Heart rate variability in patients with idiopathic Parkinson’s disease with and without obstructive sleep apnea syndrome

Prevalence and clinical aspects of obstructive sleep apnea in Parkinson disease: A meta-analysis

BACKGROUND AND PURPOSE

Obstructive sleep apnea (OSA) frequently occurs in Parkinson Disease (PD), probably caused by upper airway dysfunctions or shared pathogenetic mechanisms. OSA may precede PD diagnosis or worsen throughout its course, but its relationship with clinical features and dopaminergic medication remains unclear. This meta-analysis aimed to provide a reliable estimate of OSA prevalence in the PD population (PD-OSA) and to clarify its clinical associated factors to help clinicians in understanding the underlying pathophysiological mechanisms.

METHODS

A systematic literature search was performed up to April 2023 using the PubMed, Scopus, and PsycINFO databases. Articles were included if they provided data on PD patients with and without OSA. Pooled prevalence for PD-OSA was calculated using the proportions of PD participants diagnosed with OSA. Demographic and clinical features associated with PD-OSA were explored by comparing PD patients with and without OSA.

RESULTS

Seventeen studies were included in the meta-analysis. Pooled OSA prevalence was 45% of a total sample of 1448 PD patients and was associated with older age, male sex, higher body mass index (BMI), more severe motor disturbances and periodic limb movements, reduced risk of rapid eye movement sleep behavior disorder, intake of dopamine agonists, and worse excessive daytime sleepiness. No relationship emerged with cognitive functioning and neuropsychiatric manifestations.

CONCLUSIONS

OSA affects nearly half of PD patients as a secondary outcome of predisposing factors such as older age and higher BMI in addition to PD-related motor impairment. Future studies should focus on determining the impact of both clinical features and dopaminergic medication on the development of PD-OSA.

Current Update on Clinically Relevant Sleep Issues in Parkinson's Disease: A Narrative Review

Sleep disturbances are among the common nonmotor symptoms in patients with Parkinson’s disease (PD). Sleep can be disrupted by nocturnal motor and nonmotor symptoms and other comorbid sleep disorders. Rapid eye movement sleep behavior disorder (RBD) causes sleep-related injury, has important clinical implications as a harbinger of PD and predicts a progressive clinical phenotype. Restless legs syndrome (RLS) and its related symptoms can impair sleep initiation. Excessive daytime sleepiness (EDS) is a refractory problem affecting patients’ daytime activities. In particular, during the COVID-19 era, special attention should be paid to monitoring sleep problems, as infection-prevention procedures for COVID-19 can affect patients’ motor symptoms, psychiatric symptoms and sleep. Therefore, screening for and managing sleep problems is important in clinical practice, and the maintenance of good sleep conditions may improve the quality of life of PD patients. This narrative review focused on the literature published in the past 10 years, providing a current update of various sleep disturbances in PD patients and their management, including RBD, RLS, EDS, sleep apnea and circadian abnormalities.

Impact of Obstructive Sleep Apnea on Cognitive and Motor Functions in Parkinson's Disease

INTRODUCTION

Parkinson's disease (PD) is a chronic neurodegenerative disorder that presents with motor and non-motor manifestations. Amongst the non-motor features, various forms of sleep disturbances can occur, and obstructive sleep apnea (OSA) is considered to be a common comorbidity. We conducted this systematic review and meta-analysis to assess the impact of OSA on cognitive and motor functions in PD.

METHODS

The information sources of for this systematic review and meta-analysis were PubMed, SCOPUS, Web of Science, and ScienceDirect. Studies meeting the following criteria were included: (1) studies including idiopathic PD patients, (2) studies using polysomnography to categorize PD patients into PD with OSA and PD without OSA, and (3) studies with observational designs (case-control, cohort, or cross-sectional). Data analysis was performed using RevMan.

RESULTS

Our meta-analysis showed that OSA was associated with significantly lower scores of Montreal Cognitive Assessments (MoCA) (mean difference (MD) = -0.70, 95% confidence interval (CI) [-1.28, -0.13], P = 0.01) and Mini-Mental State Examination (MMSE) (MD = -0.69, 95% CI [-1.17, -0.21], P = 0.005). Moreover, the score of the motor part of the Unified Parkinson's Disease Rating Scale (UPDRS III) was significantly higher in PD patients with OSA as compared with those without OSA (MD = 1.63, 95% CI [0.03, 3.23], P = 0.049).

