Age, drugs, or disease: what alters the macrostructure of sleep in Parkinson's disease?

The effects of medical comorbidity, cognition, and age on patient-reported outcomes in Parkinson's disease

OBJECTIVE

The purpose of this cross-sectional study was to compare the independent contributions of medical comorbidity, cognition, and age on patient-reported outcomes in Parkinson's disease (PD).

METHODS

572 PD patients completed the Patient-Reported Outcome Measurement Information System (PROMIS®)-29 v2.0 Profile (physical function, anxiety, depression, fatigue, sleep disturbance, satisfaction with participation in social roles, pain interference) and PROMIS Global Health (mental health and physical health) scales. Comorbidity was measured with the Cumulative Illness Rating Scale-Geriatric (CIRS-G) and cognition with the Montreal Cognitive Assessment (MoCA). Multiple regression models examined the 9 PROMIS measures as predicted by comorbidity, cognition, and age, adjusting for demographic and clinical characteristics (UPDRS and disease duration).

RESULTS

Comorbidity was associated with poorer outcomes in all nine PROMIS domains. Cognition was associated with two of nine domains: physical function and anxiety. Age was associated with five domains: anxiety, depression, sleep disturbance, satisfaction with participation in social roles, and global mental health. Comorbidity showed greater effects on all nine domains than cognition or age (higher standardized beta coefficients).

CONCLUSION

Medical comorbidity, cognition, and age have different impacts on patient-reported outcomes in PD. Medical comorbidity has a greater impact than either cognition or age on a range of patient-reported physical and mental health domains. Medical comorbidity is an important contributor to the patient's perspective of their physical and mental health.

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.

Association Between Dopaminergic Medications and the Evolution of REM Sleep Behavior Disorder in Parkinson's Disease

REM sleep behavior disorder (RBD) is closely associated with Parkinson's disease (PD), however, the influence of dopaminergic replacement therapy (DRT) on the clinical course of RBD in PD remains less understood. The objective of our study is to investigate how DRTs modify the evolution of RBD in a longitudinal cohort study of initially de novo PD patients. Four hundred and five drug-naive patients with early-stage PD were included. RBD symptoms were assessed using the 10-item RBD Screening Questionnaire (RBDSQ) at baseline and during the 5-year follow-up. A generalized estimating equation was used to examine predictors of the evolution of RBD symptoms. For patients without baseline pRBD, patients on levodopa treatment showed a greater increase in RBDSQ scores than those not on levodopa treatment, and the increase in RBDSQ scores was significantly correlated with the levodopa-LEDD. Moreover, the changes in RBDSQ scores at a given post-baseline visit were significantly associated with the use of levodopa (OR = 1.875, p = 0.008) and the combined use of levodopa and DA (OR = 2.188, p = 0.012), as well as the levodopa-LEDD (OR = 1.001, p = 0.005) at that visit. The use of DA alone or the DA-LEDD was not a significant predictor of changes in RBDSQ scores. Similarly, a conversion from pRBD negative to pRBD positive was significantly associated with levodopa-LEDD (OR = 1.001, p = 0.014) but not DA-LEDD. Together, these finding implicated that the use of levodopa may act as a contributing factor to the increasing prevalence of RBD after the onset of PD, suggesting different mechanisms underlying prodromal RBD and late-onset RBD.

Effects of safinamide on REM sleep behavior disorder in Parkinson disease: A randomized, longitudinal, cross-over pilot study

BACKGROUND

Rapid Eye Movement sleep behavior disorder (RBD) is characterized by dream enactment and loss of muscle atonia during REM-sleep. RBD as a premotor feature occurred souvent in patients who develop Parkinson's disease. The glutamatergic, glycinergic, and GABA-ergic systems appear to play a crucial role in the pathogenesis of RBD.

METHODS

The present exploratory longitudinal cross-over study aimed to observe the effect of safinamide on RBD symptoms. Thirty patients with PD and RBD were randomized into two groups (15 subjects each), those that received for a period of 3-months safinamide (50 mg/die) in addition (Group A + ) or in absence (Group B - ) to the usual antiparkinsonian therapy. Patients exploring the clinical and video-polysomnographic changes occurred during this pharmacological therapy.

