The effects of rasagiline on cognitive deficits in Parkinson's disease patients without dementia: a randomized, double-blind, placebo-controlled, multicenter study

Real-World Data-Derived Pharmacovigilance on Drug-Induced Cognitive Impairment Utilizing a Nationwide Spontaneous Adverse Reporting System

Background and Objectives: Despite high incidences of cognitive impairment with aging, evidence on the prevalence and the seriousness of drug-induced cognitive impairment is limited. This study aims to evaluate the prevalence and the severity of drug-induced cognitive impairment and to investigate the clinical predictors of increased hospitalization risk from serious drug-induced cognitive impairment. Materials and Methods: Adverse drug events (ADEs) regarding drug-induced cognitive impairment reported to the Korean Adverse Event Reporting System Database (KAERS DB) from January 2012 to December 2021 were included (KIDS KAERS DB 2212A0073). The association between the etiologic classes and the reporting serious adverse events (SAEs) was evaluated using disproportionality analysis, and the effect was estimated with reporting odds ratio (ROR). Clinical predictors associated with increased risk of hospitalization from SAEs were identified via multivariate logistic analysis, and the effect was estimated with odds ratio (OR). Results: The most etiologic medication class for drug-induced cognitive impairment ADEs was analgesics, followed by sedative-hypnotics. Anticancer (ROR 57.105, 95% CI 15.174-214.909) and anti-Parkinson agents (ROR 4.057, 95% CI 1.121-14.688) were more likely to report serious drug-induced cognitive impairments. Male sex (OR 19.540, 95% CI 2.440-156.647) and cancer diagnosis (OR 18.115, 95% CI 3.246-101.101) are the major clinical predictors for increased risk of hospitalizations due to serious drug-induced cognitive impairment. Conclusions: This study highlights the significant prevalence and severity of drug-induced cognitive impairment with cancer diagnosis and anticancer agents. However, further large-scaled studies are required because of the potential underreporting of drug-induced cognitive impairments in real practice settings, which is further contributed to by the complexity of multiple contributing factors such as comorbidities.

A Systematic Review and Meta-Analysis of the Efficacy and Safety of Rasagiline or Pramipexole in the Treatment of Early Parkinson's Disease

Background

Rasagiline or pramipexole monotherapy has been suggested for the management of early Parkinson's disease (PD). The aim of this research was to systematically review the clinical efficacy and safety of rasagiline or pramipexole in early PD (defined as disease duration ≤5 years and Hoehn and Yahr stage of ≤3).

Methods

Randomized controlled trials (RCTs) of rasagiline or pramipexole for early PD published up to September 2021 were retrieved. Outcomes of interest included changes in the Unified Parkinson's Disease Rating Scale (UPDRS) Parts II and III and the incidence of adverse events. Standardized mean difference (SMD), odds ratio (OR), and 95% confidence interval (CI) were calculated, and heterogeneity was measured with the I2 test.

Results

Nine rasagiline and eleven pramipexole RCTs were included. One post hoc analysis of one rasagiline study was included. Five studies for each drug were included in meta-analyses of the UPDRS scores. The rasagiline meta-analysis focused on patients receiving 1 mg/day. Rasagiline and pramipexole significantly improved UPDRS Part II and III scores when compared to placebo. Significant heterogeneity among the studies was present (I2 > 70%). Neither rasagiline nor pramipexole increased the relative risk for any adverse events, serious adverse events, or adverse events leading to withdrawal when compared with placebo.

Conclusion

Applying a Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach to summarize the evidence, we found moderate confidence in the body of evidence for the efficacy of rasagiline or pramipexole in early PD, suggesting further well-designed, multicenter comparative RCTs remain needed.

