Abnormal sleep and sleepiness in Parkinson's disease

Sex-dependent effects of monomeric α-synuclein on calcium and cell death of lateral hypothalamic mouse neurons are altered by orexin

Parkinson's Disease (PD) patients experience sleeping disorders in addition to the disease-defining symptomology of movement dysfunctions. The prevalence of PD is sex-based and presence of sleeping disorders in PD also shows sex bias with a stronger phenotype in males. In addition to loss of dopamine-containing neurons in the striatum, arousal-related, orexin-containing neurons in the lateral hypothalamus (LH) are lost in PD, which could contribute to state-related disorders. As orexin has been shown to be involved in sleeping disorders and to have neuroprotective effects, we asked whether orexin could protect sleep-related LH neurons from damage putatively from the protein α-synuclein (α-syn), which is found at high levels in the PD brain and that we have shown is associated with putatively excitotoxic rises in intracellular calcium in brainstem sleep-controlling nuclei, especially in males. Accordingly, we monitored intracellular calcium transients induced by α-syn and whether concurrent exposure to orexin affected those transients in LH cells of the mouse brain slice using calcium imaging. Further, we used an assay of cell death to determine whether LH cell viability was influenced when α-syn and orexin were co-applied when compared to exposure to α-syn alone. We found that excitatory calcium events induced by α-syn were reduced in amplitude and frequency when orexin was co-applied, and when data were evaluated by sex, this effect was found to be greater in females. In addition, α-syn exposure was associated with cell death that was higher in males, and interestingly, reduced cell death was noted when orexin was present, which did not show a sex bias. We interpret our findings to indicate that orexin is protective to α-syn-mediated damage to hypothalamic neurons, and the actions of orexin on α-syn-induced cellular effects differ between sexes, which could underlie sex-based differences in sleeping disorders in PD.

Macro and micro-sleep dysfunctions as translational biomarkers for Parkinson's disease

Sleep disturbances are highly prevalent among patients with Parkinson's disease (PD) and often appear from the early-phase disease or prodromal stages. In this chapter, we will discuss the current evidence addressing the links between sleep dysfunctions in PD, focusing most closely on those data from animal and mathematical/computational models, as well as in human-based studies that explore the electrophysiological and molecular mechanisms by which PD and sleep may be intertwined, whether as predictors or consequences of the disease. It is possible to clearly state that leucine-rich repeat kinase 2 gene (LRRK2) is significantly related to alterations in sleep architecture, particularly affecting rapid eye movement (REM) sleep and non-REM sleep, thus impacting sleep quality. Also, decreases in gamma power, observed after dopaminergic lesions, correlates negatively with the degree of injury, which brings other levels of understanding the impacts of the disease. Besides, abnormal synchronized oscillations among basal ganglia nuclei can be detrimental for information processing considering both motor and sleep-related processes. Altogether, despite clear advances in the field, it is still difficult to definitely establish a comprehensive understanding of causality among all the sleep dysfunctions with the disease itself. Although, certainly, the search for biomarkers is helping in shortening this road towards a better and faster diagnosis, as well as looking for more efficient treatments.

Targeting the blood-brain barrier to delay aging-accompanied neurological diseases by modulating gut microbiota, circadian rhythms, and their interplays

The blood-brain barrier (BBB) impairment plays a crucial role in the pathological processes of aging-accompanied neurological diseases (AAND). Meanwhile, circadian rhythms disruption and gut microbiota dysbiosis are associated with increased morbidity of neurological diseases in the accelerated aging population. Importantly, circadian rhythms disruption and gut microbiota dysbiosis are also known to induce the generation of toxic metabolites and pro-inflammatory cytokines, resulting in disruption of BBB integrity. Collectively, this provides a new perspective for exploring the relationship among circadian rhythms, gut microbes, and the BBB in aging-accompanied neurological diseases. In this review, we focus on recent advances in the interplay between circadian rhythm disturbances and gut microbiota dysbiosis, and their potential roles in the BBB disruption that occurs in AAND. Based on existing literature, we discuss and propose potential mechanisms underlying BBB damage induced by dysregulated circadian rhythms and gut microbiota, which would serve as the basis for developing potential interventions to protect the BBB in the aging population through targeting the BBB by exploiting its links with gut microbiota and circadian rhythms for treating AAND.

Scoring sleep in neurodegenerative diseases: A pilot study in the synucleinopathies

BACKGROUND

Neurodegenerative diseases often alter sleep architecture, complicating the application of the standard sleep scoring rules. There are no recommendations to overcome this problem. Our aim was to develop a scoring method that incorporates the stages previously applied in dementia with Lewy Bodies (DLB), anti-IgLON5 disease, and fatal insomnia, and to test it in patients with alpha-synucleinopathies.

METHODS

Video-polysomnographies (VPSG) of nine patients (DLB:3, Parkinson's disease (PD):3, and multiple system atrophy (MSA):3) selected for their difficulty in applying standard rules were scored independently by two authors, using additional Sleep/Wake stages. These included Abnormal Wake, Subwake, Undifferentiated NREM sleep (UNREM), Poorly structured N2 (P-S N2) and abnormal REM sleep including REM without atonia (RWA), REM without low-amplitude, mixed-frequency EEG activity (RWL) and REM without rapid eye movements (RWR).

RESULTS

Patients (4 females) had a median age of 74 (range 63-85). Six patients (all with PD or DLB) had abnormal EEG awake and Subwake stage. UNREM sleep was present in all patients, typically at sleep onset, and was the most common sleep stage in five. P-S N2 was recorded only in the three patients with MSA. Periods of normal and abnormal NREM coexisted in three patients. RWA was the predominant REM subtype, RWR occurred mainly in patients with MSA and RWL in those with DLB. Six patients had brief REM episodes into NREM sleep which we termed "Encapsulated RBD".

CONCLUSION

Our scoring system allows an accurate description of the complex sleep-wake changes in patients with alpha-synucleinopathies.

ATP13A2 Gene Silencing in Drosophila Affects Autophagic Degradation of A53T Mutant α-Synuclein

Mutations in ATP13A2 (PARK9), an autophagy-related protein, cause Kufor-Rakeb syndrome, an autosomal recessive, juvenile-onset form of parkinsonism. α-Synuclein (α-syn) is a presynaptic neuronal protein that forms toxic aggregates in Parkinson's disease (PD). We studied α-syn aggregation and autophagic flux in ATP13A2-knockdown Drosophila expressing either wild-type (WT) or mutant α-syn. Dopaminergic (DA) neuron loss was studied by confocal microscopy. Sleep and circadian activity were evaluated in young and old flies using a Drosophila activity monitor. Thirty-day-old ATP13A2-RNAi A53T-α-syn flies had increased Triton-insoluble α-syn levels, compared to control A53T-α-syn flies without ATP13A2-RNAi. Whole-brain staining revealed significantly fewer dopaminergic (DA) neurons in the PPL2 cluster of 30-day-old ATP13A2-RNAi flies expressing WT-, A30P-, and A53T-α-syn than in that of controls. In ATP13A2-RNAi A53T-α-syn flies, autophagic flux was decreased, as indicated by increased accumulation of Ref(2)P, the Drosophila p62 homologue. ATP13A2 silencing decreased total locomotor activity in young, and enhanced sleep features, similar to PD (decreasing bout length), in old flies expressing A53T-α-syn. ATP13A2 silencing also altered the circadian locomotor activity of A30P- and A53T-α-syn flies. Thus, ATP13A2 may play a role in the autophagic degradation of A53T-α-syn.

