A Transcriptome Analysis of mRNAs and Long Non-Coding RNAs in Patients with Parkinson's Disease.

Parkinson's disease (PD) is the second most common neurodegenerative disorder. The number of cases of PD is expected to double by 2030, representing a heavy burden on the healthcare system. Clinical symptoms include the progressive loss of dopaminergic neurons in the substantia nigra of the midbrain, which leads to striatal dopamine deficiency and, subsequently, causes motor dysfunction. Certainly, the study of the transcriptome of the various RNAs plays a crucial role in the study of this neurodegenerative disease. In fact, the aim of this study was to evaluate the transcriptome in a cohort of subjects with PD compared with a control cohort. In particular we focused on mRNAs and long non-coding RNAs (lncRNA), using the Illumina NextSeq 550 DX System. Differential expression analysis revealed 716 transcripts with padj ≤ 0.05; among these, 630 were mRNA (coding protein), lncRNA, and MT_tRNA. Ingenuity pathway analysis (IPA, Qiagen) was used to perform the functional and pathway analysis. The highest statistically significant pathways were: IL-15 signaling, B cell receptor signaling, systemic lupus erythematosus in B cell signaling pathway, communication between innate and adaptive immune cells, and melatonin degradation II. Our findings further reinforce the important roles of mitochondria and lncRNA in PD and, in parallel, further support the concept of inverse comorbidity between PD and some cancers.

Role and Dysregulation of miRNA in Patients with Parkinson's Disease.

Parkinson's disease (PD) is a neurodegenerative synucleinopathy that has a not yet fully understood molecular pathomechanism behind it. The role of risk genes regulated by small non-coding RNAs, or microRNAs (miRNAs), has also been highlighted in PD, where they may influence disease progression and comorbidities. In this case-control study, we analyzed miRNAs on peripheral blood mononuclear cells by means of RNA-seq in 30 participants, with the aim of identifying miRNAs differentially expressed in PD compared to age-matched healthy controls. Additionally, we investigated the pathways influenced by differentially expressed miRNAs and assessed whether a specific pathway could potentially be associated with PD susceptibility (enrichment analyses performed using the Ingenuity Pathway Analysis tools). Overall, considering that the upregulation of miRNAs might be related with the downregulation of their messenger RNA targets, and vice versa, we found several putative targets of dysregulated miRNAs (i.e., upregulated: hsa-miR-1275, hsa-miR-23a-5p, hsa-miR-432-5p, hsa-miR-4433b-3p, and hsa-miR-4443; downregulated: hsa-miR-142-5p, hsa-miR-143-3p, hsa-miR-374a-3p, hsa-miR-542-3p, and hsa-miR-99a-5p). An inverse connection between cancer and neurodegeneration, called "inverse comorbidity", has also been noted, showing that some genes or miRNAs may be expressed oppositely in neurodegenerative disorders and in some cancers. Therefore, it may be reasonable to consider these miRNAs as potential diagnostic markers and outcome measures.

Increased Serum Prolactin and Excessive Daytime Sleepiness: An Attempt of Proof-of-Concept Study.

The objectives of this study were: (1) to identify subjects with hyperprolactinemia in a clinical sample of patients; (2) to compare the neurologic, psychiatric, and sleep conditions found in patients subgrouped by excessive daytime sleepiness (EDS) and hyperprolactinemia; and (3) to identify patients with hyperprolactinemia and EDS not supported by the presence of any other neurologic, psychiatric, or sleep disorder, or substance/medication use. A retrospective chart review of inpatients was carried out in order to identify all patients in whom the prolactin (PRL) serum levels were determined. A total of 130 subjects were retrieved: 55 had increased levels of PRL, while the remaining 75 participants had normal PRL levels. EDS was reported by 32 (58.2%) participants with increased PRL and 34 (45.3%) with normal PRL. Obstructive sleep apnea or other sleep or neurologic/psychiatric conditions could explain EDS in all participants with normal PRL. Among subjects with increased PRL, eight had no other neurologic/psychiatric or sleep disorder (or drug) potentially causing EDS; these participants, at polysomnography, had time in bed, sleep period time, and total sleep time longer than those with EDS associated to another condition. These findings can be considered as a preliminary indication of a role of hyperprolactinemia in EDS and represent a basis for future controlled studies able to test this hypothesis in a reliable, objective, and methodologically more appropriate way.