Cognitive Impairment in Parkinson's Disease: An Updated Overview Focusing on Emerging Pharmaceutical Treatment Approaches

Cognitive impairment in patients with Parkinson's disease (PD) is one of the commonest and most disabling non-motor manifestations during the course of the disease. The clinical spectrum of PD-related cognitive impairment includes subjective cognitive decline (SCD), mild cognitive impairment (MCI) and PD dementia (PDD). As the disease progresses, cognitive decline creates a significant burden for the family members and/or caregivers of patients with PD, and has a great impact on quality of life. Current pharmacological treatments have demonstrated partial efficacy and failed to halt disease progression, and novel, effective, and safe therapeutic strategies are required. Accumulating preclinical and clinical evidence shows that several agents may provide beneficial effects on patients with PD and cognitive impairment, including ceftriaxone, ambroxol, intranasal insulin, nilotinib, atomoxetine, mevidalen, blarcamesine, prasinezumab, SYN120, ENT-01, NYX-458, GRF6021, fosgonimeton, INT-777, Neuropeptide S, silibinin, osmotin, cordycepin, huperzine A, fibroblast growth factor 21, Poloxamer 188, ginsenoside Rb1, thioredoxin-1, tangeretin, istradefylline and Eugenia uniflora. Potential underlying mechanisms include the inhibition of a-synuclein aggregation, the improvement of mitochondrial function, the regulation of synaptic plasticity, an impact on the gut-brain axis, the modulation of neuroinflammation and the upregulation of neurotrophic factors, as well as cholinergic, dopaminergic, serotoninergic and norepinephrine neurotransmission. In this updated overview, we aim to cover the clinical aspects of the spectrum of PD-related cognitive impairment and discuss recent evidence on emerging treatment approaches that are under investigation at a preclinical and clinical level. Finally, we aim to provide additional insights and propose new ideas for investigation that may be feasible and effective for the spectrum of PD-related cognitive impairment.

Parkinson's disease updates: Addressing the pathophysiology, risk factors, genetics, diagnosis, along with the medical and surgical treatment

After only Alzheimer's disease (AD), Parkinson's disease (PD) is the second most prevalent neurodegenerative disease. The incidence of this disease increases with age, especially for those above 70 years old. There are many risk factors that are well-established in the contribution to the development of PD, such as age, gender, ethnicity, rapid eye movement sleep disorder, high consumption of dairy products, traumatic brain injury, genetics, and pesticides/herbicides. Interestingly, smoking, consumption of caffeine, and physical activities are the protective factors of PD. A deficiency of dopamine in the substantia nigra of the brainstem is the main pathology. This, subsequently, alters the neurotransmitter, causing an imbalance between excitatory and inhibitory signals. In addition, genetics is also involved in the pathogenesis of the disease. As a result, patients exhibit characteristic motor symptoms such as tremors, stiffness, bradykinesia, and postural instability, along with non-motor symptoms, including dementia, urinary incontinence, sleeping disturbances, and orthostatic hypotension. PD may resemble other diseases; therefore, it is important to pay attention to the diagnosis criteria. Parkinson's disease dementia can share common features with AD; this can include behavioral as well as psychiatric symptoms, in addition to the pathology being protein aggregate accumulation in the brain. For PD management, the administration of pharmacological treatment depends on the motor symptoms experienced by the patients. Non-pharmacological treatment plays a role as adjuvant therapy, while surgical management is indicated in chronic cases. This paper aims to review the etiology, risk factors, protective factors, pathophysiology, signs and symptoms, associated conditions, and management of PD.

Smaller and Denser Speech Graphs in Nondemented Patients with Progressive Supranuclear Palsy

The well-established semantic fluency test measures the ability to produce a sequence of spoken words from a particular category within a limited period of time. Like patients with Parkinson's disease (PD), patients with progressive supranuclear palsy (PSP) tend to produce fewer correct words than age-matched healthy adults. This study further examined the difference between patients with PSP and PD in their semantic fluency performance using a graph theory-based approach. Twenty-nine patients with PSP Richardson's syndrome (PSP-RS), thirty-eight patients with PD, and fifty-one healthy controls (HC) were recruited. All participants completed a standard semantic fluency test (animals). Their verbal responses were recorded, transcripted, and transformed into directed speech graphs. The speech graphs of the PSP-RS group showed higher density, shorter diameter, and shorter average shortest path than those of the PD and HC groups. It indicates that the PSP-RS group produced smaller and denser speech graphs than the PD and HC groups. In the PSP-RS group, moreover, the average shortest paths of the speech graphs correlated with the severity of motor symptoms. This study shows the potential of the graph theory-based approach in distinguishing the semantic fluency performance of nondemented patients with PSP-RS and PD.