Narcolepsy-A Neuropathological Obscure Sleep Disorder: A Narrative Review of Current Literature

Narcolepsy is a chronic, long-term neurological disorder characterized by a decreased ability to regulate sleep-wake cycles. Some clinical symptoms enter into differential diagnosis with other neurological diseases. Excessive daytime sleepiness and brief involuntary sleep episodes are the main clinical symptoms. The majority of people with narcolepsy experience cataplexy, which is a loss of muscle tone. Many people experience neurological complications such as sleep cycle disruption, hallucinations or sleep paralysis. Because of the associated neurological conditions, the exact pathophysiology of narcolepsy is unknown. The differential diagnosis is essential because relatively clinical symptoms of narcolepsy are easy to diagnose when all symptoms are present, but it becomes much more complicated when sleep attacks are isolated and cataplexy is episodic or absent. Treatment is tailored to the patient's symptoms and clinical diagnosis. To facilitate the diagnosis and treatment of sleep disorders and to better understand the neuropathological mechanisms of this sleep disorder, this review summarizes current knowledge on narcolepsy, in particular, genetic and non-genetic associations of narcolepsy, the pathophysiology up to the inflammatory response, the neuromorphological hallmarks of narcolepsy, and possible links with other diseases, such as diabetes, ischemic stroke and Alzheimer's disease. This review also reports all of the most recent updated research and therapeutic advances in narcolepsy. There have been significant advances in highlighting the pathogenesis of narcolepsy, with substantial evidence for an autoimmune response against hypocretin neurons; however, there are some gaps that need to be filled. To treat narcolepsy, more research should be focused on identifying molecular targets and novel autoantigens. In addition to therapeutic advances, standardized criteria for narcolepsy and diagnostic measures are widely accepted, but they may be reviewed and updated in the future with comprehension. Tailored treatment to the patient's symptoms and clinical diagnosis and future treatment modalities with hypocretin agonists, GABA agonists, histamine receptor antagonists and immunomodulatory drugs should be aimed at addressing the underlying cause of narcolepsy.

The association of saccadic abnormalities with rem sleep in patients with Huntington's disease

BACKGROUND

Huntington's disease (HD) is a progressive neurodegenerative disorder characterised by chorea, cognitive impairment, psychiatric and behavioral disturbances. Sleep disturbances including reduced REM sleep have been observed in HD.

OBJECTIVES

The aim of the study was to study the polysomnography findings in HD and to assess whether oculomotor abnormalities are associated with poor REM sleep.

METHODS

Twenty-nine genetically confirmed HD patients underwent clinical evaluation including extraocular movement and OKN examination. Twenty-six patients and 15 controls underwent overnight video polysomnography (VPSG).

RESULTS

VPSG of 23 HD patients and 13 controls were considered for analysis. Compared to controls, HD patients had higher median wake period and higher WASO percentage (p = 0.005). REM sleep percentage was reduced significantly in HD in comparison to controls (p < 0.001). Out of 23 patients, only two patients had REM sleep above 20% while 14 patients had REM sleep percentage less than 15%. Poor horizontal OKN (grades 2 and 3) was associated with the presence of low REM sleep percentage (REM sleep less than 15%) (p = 0.02). Low REM sleep was also associated with severe illness (UHDRS) (p = 0.038).

CONCLUSION

An association between decreased REM sleep and OKN abnormalities indicate that EOM abnormalities seen in HD could lead to errors in scoring REM sleep. To understand the actual degree of decreased REM sleep percentage will require additional parameters in AASM guidelines to score REM sleep in patients with EOM abnormalities like that seen in HD.

Lower calcium levels in hair of Parkinson's disease patients are associated with presence of sleeping disturbances

Objectives: To investigate the correlation between sleep disorders and the concentrations of three metals analyzed from hair samples of PD patients.The hypothesis of an involvement of an imbalance of metals in the development of Parkinson's Disease (PD) has been strengthened by several clinical chemistry studies. Interestingly, while sparse, some studies have correlated the imbalance of metals in PD patients with comorbidities present in this disease. Although not all PD sufferers present sleep disturbances, significant disorders of sleep are common in this population. Methods: Sleep evaluation was divided into three parameters: sleep quality, excessive daytime sleepiness and clinically probable REM Sleep Behavior Disorder. Flame atomic absorption spectrometry (F AAS) was used to assess the concentrations of calcium, iron and zinc in hair samples collected from a population of PD patients registered in a Brazilian city and from controls (a total of 53 subjects). All subjects lived within a restricted geographical region and were exposed to similar environmental conditions. Results: PD patients with poor sleep quality and excessive daytime sleepiness exhibited significant differences in concentrations of calcium, but not iron or zinc when compared to levels found in controls and PD patients who do not report these sleeping problems. Discussion: Our data suggest that different subgroups of PD patients exist, and clinical chemistry could be useful as a biomarker for these subgroups, which needs to be confirmed in a larger patient population. Further, our data raise the question regarding whether normalization of calcium levels could improve the sleep quality and somnolence in PD patients.

The orexin/hypocretin system in neuropsychiatric disorders: Relation to signs and symptoms

Hypocretin-1 and 2 (or orexin A and B) are neuropeptides exclusively produced by a group of neurons in the lateral and dorsomedial hypothalamus that project throughout the brain. In accordance with this, the two different hypocretin receptors are also found throughout the brain. The hypocretin system is mainly involved in sleep-wake regulation, but also in reward mechanisms, food intake and metabolism, autonomic regulation including thermoregulation, and pain. The disorder most strongly linked to the hypocretin system is the primary sleep disorder narcolepsy type 1 caused by a lack of hypocretin signaling, which is most likely due to an autoimmune process targeting the hypocretin-producing neurons. However, the hypocretin system may also be affected, but to a lesser extent and less specifically, in various other neurological disorders. Examples are neurodegenerative diseases such as Alzheimer's, Huntington's and Parkinson's disease, immune-mediated disorders such as multiple sclerosis, neuromyelitis optica, and anti-Ma2 encephalitis, and genetic disorders such as type 1 diabetus mellitus and Prader-Willi Syndrome. A partial hypocretin deficiency may contribute to the sleep features of these disorders.

