Bilateral Subthalamic Stimulation can Improve Sleep Quality in Parkinson's Disease

Effects of deep brain stimulation on quantitative sleep electroencephalogram during non-rapid eye movement in Parkinson's disease

Introduction

Sleep dysfunction is frequently experienced by people with Parkinson's disease (PD) and negatively influences quality of life. Although subthalamic nucleus (STN) deep brain stimulation (DBS) can improve sleep in PD, sleep microstructural features such as sleep spindles provide additional insights about healthy sleep. For example, sleep spindles are important for better cognitive performance and for sleep consolidation in healthy adults. We hypothesized that conventional STN DBS settings would yield a greater enhancement in spindle density compared to OFF and low frequency DBS.

Methods

In a previous within-subject, cross-sectional study, we evaluated effects of low (60 Hz) and conventional high (≥130 Hz) frequency STN DBS settings on sleep macroarchitectural features in individuals with PD. In this post hoc, exploratory analysis, we conducted polysomnography (PSG)-derived quantitative electroencephalography (qEEG) assessments in a cohort of 15 individuals with PD who had undergone STN DBS treatment a median 13.5 months prior to study participation. Fourteen participants had unilateral DBS and 1 had bilateral DBS. During three nonconsecutive nights of PSG, the participants were assessed under three different DBS conditions: DBS OFF, DBS LOW frequency (60 Hz), and DBS HIGH frequency (≥130 Hz). The primary objective of this study was to investigate the changes in sleep spindle density across the three DBS conditions using repeated-measures analysis of variance. Additionally, we examined various secondary outcomes related to sleep qEEG features. For all participants, PSG-derived EEG data underwent meticulous manual inspection, with the exclusion of any segments affected by movement artifact. Following artifact rejection, sleep qEEG analysis was conducted on frontal and central leads. The measures included slow wave (SW) and spindle density and morphological characteristics, SW-spindle phase-amplitude coupling, and spectral power analysis during non-rapid eye movement (NREM) sleep.

Results

The analysis revealed that spindle density was significantly higher in the DBS HIGH condition compared to the DBS LOW condition. Surprisingly, we found that SW amplitude during NREM was significantly higher in the DBS LOW condition compared to DBS OFF and DBS HIGH conditions. However, no significant differences were observed in the other sleep qEEG features during sleep at different DBS conditions.

Conclusion

This study presents preliminary evidence suggesting that conventional HIGH frequency DBS settings enhance sleep spindle density in PD. Conversely, LOW frequency settings may have beneficial effects on increasing slow wave amplitude during sleep. These findings may inform mechanisms underlying subjective improvements in sleep quality reported in association with DBS. Moreover, this work supports the need for additional research on the influence of surgical interventions on sleep disorders, which are prevalent and debilitating non-motor symptoms in PD.

Sleep outcomes and related factors in Parkinson's disease after subthalamic deep brain electrode implantation: a retrospective cohort study

Background

Subthalamic nucleus deep brain stimulation (STN-DBS) improves sleep qualities in Parkinson's disease (PD) patients; however, it remains elusive whether STN-DBS improves sleep by directly influencing the sleep circuit or alleviates other cardinal symptoms such as motor functions, other confounding factors including stimulation intensity may also involve. Studying the effect of microlesion effect (MLE) on sleep after STN-DBS electrode implantation may address this issue.

Objective

To examine the influence of MLE on sleep quality and related factors in PD, as well as the effects of regional and lateral specific correlations with sleep outcomes after STN-DBS electrode implantation.

Study Design

Case-control study; Level of evidence, 3.

Data Sources and Methods

In 78 PD patients who underwent bilateral STN-DBS surgery in our center, we compared the sleep qualities, motor performances, anti-Parkinsonian drug dosage, and emotional conditions at preoperative baseline and postoperative 1-month follow-up. We determined the related factors of sleep outcomes and visualized the electrodes position, simulated the MLE-engendered volume of tissue lesioned (VTL), and investigated sleep-related sweet/sour spots and laterality in STN.