RESULTS

Twenty-two of 30 patients reported clear improvement in symptoms during safinamide treatment, and 16 were absolutely free from clinical RBD-symptoms at the end of the treatment. Eight patients reported slight improvement in RBD-symptoms. In 6/30 patients no substantial improvement was recorded about clinical RBD-symptoms had frightening dreams or from the bed after 1-week of treatment. In addition, after safinamide, the mean UPDRS-II and III scores decreased, while PDSS-2 score indicating an improvement in both motor symptoms and nocturnal sleep features. A significant reduction of sleep behavior disorder by questionnaire-Hong Kong-score (RBDQ-HS), mainly for two individual RBDQ-HK-items (dream related movements and failing out of bed) was registered.

CONCLUSIONS

This pilot study indicated that safinamide is well tolerated and improves RBD-symptom in parkinsonian.

The Neurophysiology of Sleep in Parkinson's Disease

Sleep disturbances are among the most common nonmotor complications of Parkinson's disease (PD), can present in prodromal stages, and progress with advancing disease. In addition to being a symptom of neurodegeneration, sleep disturbances may also contribute to disease progression. Currently, limited options exist to modulate sleep disturbances in PD. Studying the neurophysiological changes that affect sleep in PD at the cortical and subcortical level may yield new insights into mechanisms for reversal of sleep disruption. In this article, we review cortical and subcortical recording studies of sleep in PD with a particular focus on dissecting reported electrophysiological changes. These studies show that slow-wave sleep and rapid eye movement sleep are both notably disrupted in PD. We further explore the impact of these electrophysiological changes and discuss the potential for targeting sleep via stimulation therapy to modify PD-related motor and nonmotor symptoms. © 2021 International Parkinson and Movement Disorder Society.

Sleep Disorders in Parkinson Disease

Sleep disorders in Parkinson disease have attracted the attention of clinicians and researchers for decades. Recently, major advances in their clinical characterization, polysomnographic description, pathophysiologic understanding, and treatment took place. Parkinson disease encompasses the whole spectrum of sleep medicine: every category of sleep disorder can be observed in these patients. Video polysomnography frequently is indicated, sometimes followed by multiple sleep latency/maintenance of wakefulness tests. Additional studies may include actigraphy, cardiorespiratory polygraphy, and dim light melatonin assessment. Treatment needs to be specific to the underlying sleep disorder and can include medications and nondrug treatments, for example, behavioral therapy and light therapy.

REM sleep behavior in Parkinson disease: Frequent, particularly with higher age

This retrospective single-center polysomnography-based study was designed to assess the frequency of REM sleep behavior disorder (RBD) in consecutive patients with Parkinsonism, including Parkinson disease, dementia with Lewy bodies, multiple system atrophy, progressive supranuclear palsy, and corticobasal degeneration. We observed RBD in 77% of 540 Parkinson patients, with rising frequency at higher age and regardless of sex, in >89% of 89 patients with dementia with Lewy bodies or multiple system atrophy, and in <15% of 42 patients with progressive supranuclear palsy or corticobasal degeneration. Thus, the prevalence of RBD in sporadic Parkinson disease might be higher than previously assumed, particularly in elderly patients.

Subthalamic deep brain stimulation improves sleep and excessive sweating in Parkinson’s disease

Parkinson’s disease (PD) is a complex multisystem disorder with motor and non-motor symptoms (NMS). NMS may have an even greater impact on quality of life than motor symptoms. Subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to improve motor fluctuations and quality of life, whereas the effects on different NMS have been less examined. Sleep disturbances and autonomic dysfunction are among the most prevalent NMS. We here report the efficacy of STN-DBS on sleep disturbances and autonomic dysfunction. In the parent trial, 60 patients were included in a single-center randomized prospective study, with MDS-UPDRS III and PDQ-39 as primary endpoints at 12 months of STN-DBS. Preplanned assessments at baseline and postoperatively at 3 and 12 months also included Parkinson’s Disease Sleep Scale (PDSS); Scopa-Aut; and MDS-UPDRS I, II, and IV. We found that STN-DBS had a significant and lasting positive effect on overall sleep quality, nocturnal motor symptoms and restlessness, and daytime dozing. Several aspects of autonomic dysfunction were also improved at 3 months postoperatively, although at 12 months only thermoregulation (sudomotor symptoms) remained significantly improved. We could not identify preoperative factors that predicted improvement in PDSS or Scopa-Aut. There was a close relationship between improved autonomic symptoms and improved quality of life after 1 year. NMS and especially sleep and autonomic dysfunction deserve more focus to improve patient outcomes further.

