanied by periodic limb movements during sleep (PLMS), which may independently disrupt sleep and may cause daytime drowsiness. Dopaminergic agents are considered to be first-line therapy in the management of RLS as well as PLMS. Ropinirole (Requip((R)), GlaxoSmithKline) is a dopamine agonist that was the first medication approved by the US Food and Drug Administration (FDA) for the treatment of moderate-to-severe primary RLS. Based on several large-scale clinical trials and open-label clinical series, this medication has been demonstrated to be effective and safe in treating the motor symptoms of RLS and improving sleep quality.

Excessive daytime sleepiness and on-road driving performance in patients with Parkinson's disease

The impact of excessive daytime sleepiness (EDS) on road test performance was examined in patients with Parkinson's disease (PD). Twenty-one patients with PD completed the Epworth Sleepiness Scale (ESS) and an on-road driving test. Five participants had EDS according to their self-report on the ESS. Neither EDS nor PD medications were associated with on-road driving performance. These findings suggest that in this pilot study EDS did not impair PD patients' driving skills on a formal driving evaluation.

Effect of cabergoline added to levodopa treatment on sleep-wake cycle in idiopathic Parkinson's disease: an open label 24-hour polysomnographic study

Few studies focused on the effects of cabergoline on sleep-wake cycle in PD. Twelve patients affected by PD treated with levodopa as monotherapy underwent two 24-hour ambulatory polysomnographic (A-PSG) sessions twice: in baseline condition (levodopa as monotherapy) and after addition of cabergoline. In each condition, a subjective evaluation of sleep quality and daytime sleepiness was obtained by means of Parkinson's disease Sleep Scale (PDSS) and the Epworth Sleepiness Scale. The statistical analysis of sleep parameters revealed a significant increase of sleep efficiency and slow wave sleep under cabergoline. The PDSS total score showed a significant improvement of overall sleep quality after cabergoline. No significant changes in daytime sleepiness were observed. No patient referred and/or showed sleep attacks before and after addition of cabergoline. We hypothesize that the long-lasting effect of cabergoline may improve the objective quality of nocturnal sleep in PD patients complaining nocturnal motor disability without inducing daytime sleepiness.

Ropinirole: use in restless legs syndrome

Ropinirole is a nonergoline dopamine agonist indicated for the treatment of Parkinson’s disease as monotherapy or combination therapy. However, recent studies have demonstrated a role for this drug in the treatment of restless legs syndrome. Dopaminergic agents, such as ropinirole, are considered the first-line treatment for restless legs syndrome. The dosage of ropinirole needed to treat the symptoms of restless legs syndrome appears to be much smaller (0.25–4.0 mg/day) than that necessary for Parkinson’s disease therapy. Ropinirole is generally well tolerated, with no serious adverse effects. The adverse effects of ropinirole are comparable with those of other dopamine agonists, including nausea and dizziness. In contrast to ergoline substances, ropinirole is free from retroperitoneal, pleural, pericardial fibroses and restrictive valvular heart disease. Clinical studies have indicated that ropinirole reduces the motor symptoms of restless legs syndrome effectively and improves sleep quantity and quality.

Ropinirole in the treatment of restless legs syndrome

Ropinirole is an original nonergoline dopamine agonist indicated for the treatment of Parkinson's disease. However, recent developments in the study of restless legs syndrome have demonstrated another role for this drug. The symptoms of restless legs syndrome are responsive to dopaminergic agents such as ropinirole. The dosage of ropinirole needed to treat the symptoms of restless legs syndrome appears to be much smaller than what is necessary for Parkinson's disease therapy. The liver is primarily responsible for the metabolism of ropinirole, which has an elimination half-life of approximately 6 h. Ropinirole is generally well tolerated, with no serious adverse effects. Clinical studies have indicated that ropinirole can effectively reduce the motor symptoms of restless legs syndrome and improve overall sleep quality.

Pramipexole for the treatment of restless legs syndrome

Restless legs syndrome (RLS) is a common disorder that is estimated to affect 10% of Americans. However, it remains largely undiagnosed and untreated by clinicians. The primary symptoms of this condition are leg discomfort or an urge to move that is temporarily relieved by movement and is worse at rest and at bedtime. RLS impacts the quality of life of the sufferer by disrupting sleep and disturbing or curtailing work and social activities. Approximately 80% of RLS sufferers also have periodic limb movements during sleep, in which repetitive leg movements fragment sleep and may result in daytime drowsiness. RLS may be treated by dopaminergic agents, benzodiazepines, anticonvulsants and opiates; dopamine agonists are currently considered first-line therapy for this condition. Pramipexole has been studied in the treatment of RLS since 1998. This article reviews the role of this medication in the management of this serious neurological disorder.