Clinical benefit of MAO-B and COMT inhibition in Parkinson's disease: practical considerations

Inhibitors of monoamine oxidase B (MAO-B) and catechol-O-methyltransferase (COMT) are major strategies to reduce levodopa degradation and thus to increase and prolong its effect in striatal dopaminergic neurotransmission in Parkinson's disease patients. While selegiline/rasagiline and tolcapone/entacapone have been available on the market for more than one decade, safinamide and opicapone have been approved in 2015 and 2016, respectively. Meanwhile, comprehensive data from several post-authorization studies have described the use and specific characteristics of the individual substances in clinical practice under real-life conditions. Here, we summarize current knowledge on both medication classes, with a focus on the added clinical value in Parkinson's disease. Furthermore, we outline practical considerations in the treatment of motor fluctuations and provide an outlook on ongoing studies with MAO-B and COMT inhibitors.

Comparative efficacy and safety of monoamine oxidase type B inhibitors plus channel blockers and monoamine oxidase type B inhibitors as adjuvant therapy to levodopa in the treatment of Parkinson's disease: a network meta-analysis of randomized controlled trials

BACKGROUND AND PURPOSE

The monoamine oxidase type B inhibitors plus channel blockers (MAO-BIs plus) are a new class of antiparkinsonian drug with additional mechanisms of action for their property as ion channel blockers. The present study aimed to compare the efficacy and safety of MAO-BIs plus and conventional MAO-BIs, as well as their corresponding doses, as adjuvant therapy to levodopa in the treatment of Parkinson's disease (PD).

METHOD

Randomized controlled trials enrolling PD patients treated with selegiline, rasagiline, safinamide or zonisamide as adjuvant therapy to levodopa were identified. Bayesian network meta-analysis was conducted.

RESULTS

Thirty-one randomized controlled trials comprising 7142 PD patients were included. Compared with levodopa monotherapy, the combination therapy of MAO-BIs and levodopa was significantly more effective, with a mean difference of 2.74 (1.26-4.18) on the Unified Parkinson's Disease Rating Scale (UPDRS) III score change for selegiline, 2.67 (1.45-3.87) for safinamide, 2.2 (0.98-3.64) for zonisamide and 2.04 (1.24-2.87) for rasagiline. No significant difference was detected amongst MAO-BIs. The surface under the cumulative ranking results showed that safinamide 100 mg and rasagiline 1 mg ranked first in improving UPDRS III and UPDRS II, respectively. Zonisamide 100 mg ranked first in reducing OFF time. For safety outcomes, rasagiline was associated with a higher incidence of adverse events than placebo and safinamide. MAO-BIs plus had a higher probability of being safer agents compared to conventional MAO-BIs.

CONCLUSIONS

Monoamine oxidase type B inhibitors plus, conventional MAO-BIs and the corresponding doses are similar in efficacy in PD treatment. MAO-BIs plus might be safer than conventional MAO-BIs. Head-to-head comparisons are needed for further investigation.

Monoamine-oxidase Type B Inhibitors and Cognitive Functions in Parkinson's Disease: Beyond the Primary Mechanism of Action