Searching for Novel Candidate Biomarkers of RLS in Blood by Proteomic Analysis.

PURPOSE: We performed comparative proteomic analyses of blood of patients with RLS and healthy individuals aiming to identify potential biomarker and therapeutic target candidate for RLS. PATIENTS AND METHODS: Blood serum samples from 12 patients with a clinical diagnosis of RLS (8 females and 4 males, with a mean age of 68.52 years) and 10 healthy controls (5 females and 5 males, with a mean age of 67.61 years) underwent proteomic profiling by liquid chromatography coupled with tandem mass spectrometry. Pathway analysis incorporating protein-protein interaction networks was carried out to identify pathological processes linked to the differentially expressed proteins. RESULTS: We quantified 272 proteins in patients with RLS and healthy controls, of which 243 were shared. Five proteins - apolipoprotein C-II, leucine-rich alpha-2-glycoprotein 1, FLJ92374, extracellular matrix protein 1, and FLJ93143 - were substantially increased in RLS patients, whereas nine proteins - vitamin D-binding protein, FLJ78071, alpha-1-antitrypsin, CD5 antigen-like, haptoglobin, fibrinogen alpha chain, complement factor H-related protein 1, platelet factor 4, and plasma protease C1 inhibitor - were decreased. Bioinformatics analyses revealed that these proteins were linked to 1) inflammatory and immune response, and complement activation, 2) brain-related development, cell aging, and memory disorders, 3) pregnancy and associated complications, 4) myocardial infarction, and 5) reactive oxygen species generation and subsequent diabetes mellitus. CONCLUSION: Our findings shed light on the multifactorial nature of RLS and identified a set of circulating proteins that may have clinical importance as biomarkers and therapeutic targets.

Peculiar lifespan changes of periodic leg movements during sleep in restless legs syndrome.

The objective of this observational cohort study was to analyse the age-related changes of periodic leg movements during sleep using the newest international scoring rules, to expand past analyses, including patients in the paediatric age range, and also to analyse the changes of short-interval and isolated leg movements during sleep throughout the lifespan. One hundred and sixty-five patients (84 women) with restless legs syndrome were recruited in the following age groups: 16 preschoolers (≤5 years of age), 29 school-age children (6-12 years), 19 adolescents (13-17 years), 17 young adults (19-40 years), 47 adults (41-60 years) and 37 seniors (>60 years). Total, periodic, short-interval and isolated leg movements during sleep and periodicity indexes were obtained by polysomnography. The total index showed (quartic polynomial interpolation) a decrease before 10 years, followed by a steady increase up to 30 years, a relatively stable period until 60 years, and a final increase up to 80 years. This course was almost entirely due to changes in periodic movements. Isolated movements did not change significantly and short-interval movements showed only an increase in seniors. Our study indicates that, in restless legs syndrome, the total index shows a peculiar and unique course throughout the lifespan, mainly due to periodic movements. These age-related changes may mirror developmental changes in network complexity known to occur in dopaminergic circuits. These data further confirm the need to better assess the periodicity of leg movements in sleep during the human development period, in order to obtain clinically useful information.

Dietary Inflammatory Index and Sleep Quality in Southern Italian Adults.

BACKGROUND: Current evidence supports the central role of a subclinical, low-grade inflammation in a number of chronic illnesses and mental disorders; however, studies on sleep quality are scarce. The aim of this study was to test the association between the inflammatory potential of the diet and sleep quality in a cohort of Italian adults. METHODS: A cross-sectional analysis of baseline data of the Mediterranean healthy Eating, Aging, and Lifestyle (MEAL) study was conducted on 1936 individuals recruited in the urban area of Catania during 2014-2015 through random sampling. A food frequency questionnaire and other validated instruments were used to calculate the dietary inflammatory index (DII®) and assess sleep quality (Pittsburg sleep quality index). Multivariable logistic regression analyses were performed to determine the association between exposure and outcome. RESULTS: Individuals in the highest quartile of the DII were less likely to have adequate sleep quality (odds ratio (OR) = 0.49, 95% CI: 0.31, 0.78). Among individual domains of sleep quality, an association with the highest exposure category was found only for sleep latency (OR = 0.60, 95% CI: 0.39, 0.93). CONCLUSIONS: The inflammatory potential of the diet appears to be associated with sleep quality in adults. Interventions to improve diet quality might consider including a dietary component that aims to lower chronic systemic inflammation to prevent cognitive decline and improve sleep quality.

