Background and Objectives The assessment of biomarkers in selecting patients with idiopathic normal pressure hydrocephalus (iNPH) for shunt surgery has been limited to small cohort studies and those with limited follow-up. We assessed the potential for CSF biomarkers in predicting immediate response to CSF tap test (TT) and long-term response after shunt surgery. Methods CSF was obtained from patients with iNPH referred for CSF TT after baseline assessment of cognition and gait. CSF neurofilament light (NfL), beta-amyloid 42 (A beta(1-42)), beta-amyloid 40 (A beta(1-40)), total tau (tTau), and phosphorylated tau 181 (pTau181) and leucine-rich alpha-2-glycoprotein-1 (LRG1) were measured by ELISA. The ability of these measures to predict immediate improvement following CSF TT and long-term improvement following shunt surgery was compared by univariate and adjusted multivariate regression. Results Lower NfL, pTau181, tTau, and A beta(1-40) were individually predictive of long-term improvement in gait outcomes after shunt surgery. A multivariate model of these biomarkers and MRI Evans index, adjusted for age, improved prediction (area under the receiver operating curve 0.76, 95% confidence interval 0.66-0.86). tTau, pTau181, and A beta(1-40) levels were statistically different in those whose gait improved after CSF TT compared with those who did not. Using a multivariate model, combining these markers with Evans index and transependymal flow did not significantly improve prediction of an immediate response to CSF TT. Discussion A combination of CSF biomarkers can predict improvement following shunt surgery for iNPH. However, these measures only modestly discriminate responders from nonresponders following CSF TT. The findings further suggest that abnormal CSF biomarkers in nonresponders may represent comorbid neurodegenerative pathology or a predegenerative phase that presents with an iNPH phenotype.

OBJECTIVE:The primary aim of the study was to assess the effect comorbid Parkinson syndromes have on results of CSF tap test (TT) and shunt outcomes for patients presenting with Normal Pressure Hydrocephalus (NPH). We hypothesized that patients with possible NPH and comorbid Parkinson syndromes with Positive DaT scans will not respond to CSF TT at the same rate as patients without comorbid Parkinson syndromes. Additionally, we followed a small number of patients with positive DaT scans who were shunted to assess long term outcome of comorbid Parkinson syndromes.METHODS:Medical records and neurological exams of 251 patients were reviewed. In our analysis 101 patients with no parkinsonian symptoms and no DaT scans were included as a control group, there were 52 patients with DaT scans, 31 patients were positive (DaT-P). Gait measures were assessed before and after CSF TT using the Wilcoxon matched-pairs signed-rank test or paired t-tests were used. To compare the effect of DaT-P and Control, we used an ANCOVA controlling for age, sex, assistive device used, and past medical history effecting gait.RESULTS:There was not a significant difference in response between Control and DaT-P group. The Control group improved on timed up and go (TUG) by 14.82%, DualTUG 16.35%, 10-meter Walk Test (10MWT) 18.13%, MiniBEST 15.91%, and 6-minute Walk Test (6MWT) 13.96%, while the DaT-P group improved on TUG by 14.93%, DualTUG 17.24%, 10MWT 22.68%, MiniBEST 18.07%, and 6MWT 16.06%.CONCLUSION:Our findings suggest that patients with possible NPH and suspected comorbid movement disorder, showed similar improvement after diagnostic CSF TT compared to participants with no parkinsonian symptoms present on exam.DATA AVAILABILITY STATEMENT:Data relevant to the study will be made available from the corresponding author upon a reasonable request.