Symptoms of cognitive impairment are rather common since the early stage of Parkinson's disease (PD); they aggravate with disease progression and may lead to dementia in a significant proportion of cases. Worsening of cognitive symptoms in PD patients depends on the progression of subcortical dopaminergic damage as well as the involvement of other brain neurotransmitter systems in cortical and subcortical regions. Beyond the negative impact on disability and quality of life, the presence and severity of cognitive symptoms may limit adjustments of dopamine replacement therapy along the disease course. This review focuses on the consequences of the administration of monoamine-oxidase type Binhibitors (MAOB-I) on cognition in PD patients. Two drugs (selegiline and rasagiline) are available for the treatment of motor symptoms of PD as monotherapy or in combination with L-DOPA or dopamine agonists in stable and fluctuating patients; a further drug (safinamide) is usable in fluctuating subjects solely. The results of available studies indicate differential effects according to disease stage and drug features. In early, non-fluctuating patients, selegiline and rasagiline ameliorated prefrontal executive functions, similarly to other dopaminergic drugs. Benefit on some executive functions was maintained in more advanced, fluctuating patients, despite the tendency of worsening prefrontal inhibitory control activity. Interestingly, high-dose safinamide improved inhibitory control in fluctuating patients. The benefit of high-dose safinamide on prefrontal inhibitory control mechanisms may stem from its dual mechanism of action, allowing reduction of excessive glutamatergic transmission, in turn secondary to increased cortical dopaminergic input.

RENEWAL: REpurposing study to find NEW compounds with Activity for Lewy body dementia-an international Delphi consensus

Drug repositioning and repurposing has proved useful in identifying new treatments for many diseases, which can then rapidly be brought into clinical practice. Currently, there are few effective pharmacological treatments for Lewy body dementia (which includes both dementia with Lewy bodies and Parkinson's disease dementia) apart from cholinesterase inhibitors. We reviewed several promising compounds that might potentially be disease-modifying agents for Lewy body dementia and then undertook an International Delphi consensus study to prioritise compounds. We identified ambroxol as the top ranked agent for repurposing and identified a further six agents from the classes of tyrosine kinase inhibitors, GLP-1 receptor agonists, and angiotensin receptor blockers that were rated by the majority of our expert panel as justifying a clinical trial. It would now be timely to take forward all these compounds to Phase II or III clinical trials in Lewy body dementia.

Effects of Anti-Parkinsonian Drugs on Verbal Fluency in Patients with Parkinson's Disease: A Network Meta-Analysis

Verbal fluency impairment is common in patients with Parkinson's disease (PD), but the effect of drugs on verbal fluency in PD patients has not been comprehensively evaluated. We conducted a network meta-analysis based on four online databases to compare the effect of drugs on verbal fluency in PD patients. This study was performed and reported according to PRISMA-NMA guidelines. In total, 6 out of 3707 articles (three RCTS and three cross-sectional studies) covering eight drug regimens were included (five for letter fluency, five for semantic fluency). In terms of letter fluency, the ranking of the overall efficacy of included drug regimens was: levodopa, levodopa combined with pramipexole, rotigotine, cabergoline, pramipexole, pergolide, but no drug regimen presented a significant advantage over the others. In terms of semantic fluency, the ranking of the overall efficacy of included drug regimens was: rotigotine, levodopa, cabergoline, pergolide, pramipexole, among which, levodopa alone (SMD = 0.93, 95%CI: 0.28-1.59) and rotigotine alone (SMD = 1.18, 95%CI: 0.28-2.09) were statistically superior to pramipexole, while no significant difference was identified between all the other drug regimens. Levodopa and rotigotine seem to be more appropriate choices for PD patients with verbal fluency impairment. Further study is needed to illustrate the efficacy of drugs on verbal fluency in PD patients.

MAO-B Polymorphism Associated with Progression in a Chinese Parkinson’s Disease Cohort but Not in the PPMI Cohort

Introduction

Genetic factors play an important role in Parkinson's disease (PD) risk. However, the genetic contribution to progression in Chinese PD patients has rarely been studied. This study investigated genetic associations with progression based on 30 PD risk loci common in a longitudinal cohort of Chinese PD patients and the Parkinson's Progression Markers Initiative (PPMI) cohort.

Methods

PD patients from the true world (TW) Chinese PD longitudinal cohort and the PPMI cohort with demographic information and assessment scales were assessed. A panel containing 30 PD risk single nucleotide polymorphisms was tested. Progression rates of each scale were derived from random-effect slope values of mixed-effects regression models. Progression rates of multiple assessments were combined by using principal component analysis (PCA) to derive scores for composite, motor, and nonmotor progression. The association of genetic polymorphism and separate scales or PCA progression was analysed via linear regression.