CONCLUSIONS

OSA is associated with increased severity of PD-associated cognitive dysfunction and motor symptoms. However, further studies are needed to corroborate these findings, assess the underlying mechanisms by which OSA influences the motor and cognitive functions in PD, and investigate whether OSA can accelerate the neurodegenerative process of PD. © 2020 International Parkinson and Movement Disorder Society.

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.

Increased Risk of Parkinson's Disease in Patients With Obstructive Sleep Apnea: A Population-Based, Propensity Score-Matched, Longitudinal Follow-Up Study

Obstructive sleep apnea (OSA), characterized by repetitive episodes of apnea/hypopnea and hypoxia, is associated with systemic inflammation and induces metabolic, endocrine, and cardiovascular diseases. Inflammation might have an impact on neurodegenerative diseases. This study investigates the possible association between OSA and Parkinson's disease (PD). Random samples out of 1 million individuals were collected from Taiwan's National Health Insurance database. A total of 16,730 patients with newly diagnosed OSA from 2002 to 2008 were recruited and compared with a cohort of 16,730 patients without OSA matched for age, gender, and comorbidities using propensity scoring. All patients were tracked until a diagnosis of PD, death, or the end of 2011.During the mean 5.6-year follow-up period, the incidence rates of PD were 2.30 per 1000 person-years in the OSA cohort and 1.71per 1000 person-years in the comparison group. The incidence rate ratio (IRR) for PD was greater in older patients (≧ 65 years) and male patients with OSA than the controls, respective IRRs being 1.34 and 1.47. After adjustment for the comorbidities, patients with OSA were 1.37 times more likely to have PD than patients without (95% CI = 1.12-1.68, P < 0.05). Subgroup analysis showed that older patients and patients with coronary artery disease, stroke, or chronic kidney disease had a higher risk for PD than their counter parts. Log-rank analysis revealed that patients with OSA had significantly higher cumulative incidence rates of PD than the comparison group (P = 0.0048). Patients with OSA are at an increased risk for subsequent PD, especially elderly male patients.

[Sleep and autonomic function: sleep related breathing disorders in Parkinson's disease and related disorders]

In patients with multiple system atrophy (MSA), sleep related breathing disorders (SRBD), including obstructive and central sleep apnea, vocal cord abductor paralysis and dysrhythmic breathing pattern, are frequently observed. SRBD may have a considerable impact on variation of autonomic nervous activity during sleep. The previous studies correlated upper airway muscle dysfunction related parkinsonism with increased prevalence of SRBD in patients with Parkinson's disease (PD). However, recently, the clinical significance of SRBD and its impact on sleepiness and disease severity have been debated. In this review, we discuss sleep and autonomic function, especially, SRBD in PD and related disorders, including the previous studies from our department.

Parkinson's disease and sleep/wake disturbances

Sleep disturbances are a common non-motor feature in patients with Parkinson's disease (PD). Early diagnosis and appropriate management are imperative for enhancing patient quality of life. Sleep disturbances can be caused by multiple factors in addition to age-related changes in sleep, such as nocturnal motor symptoms (rigidity, resting tremor, akinesia, tardive dyskinesia, and the "wearing off" phenomenon), non-motor symptoms (pain, hallucination, and psychosis), nocturia, and medication. Disease-related pathology involving the brainstem and changes in the neurotransmitter systems (norepinephrine, serotonin, and acetylcholine) responsible for regulating sleep structure and the sleep/wake cycle play a role in emerging excessive daytime sleepiness and sleep disturbances. Additionally, screening for sleep apnea syndrome, rapid eye movement sleep behavior disorder, and restless legs syndrome is clinically important. Questionnaire-based assessment utilizing the PD Sleep Scale-2 is useful for screening PD-related nocturnal symptoms. In this review, we focus on the current understanding and management of sleep disturbances in PD.

Sleep Disturbances in Essential Tremor and Parkinson Disease: A Polysomnographic Study

OBJECTIVE

Sleep problems are a common non-motor complication of Parkinson disease (PD), and patients with essential tremor (ET) share a number of motor and non-motor features of PD. To clarify the relationship between these disorders, we evaluated the sleep problems in patients with ET and PD using assessment scales and objective polysomnographic (PSG) testing.

METHOD

Twenty-one consecutive patients with PD, 16 with ET, and 14 healthy subjects participated in this study and were compared in terms of sleep related complaints, final sleep related diagnosis, and polysomnographic features.

RESULTS

The results of our study have shown that patients with PD were more likely than were those with ET to have a history of REM sleep behavior disorders (RBD) (p = 0.001) and excessive daytime sleepiness (p ≤ 0.05). Additionally, PSG data revealed that ET patients had lower mean SpO2 values (p ≤ 0.05) and REM without atonia (RWA) (p = 0.032) than did patients with PD.

