Recognition and diagnosis of sleep disorders in Parkinson's disease

Contactless monitoring of human behaviors in bed using RSSI signals

In this paper, contactless monitoring and classification of human activities and sleeping postures in bed using radio signals is presented. The major contribution of this work is the development of a contactless monitoring and classification system with a proposed framework that uses received signal strength indicator (RSSI) signals collected from only one wireless link, where different human activities and sleep postures, including (a) no one in the bed, (b) a man sitting on the bed, (c) sleeping on his back, (d) seizure sleeping, and (e) sleeping on his side, are tested. With our proposed system, there is no need to attach any sensors or medical devices to the human body or the bed. That is the limitation of the sensor-based technology. Additionally, our system does not raise a privacy concern, which is the major limitation of vision-based technology. Experiments using low-cost, low-power 2.4 GHz IEEE802.15.4 wireless networks have been conducted in laboratories. Results demonstrate that the proposed system can automatically monitor and classify human sleeping postures in real time. The average classification accuracy of activities and sleep postures obtained from different subjects, test environments, and hardware platforms is 99.92%, 98.87%, 98.01%, 87.57%, and 95.87% for cases (a) to (e), respectively. Here, the proposed system provides an average accuracy of 96.05%. Furthermore, the system can also monitor and separate the difference between the cases of the man falling from his bed and the man getting out of his bed. This autonomous system and sleep posture information can thus be used to support care people, physicians, and medical staffs in the evaluation and planning of treatment for the benefit of patients and related people. The proposed system for non-invasive monitoring and classification of human activities and sleeping postures in bed using RSSI signals.

Translation of Parkinson's Disease Sleep Scale-2 (PDSS-2) in Hindi (H-PDSS-2) and its Validation for Assessment of Sleep Disturbances among Indian Parkinson's Disease Patients

Background and Objective

Parkinson's disease sleep scale-2 (PDSS-2) is a reliable sleep assessment tool which has been validated in several languages. As sleep problems have a great impact on the quality of life of Parkinson's disease patients, we aimed to translate and validate PDSS-2 in Hindi for its wider use among Hindi-speaking Indian patients. Our study objective was to translate PDSS-2 in Hindi (H-PDSS-2) and to assess the psychometric properties of H-PDSS-2 questionnaire for its use in Hindi-speaking Indian PD patients. Secondly, we aimed to compare the results with those of the other language PDSS-2 validation studies.

Material and Methods

This study was done in two phases, enrolling 16 patients and 16 controls in the first/translation phase for assessment of internal consistency and discriminative power of PDSS-2. The test-retest reliability was determined in the second phase on 35 Parkinson's disease patients who were followed-up at an interval of 7-10 days.

Results

No difficulties were faced by the patients and controls in the first phase, and internal consistency of the scale was good (Cronbach's alpha = 0.804). There was no significant difference in total H-PDSS-2 score at baseline 16.86 ± 10.59 and on retest 16.40 ± 9.54, suggesting good reliability. Intraclass correlation coefficients ranged from 0.710 to 0.901, and precision was 2.82 over the period of 7-10 days. Subdomains of H-PDSS-2 had moderate/high internal validity, and they showed significant correlation with Unified PD Rating Scale (UPDRS) and HY disease scale.

Conclusion

H-PDSS-2 is equivalent to the original PDSS-2 for tested psychometric attributes. Its use among Indian Parkinson's disease patients will help in the comprehensive assessment of sleep problems among PD patients.

Sleep and memory: The impact of sleep deprivation on transcription, translational control, and protein synthesis in the brain

In countries around the world, sleep deprivation represents a widespread problem affecting school-age children, teenagers, and adults. Acute sleep deprivation and more chronic sleep restriction adversely affect individual health, impairing memory and cognitive performance as well as increasing the risk and progression of numerous diseases. In mammals, the hippocampus and hippocampus-dependent memory are vulnerable to the effects of acute sleep deprivation. Sleep deprivation induces changes in molecular signaling, gene expression and may cause changes in dendritic structure in neurons. Genome wide studies have shown that acute sleep deprivation alters gene transcription, although the pool of genes affected varies between brain regions. More recently, advances in research have drawn attention to differences in gene regulation between the level of the transcriptome compared with the pool of mRNA associated with ribosomes for protein translation following sleep deprivation. Thus, in addition to transcriptional changes, sleep deprivation also affects downstream processes to alter protein translation. In this review, we focus on the multiple levels through which acute sleep deprivation impacts gene regulation, highlighting potential post-transcriptional and translational processes that may be affected by sleep deprivation. Understanding the multiple levels of gene regulation impacted by sleep deprivation is essential for future development of therapeutics that may mitigate the effects of sleep loss.