Results

In the Chinese PD cohort, MAOB rs1799836 was associated with progression based on the Montreal Cognitive Assessment, the top 3 principal components (PCs) of nonmotor PCA and PC1 of the composite PCA. In the PPMI cohort, both MDS-Unified Parkinson's Disease Rating Scale II and motor PC1 progression were associated with RIT2 rs12456492. The PARK16 haplotype was associated with Geriatric Depression Scale and the State-Trait Anxiety Inventory for Adults progression, and the SNCA haplotype was associated with the Hoehn-Yahr staging progression and motor PC1 progression. Ethnicity-stratified analysis showed that the association between MAOB rs1799836 and PD progression may be specific to Asian or Chinese patients.

Conclusion

MAOB rs1799836 was associated with the progression of nonmotor symptoms, especially cognitive impairment, and the composite progression of motor and nonmotor symptoms within our Chinese PD cohort. The RIT2 rs12456492 and SNCA haplotypes were associated with motor function decline, and the PARK16 haplotype was associated with progression in mood in the PPMI cohort.

Degenerative dementias: A question of syndrome or disease?

BACKGROUND

Neurologists refer to numerous "syndromes,‿ consisting of specific combinations of clinical manifestations, following a specific progression pattern, and with the support of blood analysis (without genomic-proteomic parameters) and neuroimaging findings (MRI, CT, perfusion SPECT, or 18F-FDG-PET scans). Neurodegenerative "diseases,‿ on the other hand, are defined by specific combinations of clinical signs and histopathological findings; these must be confirmed by a clinical examination and a histology study or evidence of markers of a specific disorder for the diagnosis to be made. However, we currently know that most genetic and histopathological alterations can result in diverse syndromes. The genetic or histopathological aetiology of each syndrome is also heterogeneous, and we may encounter situations with pathophysiological alterations characterising more than one neurodegenerative disease. Sometimes, specific biomarkers are detected in the preclinical stage.

DEVELOPMENT

We performed a literature review to identify patients whose histopathological or genetic disorder was discordant with that expected for the clinical syndrome observed, as well as patients presenting multiple neurodegenerative diseases, confirming the heterogeneity and overlap between syndromes and diseases. We also observed that the treatments currently prescribed to patients with neurodegenerative diseases are symptomatic.

CONCLUSIONS

Our findings show that the search for disease biomarkers should be restricted to research centres, given the lack of disease-modifying drugs or treatments improving survival. Moreover, syndromes and specific molecular or histopathological alterations should be managed independently of one another, and new "diseases‿ should be defined and adapted to current knowledge and practice.

Effects of MAO-B inhibitors on non-motor symptoms and quality of life in Parkinson's disease: A systematic review

Non-motor symptoms (NMS) are common among patients with Parkinson's disease and reduce patients' quality of life (QOL). However, there remain considerable unmet needs for NMS management. Three monoamine oxidase B inhibitors (MAO-BIs), selegiline, rasagiline, and safinamide, have become commercially available in many countries. Although an increasing number of studies have reported potential beneficial effects of MAO-BIs on QOL and NMS, there has been no consensus. Thus, the primary objective of this study was to provide an up-to-date systematic review of the QOL and NMS outcomes from the available clinical studies of MAO-BIs. We conducted a literature search using the PubMed, Scopus, and Cochrane Library databases in November 2021. We identified 60 publications relevant to this topic. Overall, rasagiline and safinamide had more published evidence on QOL and NMS changes compared with selegiline. This was likely impacted by selegiline being introduced many years prior to the field embarking on the study of NMS. The impact of MAO-BIs on QOL was inconsistent across studies, and this was unlikely to be clinically meaningful. MAO-BIs may potentially improve depression, sleep disturbances, and pain. In contrast, cognitive and olfactory dysfunctions are likely unresponsive to MAO-BIs. Given the paucity of evidence and controlled, long-term studies, the effects of MAO-BIs on fatigue, autonomic dysfunctions, apathy, and ICD remain unclear. The effects of MAO-BIs on static and fluctuating NMS have never been investigated systematically. More high-quality studies will be needed and should enable clinicians to provide personalized medicine based on a non-motor symptom profile.

