Effect of sleep deprivation on motor performance in patients with Parkinson's disease

Sleep deprivation effects on EGFR signaling in a zebrafish exposed to rotenone

The objective of this study was to investigate the effects of exposure to rotenone, sleep deprivation, and the epidermal growth factor receptor (EGFR) inhibitor on the locomotor activity of zebrafish larvae. Observations were conducted on control groups, sleep-deprived groups without interventions, groups treated with rotenone or the EGFR inhibitor alone, and also groups with combined exposures. The results showed that sleep deprivation alone led to a decrease of speed of the locomotor activity compared to the control groups. The treatment with rotenone alone resulted in varied effects on the locomotor activity. However, a combined exposure to rotenone and sleep deprivation further reduced the locomotor activity compared to the control and rotenone-treated groups. The groups treated with the EGFR inhibitor alone exhibited variable effects on the locomotor activity. Furthermore, the combined exposure to the EGFR inhibitor and sleep deprivation resulted in diverse changes in the locomotor activity. However, the combined treatment with rotenone and the EGFR inhibitor produced complex alterations in the locomotor activity. These findings demonstrate the distinct effects of exposure to rotenone, sleep deprivation, and the EGFR inhibitor on the locomotor activity of zebrafish larvae. The interaction between these factors further modulates locomotor activity, suggesting a potential interplay between the EGFR system, sleep regulation, and the dopaminergic system. Understanding the relationship between the EGFR system, sleep regulation, and neurological regulation may contribute to the development of therapeutic strategies to address such issues as sleep disorders and neurodegenerative conditions.

Sleep deprivation induces late deleterious effects in a pharmacological model of Parkinsonism

Parkinson's disease is a degenerative, chronic and progressive disease, characterized by motor dysfunctions. Patients also exhibit non-motor symptoms, such as affective and sleep disorders. Sleep disorders can potentiate clinical and neuropathological features and lead to worse prognosis. The goal of this study was to evaluate the effects of sleep deprivation (SD) in mice submitted to a progressive pharmacological model of Parkinsonism (chronic administration with a low dose of reserpine). Male Swiss mice received 20 injections of reserpine (0.1 mg/kg) or vehicle, on alternate days. SD was applied before or during reserpine treatment and was performed by gentle handling for 6 h per day for 10 consecutive days. Animals were submitted to motor and non-motor behavioral assessments and neurochemical evaluations. Locomotion was increased by SD and decreased by reserpine treatment. SD during treatment delayed the onset of catalepsy, but SD prior to treatment potentiated reserpine-induced catalepsy. Thus, although SD induced an apparent beneficial effect on motor parameters, a delayed deleterious effect on alterations induced by reserpine was found. In the object recognition test, both SD and reserpine treatment produced cognitive deficits. In addition, the association between SD and reserpine induced anhedonic-like behavior. Finally, an increase in oxidative stress was found in hippocampus of mice subjected to SD, and tyrosine hydroxylase immunoreactivity was reduced in substantia nigra of reserpine-treated animals. Results point to a possible late effect of SD, aggravating the deficits in mice submitted to the reserpine progressive model of PD.

Combined Exposure to Chronic Sleep Deprivation and Caffeine Potentiates Behavioural Deficits by Altering Neurochemical Profile and Synaptophysin Expression in Long-Evans Rats

Using the Unpredictable Chronic Sleep Deprivation (UCSD) paradigm we developed, the combined effects of chronic sleep deprivation and high caffeine intake on prefrontal cortical synaptophysin expression, neurochemical profiles, and behavioural outcomes in Long-Evans rats were evaluated. The combination of chronic sleep deprivation and high-dose caffeine treatment produced varying degrees of behavioural impairments, depletion of antioxidants, serotonin, and an upregulation of acetylcholinesterase (AChE) activity in the prefrontal cortex. An immunohistochemical assessment revealed a reduction in synaptophysin protein expression in the prefrontal cortex following exposure to high-dose caffeine and chronic sleep deprivation. Overall, our findings support the advocacy for adequate sleep for optimal mental performance as a high intake of caffeine to attenuate the effects of sleep deprivation that may alter the neurochemical profile and synaptic plasticity in the prefrontal cortex, significantly increasing the risk of neuropsychiatric/degenerative disorders.