Results

MLE improves sleep quality with Pittsburgh Sleep Quality Index (PSQI) by 13.36% and Parkinson's Disease Sleep Scale-2 (PDSS-2) by 17.95%. Motor (P = 0.014) and emotional (P = 0.001) improvements were both positively correlated with sleep improvements. However, MLE in STN associative subregions, as an independent factor, may cause sleep deterioration (r = 0.348, P = 0.002), and only the left STN showed significance (r = 0.327, P = 0.004). Sweet spot analysis also indicated part of the left STN associative subregion is the sour spot indicative of sleep deterioration.

Conclusion

The MLE of STN-DBS can overall improve sleep quality in PD patients, with a positive correlation between motor and emotional improvements. However, independent of all other factors, the MLE in the STN associative subregion, particularly the left side, may cause sleep deterioration.

Parkinsonian daytime sleep-wake classification using deep brain stimulation lead recordings

Excessive daytime sleepiness is a recognized non-motor symptom that adversely impacts the quality of life of people with Parkinson's disease (PD), yet effective treatment options remain limited. Deep brain stimulation (DBS) of the subthalamic nucleus (STN) is an effective treatment for PD motor signs. Reliable daytime sleep-wake classification using local field potentials (LFPs) recorded from DBS leads implanted in STN can inform the development of closed-loop DBS approaches for prompt detection and disruption of sleep-related neural oscillations. We performed STN DBS lead recordings in three nonhuman primates rendered parkinsonian by administrating neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). Reference sleep-wake states were determined on a second-by-second basis by video monitoring of eyes (eyes-open, wake and eyes-closed, sleep). The spectral power in delta (1-4 Hz), theta (4-8 Hz), low-beta (8-20 Hz), high-beta (20-35 Hz), gamma (35-90 Hz), and high-frequency (200-400 Hz) bands were extracted from each wake and sleep epochs for training (70% data) and testing (30% data) a support vector machines classifier for each subject independently. The spectral features yielded reasonable daytime sleep-wake classification (sensitivity: 90.68 ± 1.28; specificity: 88.16 ± 1.08; accuracy: 89.42 ± 0.68; positive predictive value; 88.70 ± 0.89, n = 3). Our findings support the plausibility of monitoring daytime sleep-wake states using DBS lead recordings. These results could have future clinical implications in informing the development of closed-loop DBS approaches for automatic detection and disruption of sleep-related neural oscillations in people with PD to promote wakefulness.

Effects of subthalamic deep brain stimulation on non-motor symptoms of Parkinson's disease: A meta-analysis

Deep brain stimulation (DBS) is a well-defined treatment for motor symptoms in advanced PD. Although several studies have investigated the DBS effect on non-motor symptoms (NMS), controversial results exist regarding this matter. The aim of this meta-analysis and systematic review was to assess the bilateral subthalamic nucleus (STN) DBS effect on NMS of PD. We conducted a systematic search on the literature of Web of Science (WOS), PubMed/MEDLINE, Scopus, Cochrane, and Embase. An additional hand search was also done. Finally, a meta-analysis was conducted on 10 studies containing pre- and post-bilateral STN-DBS data regarding NMS acquired using Non-Motor Symptoms Scale for Parkinson's Disease (NMSS) or Non-Motor Symptoms Questionnaire (NMSQ). A random-effects model was used to determine weighted mean differences, and the heterogeneity index was evaluated using Cochrane's Q test. Our study results indicated that bilateral STN-DBS significantly reduced total NMSS and NMSQ score (WMD -17.73; 95% confidence interval [CI] -20.28 to -15.18, WMD -2.19; 95% CI -2.98 to -1.40), respectively, and no publication bias was found. Regarding each of the NMSS domains, DBS significantly reduced the scores of following domains: sleep (WMD -5.98; 95% CI -6.82 to -5.15), miscellaneous (WMD -4.19; 95% CI -4.96 to -3.43), urinary (WMD -2.99; 95% CI -3.78 to -2.19), sexual (WMD -0.65; 95% CI -1.16 to -0.14), and attention/memory (WMD -0.59; 95% CI -1.15 to -0.03). This meta-analysis demonstrated that bilateral STN-DBS has beneficial effects on NMS of PD.