Altered Motor Performance, Sleep EEG, and Parkinson's Disease Pathology Induced by Chronic Sleep Deprivation in Lrrk2G2019S Mice

Parkinson's disease (PD) is a multifaceted disease in which environmental variables combined with genetic predisposition cause dopaminergic (DAergic) neuron loss in the substantia nigra pars compacta. The mutation of leucine-rich repeat kinase 2 (Lrrk2) is the most common autosomal dominant mutation in PD, and it has also been reported in sporadic cases. A growing body of research suggests that circadian rhythm disruption, particularly sleep-wake abnormality, is common during the early phase of PD. Our present study aimed to evaluate the impact of sleep deprivation (SD) on motor ability, sleep performance, and PD pathologies in Lrrk2G2019S transgenic mice. After two months of SD, Lrrk2G2019S mice at 12 months of age showed an exacerbated PD-like phenotype with motor deficits, a reduced striatal DA level, degenerated DAergic neurons, and altered sleep structure and biological rhythm accompanied by the decreased protein expression level of circadian locomotor output cycles kaput Lrrk2 gene in the brain. All these changes persisted and were even more evident in 18-month-old mice after 6 months of follow-up. Moreover, a significant increase in α-synuclein aggregation was found in SD-treated transgenic mice at 18 months of age. Taken together, our findings indicate that sleep abnormalities, as a risk factor, may contribute to the pathogenesis and progression of PD. Early detection of sleep disorders and improvement of sleep quality may help to delay disease progression and provide long-term clinical benefits.

Sleep Disorders and Future Diagnosis of Parkinsonism: A Prospective Study Using the Canadian Longitudinal Study on Aging

BACKGROUND

Earlier detection of parkinsonism, specifically during its prodromal stage, may be key to preventing its progression. Previous studies have produced contradictory results on the association between sleep symptoms and prodromal parkinsonism.

OBJECTIVE

We conducted a prospective study within the Canadian Longitudinal Study on Aging (CLSA) to determine whether self-reported symptoms of insomnia, somnolence, apnea, and restless legs syndrome predate the diagnosis of parkinsonism after three years of follow-up.

METHODS

At baseline, amongst other information, participants completed a questionnaire for difficulty initiating or maintaining sleep, daytime somnolence, snoring or stopping breathing during sleep, and symptoms of restless legs syndrome. After 3 years of follow-up, baseline responses from participants who self-reported a new diagnosis of parkinsonism (cases) were compared to those who did not (controls). For each case, 10 controls were individually matched by age, sex, education, BMI, caffeine, smoking, and alcohol. Binary unconditional logistic regression models were used to estimate the association between sleep symptoms and new-onset parkinsonism, adjusting for age, sex, education, BMI, smoking, alcohol, and caffeine.

RESULTS

We identified 58 incident-parkinsonism cases and 580 matched controls (65.5%male, mean age = 69.60, SD = 8.0). Baseline symptoms of sleep-onset insomnia (12.1%vs. 13.0%, Adjusted OR[95%CI] = 0.87[0.32,2.33]), sleep-maintenance insomnia (24.1%vs. 20.2%, AOR = 1.01[0.46,2.20]), daytime somnolence (8.6%vs. 7.4%, AOR = 1.11[0.37,3.39]), obstructive sleep apnea (27.3%vs. 26.2%, AOR = 0.84[0.40,1.79]), and restless leg syndrome (20.6%vs. 9.9%, AOR = 1.34[0.42,4.25]) were similar among those who developed parkinsonism and those who did not.

CONCLUSION

Symptoms of insomnia, somnolence, apnea, and restless legs did not predate a new diagnosis of parkinsonism over 3 years.