Characteristics of Objective Sleep and Its Related Risk Factors Among Parkinson's Disease Patients With and Without Restless Legs Syndrome

Objective: This study aimed to investigate the objective sleep characteristics and their related risk factors among Parkinson's disease (PD) patients with and without restless legs syndrome (RLS).

Methods: A total of 125 patients with PD who underwent overnight polysomnography (PSG) were recruited consecutively. Eighty-one patients, including 27 PD with RLS (PD-RLS) and 54 PD without RLS (PD-NRLS), were included in the final analysis after 1:2 propensity score matching. Demographic, clinical, and polysomnographic data were compared between PD patients with and without RLS. The risk factors for sleep quality were examined using a multiple linear regression model.

Results: The prevalence of RLS among PD patients was 28.0% (35/125). The PD-RLS group exhibited a higher score for the Unified Parkinson Disease Rating Scale (UPDRS) III than the PD-NRLS group. Also, the PD-RLS patients displayed significantly shorter total sleep times, worse sleep quality, decreased stage 3 duration, a longer wake time after sleep onset, and a higher arousal index than those without RLS (all p < 0.05). In the multiple linear regression model, PD duration (β = −0.363, 95% CI: −0.652 to −0.074; p = 0.016), UPDRS-III (β = −0.356, 95% CI: −0.641 to −0.071; p = 0.016), and periodic limb movement index (PLMI) (β = −0.472, 95% CI: −0.757 to −0.187; p = 0.002) were determined to be the risk factors influencing sleep quality in PD-RLS patients. The UPDRS-III (β = −0.347, 95% CI: −0.590 to −0.104; p = 0.006) and HAMD scores (β = −0.343, 95% CI: −0.586 to −0.100; p = 0.007) were significantly associated with sleep quality after adjusting for confounding factors in PD-NRLS patients, respectively.

Conclusions: PD-RLS patients exhibited more disturbed and fragmented sleep in objective sleep architecture than PD-NRLS patients. The severity of motor symptoms in PD was significantly associated with poor sleep quality in both PD-RLS and PD-NRLS patients. Notably, our findings indicated that periodic limb movements during sleep (PLMS) was the risk factor that influenced the objective sleep quality in PD patients with RLS.

REM sleep behavior disorder in narcolepsy: A secondary form or an intrinsic feature?

Disrupted nighttime sleep is one of the pentad of symptoms defining Narcolepsy. REM sleep behavior disorder (RBD) largely contributes to night sleep disruption and narcolepsy is the most common cause of secondary RBD. However, RBD linked to narcolepsy (N-RBD) has been insufficiently characterized, leaving unsolved a number of issues. Indeed, it is still debated whether N-RBD is an intrinsic feature of narcolepsy, as indubitable for cataplexy, and therefore strictly linked to the cerebrospinal fluid hypocretin-1 (CSF hcrt-1) deficiency, or an associated feature, with a still unclear pathophysiology. The current review aims at rendering a comprehensive state-of-the-art of N-RBD, highlighting the open and unsettled topics. RBD reportedly affects 30-60% of patients with Narcolepsy type 1 (NT1), but it may be seen also in Narcolepsy type 2 (NT2). When compared to idiopathic/isolated RBD (iRBD), N-RBD has been reported to be characterized by less energetic and quieter episode, which however occur with the same probability in the first and the second part of the night and sometime even subcontinuously. N-RBD patients are generally younger than those with iRBD. N-RBD has been putatively linked to wake-sleep instability due to CSF hcrt-1 deficiency, but this latter by itself cannot explain completely the phenomenon as N-RBD has not been universally linked to low CSF hcrt-1 levels and it may be observed also in NT2. Therefore, other factors may probably play a role and further studies are needed to clarify this issue. In addition, therapeutic options have been poorly investigated.

Herbal medicine (Hepad) prevents dopaminergic neuronal death in the rat MPTP model of Parkinson's disease

BACKGROUND

Parkinson's disease (PD) is a neurodegenerative disorder characterized by loss of dopaminergic neurons in the substantia nigra. The purpose of this study was to examine neuroprotective effects of Hepad S1, an herbal medicine used for the treatment of PD, in in vitro and in vivo models of PD.

METHODS

Differentiated neuronal PC12 cells underwent a cytotoxicity assay and oxidative stress analysis including DCF-DA staining, glutathione, and malondialdehyde, after exposure to 1-methyl-4-phenylpyridium (MPP+). Male Sprague-Dawley rats were used as 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD models. After 4-week oral administration of Hepad S1 (200, 300, 400, and 500 mg/kg/day), the levels of complex enzyme I activity and dopamine, and dopaminergic neuronal cell number in substantia nigra were measured by enzyme linked immune-sorbent assay (ELISA) and microscopic observation, respectively. Circulating serotonin and orexin A were also examined by ELISA.

RESULTS

Hepad S1 pretreatment prevented the ability of MPP+ challenge to decrease glutathione and increase lipid peroxidation in cells, indicating antioxidant activity. Hepad S1 recovered MPTP-induced decreases in complex I enzyme activity and enhanced dopamine availability in substantia nigra. Serum levels of serotonin and orexin A were increased by Hepad S1 treatment in model animals. Hepad S1 treatment was associated with the preservation of tyrosine hydroxylase-positive cells in the substantia nigra of MPTP-treated rats.

CONCLUSIONS

Hepad S1 exerts antioxidant and neuroprotective effects on neurons of the substantia nigra in a rodent model of PD.

Daytime sleepiness may be an independent symptom unrelated to sleep quality in Parkinson's disease

Excessive daytime sleepiness (EDS) may represent a disabling non-motor symptom in patients affected by Parkinson's disease (PD). This is a secondary analysis of a previous study documenting the improvement of nocturnal sleep in PD patients treated by rotigotine vs placebo. Here we tested the supposition that EDS may represent a distinct PD non-motor symptom occurring independently of other sleep-wake disorders; moreover, we verified whether EDS can be influenced by the improvement of nocturnal sleep in PD. In the present study, we evaluated the daytime sleepiness of PD patients treated with nocturnal administration of rotigotine (PD-Rot) vs placebo (PD-Pla), as measured by both subjective (Epworth Sleepiness Scale-ESS) and objective (Multiple Sleep Latency Test-MSLT) tools. We included 21 PD-Rot compared to 21 PD-Pla patients and documented no significant changes of both ESS and MSLT data between baseline and follow-up visits in both groups. Moreover, we found no correlations between nocturnal sleep improvement and diurnal sleepiness. Therefore, these data suggest that the improvement of nocturnal sleep in PD patients does not modify the daytime sleepiness, thus suggesting that diurnal sleepiness may occur independently of nocturnal sleep disturbances in PD patients.

Brain MRI morphometric analysis in Parkinson's disease patients with sleep disturbances

Background

Sleep disturbances are common in patients with advanced Parkinson disease (PD). The aim of this study was to evaluate a possible association of cortical thickness, cortical and subcortical volume with sleep disturbances in PD patients.