The immunogenicity of midbrain dopaminergic neurons and the implications for neural grafting trials in Parkinson's disease

Dopaminergic (DA) cell replacement therapies are a promising experimental treatment for Parkinson’s disease (PD) and a number of different types of DA cell-based therapies have already been trialled in patients. To date, the most successful have been allotransplants of foetal ventral midbrain but even then, the results have been inconsistent. This coupled to the ethical and logistical problems with using this tissue has meant that an alternative cell source has been sought of which human pluripotent stem cells (hPSCs) sources have proven very attractive. Robust protocols for making mesencephalic DA (mesDA) progenitor cells from hPSCs now exist and the first in-human clinical trials have or are about to start. However, while their safety and efficacy are well understood, relatively little is known about their immunogenicity and in this review, we briefly summarise this with reference mainly to the limited literature on human foetal DA cells.

Sleep Disorders in Parkinson Disease

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

Sleep in Parkinson's disease

Sleep disturbances are common in Parkinson's disease and comprise the entire spectrum of sleep disorders. On the one hand regulation of sleep and wakefulness is affected in Parkinson's disease, leading to the development of disorders, such as insomnia and daytime sleepiness. While on the other hand control of motor activity during sleep is impaired, with subsequent manifestation of parasomnias (mainly REM sleep behavior disorders, but also, albeit more rarely, sleepwalking, and overlap parasomnia). Restless legs syndrome has been reported to be frequent in patients with Parkinson's disease, although there is no consensus on whether it is more frequent in Parkinson's disease than in the general population. The same is true for sleep-related breathing disorders. Regarding the diagnosis of sleep disorders in patients with Parkinson's disease, one of the main challenges is correctly identifying excessive daytime sleepiness as there are many potential confounding factors, for example it is necessary to distinguish sleep-related breathing disorders from medication effects, and to distinguish restless legs syndrome from the concomitant presence of potential mimics specific to Parkinson's disease, such as akathisia, nocturnal leg cramps, nocturnal hypokinesia, early morning dystonia, etc. The correct diagnosis of REM sleep behavior disorder is also not always easy, and video-polysomnography should be performed in order to exclude mimic-like movements at the end of sleep apneas or violent periodic leg movements of sleep. These aspects and specific considerations about diagnosis and treatment of sleep disorders in patients with Parkinson's disease will be reviewed.

Decreased cpg15 augments oxidative stress in sleep deprived mouse brain

Sleep deprivation (SD) has detrimental effects on the physiological function of the brain. However, the underlying mechanism remains elusive. In the present study, we investigated the expression of candidate plasticity-related gene 15 (cpg15), a neurotrophic gene, and its potential role in SD using a REM-SD mouse model. Immunofluorescent and Western blot analysis revealed that the expression of cpg15 protein decreased in the hippocampus, ventral group of the dorsal thalamus (VENT), and somatosensory area of cerebral cortex (SSP) after 24-72 h of REM-SD, and the oxidative stress in these brain regions was increased in parallel, as indicated by the ratio of glutathione (GSH) to its oxidative product (GSSG). Over-expression of cpg15 in thalamus, hippocampus, and cerebral cortex mediated by AAV reduced the oxidative stress in these regions, indicating that the decrease of cpg15 might be a cause that augments oxidative stress in the sleep deprived mouse brain. Collectively, the results imply that cpg15 may play a protective function in the SD-subjected mouse brain via an anti-oxidative function. To our knowledge, this is the first time to provide evidences in the role of cpg15 against SD-induced oxidative stress in the brain.

Synergistic anticataleptic effect of imipramine and nicotine in a rotenone-induced rat model

RATIONALE

Some antidepressants have been previously found to produce anti-parkinsonian effect; nicotine was known to mitigate experimental neurotoxic lesions. The anticataleptic efficacy of antidepressant-nicotine co-administration is unstudied.