Basal Ganglia Local Field Potentials as a Potential Biomarker for Sleep Disturbance in Parkinson's Disease

Sleep disturbances, specifically decreases in total sleep time and sleep efficiency as well as increased sleep onset latency and wakefulness after sleep onset, are highly prevalent in patients with Parkinson's disease (PD). Impairment of sleep significantly and adversely impacts several comorbidities in this patient population, including cognition, mood, and quality of life. Sleep disturbances and other non-motor symptoms of PD have come to the fore as the effectiveness of advanced therapies such as deep brain stimulation (DBS) optimally manage the motor symptoms. Although some studies have suggested that DBS provides benefit for sleep disturbances in PD, the mechanisms by which this might occur, as well as the optimal stimulation parameters for treating sleep dysfunction, remain unknown. In patients treated with DBS, electrophysiologic recording from the stimulating electrode, in the form of local field potentials (LFPs), has led to the identification of several findings associated with both motor and non-motor symptoms including sleep. For example, beta frequency (13–30 Hz) oscillations are associated with worsened bradykinesia while awake and decrease during non-rapid eye movement sleep. LFP investigation of sleep has largely focused on the subthalamic nucleus (STN), though corresponding oscillatory activity has been found in the globus pallidus internus (GPi) and thalamus as well. LFPs are increasingly being recognized as a potential biomarker for sleep states in PD, which may allow for closed-loop optimization of DBS parameters to treat sleep disturbances in this population. In this review, we discuss the relationship between LFP oscillations in STN and the sleep architecture of PD patients, current trends in utilizing DBS to treat sleep disturbance, and future directions for research. In particular, we highlight the capability of novel technologies to capture and record LFP data in vivo, while patients continue therapeutic stimulation for motor symptoms. These technological advances may soon allow for real-time adaptive stimulation to treat sleep disturbances.

The Impact of Deep Brain Stimulation on Sleep in Parkinson's Disease: An update

Background:

Parkinson’s disease (PD) can have a significant impact on sleep. Deep brain stimulation (DBS) is an effective treatment for motor features of PD, but less is understood about the impact DBS may have on sleep architecture and various sleep issues commonly seen in PD.

Objective:

To review the impact of DBS on various sleep issues in PD.

Methods:

We reviewed the literature regarding the impact of DBS on sleep patterns, nocturnal motor and non-motor symptoms, and sleep disorders in PD.

Results:

Objective sleep measures on polysomnography (PSG), including sleep latency and wake after sleep onset improve after subthalamic nucleus (STN) and globus pallidus interna (GPi) DBS. Subjective sleep measures, nocturnal motor symptoms, and some non-motor symptoms (nocturia) also may improve. Current evidence suggests STN DBS has no impact on Rapid Eye Movement Behavior Disorder (RBD), while STN DBS may improve symptoms of Restless Legs Syndrome (RLS). There are no studies that have evaluated the impact of GPi DBS on RBD, while it is unclear if GPi has an effect on RLS in PD.

Conclusion:

DBS therapy at either site appears to improve objective and subjective sleep parameters in patients with PD. Most likely, the improvement of motor and some non-motor nocturnal symptoms leads to an increase in total sleep time by up to an hour, as well as reduction of sleep fragmentation. DBS most likely has no impact on RBD, while there is evidence that STN DBS appears to help reduce RLS severity. Further studies are needed.

Sleep Issues in Parkinson's Disease and Their Management

Parkinson's disease (PD) is an alpha-synucleinopathy that leads to prominent motor symptoms including tremor, bradykinesia, and postural instability. Nonmotor symptoms including autonomic, neurocognitive, psychiatric symptoms, and sleep disturbances are also seen frequently in PD. The impact of PD on sleep is related to motor and nonmotor symptoms, in addition to the disruption of the pathways regulating sleep by central nervous system pathology. Rapid eye movement sleep behavior disorder is a parasomnia that can lead to self-injury and/or injury to partners at night. Restless legs syndrome is a subjective sensation of discomfort and urge to move the legs prior to falling asleep and can lead to insomnia and reduced sleep quality. Excessive daytime sleepiness is common in PD and exerts a negative impact on quality of life in addition to increasing the risk of falls. Obstructive sleep apnea is a breathing disorder during sleep that can cause frequent awakenings and excessive daytime sleepiness. Circadian rhythm dysfunction can lead to an advanced or delayed onset of sleep in patients and create disruption of normal sleep and wake times. All of these disorders are common in PD and can significantly reduce sleep quantity, sleep quality, or quality of life for patients and caretakers. Treatment approaches for each of these disorders are distinct and should be individualized to the patient. We review the literature regarding these common sleep issues encountered in PD and their treatment options.