Methods

Twenty-eight PD patients (14 men and 14 women, median age 58 years) were evaluated for sleep disturbances with PDSS and underwent brain MRI. Control group consisted of 28 healthy volunteers who were matched by age and gender. Automated voxel based image analysis was performed with the FreeSurfer software.

Results

PD patients when compared to controls had larger ventricles, smaller volumes of hippocampus and superior cerebellar peduncle, smaller grey matter thickness in the left fusiform, parahipocampal and precentral gyruses, and right caudal anterior cingulate, parahipocampal and precentral hemisphere gyruses, as well as smaller volume of left rostral middle frontal and frontal pole areas, and right entorhinal and transverse temporal areas. According to the Parkinson’s disease Sleep Scale (PDSS), 15 (53.58%) patients had severely disturbed sleep. The most frequent complaints were difficulties staying asleep during the night and nocturia. The least frequent sleep disturbances were distressing hallucinations and urine incontinence due to off symptoms. Patients who fidgeted during the night had thicker white matter in the left caudal middle frontal area and lesser global left hemisphere cortical surface, especially in the lateral orbitofrontal and lateral occipital area, and right hemisphere medial orbitofrontal area. Patients with frequent distressful dreams had white matter reduction in cingulate area, and cortical surface reduction in left paracentral area, inferior frontal gyrus and right postcentral and superior frontal areas. Nocturnal hallucinations were associated with volume reduction in the basal ganglia, nucleus accumbens and putamen bilaterally. Patients with disturbing nocturia had reduction of cortical surface on the left pre- and postcentral areas, total white matter volume decrease bilaterally as well in the pons.

Conclusions

PD patients with nocturnal hallucinations had prominent basal ganglia volume reduction. Distressful dreams were associated with limbic system and frontal white matter changes, meanwhile nocturia was mostly associated with global white matter reduction and surface reduction of cortical surface on the left hemisphere pre- and postcentral areas.

Silencing of Glucocerebrosidase Gene in Drosophila Enhances the Aggregation of Parkinson's Disease Associated α-Synuclein Mutant A53T and Affects Locomotor Activity

Background: Mutations in glucocerebrosidase (GBA), a lysosomal enzyme are the most common genetic risk factor for developing Parkinson's disease (PD). We studied how reduced GCase activity affects α-synuclein (α-syn) and its mutants (A30P and A53T) aggregation, neurodegeneration, sleep and locomotor behavior in a fly model of PD.

Methods: We developed drosophila with GBA gene knockdown (RNAi) (with reduced GCase activity) that simultaneously expresses either wildtype (WT) or mutants such as A30P or A53T α-syn. Western blot and confocal microscopy were performed to study the α-syn aggregation and neurodegeneration in these flies. We also studied the sleep and locomotor activity of those flies using Drosophila activity monitor (DAM) system.

Results: Western blot analysis showed that GBA RNAi A53T α-syn flies (30 days old) had an increased level of Triton insoluble synuclein (that corresponds to α-syn aggregates) compared to corresponding A53T flies without GBA RNAi (control), while mRNA expression of α-syn remained unchanged. Confocal imaging of whole brain staining of 30 days old drosophila showed a statistically significant decrease in neuron numbers in PPL1 cluster in flies expressing α-syn WT, A30P and A53T in the presence GBA RNAi compared to corresponding control. Staining with conformation specific antibody for α-syn aggregates showed an increased number of neurons staining for α-syn aggregates in A53T fly brain with GBA RNAi compared to control A53T flies, thus confirming our protein analysis finding that under decreased GBA enzyme activity, mutant A53T aggregates more than the control A53T without GBA silencing. Sleep analysis revealed decreased total activity in GBA silenced flies expressing mutant A53T compared to both A53T control flies and GBA RNAi flies without synuclein expression.

Conclusion: In A53T flies with reduced GCase activity, there is increased α-syn aggregation and dopamine (DA) neuronal loss. This study demonstrates that reduced GCase activity both in the context of heterozygous GBA1 mutation associated with PD and in old age, contribute to increased aggregation of mutant α-syn A53T and exacerbates the phenotype in a fly model of PD.

Subjective sleep dysfunction and insomnia symptoms in Parkinson's disease: Insights from a cross-sectional evaluation of the French CoPark cohort

INTRODUCTION

Twenty-seven to 80% of patients with Parkinson's Disease (PD) complain of subjective sleep dysfunction and insomnia symptoms. Our aim is to describe the prevalence and features of subjective sleep dysfunction and insomnia symptoms in patients with PD compared to other patients.

METHODS

Cross-sectional analysis of 636 adult PD patients compared to 143 age and sex-matched non-PD control patients consulting their general practitioners. Insomnia symptoms and other sleep features were assessed by the Pittsburgh Sleep Quality Index (PSQI), a global score > 5 defining impaired sleep. The Chi-square test or the Student's t-test were used to assess the potential clinical and demographic differences between groups and between PD patients with vs. without sleep dysfunction. Logistic regression analysis was employed to test multivariate effects.

RESULTS

Sleep dysfunction and insomnia symptoms were more frequent in PD patients compared to control patients (63 vs. 45%, p = 0.001). Female gender, PD duration, presence of depression and anxiety were associated with the presence of insomnia in PD. Subjective sleep efficiency, habitual sleep quality, sleep disturbance and daytime dysfunction, but not sleep latency, were reduced in PD patients compared to controls.

CONCLUSIONS

The prevalence of sleep dysfunction is higher in PD than in other general medical conditions. Insomnia in PD seems to affect sleep maintenance and consolidation, but not sleep onset.

The nature of excessive sleepiness and sudden sleep onset in Parkinson׳s disease

Objectives

Excessive daytime sleepiness (EDS) and sudden sleep onset (SOS) episodes are frequent in Parkinson׳s disease (PD). The objectives are to identify clinical characteristics and factors associated with EDS and SOS episodes.

Methods

Clinical demographic data were recorded (N=100, mean age=65.0±10.4). EDS was identified by the Epworth Sleepiness Scale (ESS>10) and SOS episodes were registered. Disease severity was evaluated by the Unified Parkinson׳s Disease Rating Scale (UPDRS, I, II, and III), sleep disturbances by the Parkinson׳s Disease Sleep Scale (PDSS<100), depressive symptoms by the Beck Depression Inventory (BDI>10) and rapid eye movement (REM) sleep behavior disorder (RBD) by the REM sleep behavior scale. Levodopa equivalent dose was measured.

Results: PD patients with EDS (67%) were predominately male (73.1%) and had worse disease severity (UPDRS II and III p= 0.005); SOS episodes (39%) were associated with disease duration, diabetes, sleep disturbances (PDSS Scale), disease severity (UPDRS I, II, III) and RBD symptoms (p<0.05). Stepwise regression analysis showed that EDS was independently associated with motor-symptoms severity (UPDRS III scale, p=0.003). SOS episodes were independently associated with disease duration (p=0.006) and sleep disturbances (PDSS scale, p=0.03): patients had more uncomfortable immobility at night, tremor on waking and snoring or difficult breathing.