OBJECTIVES

This work aimed to evaluate anticataleptic action of imipramine-nicotine combination in rotenone model.

METHODS

Catalepsy was measured by the bar test. Concentrations of tyrosine hydroxylase, dopamine, and DOPAC were determined in the substantia nigra and dorsal striatum using ELISA and HPLC techniques; additionally, dopamine/DOPAC ratio was calculated for both areas.

RESULTS

Imipramine and nicotine alone were ineffective; however, co-administration of the drugs significantly (p < 0.01) inhibited rotenone-induced catalepsy and mitigated neurochemical changes in the nigrostriatal system. Anticataleptic effect of the combination exceeded that of levodopa, a standard drug for anti-parkinsonian treatment.

CONCLUSION

The combined use of imipramine and nicotine at relatively low doses inhibits neurotoxin-induced catalepsy and nigrostriatal neurochemical changes. The co-administration of these drugs might be a new approach to the treatment of extrapyramidal dysfunctions.

Quantitative associations between objective sleep measures and early-morning mobility in Parkinson’s disease: cross-sectional analysis of the PHASE study

Study Objectives

Previous studies have suggested associations between sleep measures and early-morning akinesia; however, objective evidence is limited. The purpose of this study was to evaluate the associations between objective sleep measures and morning mobility among patients with Parkinson’s disease (PD).

Methods

In this cross-sectional study, we measured objective sleep parameters and morning mobility in 157 patients with PD (mean age, 71.4 years) for six consecutive days using an actigraph placed on the nondominant wrist. Low morning mobility was defined as less than 100 counts/min within the first 2 hours after rising.

Results

The mean duration of low morning mobility was 55.7 minutes (SD, 23.8), and the mean sleep parameters were as follows: sleep efficiency (SE), 72.1% (13.6); wake after sleep onset (WASO), 104.7 minutes (57.9); total sleep time (TST), 343.6 minutes (104.0); and fragmentation index (FI), 3.5 (3.4). Multivariable linear regression analysis adjusted for potential confounders demonstrated significant associations between better objective sleep measures and shorter low morning mobility (SE per %: β, −0.419; 95% CI = −0.635 to −0.204; p &lt; 0.001; WASO per min: β, 0.056; 95% CI = 0.003 to 0.109; p = 0.039; and FI per unit; β, 1.161; 95% CI = 0.300 to 2.023; p = 0.009) but not TST (p = 0.78). These findings were not altered by different cutoff values of mobility (50 counts/min) or duration (1 h after rising).

Conclusions

In patients with PD, better objective sleep measures are significantly associated with shorter low morning mobility. Future studies investigating whether improved sleep reduces symptoms of low morning mobility are required.

Cyclosomatostatin- and haloperidol-induced catalepsy in Wistar rats: Differential responsiveness to sleep deprivation

Total sleep deprivation (SD) has been found to mitigate motor dysfunctions in Parkinson's disease. Apparently, the similar sensitivity of an animal model for parkinsonism would support the model's validity. Recently, we described catalepsy induced in Wistar rats by somatostatin antagonist, cyclosomatostatin (cSST); this model simulates such a disease-associated abnormality as a fall in brain somatostatin levels. To evaluate the similarity between the cSST model and Parkinson's disease, we assessed here the responsiveness of cSST-induced catalepsy to 1-h and 3-h SD. In parallel, the influence of SD on catalepsy induced by a dopamine receptor antagonist, haloperidol, was examined. It was found that the short-term SD failed to influence cataleptic responses of both types (sleep deprived rats and undisturbed ones displayed a similar duration of immobility, p > 0.05). By contrast, 3-h SD suppressed (p < 0.01) cSST-induced catalepsy, however, enhanced (p < 0.01) cataleptic response to haloperidol. Thus, the anti-cataleptic effect of SD appears to be cSST-specific. These findings support the validity of the cSST-induced catalepsy in Wistar rats as a model for parkinsonian motor dysfunctions.