Sleep disruption is not observed with brain-responsive neurostimulation for epilepsy

OBJECTIVE

Neurostimulation devices that deliver electrical impulses to the nervous system are widely used to treat seizures in patients with medically refractory epilepsy, but the effects of these therapies on sleep are incompletely understood. Vagus nerve stimulation can contribute to obstructive sleep apnea, and thalamic deep brain stimulation can cause sleep disruption. A device for brain-responsive neurostimulation (RNS^® System, NeuroPace, Inc) is well tolerated in clinical trials, but potential effects on sleep are unknown.

METHODS

Six adults with medically refractory focal epilepsy treated for at least six months with the RNS System underwent a single night of polysomnography (PSG). RNS System lead locations included mesial temporal and neocortical targets. Sleep stages and arousals were scored according to standard guidelines. Stimulations delivered by the RNS System in response to detections of epileptiform activity were identified by artifacts on scalp electroencephalography.

RESULTS

One subject was excluded for technical reasons related to unreliable identification of stimulation artifact on EEG during PSG. In the remaining five subjects, PSG showed fragmented sleep with frequent arousals. Arousal histograms aligned to stimulations revealed a significant peak in arousals just before stimulation. In one of these subjects, the arousal peak began before stimulation and extended ~1 seconds after stimulation. A peak in arousals occurring only after stimulation was not observed.

SIGNIFICANCE

In this small cohort of patients, brain-responsive neurostimulation does not appear to disrupt sleep. If confirmed in larger studies, this could represent a potential clinical advantage of brain-responsive neurostimulation over other neurostimulation modalities.

Which Scale Best Detects Treatment Response of Tremor in Parkinsonism?

BACKGROUND

Several scales are available for rating the severity of tremor at present. However, the sensitivity to change of these instruments has remained to be clarified.

OBJECTIVE

To compare the sensitivity of the Fahn-Tolosa-Marin Tremor Rating Scale, the Part III of the Movement Disorder Society-sponsored Unified Parkinson's Disease Rating Scale (MDS-UPDRS) and the MDS-UPDRS Tremor Scale to the effects of various antitremor treatments.

METHODS

Enrolling subjects with parkinsonism associated with tremor, we analyzed two scenarios: (1) tremor changes associated with acute levodopa challenge (n = 287) and (2) a 12-month outcome of different treatment options (n = 512) including deep brain stimulation (n = 146), levodopa/carbidopa intestinal gel infusion (n = 30), and initiating (n = 63) or adjusting oral antiparkinsonian medication (n = 273). Changes in tremor scales were assessed by effect size values (Cohen's d and eta-square).

RESULTS

Part B of the Fahn-Tolosa-Marin Tremor Rating Scale was the most sensitive to acute levodopa challenge (Cohen's d = -1.04, η2 = 0.12). However, Part A of the Fahn-Tolosa-Marin Tremor Rating Scale showed the highest effect size, which was a small one (Cohen's d = -0.33, η2 = 0.03), for detecting a treatment-related change in the severity of tremor during long-term follow-up.

CONCLUSIONS

The Fahn-Tolosa-Marin Tremor Rating Scale has a better ability to capture changes due to levodopa challenge or antiparkinsonian treatment than MDS-UPDRS Part III or MDS-UPDRS Tremor Scale.