Discussion

EDS and or SOS episodes are frequent and manifest a differential pattern in PD. SOS episodes are associated with longer disease duration, diabetes, sleep disturbances and RBD symptoms indicating that these “sleep attacks” are of multifactorial origin and probably influenced by brain structural abnormalities.

Default-mode network changes in Huntington's disease: an integrated MRI study of functional connectivity and morphometry

Previous MRI studies of functional connectivity in pre-symptomatic mutation carriers of Huntington’s disease (HD) have shown dysfunction of the Default-Mode Network (DMN). No data however are currently available on the DMN alterations in the symptomatic stages of the disease, which are characterized by cortical atrophy involving several DMN nodes. We assessed DMN integrity and its possible correlations with motor and cognitive symptoms in 26 symptomatic HD patients as compared to 22 normal volunteers, by analyzing resting state functional MRI data, using the Precuneal Cortex/Posterior Cingulate Cortices (PC/PCC) as seed, controlling at voxel level for the effect of atrophy by co-varying for gray matter volume. Direct correlation with PC/PCC was decreased, without correlation with atrophy, in the ventral medial prefrontal cortex (including anterior cingulate and subgenual cortex), right dorso-medial prefrontal cortex, and in the right inferior parietal cortex (mainly involving the angular gyrus). Negative correlations with PC/PCC were decreased bilaterally in the inferior parietal cortices, while a cluster in the right middle occipital gyrus presented increased correlation with PC/PCC. DMN changes in the ventral medial prefrontal cortex significantly correlated with the performance at the Stroop test (p = .0002). Widespread DMN changes, not correlating with the atrophy of the involved nodes, are present in symptomatic HD patients, and correlate with cognitive disturbances.

Dysfunction of the locus coeruleus-norepinephrine system and related circuitry in Parkinson's disease-related dementia

Although resting tremor, cogwheel rigidity, hypokinesia/bradykinesia and postural instability usually dominate the clinical picture of sporadic Parkinson's disease (PD), both clinical and epidemiological data reveal that a wide variety of additional symptoms impair patients' quality of life considerably, parallel to the chronic progressive neurodegenerative movement disorder. Autopsy based retrospective studies have shown that α-synuclein immunoreactive Lewy pathology (LP) develops in the locus coeruleus (LC) of patients with neuropathologically confirmed sporadic PD, as well as in individuals with incidental (prodromal or premotor) Lewy body disease but not in age and gender matched controls. Using five case studies, this review discusses the possible role of LP (axonopathy, cellular dysfunction and nerve cell loss) in the LC, catecholaminergic tract and related circuitry in the development of PD-related dementia. The contribution of noradrenergic deficit to cognitive dysfunction in PD has been underappreciated. Noradrenergic therapeutic interventions might not only alleviate depressive symptoms and anxiety but also delay the onset of cognitive decline.

Comorbidity and mortality of narcolepsy: a controlled retro- and prospective national study

STUDY OBJECTIVES

To identify the factual morbidity and mortality of narcolepsy in a controlled design.

SETTING

National Patient Registry.

PATIENTS

All national diagnosed patients (757) with health information at least 3 years prior to and after diagnose of narcolepsy.

CONTROLS

Randomly selected four citizens (3,013) matched for age, sex, and socioeconomic status from the Danish Civil Registration System Statistics.

RESULTS

Increased morbidity prior to narcolepsy diagnosis included (odds ratio, 95% confidence interval):- diseases of the endocrine, nutritional, and metabolic systems (2.10, 1.32-3.33); nervous system (5.27, 3.65-7.60); musculoskeletal system (1.59, 1.23-2.05); and other abnormal symptoms and laboratory findings (1.66, 1.25-2.22). After the diagnosis, narcolepsy patients experienced diseases of the endocrine, nutritional, and metabolic (2.31, 1.51-3.54), nervous (9.19, 6.80-12.41), musculoskeletal (1.70, 1.28-2.26), eye (1.67, 1.03-2.71), and respiratory systems (1.84, 1.21-2.81). Specific diagnoses were diabetes (2.4, 1,2-4.7, P < 0.01), obesity (13.4, 3.1-57.6, P < 0.001), sleep apnea (19.2, 7.7-48.3, P < 0.001), other sleep disorders (78.5, 11.8-523.3, P < 0.001), chronic obstructive pulmonary disease (2.8, 1.4-5.8, P < 0.01), lower back pain (2.5, 1.4-4.2, P < 0.001), arthrosis/arthritis (2.5, 1.3-4.8, P < 0.01), observation of neurological diseases (3.5, 1.9-6.5, P < 0.001), observation of other diseases (1.7, 1.2-2.5, P < 0.01), and rehabilitation (5.0, 1.5-16.5, P < 0.005). There was a trend towards greater mortality in narcolepsy (P = 0.07).

CONCLUSIONS

Patients with narcolepsy present higher morbidity several years prior to diagnose and even higher thereafter. The mortality rate due to narcolepsy was slightly but not significantly higher.

Sleep disturbance in mental health problems and neurodegenerative disease

Sleep has been described as being of the brain, by the brain, and for the brain. This fundamental neurobiological behavior is controlled by homeostatic and circadian (24-hour) processes and is vital for normal brain function. This review will outline the normal sleep-wake cycle, the changes that occur during aging, and the specific patterns of sleep disturbance that occur in association with both mental health disorders and neurodegenerative disorders. The role of primary sleep disorders such as insomnia, obstructive sleep apnea, and REM sleep behavior disorder as potential causes or risk factors for particular mental health or neurodegenerative problems will also be discussed.

Sleep disturbances in Alzheimer's and Parkinson's diseases

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders and exact a burden on our society greater than cardiovascular disease and cancer combined. While cognitive and motor symptoms are used to define AD and PD, respectively, patients with both disorders exhibit sleep disturbances including insomnia, hypersomnia and excessive daytime napping. The molecular basis of perturbed sleep in AD and PD may involve damage to hypothalamic and brainstem nuclei that control sleep-wake cycles. Perturbations in neurotransmitter and hormone signaling (e.g., serotonin, norepinephrine and melatonin) and the neurotrophic factor BDNF likely contribute to the disease process. Abnormal accumulations of neurotoxic forms of amyloid β-peptide, tau and α-synuclein occur in brain regions involved in the regulation of sleep in AD and PD patients, and are sufficient to cause sleep disturbances in animal models of these neurodegenerative disorders. Disturbed regulation of sleep often occurs early in the course of AD and PD, and may contribute to the cognitive and motor symptoms. Treatments that target signaling pathways that control sleep have been shown to retard the disease process in animal models of AD and PD, suggesting a potential for such interventions in humans at risk for or in the early stages of these disorders.