CONCLUSION

This is the first study to use PSG to evaluate sleep problems both in ET and PD patients. The results point out different sleep problems in these two common movement disorders which should be investigated in further studies.

Dysautonomias in Parkinson's disease: cardiovascular changes and autonomic modulation in conscious rats after infusion of bilateral 6-OHDA in substantia nigra

It is important to elucidate the mechanism of dysautonomias in patients with Parkinson's disease; therefore, this study aimed to investigate the cardiovascular and autonomic changes that occur in an animal model of Parkinsonism. Adult male Wistar rats were anesthetized before bilateral microinfusions of 6-hydroxydopamine (6-OHDA) into the substantia nigra. The sham group underwent the same surgical procedure but received vehicle. After 7 days, the mean arterial pressure (MAP) and heart rate (HR) were measured, and various drugs were injected into conscious rats through cannulas previously implanted in the femoral artery and vein. Spectral analyses of systolic arterial pressure (SAP) and pulse interval (PI) were conducted with the CardioSeries software as the spontaneous baroreflex gain and effectivity. The animals were subjected to α-, β-adrenergic, or muscarinic receptor antagonism. For confirmation of the lesion, the levels of dopamine in the striatum were quantified by high-performance liquid chromatography. Animals that underwent 6-OHDA microinfusion had lower MAP and HR compared with those in the sham group. Spectral analysis of SAP showed that 6-OHDA animals exhibited a decrease in the sympathetic component. The PI values did not differ between groups. After the administration of muscarinic and β-adrenergic antagonists, the cardiovascular measures did not differ between the groups. However, upon administration of the α-adrenergic antagonist, the 6-OHDA animals exhibited a lower decrease in the MAP. We report cardiovascular impairments in 6-OHDA animals, possibly due to decreased sympathetic activity. Determination of the origin of these changes (central or peripheral) requires further investigation.

Risk of obstructive sleep apnea in Parkinson's disease: a meta-analysis

STUDY OBJECTIVES

Sleep disorders are a common symptom of Parkinson's disease (PD) and they significantly impair the sleep quality of the PD patients. However, there is no conclusive evidence to support the relation between PD and the prevalence of obstructive sleep apnea (OSA). The purpose of this meta-analysis review is to evaluate the association between PD and the prevalence of OSA.

METHODS

A comprehensive literature search was conducted on PubMed and Embase through July 2013. Only studies that referred to PD and the prevalence of OSA and that met the selection criteria were included in the analysis. The odds ratios (ORs) were used to evaluate the relationship of PD and the prevalence of OSA by the fixed-effect model.

RESULTS

Five eligible studies were analyzed in this study including 322 cases and 6,361 controls. The pooled-analysis showed the OR to be 0.60 (95% confidence interval (CI): 0.44 to 0.81, P = 0.001) and I(2) = 0.0% (χ(2) = 3.90, P = 0.420) in the fixed-effect model.

CONCLUSIONS

Although we only included five small sample studies that indicated high homogeneity in the heterogeneity test, the results suggest that there is a significant negative association between PD and the prevalence of OSA; PD patients generally have a reduced prevalence of OSA. According to our analysis, these results are primarily due to the lower BMI of PD patients when compared with the general population controls.

Cardiac autonomic impairment during sleep is linked with disease severity in Parkinson's disease

OBJECTIVE

Cardiac physiology during sleep in Parkinson's disease (PD) remains poorly explored. We studied heart rate variability (HRV) across sleep stages in PD patients and correlated the results with clinical features.

METHODS

Cross-sectional study comprising 33 patients with PD and 29 controls matched for age, gender, and number of apneas/hypopneas per hour. HRV measures, (mean R-R interval, SDNN, ULF, VLF, LF, HF and LF/HF) were calculated separately for all sleep stages as well as wakefulness just before and after sleep during one-night polysomnography. Correlation analysis was performed between HRV values and PD patients' characteristics.

RESULTS

The mean R-R interval was lower in all sleep stages in PD patients when compared with controls. VLF and LF were lower during REM sleep in PD patients. HF during N1-N2 stage was higher in PD. We found inverse correlations between VLF and LF during REM sleep and UPDRS-ON and UPDRS-OFF.

CONCLUSION

VLF and LF during REM sleep might constitute surrogate markers of disease severity.

SIGNIFICANCE

These findings provide additional clinical evidence of the autonomic impairment commonly observed in PD, and prove that cardiac autonomic dysfunction during REM sleep is correlated with disease severity.