Subtypes of Sleep Disturbance in Parkinson's Disease Based on the Cross-Culturally Validated Korean Version of Parkinson's Disease Sleep Scale-2

BACKGROUND AND PURPOSE

This study aimed to determine the clinimetric properties of the Korean version of Parkinson's Disease Sleep Scale-2 (K-PDSS-2) and whether distinct subtypes of sleep disturbance can be empirically identified in patients with Parkinson's disease (PD) using the cross-culturally validated K-PDSS-2.

METHODS

The internal consistency, test-retest reliability, scale precision, and convergent validity of K-PDSS-2 were assessed in a nationwide, multicenter study of 122 patients with PD. Latent class analysis (LCA) was used to derive subgroups of patients who experienced similar patterns of sleep-related problems and nocturnal disabilities.

RESULTS

The total K-PDSS-2 score was 11.67±9.87 (mean±standard deviation) at baseline and 12.61±11.17 at the retest. Cronbach's α coefficients of the total K-PDSS-2 scores at baseline and follow-up were 0.851 and 0.880, respectively. The intraclass correlation coefficients over the 2-week study period ranged from 0.672 to 0.848. The total K-PDSS-2 score was strongly correlated with health-related quality of life measures and other corresponding nonmotor scales. LCA revealed three distinct subtypes of sleep disturbance in the study patients: "less-troubled sleepers," "PD-related nocturnal difficulties," and "disturbed sleepers."

CONCLUSIONS

K-PDSS-2 showed good clinimetric attributes in accordance with previous studies that employed the original version of the PDSS-2, therefore confirming the cross-cultural usefulness of the scale. This study has further documented the first application of an LCA approach for identifying subtypes of sleep disturbance in patients with PD.

Multidimensional Circadian Monitoring by Wearable Biosensors in Parkinson's Disease

Parkinson's disease (PD) is associated with several non-motor symptoms that may precede the diagnosis and constitute a major source of frailty in this population. The digital era in health care has open up new prospects to move forward from the qualitative and subjective scoring for PD with the use of new wearable biosensors that enable frequent quantitative, reliable, repeatable, and multidimensional measurements to be made with minimal discomfort and inconvenience for patients. A cross-sectional study was conducted to test a wrist-worn device combined with machine-learning processing to detect circadian rhythms of sleep, motor, and autonomic disruption, which can be suitable for the objective and non-invasive evaluation of PD patients. Wrist skin temperature, motor acceleration, time in movement, hand position, light exposure, and sleep rhythms were continuously measured in 12 PD patients and 12 age-matched healthy controls for seven consecutive days using an ambulatory circadian monitoring device (ACM). Our study demonstrates that a multichannel ACM device collects reliable and complementary information from motor (acceleration and time in movement) and common non-motor (sleep and skin temperature rhythms) features frequently disrupted in PD. Acceleration during the daytime (as indicative of motor impairment), time in movement during sleep (representative of fragmented sleep) and their ratio (A/T) are the best indexes to objectively characterize the most common symptoms of PD, allowing for a reliable and easy scoring method to evaluate patients. Chronodisruption score, measured by the integrative algorithm known as the circadian function index is directly linked to a low A/T score. Our work attempts to implement innovative technologies based on wearable, multisensor, objective, and easy-to-use devices, to quantify PD circadian rhythms in huge populations over extended periods of time, while controlling at the same time exposure to exogenous circadian synchronizers.

Beyond factor analysis: Multidimensionality and the Parkinson's Disease Sleep Scale-Revised

Many studies have sought to describe the relationship between sleep disturbance and cognition in Parkinson’s disease (PD). The Parkinson’s Disease Sleep Scale (PDSS) and its variants (the Parkinson’s disease Sleep Scale-Revised; PDSS-R, and the Parkinson’s Disease Sleep Scale-2; PDSS-2) quantify a range of symptoms impacting sleep in only 15 items. However, data from these scales may be problematic as included items have considerable conceptual breadth, and there may be overlap in the constructs assessed. Multidimensional measurement models, accounting for the tendency for items to measure multiple constructs, may be useful more accurately to model variance than traditional confirmatory factor analysis. In the present study, we tested the hypothesis that a multidimensional model (a bifactor model) is more appropriate than traditional factor analysis for data generated by these types of scales, using data collected using the PDSS-R as an exemplar. 166 participants diagnosed with idiopathic PD participated in this study. Using PDSS-R data, we compared three models: a unidimensional model; a 3-factor model consisting of sub-factors measuring insomnia, motor symptoms and obstructive sleep apnoea (OSA) and REM sleep behaviour disorder (RBD) symptoms; and, a confirmatory bifactor model with both a general factor and the same three sub-factors. Only the confirmatory bifactor model achieved satisfactory model fit, suggesting that PDSS-R data are multidimensional. There were differential associations between factor scores and patient characteristics, suggesting that some PDSS-R items, but not others, are influenced by mood and personality in addition to sleep symptoms. Multidimensional measurement models may also be a helpful tool in the PDSS and the PDSS-2 scales and may improve the sensitivity of these instruments.