REM sleep without atonia with REM sleep-related motor events: broadening the spectrum of REM sleep behavior disorder.

Study Objectives: To assess the presence of increased REM-related motor activity during sleep, by questionnaires for REM sleep behavior disorder (RBD), in participants with "isolated" REM sleep without atonia (RWA). Participants and Methods: Two hundred forty-nine patients were consecutively enrolled, with age ≥18 years, sharing bedroom with a roommate, and without a severe health, neurological, or cognitive problem. Motor activity during sleep was assessed by means of the RBD Screening Questionnaire (RBDSQ) and the RBD questionnaire-Hong Kong (RBDQ-HK). A video-polysomnographic recording was obtained and the REM Atonia Index was computed. Thirteen participants were diagnosed to have RBD while the remaining 236 were subdivided into two subgroups: 34 participants with "low" (<0.8) and 202 participants with "high" Atonia Index (≥0.8). Results: RBDSQ and RBDQ-HK were both higher in participants with low Atonia Index than in those with high Atonia Index, as well as number of drugs taken and number of comorbidities. No effect of antidepressant use was found on Atonia Index and a multiple-regression analysis showed that Atonia Index was significantly (inversely) correlated only with the behavioral score obtained with the RBDQ-HK. Conclusions: Our study shows that individuals with isolated RWA have an increased motor activity/behavioral pattern during sleep, although this activity does not allow us to diagnose RBD. Our findings broaden the spectrum of RBD and the condition that we have identified should be better characterized in order to understand its eventual development into fully blown RBD or not.

Bilateral leg movements during sleep: detailing their structure and features in normal controls and in patients with restless legs syndrome.

OBJECTIVE: The aim of this study was to analyze statistically the number of single leg movements (LMs) forming bilateral LMs during sleep, along with their combined duration, to eventually provide evidence-based data for the adjustment of the current scoring rules defining bilateral LMs. METHODS: Polysomnographic recordings of 111 untreated patients with RLS with a median age of 56.0 years, along with 42 normal controls with a mean age of 60.0 years, were included. In each recording, we identified all LMs that were considered as bilateral when two or more LMs were overlapping or the onset of the following movement was <0.5 second after the offset of the preceding LM. The remaining LMs were classified as monolateral. A series of parameters were computed for both bilateral and monolateral LMs. RESULTS: The duration of monolateral LMs in RLS patients was significantly longer than that of normal controls. For bilateral LMs, the maximum number of single LMs forming a bilateral movement and the maximum duration were slightly higher in RLS patients; however, the distribution of the number of individual LMs forming a single bilateral LM was similar. Only 0.12% and 0.27% of bilateral LMs consisted of >4 individual movements, and only 0.16% and 1.90% of bilateral LMs were >15 seconds in RLS patients and healthy controls, respectively. CONCLUSION: Our results strongly suggest that bilateral LMs during sleep should be constituted by no more than four individual LMs and should have a maximum duration of 15 seconds.

Sequence analysis of leg movements during sleep with different intervals (<10, 10-90 and >90 s) in restless legs syndrome.

The aim of this study was to define the time structure of leg movements during sleep occurring with an intermovement interval (onset-to-onset) shorter than 10 s in patients with restless legs syndrome and controls, and to compare it to the structure of movements with intervals of 10-90 s or >90 s. Polysomnographic recordings of 141 untreated patients and 68 age-matched normal controls were analysed. All movements were detected and classified into three categories, separated by intervals of <10, 10-90 or >90 s. The number of movements included in each category was significantly higher in patients than in controls. The movements with an interval of >90 s occurred steadily during the night, whereas the hourly distribution of movements with intervals of <10 or 10-90 s was decreasing or bell-shaped in patients or controls, respectively. Movements with an interval of <10 s tended to have a shorter duration and constituted shorter sequences than movements with intervals of 10-90 or >90 s. The time structure features of the three categories of movements considered in this study were found to be clearly different. This, together with previous observations on the differential effects of dopamine agonists on movements with different intervals, suggests that movements with intervals of <10 and >90 s are regulated by neurotransmitter mechanisms different from those modulating movements with an interval of 10-90 s.