Parkinson's disease and sleep

Sleep disorders are common in PD and many factors can contribute to disturbed nocturnal sleep and daytime sleepiness. Factors contributing to sleep disturbance include the presence of insomnia, mood or anxiety disorders, dementia, specific sleep disorders, PD motor disorders, and the effects of PD or medications. Patients who have PD should be interrogated about sleep disturbance and daytime sleepiness and preferably, because of underestimation of the severity of sleepiness or lack of awareness, patients should be interviewed in the presence of a close friend or relative. The ability to drive, if sleepiness is present, should be assessed and appropriate recommendations made. Treatment of sleepiness involves treating any underlying sleep disturbance and may involve the use of stimulant or alerting medications in the daytime.

Effect of dopamine agonists on fatigue and somnolence in Parkinson's disease

Dopamine agonists are becoming increasingly important in the treatment of early and advanced symptoms of Parkinson disease (PD). Although dopamine agonists are known to increase somnolence, their effect on fatigue and the relationship between fatigue and somnolence have not been investigated thoroughly. The objective of this study is to quantitatively measure fatigue in patients with PD treated with dopamine agonists and to correlate fatigue with somnolence. Fifteen patients with PD (mean age, 60.6 +/- 9.7 years; mean disease duration, 4.1 +/- 1.9 years) underwent a continuous (30-second) motor task using four muscle groups before and after 3 months of treatment with dopamine agonists. A fatigue index, defined as the decay of maximal force during continuous exercise, was calculated. Findings were compared with 15 healthy, age-matched control subjects. Patients also completed the Multidimensional Fatigue Inventory (MFI), the Epworth Sleepiness Scale (ESS), and the Hamilton Depression Scale at the same time points. Mean fatigue index (FI) before treatment was significantly higher in PD patients than controls (31.37% +/- 3.81% vs. 23.39% +/- 3.03%, P < 0.001). There was no significant between-group difference after 3 months of treatment. There was no difference in FI of the more affected side before and after treatment (33.33% +/- 6.18% vs. 34.08% +/- 5.43%, P > 0.1). No significant change in MFI scores were noted after treatment, although scores on the ESS increased significantly (6.6 +/- 2.63 vs. 11.7 +/- 5.16; P < 0.05). Fatigue is prevalent in patients with PD but is not influenced by dopamine agonists. Somnolence cannot be attributed to the increase in fatigability and apparently involves a different mechanism.

Efficacy and safety of high-dose cabergoline in Parkinson's disease

OBJECTIVES

To assess the efficacy and safety of high-dose (up to 20 mg/day) cabergoline in Parkinson's disease (PD) patients with motor fluctuations and/or dyskinesias.

MATERIALS AND METHODS

Thirty-four PD patients had cabergoline up-titrated and their levodopa (L-dopa) reduced over a maximum of 20 weeks, followed by at least 6 weeks steady cabergoline dosing. Primary endpoint was change in mean hyperkinesia intensity at the final visit (week 26).

RESULTS

Mean (+/- SD) cabergoline was increased from 6.43 +/- 2.66 to 12.78 +/- 5.67 mg/day and mean L-dopa reduced from 606.6 +/- 263.9 to 370.6 +/- 192.5 mg/day. A significant reduction (P < 0.001) in mean hyperkinesia intensity occurred from baseline (day 0) to week 26. Improvements in 'on with dyskinesias', mean dystonia intensity (P < 0.05), time spent in 'severe off' condition, severity of 'off' periods as well as clinical/patient global impression, and health-related quality of life were observed. Twenty-four drug-related adverse events were recorded of which four were regarded as serious.

CONCLUSION

High-dose cabergoline was well tolerated and provided significant improvements in the Parkinson symptomatology and a reduced requirement for L-dopa.

Modafinil for daytime somnolence in Parkinson's disease: double blind, placebo controlled parallel trial

BACKGROUND

Excessive daytime somnolence (EDS) commonly complicates Parkinson's disease (PD). The aetiology of EDS is probably multifactorial but is probably exacerbated by dopaminergic medications. Modafinil is a wake-promoting agent approved for use in narcolepsy, but it is often used to treat a variety of somnolent conditions.

METHOD

A double blind, placebo controlled parallel design trial was conducted to assess the efficacy of modafinil (200-400 mg/day) for the treatment of EDS in PD. The primary efficacy measure was the Epworth Sleepiness (ES) scale score. Secondary efficacy points included the Unified Parkinson's Disease Rating Scale (UPDRS), the Fatigue Severity Scale, the Hamilton Depression Scale, and the multiple sleep latency test (MSLT).