A systematic review of the literature on disorders of sleep and wakefulness in Parkinson's disease from 2005 to 2015

Sleep disorders are among the most common non-motor manifestations in Parkinson's disease (PD) and have a significant negative impact on quality of life. While sleep disorders in PD share most characteristics with those that occur in the general population, there are several considerations specific to this patient population regarding diagnosis, management, and implications. The available research on these disorders is expanding rapidly, but many questions remain unanswered. We thus conducted a systematic review of the literature published from 2005 to 2015 on the following disorders of sleep and wakefulness in PD: REM sleep behavior disorder, insomnia, nocturia, restless legs syndrome and periodic limb movements, sleep disordered breathing, excessive daytime sleepiness, and circadian rhythm disorders. We discuss the epidemiology, etiology, clinical implications, associated features, evaluation measures, and management of these disorders. The influence on sleep of medications used in the treatment of motor and non-motor symptoms of PD is detailed. Additionally, we suggest areas in need of further research.

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.

A polysomnographic study in parkinsonian patients treated with intestinal levodopa infusion

Sleep disorders are very common in advanced Parkinson's disease (PD) and have a significant negative impact on the quality of life of patients. Questionnaire-based studies suggest that sleep quality might improve following levodopa-carbidopa intestinal gel (LCIG) infusion. The objective of this study was to evaluate the impact of LCIG infusion and subsequent oral medication changes on polysomnography (PSG) and sleep symptoms in advanced PD patients. Eleven PD patients underwent PSG at baseline and after 3.8 ± 1.2 months of LCIG treatment. LCIG infusion therapy was halted during PSG. Patients were assessed with the Unified-PD-rating-Scale and completed the PD-Sleep-Scale-version-2 (PDSS-2), the Epworth Sleepiness Scale and the RBD single question. Subjective sleep quality improved in all patients. PSG showed a reduction of the number of awakenings in sleep, a trend towards a lower apnea-hypopnea index and no change in sleep latency, total sleep time and sleep efficiency. There was a positive correlation between the number of awakenings and PDSS-2 scores for "difficulty staying asleep", "muscle cramps of arms or legs" and "urge to move arms or legs". Motor complications and activities of daily living improved with LCIG. Subjective sleep quality improved significantly and the PSG study showed a less fragmented sleep pattern in advanced PD patients treated with LCIG infusion.

Effects of Rotigotine on REM Sleep Behavior Disorder in Parkinson Disease

STUDY OBJECTIVES

REM sleep behavior disorder (RBD) is a common manifestation of Parkinson disease (PD). In this study, we assessed the effects of rotigotine transdermal patch on RBD features in patients with PD.

METHODS

In this prospective open-label study, eleven PD patients with untreated RBD were administered rotigotine patches for up to seven months to ameliorate their parkinsonism. The severities of their RBD symptoms before and after rotigotine therapy were evaluated through patient and bed partner interviews, a validated evaluation scale (REM sleep behavior disorder questionnaire-Hong Kong, RBDQ-HK), and blinded assessments based on video-polysomnographic (VPSG) measure.

RESULTS

Rotigotine improved parkinsonism and subjective sleep quality in PD patients with RBD. The RBDQ-HK total score, especially the Factor 2 score, was decreased, which demonstrated that the subjective severity of RBD symptoms was improved after rotigotine treatment, especially the frequency and severity of abnormal RBD-related motor behaviors. The VPSG analyses showed that the total sleep time (TST) and stage 1% were increased and that the PLMS index was decreased. However, no differences in the RBD-related sleep measures were observed.

CONCLUSIONS

The improved RBD symptoms and VPSG measures of PD patients in this study (TST, stage 1%, and PLMS index) suggest that, in PD, rotigotine may partially improve RBD-related symptoms. Rotigotine should be considered to be an optional drug for the treatment of RBD symptoms in PD.

An observational clinical and video-polysomnographic study of the effects of rotigotine in sleep disorder in Parkinson's disease

PURPOSE

Sleep disturbance is common in Parkinson's disease (PD) and negatively impacts quality of life. There is little data on how dopamine agonists influence nocturnal sleep in PD, particularly in sleep laboratory data to measure sleep parameters and their changes objectively. The goal of this open-label study was to objectively evaluate the effect of rotigotine on sleep in PD patients by video-polysomnographic methods.