Bidirectional Relationship between Opioids and Disrupted Sleep: Putative Mechanisms

Millions of Americans suffer from opiate use disorder, and over 100 die every day from opioid overdoses. Opioid use often progresses into a vicious cycle of abuse and withdrawal, resulting in very high rates of relapse. Although the physical and psychologic symptoms of opiate withdrawal are well-documented, sleep disturbances caused by chronic opioid exposure and withdrawal are less well-understood. These substances can significantly disrupt sleep acutely and in the long term. Yet poor sleep may influence opiate use, suggesting a bidirectional feed-forward interaction between poor sleep and opioid use. The neurobiology of how opioids affect sleep and how disrupted sleep affects opioid use is not well-understood. Here, we will summarize what is known about the effects of opioids on electroencephalographic sleep in humans and in animal models. We then discuss the neurobiology interface between reward-related brain regions that mediate arousal and wakefulness as well as the effect of opioids in sleep-related brain regions and neurotransmitter systems. Finally, we summarize what is known of the mechanisms underlying opioid exposure and sleep. A critical review of such studies, as well as recommendations of studies that evaluate the impact of manipulating sleep during withdrawal, will further our understanding of the cyclical feedback between sleep and opioid use. SIGNIFICANCE STATEMENT: We review recent studies on the mechanisms linking opioids and sleep. Opioids affect sleep, and sleep affects opioid use; however, the biology underlying this relationship is not understood. This review compiles recent studies in this area that fill this gap in knowledge.

Sleep Disturbances in Patients with Autoimmune Encephalitis

PURPOSE OF REVIEW

To review sleep complaints reported in patients with autoimmune encephalitis, explore the relationship between sleep disturbances and subtypes of autoimmune encephalitis, and leverage knowledge concerning antibody-antigen specificity to inform the receptors, structures, and disseminated neural networks that contribute to sleep function in health and disease.

RECENT FINDINGS

Autoimmune encephalitis is an inflammatory brain disorder characterized by the subacute onset of psychiatric symptoms, cognitive impairment, and focal neurologic deficits or seizures. Sleep disturbances are detected in a majority of patients systematically screened for sleep complaints, may be the presenting symptom in patients with autoimmune encephalitis, and may compromise recovery in patients with autoimmune encephalitis. Early recognition of specific sleep disturbances in patients with subacute changes in behavior or cognition may support the diagnosis of autoimmune encephalitis. Similarly, recognition and treatment of sleep dysfunction in patients with known autoimmune encephalitis may speed recovery and improve long-term outcomes.

The Rostromedial Tegmental Nucleus: Anatomical Studies and Roles in Sleep and Substance Addictions in Rats and Mice

The rostromedial tegmental nucleus (RMTg), a brake of the dopamine system, is specifically activated by aversive stimuli, such as foot shock. It is principally composed of gamma-aminobutyric acid neurons. However, there is no exact location of the RMTg on the brain stereotaxic atlas. The RMTg can be defined by c-Fos staining elicited by psychostimulants, the position of retrograde-labeled neurons stained by injections into the ventral tegmental area (VTA), the terminal field formed by axons from the lateral habenula, and some molecular markers identified as specifically expressed in the RMTg such as FoxP1. The RMTg receives a broad range of inputs and produces diverse outputs, which indicates that the RMTg has multiple functions. First, the RMTg plays an essential role for non-rapid eye movement sleep. Additionally, the RMTg serves a vital role in response to addiction. Opiates increase the firing rates of dopaminergic neurons in the VTA by acting on μ-opioid receptors on RMTg neurons and their terminals inside the VTA. In this review, we summarize the recent research advances on the anatomical location of the RMTg in rats and mice, its projections, and its regulation of sleep-wake behavior and addiction.

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

BACKGROUND AND PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Sleep disturbances are common in patients with autoimmune encephalitis

OBJECTIVES

Autoimmune encephalitis (AE) is increasingly recognized as an important cause of subacute cognitive decline, seizures, and encephalopathy, with an ever-broadening clinical phenotype. Sleep disturbances are reported in AE patients, including rapid eye movement sleep behavior disorder, hypersomnia, fragmented sleep, and sleep-disordered breathing; however, the prevalence of sleep disturbances and contributions to outcomes in AE patients remain unknown. There is a need to determine the prevalence of sleep disturbances in AE patients, and to clarify the relationship between specific autoantibodies and disruptions in sleep.