RESULTS

Of a total of 40 subjects (29 men, mean (SD) age 64.8 (11.3) years), randomised to modafinil or placebo, 37 completed the study. Modafinil failed to significantly improve ES scores compared with placebo (2.7 v 1.5 points improvement, respectively, p = 0.28). MSLT failed to improve with modafinil relative to placebo (-0.16 v -0.70, respectively, p = 0.14). UPDRS, global impressions, Fatigue Severity Scale, and Hamilton Depression Scale scores were unchanged. Adverse events were minimal.

CONCLUSION

Modafinil failed to significantly improve EDS in PD compared with placebo. The drug did not alter motor symptoms in PD and was well tolerated.

Excessive daytime sleepiness in parkinsonism

Excessive daytime sleepiness (EDS) can affect 20-50% of patients with Parkinson's disease (PD), whereas sleep attacks (SA), which are sleep episodes without prodroma, seem infrequent. EDS is associated with more advanced disease, higher doses of levodopa-equivalent, and sometimes the use of dopamine agonists. Patients at risk for SA have higher Epworth sleepiness scores (ESS) (although an important subset of patients under-score on this scale) and a more frequent use of ergot or non-ergot dopamine agonists. Polysomnography is a valuable tool in patients with PD, because sleep apnea may occur in 20% of patients, whereas a specific narcolepsy-like phenotype, identified on multiple-sleep latency tests, occurs in patients with most severe EDS; this suggests a lesion in sleep-wake systems. Removal or replacement of a recently introduced dopamine agonist may offer some relief for EDS. If not, the adjunction of modafinil has a good benefit-risk ratio in patients with PD. EDS (and sometimes the narcolepsy-like phenotype) may also affect patients with atypical parkinsonism, such as dementia with Lewy bodies, multiple-system atrophy, and progressive supranuclear palsy.

Excessive daytime somnolence in Japanese patients with Parkinson's disease

To investigate the prevalence and severity of excessive daytime somnolence (EDS) in Japanese patients with Parkinson's disease (PD) and to examine the main cause of EDS. Fifty-three Japanese patients with PD (PDs: 32 females and 21 males) and 17 controls (10 females and seven males) were evaluated using the Epworth Sleepiness Scale (ESS). The severity of the disease was evaluated by Unified Parkinson's disease Rating Scale (UPDRS), and information about quality and quantity of medications was collected. The correlations amongst EDS and age, severity of PD, duration of illness and medications were analyzed. The mean ESS score was significantly higher in advanced PDs than in controls, and correlated with the UPDRS score (r(s) = 0.743, P < 0.0001). Age, duration of illness and the dose of levodopa weakly correlated with ESS score. The intake of dopamine agonists did not affect the severity of EDS. The mean ESS score in PDs was lower than that reported in PD in European and American studies. EDS in Japanese patients with PD was milder compared with Caucasian patients, which might be due to the lower doses of the medications used in Japan. The results suggest that EDS in PD is mainly because of neuropathological changes of the disease itself.

Sleep and fatigue in Parkinson's disease

Sleep disorders and fatigue are common problems in Parkinson's disease (PD). Although they frequently appear together, they are often distinct symptoms that must be understood separately. Fatigue has been reported to be the most bothersome aspect of PD in about one-third of patients, yet it is poorly understood and not clearly treatable. Sleep disorders, while more common, are less bothersome to the patients and often responsive to therapy. An overview of sleep disorders in PD and an approach to therapy will also be outlined. The little that is known about fatigue in PD will be reviewed.

Nocturnal sleep disturbances and daytime dysfunction in patients with Parkinson's disease and in their caregivers

BACKGROUND

The role of aging, disease, medications, and mood disturbances in sleep disturbances (SD) in patients with Parkinson's disease (PD) is poorly understood, and the impact of SD on the quality of life of their caregivers (CG) largely undocumented.

OBJECTIVES

To evaluate the pattern and determinants of disturbed sleep in PD patients complaining of SD, and in their primary CG.

METHODS

A prospective evaluation of 40 non-demented patients with PD complaining of SD and 23 of their primary CG (all were spouses) was conducted using Pittsburgh Sleep Quality Index, Zung's self-rating depression and anxiety scales, Parkinson's Impact Scale (PIMS) (only for PD), and an additional sleep questionnaire.