METHODS

A total of 25 PD patients with complaints of nocturnal sleep impairment were enrolled. The sleep quality before and after stable rotigotine therapy was evaluated subjectively through questionnaire assessments and objectively measured by video-polysomnographic methods. The Parkinsonism, depression, anxiety, and quality of life of PD patients were also evaluated through questionnaire assessments.

RESULTS

At the end of rotigotine treatment, the PD daytime functioning, motor performance, depression, subjective quality of sleep, and the quality of life improved. Video-polysomnographic analysis showed that the sleep efficiency and stage N1% were increased, while the sleep latency, wake after sleep onset, and the periodic leg movements in sleep index were decreased after rotigotine treatment.

CONCLUSIONS

Video-polysomnographic analysis confirmed the subjective improvement of sleep after rotigotine treatment. This observation suggests that in PD rotigotine is a treatment option for patients complaining from sleep disturbances.

Sleep quality assessment in 35 Parkinson's disease patients in the Fann Teaching Hospital, Dakar, Senegal

INTRODUCTION

Sleep disorders are diverse in Parkinson's disease. We aimed to assess the quality of sleep in patients with Parkinson's disease in an African population.

METHODS

In a transversal and prospective study from April to June 2014, all parkinsonian patients followed at the Fann Teaching Hospital Neurology Clinic (Dakar, Senegal) were assessed using the Hoehn and Yahr's scale and filled out the following questionnaires: Parkinson's disease sleep scale (PDSS), the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale (ESS). A PDSS score<82 (or a subscore<5) and a PSQI score>5 indicated poor quality or impaired sleep. An ESS score>10 indicated excessive daytime sleepiness. We used the Pearson coefficient to search for correlation between age, disease stage, disease duration, and the importance of sleep impairment.

RESULTS

Hoehn and Yahr staging was 2.42±0.90 in the 35 patients (60% male, mean age 65.7±7.4years, disease duration 32.4±23.4months). The mean total PDSS score was 99.5±24.1 and 74.3% of the patients had an abnormally high PSQI score, indicating high frequency and intensity of sleep disorders. Most frequent disorders were pain or cramps interrupting sleep, night waking to urinate and fatigue or sleepiness on waking. Patients exhibited excessive diurnal sleepiness in 22.9% of the cases; they often had an abnormal PSQI score. Both the total PDSS score and the difficulty to sleep increased with disease stage, but not with age or disease duration.

CONCLUSION

We found evidence of major alteration of sleep quality in Senegalese Parkinson patients.

Serum Ferritin Levels in Parkinson's Disease Patients with and without Restless Legs Syndrome

Background

The frequency of RLS in Parkinson's disease (PD) patients has been reported to be between 10% and 26%. Several hypotheses have sought to link these two diseases; however, the pathophysiology of RLS in PD patients has yet to be completely defined. Many patients with idiopathic RLS have low serum ferritin levels, which negatively influence RLS symptomatology. Our objective was to investigate the role of iron deficiency in PD patients with and without RLS.

Methods

We consecutively included 42 PD inpatients undergoing pharmacological treatment. Patients with anemia, renal insufficiency, or polyneuropathy were excluded from the study. The control group consisted of 42 PD inpatients without RLS (PD-nonRLS), matched for age and severity of PD. RLS was diagnosed clinically according to diagnostic criteria. Serum ferritin levels were measured at admission for all patients.

Results

Mean serum ferritin values were 142.20 ± 91.17 ng/dL for PD patients with RLS (PD+RLS) and 160.65 ± 142.57 ng/dL in PD-nonRLS (P = 0.704). There was no difference concerning the total dopaminergic dose (levodopa equivalent dose) between PD+RLS and PD-nonRLS patients (828.22 ± 389.02 vs. 775.32 ± 324.69 mg; P = 0.501). The frequency of dopamine agonist (DA) use did not differ between the two groups (P = 0.306).

Conclusions

There were no significant differences in serum ferritin levels between PD+RLS and PD-nonRLS in our study. This suggests a different pathophysiology of RLS in PD patients, where iron deficiency is not necessarily observed. DA use was not found to be associated with the occurrence of RLS symptoms.

REM Sleep Behavioral Events and Dreaming

STUDY OBJECTIVES

To clarify whether motor behaviors and/ or vocalizations during REM sleep, which do not yet fulfill diagnostic criteria for REM sleep behavior disorder (RBD) and were defined as REM sleep behavioral events (RBEs), correspond to dream enactments.