METHODS

Clinical history, results of serum and cerebrospinal fluid testing, electroencephalography, and neuroimaging were reviewed from 26 AE patients diagnosed and managed at our tertiary care hospital. Polysomnography was performed in patients with clinical indications, yielding data from 12 patients.

RESULTS

The median age of AE patients was 53 years (range 18-83). Autoantibodies against intracellular antigens (including Ma and Hu autoantibodies) were identified in 6/26 (23%) patients, while autoantibodies against cell-surface neuronal antigens (including NMDAR and LGI1) were identified in 20/26 (77%) patients. New sleep complaints were reported by 19/26 (73%) AE patients, including gasping or snoring (9/19, 47%), dream enactment behavior (6/19, 32%), insomnia (5/19, 29%), hypersomnia (4/19, 21%), other parasomnias (4/19, 21%), and dream-wake confusional states (2/19, 11%). Dream enactment behaviors were particularly common in AE associated with LGI1 autoantibodies, reported in 4/7 (57%) patients. Polysomnography showed reduced total sleep time, stage 3 and rapid eye movement sleep, and prominent sleep fragmentation.

CONCLUSION

Sleep disturbances are common in AE, warranting active surveillance in affected patients. Improved identification and treatment of sleep disorders may reduce morbidity associated with AE and improve long-term outcomes.

The rostromedial tegmental nucleus is essential for non-rapid eye movement sleep

The rostromedial tegmental nucleus (RMTg), also called the GABAergic tail of the ventral tegmental area, projects to the midbrain dopaminergic system, dorsal raphe nucleus, locus coeruleus, and other regions. Whether the RMTg is involved in sleep-wake regulation is unknown. In the present study, pharmacogenetic activation of rat RMTg neurons promoted non-rapid eye movement (NREM) sleep with increased slow-wave activity (SWA). Conversely, rats after neurotoxic lesions of 8 or 16 days showed decreased NREM sleep with reduced SWA at lights on. The reduced SWA persisted at least 25 days after lesions. Similarly, pharmacological and pharmacogenetic inactivation of rat RMTg neurons decreased NREM sleep. Electrophysiological experiments combined with optogenetics showed a direct inhibitory connection between the terminals of RMTg neurons and midbrain dopaminergic neurons. The bidirectional effects of the RMTg on the sleep-wake cycle were mimicked by the modulation of ventral tegmental area (VTA)/substantia nigra compacta (SNc) dopaminergic neuronal activity using a pharmacogenetic approach. Furthermore, during the 2-hour recovery period following 6-hour sleep deprivation, the amount of NREM sleep in both the lesion and control rats was significantly increased compared with baseline levels; however, only the control rats showed a significant increase in SWA compared with baseline levels. Collectively, our findings reveal an essential role of the RMTg in the promotion of NREM sleep and homeostatic regulation.

Cognitive Function Characteristics of Parkinson's Disease with Sleep Disorders

Objective. The aim of this study was to investigate the cognitive function characteristics of Parkinson's disease (PD) with sleep disorders. Methods. Consecutive patients with PD (n = 96), patients with primary sleep disorders (n = 76), and healthy control subjects (n = 66) were assessed. The patients with PD were classified into sleep disorder (PD-SD) and non-sleep disorder (PD-NSD) groups. Results. Among 96 patients with PD, 69 were diagnosed with a sleep disorder. There were 38 sleep disorder cases, 31 RBD cases, and 27 NSD cases. On the Mini-Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and MoCA subtests, patients in the PD-SD, primary sleep disorder, and PD-NSD groups exhibited lower scores than those in the control group. Moreover, the PD-SD patients exhibited more significant cognitive impairment than was observed in the primary sleep disorder patients. In the PD-SD subgroup, the attention scores on the MoCA and on MoCA subtests were lower in the PD with RBD group than in the PD with insomnia group. Conclusion. PD with sleep disorders may exacerbate cognitive dysfunction in patients. PD associated with different types of sleep disorders differentially affects cognitive functions, and patients with PD with RBD exhibited poorer cognitive function than was seen in patients with PD with insomnia.