Circadian and Homeostatic Modulation of Multi-Unit Activity in Midbrain Dopaminergic Structures

Although the link between sleep disturbances and dopamine (DA)-related neurological and neuropsychiatric disorders is well established, the impact of sleep alterations on neuronal activity of midbrain DA-ergic structures is currently unknown. Here, using wildtype C57Bl mice, we investigated the circadian- and sleep-related modulation of electrical neuronal activity in midbrain ventral-tegmental-area (VTA) and substantia nigra (SN). We found no significant circadian modulation of activity in SN while VTA displayed a low amplitude but significant circadian modulation with increased firing rates during the active phase. Combining neural activity recordings with electroencephalogram (EEG) recordings revealed a strong vigilance state dependent modulation of neuronal activity with increased activity during wakefulness and rapid eye movement sleep relative to non-rapid eye movement sleep in both SN and VTA. Six-hours of sleep deprivation induced a significant depression of neuronal activity in both areas. Surprisingly, these alterations lasted for up to 48 hours and persisted even after the normalization of cortical EEG waves. Our results show that sleep and sleep disturbances significantly affect neuronal activity in midbrain DA structures. We propose that these changes in neuronal activity underlie the well-known relationship between sleep alterations and several disorders involving dysfunction of the DA circuitry such as addiction and depression.

Validation of a Smartphone Application Measuring Motor Function in Parkinson's Disease

BACKGROUND

Measurement of motor function is critical to the assessment and management of Parkinson's disease. Ambulatory motor assessment has the potential to provide a glimpse of the patient's clinical state beyond the consultation. We custom-designed a smartphone application that quantitatively measures hand dexterity and hypothesized that this can give an indication of a patient's overall motor function.

OBJECTIVE

The aims of this study were to (i) validate this smartphone application against MDS-UPDRS motor assessment (MDS-UPDRS-III) and the two-target tapping test; (ii) generate a prediction model for MDS-UPDRS-III; (iii) assess repeatability of our smartphone application and (iv) examine compliance and user-satisfaction of this application.

METHODS

103 patients with Parkinson's disease were recruited from two movement disorders clinics. After initial assessment, a group of patients underwent repeat assessment within two weeks. Patients were invited to use the smartphone application at home over three days, followed by a survey to assess their experience.

RESULTS

Significant correlation between key smartphone application test parameters and MDS-UPDRS-III (r = 0.281-0.608, p < 0.0001) was demonstrated. A prediction model based on these parameters accounted for 52.3% of variation in MDS-UPDRS-III (R2 = 0.523, F(4,93) = 25.48, p < 0.0001). Forty-eight patients underwent repeat assessment under identical clinical conditions. Repeatability of key smartphone application tests parameters and predicted MDS-UPDRS-III was moderate to strong (intraclass correlation coefficient 0.584-0.763, p < 0.0001). The follow-up survey identified that our patients were very comfortable with the smartphone application and mobile technology.

CONCLUSIONS

Our smartphone application demonstrated satisfactory repeatability and validity when measured against MDS-UPDRS-III. Its performance is acceptable considering our smartphone application measures hand dexterity only.

Objective Measurement and Characterization of Sleep Benefit in Parkinson's Disease

Background

Sleep benefit (SB) in Parkinson's disease refers to improved motor symptoms upon waking despite an entire night without medications. Although it was first proposed 30 years ago, this phenomenon proved difficult to investigate, and its true prevalence and underlying mechanisms remain unclear.

Objective

This study aimed to identify and quantify SB through measurement of motor function using a validated smartphone application and to identify disease characteristics that predicted SB.

Methods

Ninety-two patients recruited from 2 Movement Disorder Services were clinically assessed at home using a validated smartphone application. Each patient was tested in the on-state, at the end of dose, and on waking (before medications) 3 times. Differences between the 3 states were used to determine the impact of sleep and levodopa on motor function. SB was considered to be a "measurable improvement in parkinsonism from the end of dose."