RESULTS

Eighty-four percent of patients were 'poor sleepers' with global sleep scores (GLSc) > 5. Other abnormalities were: excessive daytime sleepiness-57.5%, excessive daytime fatigue-72.5%, depression-51.5%, anxiety-63.1%, and abnormal PIMS score-83.8%. There was no correlation between the degree of sleep dysfunction and the age, severity, duration of PD or its treatment. Several component sleep scores correlated with anxiety scores, PIMS score with depression, and, subjects with GLSc > or = 10 had higher mean anxiety index. Daytime dysfunction (97.5%) was mainly associated with reduced enthusiasm, rather than excessive sleepiness. Among CG, 40% had a GLSc > 5, 21% had depression, and 10.5% had anxiety. Their depression, anxiety and sleep scores correlated with those of their spouses.

CONCLUSIONS

PD patients with significant SD may represent a subset of patients with early, progressive degeneration of sleep centres, rather than an enhanced aging process. They are more susceptible mood disturbances, which correlate with the severity of sleep dysfunction. Sleep and mood disturbances also adversely affect the quality of life of spousal caregivers.

Excessive daytime sleepiness and sleep disturbances in patients with neurological diseases: epidemiology and management

Up to 12% of the general population experience excessive daytime sleepiness (EDS), with increasing prevalence in the elderly. EDS may lead to cognitive impairment, resulting in inattentiveness, poor memory, mood disorders and an increased risk of accidents. As a result, quality of life is reduced in most patients with EDS as well as in their caregiving spouses. There are a variety of causes leading to EDS, including CNS pathology, neurological dysfunction, associated sleep disorders with insufficient or fragmented sleep, and drug therapy. Since EDS accompanies many neurological disorders, such as neurodegenerative and neuromuscular diseases, neurologists should be familiar with the diagnosis, its major causes and with treatment options. The main focus of this article is on movement disorders, neuromuscular diseases, multiple sclerosis, dementia, cerebrovascular diseases, head and brain trauma, pain and epilepsy. General management strategies for EDS in all these neurological diseases include sleep hygiene aspects such as extensions of noctural time in bed and frequent naps during the day. Pharmacological treatment is generally achieved with stimulants such as amphetamine, methylphenidate and pemoline, or newer compounds such as modafinil.

Role of dopamine receptor agonists in the treatment of restless legs syndrome

The restless legs syndrome (RLS) is defined by four essential criteria obligatory for clinical diagnosis which were established, and recently revised, by the International RLS Study Group. These are (i) the urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs, which are (ii) worse during rest/inactivity, (iii) partially or totally relieved by movement and (iv) worse at night/in the evening. Treatment with levodopa leads to symptom relief, but augmentation (occurrence of symptoms before levodopa administration in the evening) may occur, limiting the long-term use of this drug. This article gives an overview of the treatment in general and the role of dopamine receptor agonists in the therapy of RLS and periodic limb movements (PLMs). Dopamine receptor agonists are widely used as an effective treatment for RLS and PLMs, presumably because of their longer half-lives, lower likelihood of augmentation and good tolerability compared with levodopa. It was shown that, for example, pergolide, ropinirole, pramipexole and cabergoline alleviated RLS symptoms in 70-90% of patients. A new non-oral (transdermal) formulation of one dopamine receptor agonist, rotigotine, has recently been developed and shown to be efficacious in RLS. Further research should focus on long-term observations and comparisons of different dopamine receptor agonists in RLS.

Snoring and excessive daytime sleepiness in Parkinson's disease

Recent recognition of daytime sleepiness in Parkinson's disease (PD) has prompted a search for its causes. Sleepy patients may be more susceptible to sleep attacks after the use of dopamine agonists and the recognition of sleep disturbances in PD may influence important therapeutic decisions. To identify clinical factors influencing excessive daytime sleepiness (EDS) and sleep complaints in PD, we studied 86 consecutive patients with clinical diagnosis of PD using a sleep questionnaire, the Epworth Sleepiness Scale, the Unified Parkinson's Disease Rating Scale and the Montgomery and Asberg Depression Rating Scale. Patients with cognitive dysfunction were not included in the study. We found that 49 patients (53.3%) had insomnia, 45 (49.9%) restless legs syndrome (RLS), 51 (55.4%) vivid dreams, 61 (71.8%) snoring and 29 (31.5%) had EDS. RLS was more frequent in patients with longer duration of illness. Snoring was the most important risk factor associated with EDS (OR=3.64, 95% CI=1.11-11.9, P=0.03) and a marginal association between motor dysfunction and EDS was observed (OR=1.06, 95% CI=1.00-1.12, P=0.05).