Efficacy of rasagiline monotherapy for early Parkinson disease: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Rasagiline monotherapy is approved in early Parkinson's disease (PD) for motor benefit. However, the efficacy and optimal rasagiline dosage in improving Unified Parkinson's Disease Rating Scale (UPDRS) subscale scores between Japanese and Caucasian individuals remain uncertain.

AIMS

To investigate the efficacy of rasagiline monotherapy and evaluate differences between early PD patients in Eastern and Western countries.

METHODS

The study design involved the meta-analysis of randomized controlled trials identified using electronic databases.

RESULTS

The mean difference (MD) in total UPDRS scores indicated no significant difference between the 1 and 2 mg rasagiline (MD = -0.00, 95% confidence interval (CI) = -0.82 to 0.81). Compared with the placebo, the MD of UPDRS part I scores significantly improved in the 1 mg (MD = -0.33, 95% CI = -0.57 to -0.10) but not in the 2 mg. For UPDRS part II scores, the MD significantly improved in the 1 mg (MD = -0.87, 95% CI = -1.48 to -0.27) and 2 mg (MD = -0.98, 95% CI = -1.28 to -0.68). Regarding the UPDRS part III, the MD significantly improved in both (1 mg: MD = -2.41, 95% CI = -3.26 to -1.56; 2 mg: MD = -2.05, 95% CI = -2.64 to -1.46). The most commonly reported adverse events were headaches, back pain, and dizziness, with no statistical difference between the 1 mg rasagiline and placebo groups. Subgroup analysis revealed similar effects between Asian and Western participants.

CONCLUSION

Rasagiline monotherapy at 1 mg per day is recommended for patients with early PD because of the benefits for motor, nonmotor functions, and safety.

Graph Theoretical Analysis of Semantic Fluency in Patients with Parkinson’s Disease

Semantic fluency is the ability to name items from a given category within a limited time, which relies on semantic memory, working memory, and executive function. Semantic disfluency is a common problem in Parkinson's disease (PD) and Alzheimer's disease (AD). We demonstrated a graph theoretical analysis of semantic fluency in patients with PD (N = 86), patients with AD (N = 40), and healthy controls (HC, N = 88). All participants completed a standard animal fluency test. Their verbal responses were recorded, transcripted, and transformed into directed speech graphs. Patients with PD generated fewer correct words than HC and more correct words than patients with AD. Patients with PD showed higher density, shorter diameter, and shorter average shortest path length than HC, but lower density, longer diameter, and longer average shortest path length than patients with AD. It suggests that patients with PD produced relatively smaller and denser speech graphs. Moreover, in PD, the densities of speech graphs correlated with the severity of non-motor symptoms, but not the severity of motor symptoms. The graph theoretical analysis revealed new features of semantic disfluency in patients with PD.

Caring for patients with cognitive dysfunction, fluctuations and dementia caused by Parkinson's disease

Cognitive dysfunction is one of the most prevalent non-motor symptoms in patients with Parkinson's disease (PD). While it tends to worsen in the later stages of disease, it can occur at any time, with 15-20% of patients exhibiting cognitive deficits at diagnosis (Aarsland et al., 2010; Goldman and Sieg, 2020). The characteristic features of cognitive dysfunction include impairment in executive function, visuospatial abilities, and attention, which vary in severity from subtle impairment to overt dementia (Martinez-Horta and Kulisevsky, 2019). To complicate matters, cognitive dysfunction is prone to fluctuate in PD patients, impacting diagnosis and the ability to assess progression and decision-making capacity. The diagnosis of cognitive impairment or dementia has a huge impact on patient independence, quality of life, life expectancy and caregiver burden (Corallo et al., 2017; Lawson et al., 2016; Leroi et al., 2012). It is therefore essential that physicians caring for patients with PD provide education, screening and treatment for this aspect of the disease. In this chapter, we provide a practical guide for the assessment and management of various degrees of cognitive dysfunction in patients with PD by approaching the disease at different stages. We address risk factors for cognitive dysfunction, prevention strategies prior to making the diagnosis, available tools for screening. Lastly, we review aspects of care, management and considerations, including decision-making capacity, that occur after the patient has been diagnosed with cognitive dysfunction or dementia.