Results

The morning waking motor function of 20 patients (22%) improved compared with the end-of-dose function, with 9 patients demonstrating superior function compared with their on-state. No clinical features predicted SB. Although all participants subjectively reported motor fluctuations, only 35 patients (38%) demonstrated an objective improvement with levodopa. Patients who had SB more often demonstrated objective motor fluctuations compared with those who did not (65% vs. 31%; P = 0.008).

Conclusions

SB is a genuine motor phenomenon: 1 in 5 patients have a measurable improvement in motor function on waking. It remains questionable whether this improvement is a direct effect of sleep. Until its underlying mechanism is better understood, it is more appropriate to refer to this phenomenon as simply morning improvement or diurnal fluctuation of motor symptoms.

Chronic sleep disturbance and neural injury: links to neurodegenerative disease

Sleep-wake disruption is frequently observed and often one of the earliest reported symptoms of many neurodegenerative disorders. This provides insight into the underlying pathophysiology of these disorders, as sleep-wake abnormalities are often accompanied by neurodegenerative or neurotransmitter changes. However, in addition to being a symptom of the underlying neurodegenerative condition, there is also emerging evidence that sleep disturbance itself may contribute to the development and facilitate the progression of several of these disorders. Due to its impact both as an early symptom and as a potential factor contributing to ongoing neurodegeneration, the sleep-wake cycle is an ideal target for further study for potential interventions not only to lessen the burden of these diseases but also to slow their progression. In this review, we will highlight the sleep phenotypes associated with some of the major neurodegenerative disorders, focusing on the circadian disruption associated with Alzheimer's disease, the rapid eye movement behavior disorder and sleep fragmentation associated with Parkinson's disease, and the insomnia and circadian dysregulation associated with Huntington's disease.

Sleep deprivation therapy for depression

Sleep deprivation (SD) is the most widely documented rapid-onset antidepressant therapy, targeting the broadly defined depressive syndrome. Although SD responses are transient, its effects can be sustained by concomitant medications (e.g., selective serotonin reuptake inhibitors and lithium) and circadian-related interventions (e.g., bright light and sleep phase advance). Thus, considering its safety, this technique can now be considered among the first-line antidepressant treatment strategies for patients affected by mood disorders. SD is a complex intervention and it should be considered multi-target in nature. Thus, the mechanisms explaining its antidepressant effect can be looked for on many levels, involving not only monoaminergic mechanisms but also sleep homeostatic and circadian mechanisms, glutamatergic mechanisms and synaptic plasticity.

Sleep deprivation in mood disorders

Growing clinical evidence in support of the efficacy and safety of sleep deprivation (SD), and its biological mechanisms of action suggest that this technique can now be included among the first-line antidepressant treatment strategies for mood disorders. SD targets the broadly defined depressive syndrome, and can be administered according to several different treatment schedules: total versus partial, single versus repeated, alone or combined with antidepressant drugs, mood stabilizers, or other chronotherapeutic techniques, such as light therapy and sleep phase advance. The present review focuses on clinical evidence about the place of SD in therapy, its indications, dosage and timing of the therapeutic wake, interactions with other treatments, precautions and contraindications, adverse reactions, mechanism of action, and comparative efficacy, with the aim of providing the clinical psychiatrist with an updated, concise guide to its application.

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 problems in Parkinson’s disease patients

SUMMARY Parkinson’s disease (PD) patients demonstrate a variety of sleep/wake complaints. Some of these are associated with dopaminergic dysfunction, some presumed to arise from nondopaminergic PD pathology, some from PD treatments and, in some, the etiologies are multifactorial or unknown. Optimal management of sleep/wake problems requires a good understanding of sleep/wake principals in the PD population, as there are few controlled trials to dictate therapy. In this article, we review the main causes of sleep/wake disorders in PD patients, namely sleep fragmentation, excessive daytime sleepiness, restless legs syndrome, periodic limb movement of sleep, rapid eye movement sleep behavioral disorder and sleep apnea. Available therapies and management recommendations for each disorder are given particular emphasis.