Abstract Background Presently, for patients presenting with suspected Normal Pressure Hydrocephalus (NPH) who undergo temporary drainage of cerebrospinal fluid (CSF) there is no defined model to differentiate chance improvement form clinical significance change at the individual patient level. To address this lack of information we computed standard regression based clinical change models for the 10 Meter Walk Test, Timed Up & Go, Dual Timed Up & Go, 6-Minute Walk Test, Mini-Balance Evaluation Systems Test, Montreal Cognitive Assessment, and Symbol Digit Modalities using data from patients with suspected NPH that underwent temporary drainage of CSF. These clinically significant change modes can classify clinically significant improvement following temporary drainage of CSF at the individual patient level. This allows for physicians to differentiate a clinically significant improvement in symptoms from chance improvement. Methods Data was collected from 323 patients, over the age of 60, with suspected NPH that underwent temporary drainage of CSF with corresponding gait and cognitive testing. McSweeney Standardized Regression Based Clinical Change Models were computed for standard gait and cognitive measures: Timed Up & Go, Dual Timed Up & Go, 10 Meter Walk Test, MiniBESTest, 6-Minute Walk Test, Montreal Cognitive Assessment, and Symbol Digit Modalities Test. To assess the discriminate validity of the measures we used correlations, Chi2, and regression analyses. Results The clinical change models explained 69–91.8% of the variability in post-drain performance (p < 0.001). As patient scores became more impaired, the percent change required for improvement to be clinically significant increased for all measures. We found that the measures were not discriminate, the Timed Up & Go was highly related to the 10 Meter Walk Test (r = 0.85, R 2 = 0.769–0.738, p < 0.001), MiniBESTest (r = − 0.67, R 2 = 0.589–0.734, p < 0.001), and 6 Minute Walk Test (r = − 0.77, R 2 = 0.71–0.734, p < 0.001). Conclusion Standardized Regression Based Clinically Significant Change Models allow for physicians to use an evidence-based approach to differentiate clinically significant change from chance improvement at the individual patient level. The Timed Up & Go was shown to be predictive of detailed measures of gait velocity, balance, and endurance.

BACKGROUND Cerebrospinal fluid (CSF) biomarkers are increasingly used to confirm the accuracy of a clinical diagnosis of mild cognitive impairment or dementia due to Alzheimer disease (AD). Recent evidence suggests that fully automated assays reduce the impact of some preanalytical factors on the variability of these measures. This study evaluated the effect of several preanalytical variables common in clinical settings on the variability of CSF β-amyloid 1-42 (Aβ1-42) concentrations. METHODS Aβ1-42 concentrations were measured using the LUMIPULSE G1200 from both freshly collected and frozen CSF samples. Preanalytic variables examined were: (1) patient fasting prior to CSF collection, (2) blood contamination of specimens, and (3) aliquoting specimens sequentially over the course of collection (i.e., CSF gradients). RESULTS Patient fasting did not significantly affect CSF Aβ1-42 levels. While assessing gradient effects, Aβ1-42 concentrations remained stable within the first 5 1-mL aliquots. However, there is evidence of a gradient effect toward higher concentrations over successive aliquots. Aβ1-42 levels were stable when fresh CSF samples were spiked with up to 2.5% of blood. However, in frozen CSF samples, even 0.25% blood contamination significantly decreased Aβ1-42 concentrations. CONCLUSIONS The preanalytical variables examined here do not have significant effects on Aβ1-42 concentrations if fresh samples are processed within 2 h. However, a gradient effect can be observed on Aβ1-42 concentrations after the first 5 mL of collection and blood contamination has a significant impact on Aβ1-42 concentrations once specimens have been frozen.

BACKGROUND Strong preclinical evidence suggests that exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist used for treating type 2 diabetes, is neuroprotective and disease- modifying in Alzheimer's disease (AD). OBJECTIVE We performed an 18-month double-blind randomized placebo-controlled Phase II clinical trial to assess the safety and tolerability of exenatide and explore treatment responses for clinical, cognitive, and bio- marker outcomes in early AD. METHOD Eighteen participants with high probability AD based on cerebrospinal fluid (CSF) biomarkers completed the entire study prior to its early termination by the sponsor; partial outcomes were available for twenty-one. RESULTS Exenatide was safe and well-tolerated, showing an expectedly higher incidence of nausea and decreased appetite compared to placebo and decreasing glucose and GLP-1 during Oral Glucose Tolerance Tests. Exenatide treatment produced no differences or trends compared to placebo for clinical and cognitive measures, MRI cortical thickness and volume, or biomarkers in CSF, plasma, and plasma neuronal extracellular vesicles (EV) except for a reduction of Aβ42 in EVs. CONCLUSION The positive finding of lower EV Aβ42 supports emerging evidence that plasma neuronal EVs provide an effective platform for demonstrating biomarker responses in clinical trials in AD. The study was underpowered due to early termination and therefore we cannot draw any firm conclusions. However, the analysis of secondary outcomes shows no trends in support of the hypothesis that exenatide is disease- modifying in clinical AD, and lowering EV Aβ42 in and of itself may not improve cognitive outcomes in AD.