Silent Cerebral Small Vessel Disease in Restless Legs Syndrome.

STUDY OBJECTIVES: Growing literature suggests that patients with restless legs syndrome (RLS) may be at increased risk for hypertension, heart disease, and stroke. Cerebral small vessel disease (SVD) is a known risk factor for clinical stroke. This study evaluated silent cerebral SVD by MRI in patients with RLS, in the absence of a history of previous clinical stroke or known stroke risk factors and taking into account disease duration. METHODS: Fifty-three patients with RLS < 10 y were prospectively recruited along with 44 with RLS > 10 y and 74 normal controls. A magnetic resonance imaging study was obtained from all subjects and scans were analyzed for area and volume of SVD. RESULTS: There was a significant increase in SVD area in the entire group of RLS patients compared to controls (P = 0.036); this was almost entirely driven by the group with RLS > 10 y. SVD area and volume were significantly increased in patients with RLS > 10 y with respect to both controls (P < 0.0001 and P < 0.0014, respectively) and RLS < 10 y (P < 0.00022 and P < 0.003, respectively). Age, duration of RLS, and the interaction of age and duration of RLS were independent predictors of SVD disease. Duration of RLS was an independent predictor of the burden of cerebral SVD (area P < 0.00012 and volume P < 0.0025), whereas sex and insomnia were not. CONCLUSION: RLS duration should be taken into account when analyzing the association between RLS and cerebrovascular disease; our data support the hypothesis that a long-lasting RLS and its accompanying periodic limb movements in sleep are a risk factor for silent SVD and perhaps for the development of clinical stroke.

Increased electroencephalographic high frequencies during the sleep onset period in patients with restless legs syndrome.

STUDY OBJECTIVES: To analyze the electroencephalographic (EEG) spectral content in untreated patients with restless legs syndrome (RLS) during the sleep onset period (SOP) and during the quiet wakefulness preceding sleep, in order to test the hypothesis that a state of hyperarousal might be present during the SOP with RLS. SETTING: Sleep Research Centre. PATIENTS: Twenty-seven untreated consecutive patients with RLS (mean age = 53.6 y), 11 untreated consecutive patients with primary insomnia (mean age = 58.9 y), and 14 normal controls (mean age = 50.3 y). METHODS: SOP was defined as the 10-min period centered with the occurrence of the first sleep spindle in the EEG, and then subdivided into SOP-1 (period of 5 min before the first spindle) and SOP-2 (period of 5 min following). Leg movements occurring during SOP were counted and used as a covariate in the statistical analysis. Also, one period of 1 min of artifact-free quiet wakefulness after lights off was identified. EEG spectral analysis was run during these periods using the C3/A2 or C4/A1 channel. MEASUREMENTS AND RESULTS: Increased EEG alpha and beta bands and/or beta/delta ratio in RLS versus normal controls, during both wakefulness preceding sleep and SOP (both parts SOP-1 and SOP-2) were found, which were, however, smaller than the increases found in patients with insomnia. CONCLUSION: The results of this study support the hypothesis of the presence of a state of hyperarousal in restless legs syndrome (RLS) during the sleep onset period. Treatment for RLS might need to take these findings into consideration. CITATION: Ferri R, Cosentino FI, Manconi M, Rundo F, Bruni O, Zucconi M. Increased electroencephalographic high frequencies during the sleep onset period in patients with restless legs syndrome.

A case of REM sleep behavior disorder, narcolepsy-cataplexy, parkinsonism, and rheumatoid arthritis.

A patient is reported in whom signs and symptoms of REM sleep behavior disorder (RBD) and narcolepsy have been associated for almost two decades with a late development of parkinsonism and rheumatoid arthritis. A 78-year-old male patient in whom RBD was first diagnosed was followed-up by clinical examination, video-polysomnography, multiple sleep latency test, cerebral magnetic resonance imaging, and dopamine transporter imaging by single-photon emission computerized tomography. The patient was found to present for almost two decades, in addition to RBD, also narcolepsy. Moreover, a late development of parkinsonism and the occurrence of rheumatoid arthritis were detected and clinically and instrumentally characterized. Patients predisposed to RBD and later parkinsonism might be susceptible to a variety of triggers that, in our patient, might have been represented by a possible latent autoimmune process leading to the development of narcolepsy with cataplexy and rheumatoid arthritis, later.