METHODS

13 subjects (10 patients with Parkinson disease [PD] and 3 healthy controls) originally identified with RBE in a prospective study (DeNoPa cohort) were reinvestigated 2 years later with 2 nights of video-supported polysomnography (vPSG). The first night was used for sleep parameter analysis. During the 2nd night, subjects were awakened and questioned for dream recall and dream content when purposeful motor behaviors and/or vocalizations became evident during REM sleep. REM sleep without atonia (RWA) was analyzed on chin EMG and the cutoff set at 18.2% as specific for RBD.

RESULTS

At the time of this investigation 9 of 13 subjects with previous RBE were identified with RBD based upon clinical and EMG criteria. All recalled vivid dreams, and 7 subjects were able to describe dream content in detail. Four of 13 subjects with RBE showed RWA values below cutoff values for RBD. Three of these 4 subjects recalled having non-threatening dreams, and 2 (of these 3) were able to describe these dreams in detail.

CONCLUSION

RBE with RWA below the RBD defining criteria correlate to dreaming in this selected cohort. There is evidence that RBEs are a precursor to RBD.

Tremor and clinical fluctuation are related to sleep disorders in Chinese patients with Parkinson's disease

Objective

To study the relationship between sleep disturbances and symptoms in patients with Parkinson’s disease (PD).

Methods

The Parkinson’s Disease Sleep Scale-Chinese Version (PDSS-CV) was used to evaluate the sleep disturbances of PD patients in a cross sectional study. The Unified Parkinson’s Disease Rating Scale (UPDRS) parts II-IV, and the Hoehn & Yahr (H&Y) stage were used to determine the level of motor function in PD and the severity of PD. The Spearman correlation and a multiple regression analysis were used to identify the relationship between sleep disturbances and symptoms of PD. The quantities derived from the UPDRS and the H&Y stage and disease duration were compared between groups of patients either with or without sleep disturbances identified by the PDSS. This study was conducted from December 2011 to March 2012 at the First Affiliated Hospital of Sun Yat-sen University, in Guangzhou.

Results

A total of 136 PD patients were included in this study. The overall total PDSS score in PD patients was 107.58 ± 23.35 points (range: 30–146). There were significant differences in the disease duration, the H&Y stage, and the UPDRS section subscores between groups of patients either with or without sleep disturbances (Kruskal-Wallis Test, p <0.05). There were significant negative correlations between PDSS scores and the UPDRS subscores, the H&Y stage and the disease duration (Spearman correlation, p < 0.05). The multiple regression analysis indicated that sleep disturbances identified by the PDSS were only associated with daily life activity, tremor intensity and clinical fluctuation (R² = 0.22, F(3,132) = 12.4, p < 0.001). The correlations were also significant when the contribution of the other two factors was excluded using partial correlations.

Conclusions

The level of daily life activity and the occurrences of tremor and clinical fluctuation are likely to be important factors that lead to PD patients’ sleep disturbances. This study may elucidate an important clue for the relationship between sleep disturbances and PD symptoms.

Sleep spindles in Parkinson's disease may predict the development of dementia

Sleep disturbances and cognitive impairment are common non-motor manifestations of Parkinson's disease (PD). Recent studies suggest that sleep spindles and slow waves play a role in brain plasticity mechanisms and are associated with cognitive performance. However, it remains unknown whether these sleep parameters could serve as markers of cognitive decline in PD. Therefore, we examined whether alterations in sleep spindles and slow waves at baseline visit were associated with increased likelihood of developing dementia at follow-up in PD. Sixty-eight nondemented PD patients (64.9 ± 8.8 years old; 46 men) participated in the study, along with 47 healthy individuals (65.0 ± 10.6 years old; 30 men). All participants underwent baseline polysomnographic recording and a comprehensive neuropsychological assessment. Sleep spindles (12-15 Hz) and slow waves (>75 μV and <4 Hz) were automatically detected on all-night non-rapid eye movement sleep electroencephalography. At follow-up (mean: 4.5 years later), 18 PD patients developed dementia (70.2 ± 7.6 years old; 13 men) and 50 remained dementia-free (63.0 ± 8.5 years old; 33 men). Sleep spindle density and amplitude were lower in PD patients who converted to dementia compared with both patients who remained dementia-free and controls, mostly in posterior cortical regions (p < 0.05). Dementia-free PD patients were intermediate between dementia patients and controls, with lower baseline sleep spindle density in all cortical areas compared with controls (p < 0.01). In demented PD patients, lower sleep spindle amplitude in parietal and occipital areas was associated with poorer visuospatial abilities. Although slow wave amplitude was lower in PD patients compared with controls (p < 0.0001), no difference was observed between those who developed or did not develop dementia. Results demonstrate non-rapid eye movement sleep electroencephalographic abnormalities in PD patients. Sleep spindle activity was particularly impaired in PD patients who developed dementia, with a more posterior topographic pattern. Sleep spindle alterations are associated with later development of dementia in PD, and thus may serve as an additional marker of cognitive decline in these patients.