Study Objectives Determine abnormalities in levels of iron-management proteins in neuronal origin-enriched extracellular vesicles (nEVs) in restless legs syndrome (RLS). Methods We used immunoprecipitation for neuronal marker L1CAM to isolate nEVs from the serum of 20 participants with RLS from a study including magnetic resonance imaging (MRI) determinations of iron deposition in the substantia nigra and hematologic parameters and 28 age- and sex-matched Controls. Results RLS compared with Control participants showed higher levels of nEV total ferritin but similar levels of transferrin receptor and ferroportin. Western blot analysis showed that heavy- but not light-chain ferritin was increased in nEVs of RLS compared with Control participants. In RLS but not Control participants, nEV total ferritin was positively correlated with systemic iron parameters; the two groups also differed in the relation of nEV total ferritin to MRI measures of iron deposition in substantia nigra. Conclusions Given the neuronal origin and diversity of EV cargo, nEVs provide an important platform for exploring the underlying pathophysiology and possible biomarkers of RLS.

IMPORTANCE Exenatide, a glucagon-like peptide 1 agonist used in type 2 diabetes, was recently found to have beneficial effects on motor function in a randomized, placebo-controlled trial in Parkinson disease (PD). Accumulating evidence suggests that impaired brain insulin and protein kinase B (Akt) signaling play a role in PD pathogenesis; however, exploring the extent to which drugs engage with putative mechnisms in vivo remains a challenge. OBJECTIVE To assess whether participants in the Exenatide-PD trial have augmented activity in brain insulin and Akt signaling pathways. DESIGN, SETTING, AND PARTICIPANTS Serum samples were collected from 60 participants in the single-center Exenatide-PD trial (June 18,2014, to June 16,2016), which compared patients with moderate PD randomized to 2 mg of exenatide once weekly or placebo for 48 weeks followed by a 12-week washout period. Serum extracellular vesicles, including exosomes, were extracted, precipitated, and enriched for neuronal source by anti-L1cell adhesion molecule antibody absorption, and proteins of interest were evaluated using electrochemiluminescence assays. Statistical analysis was performed from May 1,2017, to August 31,2017. MAIN OUTCOMES AND MEASURES The main outcome was augmented brain insulin signaling that manifested as a change in tyrosine phosphorylated insulin receptor substrate 1 within neuronal extracellular vesicles at the end of 48 weeks of exenatide treatment. Additional outcome measures were changes in other insulin receptor substrate proteins and effects on protein expression in the Akt and mitogen-activated protein kinase pathways. RESULTS Sixty patients (mean [SD] age, 59.9 [8.4] years; 43 [72%] male) participated in the study: 31 in the exenatide group and 29 in the placebo group (data from 1 patient in the exenatide group were excluded). Patients treated with exenatide had augmented tyrosine phosphorylation of insulin receptor substrate tat 48 weeks (0.27 absorbance units [AU]; 95% CI, 0.09-0.44 AU; P = .003) and 60 weeks (0.23 AU; 95% CI, 0.05-0.41AU; P = .01) compared with patients receiving placebo. Exenatide-treated patients had elevated expression of downstream substrates, including total Akt (0.35 U/mL; 95% CI, 0.16-0.53 U/mL; P < .001) and phosphorylated mechanistic target of rapamycin (mTOR) (0.22 AU; 95% CI, 0.04-0.40 AU; P = .02). Improvements in Movement Disorders Society Unified Parkinson's Disease Rating Scale part 3 off-medication scores were associated with levels of total mTOR (F-4.50 = 5.343, P = .001) and phosphorylated mTOR (F-4.50 = 4.384, P = .04). CONCLUSIONS AND RELEVANCE The results of this study are consistent with target engagement of brain insulin, Akt, and mTOR signaling pathways by exenatide and provide a mechanistic context for the clinical findings of the Exenatide-PD trial. This study suggests the potential of using exosome-based biomarkers as objective measures of target engagement in clinical trials using drugs that target neuronal pathways.