Deep Brain Stimulation and Sleep-Wake Disturbances in Parkinson Disease: A Review

Sleep-wake disturbances are common non-motor manifestations in Parkinson Disease (PD). Complex pathophysiological changes secondary to neurodegeneration in combination with motor symptoms and dopaminergic medications contribute to development of sleep-wake disturbances. The management of sleep complaints in PD is important as this symptom can affect daily activities and impair quality of life. Deep brain stimulation (DBS) is an effective adjunctive therapy for management of motor symptoms in PD. However, its effect on non-motor symptoms including sleep-wake disturbances is not widely understood. In this article, we reviewed studies assessing the effect of DBS at various therapeutic targets on sleep-wake disturbances. Of the studies examining the role of DBS in sleep-wake disturbances, the effect of subthalamic nucleus stimulation is most widely studied and has shown improvement in sleep quality, sleep efficiency, and sleep duration. Although, studies investigating changes in sleep with stimulation of thalamus, globus pallidus interna, and pedunculopontine nucleus are limited, they support the potential for modulation of sleep-wake centers with DBS at these sites. The mechanism by which DBS at different anatomical targets affects sleep-wake disturbances in PD is unclear and may involves multiple factors, including improved motor symptoms, medication adjustment, and direct modulation of sleep-wake centers.

Changes in Parkinson's disease sleep symptoms and daytime somnolence after bilateral subthalamic deep brain stimulation in Parkinson's disease

INTRODUCTION

Deep brain stimulation (DBS) markedly improves motor function in advanced Parkinson's disease (PD), but its effect on sleep is less clear.

PATIENTS AND METHODS

Forty PD patients who had subthalamic DBS (STN-DBS) were identified from an on-going non-motor naturalistic longitudinal study (NILS). All patients were followed up for at least 6 months, 26 patients had a 1 year follow-up. A total PDSS score of 100 or less, a score in any PDSS-item of 6 or less, and a Epworth score of 10 or more were classified as being significant.

RESULTS

Forty-five percent of patients reported significant improvement in the total PDSS score at 6 months, and 35% at 12 months. In terms of magnitude, the total PDSS score at 6 months was significantly improved from baseline while the improvement at 12 months was not statistically significant. The most frequently reported improvements were overall sleep quality and maintenance of sleep. Some patients reported worsening of the total PDSS score. More than half of the patients reporting daytime sleepiness at baseline had persistent sleepiness at 6 and 12 months. The mean Epworth Score did not improve because a significant number of patients without sleepiness at baseline reported new-onset sleepiness at 6 and 12 months. Neither medication changes nor motor improvement were consistently related to sleep changes after DBS.

CONCLUSION

Subthalamic DBS is associated with a statistically and clinically significant, but variable, improvement in sleep as measured by the PDSS. The most frequent improvements were better overall sleep quality and better sleep maintenance.

Prevalence of Anxiety among Hungarian Subjects with Parkinson's Disease

Although anxiety is one of the most frequent symptoms of Parkinson's disease (PD), only a few clinical tools can efficiently and reliably detect its presence. The aim of the present study was to validate the Hungarian patient-rated version of Parkinson Anxiety Scale (PAS). A total of 190 PD patients were enrolled into the clinimetric validation phase of the study and another 590 participated in the cross-sectional screening phase. The presence of anxiety disorder was diagnosed based on the Diagnostic and Statistical Manual of Mental Disorders criteria. The cutoff value for PAS which best discriminated the presence of anxiety from the absence was 12.5 points (sensitivity of 88.6%, specificity of 79.9). The area under the curve was 0.847 whereas the ROC analysis yielded the statistical significance level (p < 0.001). The optimal threshold values for mild (Hoehn and Yahr Stage, HYS 1 and 2), moderate (HYS 3), and severe (HYS 4 and 5) disease stages were 10.5, 12.5, and 13.5 points, respectively. Based on the general threshold anxiety occurred in 35.8% of the patients (persistent anxiety: 29.2%, episodic anxiety: 20.7%, and avoidant anxiety disorder: 16.8%). We demonstrate that the PAS is a valid, highly reliable, and sensitive tool for assessing anxiety.