Nonmotor symptoms in Parkinson's disease in 2012: relevant clinical aspects

Nonmotor symptoms (NMSs) of Parkinson's disease (PD) are common, but they are often underrecognized in clinical practice, because of the lack of spontaneous complaints by the patients, and partly because of the absence of systematic questioning by the consulting physician. However, valid specific instruments for identification and assessment of these symptoms are available in 2012. The administration of the self-completed screening tool, NMSQuest, associated with questioning during the consultation, improves the diagnosis of NMSs. NMSs play a large role in degradation of quality of life. More relevant NMSs are described in this review, mood disorders, impulse control disorders, cognitive deficits, hallucinations, pain, sleep disorders, and dysautonomia.

Nocturnal disturbances and restlessness in Parkinson's disease: using the Japanese version of the Parkinson's disease sleep scale-2

OBJECTIVE

The aim of this study was to assess the validity and the reliability of the Japanese version of the Parkinson's disease sleep scale (PDSS)-2 and to use this scale to identify nocturnal symptoms and their impact on patient's quality of life.

METHODS

A cross-sectional, case-controlled study was conducted consisting of 93 patients with Parkinson's disease (PD) and 93 age- and gender-matched control subjects. The Japanese version of the PDSS-2 was used for the evaluation of nocturnal disturbances. The patient's quality of life was evaluated with the Parkinson's Disease Quality of Life questionnaire (PDQ-39) and their depressive symptoms were assessed with the Beck Depression Inventory-II (BDI-II), respectively. In addition, the Pittsburgh Sleep Quality Index (PSQI), Epworth Sleepiness Scale (ESS) and Parkinson Fatigue Scale (PFS) were administered.

RESULTS

As assessed using the PDSS-2, PD patients had significantly impaired scores compared with control subjects (15.0±9.7 vs. 9.1±6.6, p<0.001). The ESS, BDI-II and PFS scores were significantly impaired in PD patients compared with controls. A satisfactory internal consistency and test-retest reliability score were obtained for the PDSS-2 total score (Cronbach's alpha=0.86). The PDSS-2 was correlated with the PSQI, ESS, BDI-II, PFS, PDQ-39 summary index, all of the PDQ-39 domains and Unified Parkinson's Disease Rating Scale part III. The frequency of restless legs syndrome (RLS) was not significantly different between PD patients and controls (5.5% vs. 2.2%), but nocturnal restlessness was significantly more frequent in PD patients than controls. Stepwise linear regression analyses revealed the PDQ-39 summary index and the PSQI global score as significant predictors for the PDSS-2 total score.

CONCLUSIONS

Our study confirmed the usefulness of the Japanese version of the PDSS-2 that enables the comprehensive assessment of nocturnal disturbances in PD. The association between RLS and nocturnal restlessness in PD requires further study.

Sleep in essential tremor: a comparison with normal controls and Parkinson's disease patients

BACKGROUND

Recent studies have shed light on non-motor features of ET, such as depressive symptoms and cognitive changes, which might be attributed to pathophysiological changes in the brains of ET patients. Given these brain changes, we explored sleep abnormalities in ET patients.

METHODS

Sleep was assessed using the Epworth Sleepiness Scale (ESS) and the Pittsburgh Sleep Quality Index (PSQI) in 120 ET cases, 120 normal controls, and 40 PD cases.

RESULTS

The mean±SD (median) ESS score increased from normal controls (5.7±3.7 (5.0)), to ET cases (6.8±4.6 (6.0)), to PD cases (7.8±4.9 (7.0)), test for trend p=0.03. An ESS score >10 (an indicator of greater than normal levels of daytime sleepiness) was observed in 11 (9.2%) normal controls, compared to 27 (22.5%) ET cases and 10 (25.0%) PD cases (p=0.008 when comparing all three groups, and p=0.005 when comparing ET to normal controls). The global PSQI score was 7.8±2.8 (7.5) in controls, 8.0±3.3 (8.0) in ET cases, and 9.9±3.9 (10.0) in PD cases. The ET case-control difference was not significant (p=0.8), yet in a test for trend, PD cases had the highest PSQI score (most daytime sleepiness), followed by ET (intermediate), and lowest scores in controls (p=0.02).

CONCLUSIONS

Some sleep scores in ET were intermediate between those of PD cases and normal controls, suggesting that a mild form of sleep dysregulation could be present in ET.

Pre-fibrillar α-synuclein mutants cause Parkinson's disease-like non-motor symptoms in Drosophila

Parkinson's disease (PD) is linked to the formation of insoluble fibrillar aggregates of the presynaptic protein α-Synuclein (αS) in neurons. The appearance of such aggregates coincides with severe motor deficits in human patients. These deficits are often preceded by non-motor symptoms such as sleep-related problems in the patients. PD-like motor deficits can be recapitulated in model organisms such as Drosophila melanogaster when αS is pan-neurally expressed. Interestingly, both these deficits are more severe when αS mutants with reduced aggregation properties are expressed in flies. This indicates that that αS aggregation is not the primary cause of the PD-like motor symptoms. Here we describe a model for PD in Drosophila which utilizes the targeted expression of αS mutants in a subset of dopadecarboxylase expressing serotonergic and dopaminergic (DA) neurons. Our results show that targeted expression of pre-fibrillar αS mutants not only recapitulates PD-like motor symptoms but also the preceding non-motor symptoms such as an abnormal sleep-like behavior, altered locomotor activity and abnormal circadian periodicity. Further, the results suggest that the observed non-motor symptoms in flies are caused by an early impairment of neuronal functions rather than by the loss of neurons due to cell death.

Early presymptomatic and long-term changes of rest activity cycles and cognitive behavior in a MPTP-monkey model of Parkinson's disease

Background

It is increasingly recognized that non-motor symptoms are a prominent feature of Parkinson's disease and in the case of cognitive deficits can precede onset of the characteristic motor symptoms. Here, we examine in 4 monkeys chronically treated with low doses of the neurotoxin MPTP the early and long-term alterations of rest-activity rhythms in relationship to the appearance of motor and cognitive symptoms.

Methodology/Principal Findings

Behavioral activity recordings as well as motor and cognitive assessments were carried out continuously and in parallel before, during and for several months following MPTP-treatment (12–56 weeks). Cognitive abilities were assessed using a task that is dependent on the functional integrity of the fronto-striatal axis. Rest-activity cycles were monitored continuously using infrared movement detectors of locomotor activity. Motor impairment was evaluated using standardized scales for primates. Results show that MPTP treatment led to an immediate alteration (within one week) of rest-activity cycles and cognitive deficits. Parkinsonian motor deficits only became apparent 3 to 5 weeks after initiating chronic MPTP administration. In three of the four animals studied, clinical scores returned to control levels 5–7 weeks following cessation of MPTP treatment. In contrast, both cognitive deficits and chronobiological alterations persisted for many months. Levodopa treatment led to an improvement of cognitive performance but did not affect rest-activity rhythms in the two cases tested.