IMPORTANCE:Blood biomarkers able to diagnose Alzheimer disease (AD) at the preclinical stage would enable trial enrollment when the disease is potentially reversible. Plasma neuronal-enriched extracellular vesicles (nEVs) of patients with AD were reported to exhibit elevated levels of phosphorylated (p) tau, Aβ42, and phosphorylated insulin receptor substrate 1 (IRS-1). OBJECTIVE:To validate nEV biomarkers as AD predictors. DESIGN, SETTING, PARTICIPANTS:This case-control study included longitudinal plasma samples from cognitively normal participants in the Baltimore Longitudinal Study of Aging (BLSA) cohort who developed AD up to January 2015 and age- and sex-matched controls who remained cognitively normal over a similar length of follow-up. Repeated samples were blindly analyzed over 1 year from participants with clinical AD and controls from the Johns Hopkins Alzheimer Disease Research Center (JHADRC). Data were collected from September 2016 to January 2018. Analyses were conducted in March 2019. MAIN OUTCOMES AND MEASURES:Neuronal-enriched extracellular vesicles were immunoprecipitated; tau, Aβ42, and IRS-1 biomarkers were quantified by immunoassays; and nEV concentration and diameter were determined by nanoparticle tracking analysis. Levels and longitudinal trajectories of nEV biomarkers between participants with future AD and control participants were compared. RESULTS:Overall, 887 longitudinal plasma samples from 128 BLSA participants who eventually developed AD and 222 age and sex-matched controls who remained cognitively normal were analyzed. Participants were followed up (from earliest sample to AD symptom onset) for a mean (SD) of 3.5 (2.31) years (range, 0-9.73 years). Overall, 161 participants were included in the training set, and 80 were in the test set. Participants in the BLSA cohort with future AD (mean [SD] age, 79.09 [7.02] years; 68 women [53.13%]) had longitudinally higher p-tau181, p-tau231, pSer312-IRS-1, pY-IRS-1, and nEV diameter than controls (mean [SD] age, 76.2 [7.36] years; 110 women [50.45%]) but had similar Aβ42, total tau, TSG101, and nEV concentration. In the training BLSA set, a model combining preclinical longitudinal data achieved 89.6% area under curve (AUC), 81.8% sensitivity, and 85.8% specificity for predicting AD. The model was validated in the test BLSA set (80% AUC, 55.6% sensitivity, 88.7% specificity). Preclinical levels of nEV biomarkers were associated with cognitive performance. In addition, 128 repeated samples over 1 year from 64 JHADRC participants with clinical AD and controls were analyzed. In the JHADRC cohort (35 participants with AD: mean [SD] age, 74.03 [8.73] years; 18 women [51.43%] and 29 controls: mean [SD] age, 72.14 [7.86] years; 23 women [79.31%]), nEV biomarkers achieved discrimination with 98.9% AUC, 100% sensitivity, and 94.7% specificity in the training set and 76.7% AUC, 91.7% sensitivity, and 60% specificity in the test set. CONCLUSIONS AND RELEVANCE:We validated nEV biomarker candidates and further demonstrated that their preclinical longitudinal trajectories can predict AD diagnosis. These findings motivate further development of nEV biomarkers toward a clinical blood test for AD.