The missing link between sleep disorders and age-related dementia: recent evidence and plausible mechanisms

Sleep disorders are among the most common clinical problems and possess a significant concern for the geriatric population. More importantly, while around 40% of elderly adults have sleep-related complaints, sleep disorders are more frequently associated with co-morbidities including age-related neurodegenerative diseases and mild cognitive impairment. Recently, increasing evidence has indicated that disturbed sleep may not only serve as the consequence of brain atrophy, but also contribute to the pathogenesis of dementia and, therefore, significantly increase dementia risk. Since the current therapeutic interventions lack efficacies to prevent, delay or reverse the pathological progress of dementia, a better understanding of underlying mechanisms by which sleep disorders interact with the pathogenesis of dementia will provide possible targets for the prevention and treatment of dementia. In this review, we briefly describe the physiological roles of sleep in learning/memory, and specifically update the recent research evidence demonstrating the association between sleep disorders and dementia. Plausible mechanisms are further discussed. Moreover, we also evaluate the possibility of sleep therapy as a potential intervention for dementia.

Deep brain stimulation and sleep-wake functions in Parkinson's disease: A systematic review

Sleep-wake disturbances (SWD) are common nonmotor symptoms (NMS) and have a great impact on quality of life of patients with Parkinson's disease (PD). Deep brain stimulation (DBS) is an established treatment in PD. While the beneficial effects of DBS on cardinal PD motor symptoms are indisputable, the data for several NMS, including sleep-wake functions, are limited and often controversial. Our primary objective was to review the literature on the impact of DBS on sleep-wake functions in patients with PD. A systematic review of articles, published in PubMed between January 1st, 2000 and December 31st, 2015 was performed to identify studies addressing the evolution of sleep-wake functions after DBS in patients with PD. Only 38 of 208 studies, involving a total of 1443 subjects, met the inclusion criteria. Most of them reported a positive effect of subthalamic DBS on sleep quality and consequently on quality of life. Seven studies used polysomnography to objectively assess sleep parameters. The data concerning subthalamic DBS and wake functions are controversial and studies using objective, laboratory-based measures for the assessment of wake functions are lacking. Very few studies assessed the impact of other DBS targets (e.g. pallidal stimulation) on SWD. Further prospective observational DBS studies assessing subjectively and objectively specific sleep-wake parameters in patients with PD are needed.

Impact of Sex on the Nonmotor Symptoms and the Health-Related Quality of Life in Parkinson's Disease

Background. Female Parkinson's disease (PD) patients seem to experience not only more severe motor complications and postural instability but also more pronounced depression, anxiety, pain, and sleep disturbances. Objective. The aim of the present study was to evaluate the role of sex as a possible independent predictor of HRQoL in PD. Methods. In this cross-sectional study, 621 consecutive patients treated at the University of Pécs were enrolled. Severity of PD symptoms was assessed by MDS-UPDRS, UDysRS, Non-Motor Symptoms Scale, PDSS-2, Hamilton Anxiety Scale, Montgomery-Asberg Depression Rating Scale, Lille Apathy Rating Scale, and Addenbrooke Cognitive Examination. HRQoL was assessed by PDQ-39 and EQ-5D. Multiple regression analysis was performed to estimate the PDQ-39 and EQ-5D index values based on various clinical factors. Results. Although females received significantly lower dosage of levodopa, they had significantly more disabling dyskinesia and worse postural instability. Anxiety, pain, sleep disturbances, and orthostatic symptoms were more frequent among females while sexual dysfunction, apathy, and daytime sleepiness were more severe among males. Women had worse HRQoL than men (EQ-5D index value: 0.620 ± 0.240 versus 0.663 ± 0.229, p = 0.025, and PDQ-39 SI: 27.1 ± 17.0 versus 23.5 ± 15.9, p = 0.010). Based on multiple regression analysis, sex was an independent predictor for HRQoL in PD. Conclusions. Based on our results, female sex is an independent predictor for having worse HRQoL in PD.