Palliative Care for Patients and Families With Parkinson's Disease

Parkinson's disease is the second most common neurodegenerative disease worldwide. There is widespread consensus that Parkinson patients, their carers, and clinicians involved in their care would benefit from a fully integrated, need-based provision of palliative care. However, the concept of palliative care in Parkinson's disease is still poorly defined and, consequently, poorly implemented into daily clinical practice. A particular challenge is the gradually progressive nature of Parkinson's disease-with insidiously increasing disability-making it challenging to clearly define the onset of palliative care needs for Parkinson patients. As people with Parkinson's disease are now living longer than in the past, future research needs to develop a more robust evidence-based approach to clarify the disease events associated with increased palliative care needs, and to examine these, prospectively, in an integrated palliative care service. The modern palliative care outlook, termed "simultaneous care,",is no longer restricted to the final stage of disease. It involves incorporating a continuity of care, effective management of the chronic-palliative interface, and a multidisciplinary network of professionals working both in the community and in specialized clinics, with active involvement of caregivers. Although promising, there is still a need to demonstrate the effectiveness of palliative care for patients with Parkinson's disease.

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

PURPOSE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Effects of various factors on sleep disorders and quality of life in Parkinson's disease

In Parkinson's disease (PD), sleep disorders (SD) occur as a result of the neurochemical changes in sleep centres, neurodegenerative changes in dopaminergic neurons, and other factors. The most common SD include excessive daytime sleepiness, insomnia, restless legs syndrome and nocturia. The aim of the study was to compare quality of sleep, as a factor that greatly impacts quality of life (QoL), between PD patients and a control group and to further examine SD in the PD group with focus on incidence and SD types as well as on effects various factors (age, sex, PD characteristics, medication usage) have on these disorders. The study included 110 patients who met the criteria for the diagnosis of PD and 110 age-matched healthy controls. We used the Pittsburgh Sleep Quality Index, PD Sleep Scale, Epworth Sleepiness Scale, PD QoL Questionnaire-8 and PD Questionnaire-39 (items 30 and 33). In the group with PD, we considered the duration of the disease, the stage of disease according to the Hoehn and Yahr scale, medications and their impact on the SD. The average duration of the disease was 6 years and the mean stage was 2.44. The result showed significant differences in the sleep quality between groups. In the PD group, SD differences were also found according to gender, duration of the disease and medication usage. The most common SD were fragmented sleep, insomnia and nocturia. To improve the QoL of PD patients, it is necessary to pay more attention to detecting and solving SD.

Prospective assessment of subjective sleep benefit in Parkinson's disease

Background

Parkinson’s disease (PD) patients may experience ‘sleep benefit’ (SB): a temporarily improved mobility upon awakening. SB has mainly been studied retrospectively using questionnaires, but it remains unclear whether it is associated with actual changes in motor functioning.

Methods

We performed a prospective study on sleep-related changes in motor functioning, using a PD symptom diary during 7 days in 240 randomly selected PD patients (140 men; 66.8 ± 9.6 years; disease duration 9.3 ± 6.2 years). Afterwards, patients received a questionnaire on the possible subjective experience of SB.

Results

Using the PD symptom diary, a positive change in motor function was observed after 267 nights (17.8%) and after 138 daytime naps (23.4%). Based on these results, 75 patients (32%) were classified as having SB. In response to the subsequent questionnaire, 73 patients (31%) reported SB. Interestingly, the groups with SB according to either the diary or the questionnaire overlapped only partially: outcomes were congruent in 63% of subjects (both negative 49%, both positive 14%). In both the diary and questionnaire, patients with SB showed a longer disease duration and longer medication use. According to the questionnaire, there was a trend towards a shorter sleep duration and lower sleep efficiency in the SB group. The mean change in motor function after sleep as assessed using the diary was higher in patients reporting subjective SB.