Conclusions/Significance

Present results show that i) changes in the rest activity cycles constituted early detectable consequences of MPTP treatment and, along with cognitive alterations, characterize the presymptomatic stage; ii) following motor recovery there is a long-term persistence of non-motor symptoms that could reflect differential underlying compensatory mechanisms in these domains; iii) the progressive MPTP-monkey model of presymptomatic ongoing parkinsonism offers possibilities for in-depth studies of early non-motor symptoms including sleep alterations and cognitive deficits.

Anatomy of disturbed sleep in pallido-ponto-nigral degeneration

OBJECTIVE

Pallido-ponto-nigral degeneration (PPND), caused by an N279K mutation of the MAPT gene, is 1 of a family of disorders collectively referred to as frontotemporal dementia and parkinsonism linked to chromosome 17. This study aims to characterize the nature of the sleep disturbance in PPND and compare these findings to those in other progressive neurological illnesses. Pathological findings are also provided.

METHODS

Ten subjects were recruited from the PPND kindred; 5 affected and 5 unaffected. The subjects underwent clinical assessment, polysomnography, and wrist actigraphy. Available sleep-relevant areas (pedunculopontine/laterodorsal tegmentum, nucleus basalis of Meynert, thalamus, and locus ceruleus) of affected subjects were analyzed postmortem.

RESULTS

The affected group's total sleep time was an average of 130.8 minutes compared to 403.6 minutes in the control group (p < 0.01). Initial sleep latency was significantly longer in affected subjects (range, 58-260 minutes vs 3-34 minutes). Affected subjects also had an increase in stage I sleep (8.5% vs 1%), and less stage III/IV sleep (8.5% vs 17%). At the time of autopsy, all cases had severe neuronal tau pathology in wake-promoting nuclei, as well as decreases in thalamic cholinergic innervations. There was no difference in orexinergic fiber density in nucleus basalis of Meynert or locus ceruleus compared to controls.

INTERPRETATION

The PPND kindred showed severe sleep disturbance. Sleep abnormalities are common in neurodegenerative illnesses, but this is the first study of sleep disorders in PPND. Unlike most neurodegenerative conditions, PPND is characterized by decreased total sleep time, increased sleep latency, and decreased sleep efficiency, without daytime hypersomnolence.

Sleep disturbances associated with Parkinson's disease

Sleep disturbances are common problems affecting the quality life of Parkinson's disease (PD) patients and are often underestimated. The causes of sleep disturbances are multifactorial and include nocturnal motor disturbances, nocturia, depressive symptoms, and medication use. Comorbidity of PD with sleep apnea syndrome, restless legs syndrome, rapid eye movement sleep behavior disorder, or circadian cycle disruption also results in impaired sleep. In addition, the involvement of serotoninergic, noradrenergic, and cholinergic neurons in the brainstem as a disease-related change contributes to impaired sleep structures. Excessive daytime sleepiness is not only secondary to nocturnal disturbances or dopaminergic medication but may also be due to independent mechanisms related to impairments in ascending arousal system and the orexin system. Notably, several recent lines of evidence suggest a strong link between rapid eye movement sleep behavior disorder and the risk of neurodegenerative diseases such as PD. In the present paper, we review the current literature concerning sleep disorders in PD.

Sleep neurobiology from a clinical perspective

Many neurochemical systems interact to generate wakefulness and sleep. Wakefulness is promoted by neurons in the pons, midbrain, and posterior hypothalamus that produce acetylcholine, norepinephrine, dopamine, serotonin, histamine, and orexin/hypocretin. Most of these ascending arousal systems diffusely activate the cortex and other forebrain targets. NREM sleep is mainly driven by neurons in the preoptic area that inhibit the ascending arousal systems, while REM sleep is regulated primarily by neurons in the pons, with additional influence arising in the hypothalamus. Mutual inhibition between these wake- and sleep-regulating regions likely helps generate full wakefulness and sleep with rapid transitions between states. This up-to-date review of these systems should allow clinicians and researchers to better understand the effects of drugs, lesions, and neurologic disease on sleep and wakefulness.

Impaired driving from medical conditions: a 70-year-old man trying to decide if he should continue driving

Some medical disorders can impair performance, increasing the risk of driving safety errors that can lead to vehicle crashes. The causal pathway often involves a concatenation of factors or events, some of which can be prevented or controlled. Effective interventions can operate before, during, or after a crash occurs at the levels of driver capacity, vehicle and road design, and public policy. A variety of systemic, neurological, psychiatric, and developmental disorders put drivers at potential increased risk of a car crash in the short or long term. Medical diagnosis and age alone are usually insufficient criteria for determining fitness to drive. Strategies are needed for determining what types and levels of reduced function provide a threshold for disqualification in drivers with medical disorders. Evidence of decreased mileage, self-restriction to driving in certain situations, collisions, moving violations, aggressive driving, sleepiness, alcohol abuse, metabolic disorders, and multiple medications may trigger considerations of driver safety. A general framework for evaluating driver fitness relies on a functional evaluation of multiple domains (cognitive, motor, perceptual, and psychiatric) that are important for safe driving and can be applied across many disorders, including conditions that have rarely been studied with respect to driving, and in patients with multiple conditions and medications. Neurocognitive tests, driving simulation, and road tests provide complementary sources of evidence to evaluate driver safety. No single test is sufficient to determine who should drive and who should not.

New thoughts on thought disorders in Parkinson's disease: review of current research strategies and challenges

Psychosis is a frequent nonmotor complication in Parkinson's disease (PD), characterized by a broad phenomenology and likely due to a variety of intrinsic (i.e., PD-related) and extrinsic factors. Safe and effective therapies are greatly needed as PD psychosis contributes significantly to morbidity, mortality, nursing home placement, and quality of life. Novel research strategies focused on understanding the pharmacology and pathophysiology of PD psychosis, utilizing translational research including animal models, genetics, and neuroimaging, and even looking beyond the dopamine system may further therapeutic advances. This review discusses new research strategies regarding the neurobiology and treatment of PD psychosis and several associated challenges.

Parkinson's disease sleep scale--validation of the revised version PDSS-2

BACKGROUND

The previous Parkinson's disease sleep scale (PDSS) is a 15-item visual analogue scale that assesses the profile of nocturnal disturbances in Parkinson's disease (PD) patients.

OBJECTIVE

To extend the scale so that it becomes a frequency measure scale with five categories and encompasses unmet needs such as restless legs syndrome, akinesia, pain, and sleep apnea.

METHODS

For validation of the PDSS-2, PD patients' ratings and investigators' interviews were compared to ratings from a semistructured interview with a caregiver/partner, and to related scales. PDSS-2 was repeated for test-retest-reliability after 1-3 days.