Neural cell adhesion molecule L1CAM may be used for enriching blood extracellular vesicles (EVs) for neuronal origin. We previously conducted case-control discovery studies showing that plasma neuronal origin-enriched EVs may provide diagnostic and predictive biomarkers for Alzheimer's disease (AD), including Aβ42, pTau181, and phospho-insulin receptor substrate-1 (pSer312-IRS-1 and p-panY-IRS-1). In the present validation study, we analyzed samples from the Baltimore Longitudinal Study of Aging (BLSA) to replicate findings in a much larger dataset and assess diagnostic performance of candidate biomarkers for clinical and preclinical AD. We studied 969 samples from 373 BLSA participants, 128 diagnosed with AD during a given visit and 245 age and sex-matched controls. We analyzed samples from the visit of AD diagnosis and 2 to 8 visits before. The average times between diagnosis and the two preceding visits were 2.3 and 4.5 years respectively. We isolated total plasma EVs using Exoquick®, followed by immunoabsorption with anti-L1CAM antibody to isolate EVs enriched for neuronal origin. All assays were conducted blindly, using electrochemiluminescence (Mesoscale Discovery) for total-tau, pTau181, pSer312-IRS-1, p-panY-IRS-1, TSG101 and Simoa platform (Quanterix) for Aβ42. EV concentration and size distribution were determined by Nanoparticle tracking analysis (NTA). Statistical analysis was based on mixed linear models including NTA parameters, age and sex. Stepwise logistic regression and Receiver Operating Characteristic analyses were used to determine the best model for diagnostic classification. AD patients compared to controls had higher pTau181 both at the earliest preclinical visit (p<0.0001) and at the time of diagnosis (p<0.0001)(Fig 1); higher p-panY-IRS-1 preclinically (p<0.05) and at the time of diagnosis (p<0.05); higher pSer312 IRS-1 at the time of diagnosis (p<0.05); and lower Aβ42 both preclinically (p<0.05) and at the time of diagnosis (p<0.05). A combination of longitudinal changes of these proteins achieved a 0.863 area-under-curve (AUC) for AD diagnosis (Fig 2). P-Tau(Thr181) measured in L1CAM+ EVs isolated from plasma of AD patients and controls at the earliest preclinical visit and at AD onset. Receiver operating characteristic (ROC) curve showing biomarker diagnostic performance assessed by area under the curve (AUC) for a binary classifier (normal vs AD); internal cross-validation (CV) was done with leave-10-out. The results of this study validate previous findings and suggest that plasma neuronal EVs can be used to diagnose and predict AD 5 years prior to diagnosis outperforming previous blood-based biomarkers. This research was supported entirely by the Intramural research Program of the NIH, National institute on Aging.

Objective: Identify biomarkers in peripheral blood that relate to chronic post-concussive and behavioural symptoms following traumatic brain injuries (TBIs) to ultimately improve clinical management. Research design: We compared military personnel with mild TBIs (mTBIs) (n = 42) to those without TBIs (n = 22) in concentrations of tau, amyloid-beta (A beta 42) and cytokines (tumour necrosis factor alpha (TNF alpha, interleukin (IL)-6 and -10) in neuronal-derived exosomes from the peripheral blood. We utilized nanosight technology coupled with ultra-sensitivity immunoassay methods. We also examined the impact of post-concussive and behavioural symptoms including depression and post-traumatic stress disorder (PTSD) on these neuronal-derived markers. Results: We report that concentrations of exosomal tau (F-1,F- (62) = 10.50), A beta 42 (F-1,F- (61) = 5.32) and IL-10 (F-1,F-59 = 4.32) were elevated in the mTBI group compared to the controls. Within the mTBI group, regression models show that post-concussive symptoms were most related to exosomal tau elevations, whereas exosomal IL-10 levels were related to PTSD symptoms. Conclusions: These findings suggest that chronic post-concussive symptoms following an mTBI relate to altered exosomal activity, and that greater tau pathology may underlie chronic post-concussive symptoms that develop following mTBIs. It also suggests that central inflammatory activity contributes to PTSD symptoms following an mTBI, providing necessary insights into the role of inflammation in chronic PTSD symptoms.