Arguments for the use of dopamine receptor agonists in clinical and preclinical Parkinson's disease

On the basis of experimental studies which have demonstrated deleterious effects of L-DOPA (L-3,4-dihydroxyphenylalanine) in vivo and in vitro, it has been suggested that L-DOPA itself may contribute to the progression of Parkinson's disease. This hypothesis is, for many clinicians, the rationale for postponing the employment of and reducing the applied dosage of L-DOPA and for beginning therapy with dopamine receptor agonists or the monoamine oxidase type B (MAO-B) inhibitor selegiline. Furthermore, clinical studies have demonstrated that early treatment with dopamine receptor agonists is associated with a lower incidence of motor fluctuations and dyskinesia. Dopamine receptor agonists exert their symptomatic effect by directly activating dopamine receptors, bypassing the presynaptic synthesis of dopamine and the degenerating nigro-striatal dopaminergic system. They can thus also be of benefit late in the therapy of the disorder. In addition, the pharmacological profile of dopamine receptor agonists suggests a possible neuroprotective effect. This paper reviews briefly the pharmacology of dopamine receptor agonists and basic knowledge concerning the dopamine receptor stimulation which underlies their therapeutic effect. Preclinical approaches for demonstrating neuroprotective effects and their clinical relevance are also discussed.

Parkinson's disease and sleep

Sleep disorders are common in Parkinson's disease (PD), as almost two thirds of PD patients report them. From a clinical point of view, they can be classified into disorders of initiation and maintenance of sleep (DIMS), parasomnias, and excessive daytime sleepiness (EDS). Among the causes of DIMS are degenerative changes in the CNS affecting centers for sleep regulation, persistence into the night of daytime PD-related symptoms, concomitant medical or psychiatric disease, disruption of circadian rhythms, and effects of dopaminergic (and other) medication on sleep regulation. Parasomnias might further contribute to sleep disturbance, as they can be accompanied by motor desinhibition during REM sleep. Parasomnias can precede by several years the presence of daytime PD symptoms. EDS has been over the last years the focus of attention for both sleep and movement disorders specialists, due to the fact that it might predispose to traffic accidents. However, the so-called "sleep attacks" never occur without preexisting somnolence. Thus, a careful sleep history can be helpful to determine which patients are exposed to suffer them. Although EDS was initially attributed to the effects of dopaminergic medication, it seems likely that several disease-related factors might also play an important role. An adequate education of the PD patients in sleep hygiene measures and a skilled use of the medication seem necessary to prevent sleep disturbance.

Increased daytime sleepiness in Parkinson's disease: a questionnaire survey

We evaluated the frequency and severity of excessive daytime sleepiness in an outpatient population with Parkinson's disease in comparison to age-matched controls and examined its relationship with antiparkinsonian drug therapy and sleep history. Increased daytime sleepiness and involuntary sleep episodes have been described in Parkinson's disease, but the etiology is not completely understood. The Epworth Sleepiness Scale (ESS), a validated questionnaire for daytime sleepiness, was prospectively administered to 99 consecutive outpatients with Parkinson's disease and 44 age-matched controls. In addition, a short sleep-screening questionnaire was used. The ESS revealed significantly increased daytime sleepiness in PD patients compared to controls (7.5 +/- 4.6 vs. 5.8 +/- 3.0, P = 0.013). The ESS score was abnormally high (10 or more) in 33 % of PD patients and 11.4% of controls (P = 0.001). ESS was not different between PD patients on levodopa monotherapy and those on levodopa and dopamine agonists, or between patients taking ergoline or non-ergoline dopamine agonists. In PD patients and in controls, sleepiness was significantly associated with reported heavy snoring. Increased daytime sleepiness is more frequent in patients with PD than in elderly controls. Similar to controls, increased daytime sleepiness in PD patients is correlated with heavy snoring.

Sleep disturbances in Parkinson's disease

Disorders of sleep and daytime alertness are frequent in Parkinson's disease patients and arise from a number of diverse factors. The most common complaint of night-time sleep disturbance in Parkinson's disease is sleep fragmentation. Sleep fragmentation can be associated with recurrent parkinsonian symptoms, the effect of medications, concomitant medical disorders such as nocturia, or psychiatric disorders such as depression or anxiety. Likewise, nocturnal sleep disturbance may arise from sleep apnea, periodic limb movements of sleep, or rapid eye movement (REM) sleep behavior disorder. Nocturnal sleep deprivation may lead to excessive daytime sleepiness. Other potential sources of daytime sleepiness include the effects of medications or disruption of central sleep mechanisms due to the pathologic processes of Parkinson's disease itself. Diagnosis of sleep disturbances and daytime sleepiness requires a direct interview of the patient and the caregiver, and may involve consultation with the sleep specialist or medical physician. Treatment is aimed toward improving night-time sleep and daytime drowsiness by addressing the causative factors.