RESULTS

A total of 113 PD patients showed a mean (SD) total score of 16.5 (±8.9) (range: 2-40) indicating mild to moderate sleep disturbances. PDSS-2 item-total correlation for proving internal consistency was satisfactory (correlations >0.30). From a factor analysis, three subscales were derived: (1) "motor problems at night," (2) "PD symptoms at night" and (3) "disturbed sleep." The alpha coefficient for the total score was 0.73, for subscales 0.47 to 0.66. The test-retest-reliability intra-class-coefficient for the total score was 0.80, with 0.69 and 0.77 within the subscales. For discriminative validity, significant differences were found in the PDSS-2 total score depending on CGI and Hoehn and Yahr severity levels. A comparison between caregivers' and patients' ratings was carried out.

CONCLUSION

The PDSS-2, with an extended spectrum of nocturnal disabilities and easier use for patients, is a reliable, valid, precise, and potentially treatment-responsive tool for measuring sleep disorders in PD.

Gene therapy: a viable therapeutic strategy for Parkinson's disease?

Gene therapy represents a potentially useful additional technique to ameliorate the motor symptoms of Parkinson's disease (PD), and the motor complications of its treatment. The neurodegenerative process itself, as well as the non-motor symptoms of PD, both remain less amenable to most of the current gene therapy approaches. This review presents an overview of the four gene therapies in phase I/II clinical trials, outlines some of the challenges they face, and proposes additional alternative strategies that might improve the clinical prospects of gene therapy for PD. In so doing, we hope to highlight the issue of the current absence of effective treatment for non-motor symptoms of PD and the potential of further candidate targets for gene therapy intervention that might improve upon this, for both specific individuals with genetic forms of PD as well as "sporadic" PD patients.

The effect of memantine on sleep behaviour in dementia with Lewy bodies and Parkinson's disease dementia

OBJECTIVE

Two common and characteristic sleep disturbances have been described in dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD); excessive daytime sleepiness and REM sleep behaviour disorder (RBD). This study is an analysis of a secondary outcome measure of a larger study already reported, aimed to determine whether memantine has an effect on the sleep disturbances in DLB and PDD patients.

METHODS

Patients with DLB or PDD were included in a placebo-controlled, randomised controlled study of memantine (20 mg per day) for 24 weeks. The Stavanger Sleep Questionnaire and the Epworth Sleepiness Scale were used to evaluate the effect on sleep disturbances.

RESULTS

Forty two patients started treatment; 20 with memantine and 22 with placebo. The primary analysis was the comparison of change between the two groups during a 24-week period, using the modified ITT population (last observation carried forward). At 24 weeks, patients treated with memantine were less physically active during sleep while patients in the placebo group worsened. Mean difference between the groups (0.5 [0.05-0.90]) was significant (p = 0.006). No significant change was observed in severity of excessive daytime sleepiness.

CONCLUSIONS

Memantine decreases probable REM sleep behaviour disorder in patients with DLB and PDD. Both diagnostic groups contributed equally to the outcome.

[Non-dopaminergic treatments for Parkinson's disease]

It has become increasingly evident over the past years that the pathological process in Parkinson's disease extends well beyond the substantia nigra and involves non-dopaminergic neurotransmitter systems that mediate motor and non-motor symptoms. In this article, both the pathophysiology and the pharmacological management of these non-dopaminergic symptoms are discussed.

Mood, side of motor symptom onset and pain complaints in Parkinson's disease

OBJECTIVE

Patients with Parkinson's disease (PD) present with a variety of non-motor symptoms including sensory complaints and mood disturbances. In the current pilot study, we aimed to explore pain complaints and the association between mood and pain in PD. We hypothesized that pain ratings would be elevated in patients with PD relative to controls. As PD is lateralized at onset and studies have found lateralization of some non-motor symptoms in PD, we also hypothesized that PD patients would exhibit differing pain profiles depending on side of onset of the disease.

METHODS

Twenty-three PD patients (11 right-onset (RPD), 12 left-onset (LPD) disease), and 11 control participants (CS) completed a mood questionnaire (Depression Anxiety Stress Scale; DASS) as well as the short form of the McGill Pain Questionnaire.

RESULTS

Both PD groups reported higher present pain intensity scores (p = 0.001), more evaluative pain intensity (p = 0.02), and more overall pain (p = 0.02) than control participants. There was a significant association between mood and all of the McGill pain ratings in the LPD patients, with those reporting more mood symptoms rating higher on all pain scales (all p-values < 0.001). This association was not found in the RPD group.

CONCLUSIONS

Our results suggest an association between mood and pain in patients with PD that may be related to the differential contribution of right-hemispheric neural networks in processing of mood and pain states. These findings merit further investigation into the relation between mood and pain in patients with PD.

Sleep dysfunction and role of dysautonomia in Parkinson's disease

Altered sleep is a common non motor symptom in Parkinson's disease. Sleep dysfunction has been reported to occur in 60-90% of all PD patients, having a detrimental impact on quality of life and increasing disability. alpha-Synuclein deposits in the lower brainstem affecting autonomic and sleep regions have been identified in the pathophysiology. The resultant non motor symptoms such as REM sleep behaviour disorder (RBD) can precede the motor symptoms by years. RBD is violent, enacted dreams that expose the patient or their sleeping partner to night-time injuries. Excessive daytime sleepiness, sometimes with a narcolepsy-like phenotype, is a common occurrence in PD, owing to lesions in the arousal systems of the brain. Restless legs syndrome and sleep disordered breathing can all affect daytime alertness of PD patients. Autonomic deregulation can also negatively affect sleep patterns, by adding to night-time wakening and disrupting sleep.

Sleep disturbances and brain MRI morphometry in Parkinson's disease, multiple system atrophy and progressive supranuclear palsy - a comparative study

Despite common reports in Parkinson's disease (PD), in other parkinsonian syndromes, sleep disturbances have been less frequently described. This study evaluated and compared sleep disturbances in patients with PD, multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) and analyzed associations with brain magnetic resonance imaging (MRI) morphometry. This was a cross-sectional study of 16 PD cases, 13 MSA, 14 PSP and 12 control. Sleep disturbances were evaluated by Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index (PSQI), Restless Legs Scale and Berlin questionnaire. Pons area, midbrain area, medial cerebellar peduncle (MCP) width, and superior cerebellar peduncle width were measured using MRI. Poor quality sleep, risk of obstructive sleep apnea (OSA) and restless legs syndrome (RLS) were detected in all groups. Patients with MSA showed higher risk of OSA and less frequent RLS. In MSA, a correlation between PSQI scores and Hoehn and Yahr stage was observed (p<0.05). In PSP, RLS was frequent (57%) and related with reduced sleep duration and efficiency. In PD, excessive daytime sleepiness was related to atrophy of the MCP (p=0.01). RLS was more frequent in PD and PSP, and in PSP, was associated with reduced sleep efficiency and sleep duration. Brain morphometry abnormalities were found in connection with excessive daytime sleepiness and risk of OSA in PD and PSP suggesting widespread degeneration of brainstem sleep structures on the basis of sleep abnormalities in these patients.