REM sleep behavior disorder in Parkinson's disease

Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disorder characterized by loss of normal muscle atonia during REM sleep with recurrent dream enactment and excessive motor activity. It is a frequent feature in patients with Parkinson's disease (PD) and other alpha-synucleinopathies, and can occur at any stage of the disease. RBD could be considered a premotor clinical manifestation, and can antedate by many years the motor symptomatology. The prognostic value of RBD for the risk of developing PD still needs to be established. This review article focuses on the clinical aspects, screening and diagnostic criteria as well as therapeutic aspects of RBD in PD patients. Pathophysiological pathways are also briefly reviewed.

Clinical manifestations of Parkinson disease and the onset of rapid eye movement sleep behavior disorder

OBJECTIVE

To identify whether the presence and/or timing of rapid eye movement (REM) sleep behavior disorder (RBD) onset were associated with differences in clinical features and sleep parameters of Parkinson disease (PD).

METHODS

In all, 112 PD patients were enrolled and all underwent extensive clinical evaluations and video-polysomnography (PSG). Clinical features and PSG parameters were compared in PD patients with (PD+RBD) or without (PD-RBD) RBD, RBD preceding (RBD>PD), or not (PD⩾RBD) PD onset.

RESULTS

Sixty-three of the 112 PD patients were affected by RBD. Adjusted for age, gender, education, body mass index (BMI), levodopa equivalent daily dose (LED) and PD duration, PD+RBD patients had higher Hoehn & Yahr stage, higher scores for UPDRS parts I, II and III, more dyskinesia, higher ratio of axial/limb manifestations, and more hallucinations. Their cognitive and quality-of-life status was significantly lower (all P<0.05). For PSG, PD+RBD patients exhibited higher percentages of phasic and tonic EMG activities, lower apnea hypopnea (AHI) and oxygen desaturation index (ODI), and less time in arterial oxygen saturation (SaO2) <90% during REM sleep (all P<0.05). PD⩾RBD (n=22) patients did not significantly differ from RBD>PD (n=41) patients in clinical manifestations, whereas the PD⩾RBD subgroup had significantly higher UPDRS part I score, lower PDQ score and lower AHI during REM than the PD-RBD group (all P<0.05), but not RBD>PD subgroup. Correlation analysis showed that worse cognition was associated with shorter interval of RBD preceding PD onset (r=0.297, P=0.018), but not RBD duration (P=0.202).

CONCLUSIONS

Clinical manifestations of PD may vary depending on the presence and timing of RBD onset. These findings are compatible with the hypothesis that RBD may be a marker of complex subtypes of PD.

Rapid eye movement sleep behavioral events: a new marker for neurodegeneration in early Parkinson disease?

OBJECTIVE

To analyze potential markers in sleep for early recognition of neurodegenerative disease in newly diagnosed, unmedicated patients with Parkinson disease (PD) compared to controls.

METHODS

Videopolysomnography (vPSG) was available in 158 newly diagnosed, unmedicated patients with PD and 110 age-, sex-, and education-matched healthy controls (HC). Rapid eye movement (REM) sleep was analyzed for REM without atonia (RWA) and studied by review of time-synchronized video. Motor behaviors and/or vocalizations in REM sleep with a purposeful component other than comfort moves were identified as REM sleep behavioral events (RBE). Two or more events had to be present to be classified as "RBE positive." RBE subjects included rapid eye movement sleep behavior disorder (RBD) and non-RBD subjects based on the presence or absence of RWA > 18.2%.

RESULTS

RBE were detected in 81 of 158 patients with de novo PD (51%) and 17 of 110 HC (15%) (P < 0.001). RBD was identified in 40/81 RBE-positive patients with PD (25% of all PD patients) and 2 of 17 RBE-positive HC (2% of all controls). RBE-positive patients showed no specific motor or neuropsychological features compared to RBE-negative patients. Patients with PD and HC with RBE had more REM sleep (P = 0.002) and a higher periodic leg movements in sleep index (P = 0.022) compared to subjects without RBE.