Persistent short-term memory defects following sleep deprivation in a drosophila model of Parkinson disease

STUDY OBJECTIVES

Parkinson disease (PD) is the second most common neurodegenerative disorder in the United States. It is associated with motor deficits, sleep disturbances, and cognitive impairment. The pathology associated with PD and the effects of sleep deprivation impinge, in part, upon common molecular pathways suggesting that sleep loss may be particularly deleterious to the degenerating brain. Thus we investigated the long-term consequences of sleep deprivation on shortterm memory using a Drosophila model of Parkinson disease.

PARTICIPANTS

Transgenic strains of Drosophila melanogaster.

DESIGN

Using the GAL4-UAS system, human alpha-synuclein was expressed throughout the nervous system of adult flies. Alpha-synuclein expressing flies (alpha S flies) and the corresponding genetic background controls were sleep deprived for 12 h at age 16 days and allowed to recover undisturbed for at least 3 days. Short-term memory was evaluated using aversive phototaxis suppression. Dopaminergic systems were assessed using mRNA profiling and immunohistochemistry. MEASURMENTS AND RESULTS: When sleep deprived at an intermediate stage of the pathology, alpha S flies showed persistent short-term memory deficits that lasted > or = 3 days. Cognitive deficits were not observed in younger alpha S flies nor in genetic background controls. Long-term impairments were not associated with accelerated loss of dopaminergic neurons. However mRNA expression of the dopamine receptors dDA1 and DAMB were significantly increased in sleep deprived alpha S flies. Blocking D1-like receptors during sleep deprivation prevented persistent shortterm memory deficits. Importantly, feeding flies the polyphenolic compound curcumin blocked long-term learning deficits.

CONCLUSIONS

These data emphasize the importance of sleep in a degenerating/reorganizing brain and shows that pathological processes induced by sleep deprivation can be dissected at the molecular and cellular level using Drosophila genetics.

Levodopa availability improves with progression of Parkinson’s disease

BACKGROUND

Previous pharmacokinetic trials with standard levodopa formulations showed a different behaviour of levodopa degradation in plasma of patients with Parkinson's disease (PD) in various stages.

OBJECTIVES

To investigate associations between levodopa plasma levels in relation to the scored intensity of PD.

SUBJECTS AND METHODS

We administered water soluble 100 mg levodopa and 25 mg benserazide to 50 PD patients, taken off medication for at least 12 hours, and assessed the levodopa plasma concentrations during an 180 minutes period under standardised conditions.

RESULTS

The computed area under the curve (AUC) values of levodopa plasma levels were significant higher in advanced PD patients. PD rating scores significantly correlated to the AUC outcomes and the maximum levodopa plasma concentration.

CONCLUSIONS

Levodopa availability improves with progression of PD. This may result from deteriorated peripheral activity of levodopa metabolising enzymes or an increasing enteric dysfunction with subsequent better duodenal levodopa absorption or both.

Depression and neurological disorders

PURPOSE OF REVIEW

Clinical studies support a bidirectional link between depression and neurological diseases. Here we review the most recent findings supporting the hypothesis that major depression is a medical illness of the brain which can be elicited by neurological illnesses.

RECENT FINDINGS

In the last year major improvements in brain-imaging techniques allowed correlations to be demonstrated between functional and structural brain abnormalities in specific brain areas (prefrontal cortex, hippocampus, cingulate gyrus) and the presence and severity of affective disorders, thus suggesting a neural basis for their onset and progression. Similar lesions, caused by neurological diseases, have been found to correlate with the presence of depression in neurological illnesses, but literature on the topic is still lacking. Depression in neurological disorders responds to the same treatments available for idiopathic major depression, but patients seem to have different sensitivities to side effects depending on their specific neurological syndrome. Most available data come from case reports and open trials.

SUMMARY

'Psychiatric' and 'neurologic' depression seem to share common abnormalities in specific brain areas, but sound brain-imaging studies of the neural correlates of depression in neurological disorders are still lacking. Available treatments are efficacious, but no clear-cut guidelines about the best drugs and dosages can be defined because double-blind placebo-controlled studies are still scarce.