A critical appraisal of MAO-B inhibitors in the treatment of Parkinson's disease

Since the 1980s, the MAO-B inhibitors have gained considerable status in the therapy of the Parkinson's disease. In addition to the symptomatic effect in mono- and combination therapies, a neuroprotective effect has repeatedly been a matter of some discussion, which has unfortunately led to a good many misunderstandings. Due to potential interactions, selegiline has declined in significance in the field. For the MAO-B inhibitor safinamide, recently introduced to the market, an additional inhibition of pathological release of glutamate has been postulated. At present, rasagiline and selegiline are being administered in early therapy as well as in combination with levodopa. Safinamide has been approved only for combination therapy with levodopa when motor fluctuations have occurred. MAO-B inhibitors are a significant therapeutic option for Parkinson's disease, an option which is too often not appreciated properly.

Selenomethionine Ameliorates Cognitive Impairment, Decreases Hippocampal Oxidative Stress and Attenuates Dysbiosis in D-Galactose-Treated Mice

The prevalence of age-related cognitive impairment is increasing as the proportion of older individuals in the population grows. It is therefore necessary and urgent to find agents to prevent or ameliorate age-related cognitive impairment. Selenomethionine (SeMet) is a natural amino acid occurring in yeast and Brazil nuts. It mitigates cognitive impairment in an Alzheimer’s disease mouse model, however, whether it works on age-related cognitive impairment remains unknown. In this study, SeMet significantly improved the performance of D-galactose-treated mice in the novel object recognition test, passive avoidance task and Morris water maze test. SeMet reversed D-galactose-induced reduction of hippocampal acetylcholine levels, suppression of choline acetyltransferase activity and activation of acetyl cholinesterase. It decreased D-galactose-induced oxidative stress and increased the selenoprotein P levels in the hippocampus. Besides, it attenuated D-galactose-induced dysbiosis by increasing the α-diversity and modulating the taxonomic structure. Correlations between certain taxa and physiological parameters were observed. Our results provide evidence of the effectiveness of SeMet on ameliorating D-galactose-induced cognitive impairment and suggest SeMet has potential to be used in the prevention or adjuvant treatment of age-related cognitive impairment.

Parkinson disease-associated cognitive impairment

Parkinson disease (PD) is the second most common neurodegenerative disorder, affecting >1% of the population ≥65 years of age and with a prevalence set to double by 2030. In addition to the defining motor symptoms of PD, multiple non-motor symptoms occur; among them, cognitive impairment is common and can potentially occur at any disease stage. Cognitive decline is usually slow and insidious, but rapid in some cases. Recently, the focus has been on the early cognitive changes, where executive and visuospatial impairments are typical and can be accompanied by memory impairment, increasing the risk for early progression to dementia. Other risk factors for early progression to dementia include visual hallucinations, older age and biomarker changes such as cortical atrophy, as well as Alzheimer-type changes on functional imaging and in cerebrospinal fluid, and slowing and frequency variation on EEG. However, the mechanisms underlying cognitive decline in PD remain largely unclear. Cortical involvement of Lewy body and Alzheimer-type pathologies are key features, but multiple mechanisms are likely involved. Cholinesterase inhibition is the only high-level evidence-based treatment available, but other pharmacological and non-pharmacological strategies are being tested. Challenges include the identification of disease-modifying therapies as well as finding biomarkers to better predict cognitive decline and identify patients at high risk for early and rapid cognitive impairment.