April 25, 2018April 10, 2018Free AccessExenatide Modulates Neuronal Insulin Signalling in Parkinson’s Disease (S27.002)Dilan Athauda, Seema Gulyani, Hanuma Karnati, Yazhou Li, David Tweedie, Simon Skene, Kashfia Chowdhury, Nigel Greig, Dimitrios Kapogiannis, and Thomas FoltynieAuthors Info & AffiliationsApril 10, 2018 issue90 (15_supplement)https://doi.org/10.1212/WNL.90.15_supplement.S27.002 Letters to the Editor

Dopaminergic drugs have been used as the first-line treatment for restless legs syndrome (RLS) for many years and are considered to be, at least over the short-term, effective and safe. However, the main long-term complication of dopaminergic treatment is augmentation, which is an overall increase in symptom severity and intensity, with symptoms starting earlier in the afternoon and expanding to previously unaffected parts of the body. Augmentation is a common complication, with prevalence rates of nearly 50%, and is a common cause of treatment failure. Furthermore, augmentation occurs almost exclusively during treatment with dopaminergic drugs. Due to its frequency, there is a strong clinical need for treatment alternatives to dopaminergic drugs. Moreover, recent treatment guidelines recommend that treatment be initiated, whenever possible, with non-dopaminergic drugs (ie, α2δ ligands). Alternative treatments such as intravenous iron preparations directly address iron deficiency, as well as the consequences of iron deficiency in regard to glutamate and adenosine. This article also reviews current knowledge supporting an involvement of glutamatergic and adenosinergic neurotransmission in the pathophysiology of RLS, and explores the potential development of drugs acting on both systems.

See Stayte and Vissel (doi:10.1093/awx064) for a scientific commentary on this article. Multiple system atrophy is a fatal sporadic adult-onset neurodegenerative disorder with no symptomatic or disease-modifying treatment available. The cytopathological hallmark of multiple system atrophy is the accumulation of α-synuclein aggregates in oligodendrocytes, forming glial cytoplasmic inclusions. Impaired insulin/insulin-like growth factor-1 signalling (IGF-1) and insulin resistance (i.e. decreased insulin/IGF-1) have been reported in other neurodegenerative disorders such as Alzheimer's disease. Increasing evidence also suggests impaired insulin/IGF-1 signalling in multiple system atrophy, as corroborated by increased insulin and IGF-1 plasma concentrations in multiple system atrophy patients and reduced IGF-1 brain levels in a transgenic mouse model of multiple system atrophy. We here tested the hypothesis that multiple system atrophy is associated with brain insulin resistance and showed increased expression of the key downstream messenger insulin receptor substrate-1 phosphorylated at serine residue 312 in neurons and oligodendrocytes in the putamen of patients with multiple system atrophy. Furthermore, the expression of insulin receptor substrate 1 (IRS-1) phosphorylated at serine residue 312 was more apparent in inclusion bearing oligodendrocytes in the putamen. By contrast, it was not different between both groups in the temporal cortex, a less vulnerable structure compared to the putamen. These findings suggest that insulin resistance may occur in multiple system atrophy in regions where the neurodegenerative process is most severe and point to a possible relation between α-synuclein aggregates and insulin resistance. We also observed insulin resistance in the striatum of transgenic multiple system atrophy mice and further demonstrate that the glucagon-like peptide-1 analogue exendin-4, a well-tolerated and Federal Drug Agency-approved antidiabetic drug, has positive effects on insulin resistance and monomeric α-synuclein load in the striatum, as well as survival of nigral dopamine neurons. Additionally, plasma levels of exosomal neural-derived IRS-1 phosphorylated at serine residue 307 (corresponding to serine residue 312 in humans) negatively correlated with survival of nigral dopamine neurons in multiple system atrophy mice treated with exendin-4. This finding suggests the potential for developing this peripheral biomarker candidate as an objective outcome measure of target engagement for clinical trials with glucagon-like peptide-1 analogues in multiple system atrophy. In conclusion, our observation of brain insulin resistance in multiple system atrophy patients and transgenic mice together with the beneficial effects of the glucagon-like peptide-1 agonist exendin-4 in transgenic mice paves the way for translating this innovative treatment into a clinical trial.