Long-term impact on quality of life of subthalamic nucleus stimulation in Parkinson's disease

Long-term impact of bilateral subthalamic nucleus deep brain stimulation (STN-DBS) on health-related quality of life (HRQOL) and associated factors in patients with Parkinson's disease (PD) are not clear. In this prospective study, we included 69 PD patients (64 % men, mean age 61.3 ± 7.4 and disease duration 13.2 ± 5.7 years) undergoing STN-DBS. They were evaluated preoperatively (baseline), 1 and 5 years postoperatively assessing 39-item Parkinson's Disease Questionnaire (PDQ-39), Schwab and England Activities of Daily Living Scale (SEADL), Unified Parkinson's Disease Rating Scale (UPDRS) off- and on-medication, patient diaries, dopaminergic treatment, mortality and surgical complications. Five years postoperatively, off-medication, there were improvements from baseline in UPDRS-II and III total (27.2 and 26.7 %, respectively) and SEADL (18.6 % more completely independent patients) (p < 0.05) scores, while on-medication, there was a deterioration in UPDRS-III (37.8 %, mainly axial signs) (p < 0.05) and minor improvements in SEADL (3.7 %). While at 1 year PDQ-39, the summary index improved substantially (36.5 %) (p < 0.05), at 5 years patients regressed (only 8.8 %) (p < 0.05), though changes in PDQ-39 subscores remained significant, with improvements in ADL (18.8 %), emotional well-being (19.0 %), stigma (36.4 %) and discomfort (20.6 %), despite worsening in communication (47.8 %) (p < 0.05). Lower preoperative PDQ-39 summary index and greater 1-year UPDRS-III-off total score gain predicted better long-term HRQOL. STN-DBS produces long-term improvements in HRQOL in PD. Preoperative HRQOL and short-term postoperative changes in off-medication motor status may predict long-term HRQOL in PD following STN-DBS.

Minimal Clinically Important Difference on Parkinson's Disease Sleep Scale 2nd Version

Background and Aims. The aim of the present study was to determine the estimates of minimal clinically important difference for Parkinson's Disease Sleep Scale 2nd version (PDSS-2) total score and dimensions. Methods. The subject population consisted of 413 PD patients. At baseline, MDS-UPDRS, Hoehn-Yahr Scale, Mattis Dementia Rating Scale, and PDSS-2 were assessed. Nine months later the PDSS-2 was reevaluated with the Patient-Reported Global Impression Improvement Scale. Both anchor-based techniques (within patients' score change method and sensitivity- and specificity-based method by receiver operating characteristic analysis) and distribution-based approaches (effect size calculations) were utilized to determine the magnitude of minimal clinically important difference. Results. According to our results, any improvements larger than −3.44 points or worsening larger than 2.07 points can represent clinically important changes for the patients. These thresholds have the effect size of 0.21 and −0.21, respectively. Conclusions. Minimal clinically important differences are the smallest change of scores that are subjectively meaningful to patients. Studies using the PDSS-2 as outcome measure should utilize the threshold of −3.44 points for detecting improvement or the threshold of 2.07 points for observing worsening.

Screening Mild and Major Neurocognitive Disorders in Parkinson's Disease

Introduction. Among the nonmotor features of Parkinson's disease (PD), cognitive impairment is one of the most troublesome problems. New diagnostic criteria for mild and major neurocognitive disorder (NCD) in PD were established by Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5). The aim of our study was to establish the diagnostic accuracy of widely used screening tests for NCD in PD. Methods. Within the scope of our study we evaluated the sensitivity and specificity of different neuropsychological tests (Addenbrooke's Cognitive Examination (ACE), Mattis Dementia Rating Scale (MDRS), Mini Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA)) in 370 PD patients without depression. Results. MoCA and ACE feature the finest diagnostic accuracy for detecting mild cognitive disorder in PD (DSM-5) at the cut-off scores of 23.5 and 83.5 points, respectively. The diagnostic accuracy of these tests was 0.859 (95% CI: 0.818–0.894, MoCA) and 0.820 (95% CI: 0.774–0.859, ACE). In the detection of major NCD (DSM-5), MoCA and MDRS tests exhibited the best diagnostic accuracy at the cut-off scores of 20.5 and 132.5 points, respectively. The diagnostic accuracy of these tests was 0.863 (95% CI: 0.823–0.897, MoCA) and 0.830 (95% CI: 0.785–0.869, MDRS). Conclusion. Our study demonstrated that the MoCA may be the most suitable test for detecting mild and major NCD in PD.