The timing between REM sleep behavior disorder and Parkinson's disease.

PURPOSE: In Parkinson's disease (PD) patients, REM sleep behavior disorder (RBD) might precede PD or develop with or after the onset of PD. No previous study has explored differences between these two groups. The aim of this study was therefore to compare clinical features and REM sleep chin electromyographic patterns between patients in whom RBD heralded PD and those in whom RBD occurrence coincided with or followed the clinical manifestations of PD. METHOD: Twenty-seven consecutive PD patients (mean age 67.9 years) were enrolled. Detailed clinical, laboratory, and polysomnographic studies were obtained in all participants. RESULTS: Sixteen of the 27 patients were affected by RBD. These had a significantly higher stage of PD and took significantly higher doses of dopaminergic therapy; their disease duration tended to be longer, and their cognitive status tended to be lower. PD patients in whom RBD preceded PD (n = 6) did not differ from PD patients without RBD in disease parameters, while PD patients in whom RBD developed with or after PD (n = 10) showed a significantly higher disease stage, took significantly higher dopaminergic therapy, and had a longer disease duration. CONCLUSION: Our findings are compatible with the hypothesis that patients in whom RBD precedes, or does not precede, PD might constitute two possibly distinct clinical and physiopathological groups, based on different progressive neuropathological sequences of events.

Night-to-night variability of automatic quantitative parameters of the chin EMG amplitude (Atonia Index) in REM sleep behavior disorder.

STUDY OBJECTIVES: To analyze the night-to-night variability of REM sleep electromyographic (EMG) features of REM sleep behavior disorder (RBD) by using the automatic quantitative method known as atonia index (AI), and to evaluate the improvement in sensitivity and specificity of AI for the diagnosis of RBD when a second recording night is available. SETTING: Sleep research center. INTERVENTIONS: N/A. METHODS: A group of 17 idiopathic RBD patients was recruited for whom 2 all-night polysomnographic (PSG) recordings were available. Thirty normal controls were also recruited and subgrouped into Young (< 45 years of age) or Aged (> 45 years). Chin EMG analysis was run on all recordings; night-to-night variability of both AI and number of chin EMG activations/h during REM sleep was additionally quantified as the absolute difference between the 2 nights standardized as the percentage of their mean. MEASUREMENTS AND RESULTS: Night-to-night variability of AI was higher in RBD patients (19.7%) than in the 2 groups of controls (Young 1.8% and Aged 2.8%). The values of variability of chin EMG activations were much higher than those of AI, especially in the Aged controls. Sensitivity of AI ≤ 0.9 for RBD was always higher than 82% and reached 88.9% for the combined-night analysis; specificity was also high, with a value of 92.3% for the combined-value analysis. CONCLUSION: The night-to-night variability of AI seems to be very low in normal controls and remains under 20% in RBD patients; that of the number of EMG activations is higher. However, even a single PSG recording provides high values of sensitivity and specificity when a threshold value of AI ≤ 0.9 is used to define abnormal chin EMG levels during REM sleep that increase only moderately when a second night recording is available.

Cortical sources of resting state EEG rhythms are sensitive to the progression of early stage Alzheimer's disease.

Cortical sources of resting state electroencephalographic (EEG) rhythms are abnormal in subjects with Alzheimer's disease (AD). Here we tested the hypothesis that these sources are also sensitive to the progression of early stage AD over the course of one year. The resting state eyes-closed EEG data were recorded in 88 mild AD patients at baseline (Mini Mental State Evaluation, MMSE I = 21.7 ± 0.2 standard error, SE) and at approximately one-year follow up (13.3 months ± 0.5 SE; MMSE II = 20 ± 0.4 SE). All patients received standard therapy with acetylcholinesterase inhibitors. EEG recordings were also performed in 35 normal elderly (Nold) subjects as controls. EEG rhythms of interest were delta (2-4 Hz), theta (4-8 Hz), alpha 1 (8-10.5 Hz), alpha 2 (10.5-13 Hz), beta 1 (13-20 Hz), beta 2 (20-30 Hz), and gamma (30-40 Hz). Cortical EEG sources were estimated by low-resolution brain electromagnetic tomography (LORETA). Compared to the Nold subjects, the mild AD patients were characterized by a power increase of widespread delta sources and by a power decrease of posterior alpha sources. In the mild AD patients, the follow-up EEG recordings showed increased power of widespread delta sources as well as decreased power of widespread alpha and posterior beta 1 sources. These results suggest that the resting state EEG sources were sensitive, at least at group level, to the cognitive decline occurring in the mild AD group over a one-year period, and might represent cost-effective and non-invasive markers with which to enrich cohorts of AD patients that decline faster for clinical studies.