Dopaminergic drugs have been used as the first-line treatment for restless legs syndrome (RLS) for many years and are considered to be, at least over the short-term, effective and safe. However, the main long-term complication of dopaminergic treatment is augmentation, which is an overall increase in symptom severity and intensity, with symptoms starting earlier in the afternoon and expanding to previously unaffected parts of the body. Augmentation is a common complication, with prevalence rates of nearly 50%, and is a common cause of treatment failure. Furthermore, augmentation occurs almost exclusively during treatment with dopaminergic drugs. Due to its frequency, there is a strong clinical need for treatment alternatives to dopaminergic drugs. Moreover, recent treatment guidelines recommend that treatment be initiated, whenever possible, with non-dopaminergic drugs (ie, α2δ ligands). Alternative treatments such as intravenous iron preparations directly address iron deficiency, as well as the consequences of iron deficiency in regard to glutamate and adenosine. This article also reviews current knowledge supporting an involvement of glutamatergic and adenosinergic neurotransmission in the pathophysiology of RLS, and explores the potential development of drugs acting on both systems.

Deficits of sensorimotor integration with periodic limb movements during sleep (PLMS) and hyperarousal and sleep disturbances in Restless Legs Syndrome (RLS) constitute two pathophysiologically distinct but interrelated clinical phenomena, which seem to depend mostly on alterations in dopaminergic and glutamatergic neurotransmission, respectively. Brain iron deficiency is considered as a main pathogenetic mechanism in RLS. Rodents with brain iron deficiency represent a valuable pathophysiological model of RLS, although they do not display motor disturbances. Nevertheless, they develop the main neurochemical dopaminergic changes found in RLS, such as decrease in striatal dopamine D2 receptor density. On the other hand, brain iron deficient mice exhibit the characteristic pattern of hyperarousal in RLS, providing a tool to find the link between brain iron deficiency and sleep disturbances in RLS. The present study provides evidence for a role of the endogenous sleep-promoting factor adenosine. Three different experimental preparations, long-term (22 weeks) severe or moderate iron-deficient (ID) diets (3- or 7-ppm iron diet) in mice and short-term (3 weeks) severe ID diet (3-ppm iron diet) in rats, demonstrated a significant downregulation (Western blotting in mouse and radioligand binding saturation experiments in rat brain tissue) of adenosine A1 receptors (A1R) in the cortex and striatum, concomitant to striatal D2R downregulation. On the other hand, the previously reported upregulation of adenosine A2A receptors (A2AR) was only observed with severe ID in both mice and rats. The results suggest a key role for A1R downregulation in the PLMS and hyperarousal in RLS.

Parkinson's disease is a multi-systems neurodegenerative disorder that is characterized by a combination of motor and non-motor symptoms. Non-motor symptoms of Parkinson's disease comprise a variety of cognitive, neuropsychiatric, autonomic, sensory, and sleep complaints. Although sleep disruption represents one of the most common non-motor symptom complaints among Parkinson's disease patients, recommendations regarding effective evaluation and management strategies for this specific population remain limited. This review gives an evidence based summary of the available treatment options and management strategies for the sleep complaints commonly encountered by patients with Parkinson's disease.

Objective: Over 40-million Americans are undiagnosed, misdiagnosed, or untreated for sleep disorders. Despite the growing need to integrate sleep medicine knowledge into the medical education curriculum, educational leaders have struggled to incorporate contemporary medical topics such as sleep medicine into the already packed curricula. We set out to examine the efficacy of an online, self-paced, sleep medicine learning module as an educational tool for medical students.Methods: We studied 87 Johns Hopkins medical students. Participants were randomly assigned to the sham module (SM, n = 40) or learning module (LM, n = 47). The efficacy of the tool was assessed based on changes in performance (pre- and post-module completion) on a validated sleep knowledge questionnaire (the Dartmouth Sleep Knowledge and Attitude Survey).Results: Improvement in overall sleep knowledge, as measured by the Dartmouth Sleep Knowledge and Attitude Survey, was significantly higher in the LM group compared to the SM group (F(1,84) = 9.71, p < .01, eta(2) = 0.10). Although the SM group's improvement was significantly lower than the LM group, within-subject comparisons did show improvement from their pre- to post-assessment scores as well.Conclusion: A self-paced learning module is an effective educational tool for delivering sleep medicine knowledge to medical students. (C) 2012 Elsevier B. V. All rights reserved.