CONCLUSION

This first description of REM sleep behavioral events (RBE) shows it occurs more frequently in patients with de novo Parkinson disease (PD) than in healthy controls and may be an early sign of neurodegeneration and precede rapid eye movement sleep behavior disorder (RBD). There is no specific phenotype of PD associated with newly defined RBE or RBD at this early stage.

Treatment of the sleep disorders associated with Parkinson's disease

Sleep disorders are common in patients with Parkinson's disease (PD), and preliminary work has suggested viable treatment options for many of these disorders. For rapid eye movement sleep behavior disorder, melatonin and clonazepam are most commonly used, while rivastigmine might be a useful option in patients whose behaviors are refractory to the former. Optimal treatments for insomnia in PD have yet to be determined, but preliminary evidence suggests that cognitive-behavioral therapy, light therapy, eszopiclone, donepezil, and melatonin might be beneficial. Use of the wake-promoting agent modafinil results in significant improvement in subjective measures of excessive daytime sleepiness, but not of fatigue. Optimal treatment of restless legs syndrome and obstructive sleep apnea in PD are not yet established, although a trial of continuous positive airway pressure for sleep apnea was recently completed in PD patients. In those patients with early morning motor dysfunction and disrupted sleep, the rotigotine patch provides significant benefit.

What treatment works best for restless legs syndrome? Meta-analyses of dopaminergic and non-dopaminergic medications

BACKGROUND

At the time of writing only dopamine agonists are licensed for the treatment of restless legs syndrome (RLS) in various countries, but randomized controlled trials (RCTs) have been performed with other treatments. We performed comprehensive meta-analyses and indirect comparisons of RCTs for all currently recommended treatments of RLS.

METHODS

We searched the Central, Medline, Embase, PsycINFO and CINAHL databases. Outcome measures were the international RLS study group severity scale (IRLS), clinical global impression-improvement, (CGI-I), periodic limb movement index (PLMI), and psychosocial parameters such as quality of life (QoL). We also conducted indirect comparisons by testing for heterogeneity between the substance groups.

RESULTS

Placebo (58 trials) and actively (4 trials) controlled RCTs with dopamine agonists (38 trials), levodopa (4 trials), anticonvulsants (13 trials), most of them with α₂δ ligands (11 trials), opioids (1 trial), and iron treatments (6 trials) were included (9596 patients). Although treatment effects showed large variations, changes in the IRLS in the substance groups were comparable (P = 0.78), with a mean reduction in the IRLS of -5.47 points for dopamine agonists, -5.12 points for anticonvulsants (α₂δ ligands and levetiracetam), and -4.59 points for iron treatments. The CGI-I indicated slightly different treatment effects between the substance groups, while PLMI changes during treatment differed (P = 0.002), showing a marked decrease with dopamine agonists (-22.50/h), levodopa (-26.01/h), and oxycodone (-34.46/h) compared with a slight decrease for anticonvulsants (α₂δ ligands and levetiracetam; -8.48/h) and iron treatments (-13.10/h). Quality of sleep and QoL improved moderately in most of the RCTs investigating these parameters (standardized mean difference, SMD) 0.40 and 0.33, respectively). In the few studies evaluating the change of depressive (n = 4) or anxiety symptoms (n = 3), these symptoms improved slightly (SMD -0.24, and -0.21). Adverse effects and dropouts were comparable in number across all substance groups. In meta-regressions, the treatment effect was predicted by the design of the trial (the more sites involved in a trial the lower the effect) and by the duration of action of a medication (the longer the duration of action, expressed as the half-life time of a substance, the greater the improvement), the latter indicating potential superiority of treatments with stable blood concentration.

CONCLUSION

This first meta-analysis of all RCTs for the pharmacological treatment of RLS provides evidence that, besides the well-defined efficacy of dopaminergic treatment, other treatments with different pharmacological principles show efficacy in small samples and may be well-tolerated alternatives for the treatment of RLS. In the group of anticonvulsants, only the trials performed with α₂δ ligands such as gabapentin, gabapentin enacarbil, and pregabalin showed good efficacy. This indicates a specific mechanism of action of these substances in RLS. The group of iron treatments consisted of a few trials with different compounds in oral and intravenous application form, respectively. For a more differentiated evaluation of the efficacy of iron treatments further studies are necessary. The large efficacy of one opioid RCT in RLS has to be confirmed in further studies.