Polysomnographic study of nocturnal sleep in idiopathic hypersomnia without long sleep time.

We investigated nocturnal sleep abnormalities in 19 patients with idiopathic hypersomnia without long sleep time (IH) in comparison with two age- and sex- matched control groups of 13 normal subjects (C) and of 17 patients with narcolepsy with cataplexy (NC), the latter considered as the extreme of excessive daytime sleepiness (EDS). Sleep macro- and micro- (i.e. cyclic alternating pattern, CAP) structure as well as quantitative analysis of EEG, of periodic leg movements during sleep (PLMS), and of muscle tone during REM sleep were compared across groups. IH and NC patients slept more than C subjects, but IH showed the highest levels of sleep fragmentation (e.g. awakenings), associated with a CAP rate higher than NC during lighter sleep stages and lower than C during slow wave sleep respectively, and with the highest relative amount of A3 and the lowest of A1 subtypes. IH showed a delta power in between C and NC groups, whereas muscle tone and PLMS had normal characteristics. A peculiar profile of microstructural sleep abnormalities may contribute to sleep fragmentation and, possibly, EDS in IH.

A preliminary quantitative analysis of REM sleep chin EMG in Parkinson's disease with or without REM sleep behavior disorder.

OBJECTIVES: To compare REM sleep chin EMG quantitative features between Parkinson's disease (PD) patients with or without REM sleep behavior disorder (RBD). SUBJECTS AND METHODS: Twenty-seven consecutive PD patients (mean age 67.9 years) and 19 normal controls (mean age 67.5 years) were enrolled. Detailed clinical, laboratory, and polysomnographic studies were obtained in all participants and characteristics of chin electromyographic amplitude during rapid eye movements sleep were analyzed by means of an automatic quantitative approach (Atonia Index). RESULTS: Sixteen of the 27 patients were affected by RBD. An Atonia Index below 0.90 showed high sensitivity (0.938) and specificity (0.909) for the diagnosis of RBD within the group of PD patients. CONCLUSION: This study recommends the Atonia Index as an objective measure to support and aid the diagnosis of RBD in PD.

Leg movements during wakefulness in restless legs syndrome: time structure and relationships with periodic leg movements during sleep.

BACKGROUND AND OBJECTIVE: Approximately one third of patients with restless legs syndrome (RLS) also show periodic leg movements (PLM) during relaxed wake fulness (PLMW). In contrast with the large amount of data published on periodic leg movements during sleep (PLMS), PLMW have received less attention from the scientific community. The objective of this study was to evaluate the correlations/differences of time-structure and response to a dopamine-agonist between PLMW and PLMS in patients with RLS. METHODS: Ninety idiopathic RLS patients and 28 controls were recruited. Subjects underwent clinical and neurophysiological evaluation, hematological screening, and one or two consecutive full-night polysomnographic studies. A subset of patients received 0.25mg of pramipexole or placebo before the second recording. Polysomnographic recordings were scored and LM activity was analyzed during sleep and during the epochs of wakefulness occurring during the first recording hour. RESULTS: RLS patients had higher LM activity during wakefulness than controls, but with a similar periodicity. Even if correlated, the ability of the PLMW index to predict the PLMS index decreased with increasing LM activity. Intermovement intervals during wakefulness showed one peak only at approximately 4s, gradually decreasing with increasing interval in both patients and controls. The effect of pramipexole was very limited and involved the small periodic portion of LM activity during wakefulness. CONCLUSIONS: PLMW index and PLMS index were correlated; however, the magnitude of this correlation was not sufficient to suggest that PLMW can be good predictors of PLMS. Short-interval LM activity during wakefulness and sleep might be linked to the severity of sleep disruption in RLS patients and the differences between their features obtained during wakefulness or sleep might be relevant for the diagnosis of sleep disturbances in RLS.