Conclusion

We show that the subjective experience of SB in PD is not always related to an actual increase in reported motor function after sleep. Defining SB using either a symptom diary or a questionnaire on subjective experience, results in only partly overlapping groups. These data suggest that SB may be a more heterogeneous phenomenon than previously thought and that subjective experience of symptom severity is not necessarily related to actual motor function.

Electronic supplementary material

The online version of this article (doi:10.1186/s12883-014-0256-2) contains supplementary material, which is available to authorized users.

Sleep Attacks in Patients With Parkinson's Disease on Dopaminergic Medications: A Systematic Review

Dopaminergic medications are used as first-line treatment for Parkinson's disease (PD). In 1999, a case series was published describing 9 patients who took dopamine agonists (pramipexole or ropinirole) and experienced sudden irresistible sleep attacks. Sleep attacks have subsequently been reported with other dopaminergic medications, including levodopa. Because these symptoms might not be rare and can affect health-related quality of life, we set out to review the prevalence and clinical characteristics of sleep attacks in patients with PD on dopaminergic medications. We conducted a systematic literature review using the terms parkinson* AND dopamine* AND narcolep* OR sleep attack in multiple databases (PubMed, Embase, and PsycINFO). The systematic literature review yielded 23 relevant articles, including nine case reports or case series and 14 original studies. According to the pooled data from the five studies reporting prevalence figures (n = 10,084), sleep attacks occur in 13.0% of patients with PD on dopaminergic medications. Our analysis failed to show significant differences in the Epworth Sleepiness scores between patients with and without sleep attacks (mean difference: 2.92; 95% confidence interval: -0.47-6.31). The I² value of 76% indicated high heterogeneity among the studies. Sleep attacks are not a rare occurrence in patients with PD on dopamine agonist treatment. We found conflicting results on whether sleep attacks in PD resemble narcolepsy. The pathophysiology of these symptoms might be related to dopamine D2 and D4 receptor gene polymorphisms. The most effective management strategies were dose reduction and discontinuation of the offending drugs.

Clinical utility of DaTscan™ (123I-Ioflupane Injection) in the diagnosis of Parkinsonian Syndromes

The diagnosis of movement disorders including Parkinsonian syndromes and essential tremor is mainly clinical. The most common diagnostic errors for Parkinson's disease include misdiagnoses such as Parkinson plus syndromes and cases of essential tremor. In this article, we discuss the clinical utility of DaTscan™ (123I-Ioflupane injection) and its diagnostic value in Parkinson's disease and the other Parkinsonian syndromes. Single photon emission computed tomography with 123I-Ioflupane can be useful to assist in the diagnosis of uncertain cases of Parkinsonism. An accurate diagnosis can aid clinicians in making correct decisions that are related to the overall management and treatment of Parkinson's disease, avoiding common therapeutic errors.

Circadian dysfunction may be a key component of the non-motor symptoms of Parkinson's disease: insights from a transgenic mouse model

Sleep disorders are nearly ubiquitous among patients with Parkinson's disease (PD), and they manifest early in the disease process. While there are a number of possible mechanisms underlying these sleep disturbances, a primary dysfunction of the circadian system should be considered as a contributing factor. Our laboratory's behavioral phenotyping of a well-validated transgenic mouse model of PD reveals that the electrical activity of neurons within the master pacemaker of the circadian system, the suprachiasmatic nuclei (SCN), is already disrupted at the onset of motor symptoms, although the core features of the intrinsic molecular oscillations in the SCN remain functional. Our observations suggest that the fundamental circadian deficit in these mice lies in the signaling output from the SCN, which may be caused by known mechanisms in PD etiology: oxidative stress and mitochondrial disruption. Disruption of the circadian system is expected to have pervasive effects throughout the body and may itself lead to neurological and cardiovascular disorders. In fact, there is much overlap in the non-motor symptoms experienced by PD patients and in the consequences of circadian disruption. This raises the possibility that the sleep and circadian dysfunction experienced by PD patients may not merely be a subsidiary of the motor symptoms, but an integral part of the disease. Furthermore, we speculate that circadian dysfunction can even accelerate the pathology underlying PD. If these hypotheses are correct, more aggressive treatment of the circadian misalignment and sleep disruptions in PD patients early in the pathogenesis of the disease may be powerful positive modulators of disease progression and patient quality of life.