Emulated Clinical Trials from Longitudinal Real-World Data Efficiently Identify Candidates for Neurological Disease Modification: Examples from Parkinson's Disease

Real-world healthcare data hold the potential to identify therapeutic solutions for progressive diseases by efficiently pinpointing safe and efficacious repurposing drug candidates. This approach circumvents key early clinical development challenges, particularly relevant for neurological diseases, concordant with the vision of the 21st Century Cures Act. However, to-date, these data have been utilized mainly for confirmatory purposes rather than as drug discovery engines. Here, we demonstrate the usefulness of real-world data in identifying drug repurposing candidates for disease-modifying effects, specifically candidate marketed drugs that exhibit beneficial effects on Parkinson's disease (PD) progression. We performed an observational study in cohorts of ascertained PD patients extracted from two large medical databases, Explorys SuperMart (N = 88,867) and IBM MarketScan Research Databases (N = 106,395); and applied two conceptually different, well-established causal inference methods to estimate the effect of hundreds of drugs on delaying dementia onset as a proxy for slowing PD progression. Using this approach, we identified two drugs that manifested significant beneficial effects on PD progression in both datasets: rasagiline, narrowly indicated for PD motor symptoms; and zolpidem, a psycholeptic. Each confers its effects through distinct mechanisms, which we explored via a comparison of estimated effects within the drug classification ontology. We conclude that analysis of observational healthcare data, emulating otherwise costly, large, and lengthy clinical trials, can highlight promising repurposing candidates, to be validated in prospective registration trials, beneficial against common, late-onset progressive diseases for which disease-modifying therapeutic solutions are scarce.

Treatment of Parkinson's Disease with Cognitive Impairment: Current Approaches and Future Directions

Cognitive impairment risk in Parkinson's disease increases with disease progression and poses a significant burden to the patients, their families and society. There are no disease-modifying therapies or preventative measures for Parkinson's disease mild cognitive impairment (PD-MCI), or Parkinson's disease dementia (PDD). This article reviews current and previously investigated treatments and those under investigation, including pharmacologic, non-pharmacologic and surgical procedures. There are currently no effective pharmacologic or non-pharmacologic treatments for PD-MCI. The only recommended treatment for PDD currently is rivastigmine, a cholinesterase inhibitor. Donepezil and galantamine-other cholinesterase inhibitors-are possibly useful. Memantine, a N-methyl-D-aspartate (NMDA) receptor antagonist, is considered investigational in PDD. Drug repurposing (atomoxetine, levodopa, insulin, atomoxetine for PD-MCI; ambroxol and ceftriaxone for PDD) and novel medications (SYN120, GRF6021, NYX-458 for PD-MCI; ANAVEX2-73, LY3154207, ENT-01, DAAOI-P for PDD) currently have insufficient evidence. There is growing research supporting exercise in the treatment of PD-MCI, but most non-pharmacological approaches have insufficient evidence for use in PD-MCI (cognitive rehabilitation, deep brain stimulation, transcranial direct current stimulation, transcranial ultrasound, vestibular nerve stimulation) and PDD (cognitive intervention, deep brain stimulation, transcranial alternating current stimulation, transcranial ultrasound, temporal blood brain barrier disruption). Research is needed for both disease-modifying and symptomatic treatments in PD cognitive impairment.

Rasagiline effects on glucose metabolism, cognition, and tau in Alzheimer's dementia

BACKGROUND

A Phase II proof of concept (POC) randomized clinical trial was conducted to evaluate the effects of rasagiline, a monoamine oxidase B (MAO-B) inhibitor approved for Parkinson disease, in mild to moderate Alzheimer's disease (AD). The primary objective was to determine if 1 mg of rasagiline daily for 24 weeks is associated with improved regional brain metabolism (fluorodeoxyglucose-positron emission tomography [FDG-PET]) compared to placebo. Secondary objectives included measurement of effects on tau PET and evaluation of directional consistency of clinical end points.

METHODS

This was a double-blind, parallel group, placebo-controlled, community-based, three-site trial of 50 participants randomized 1:1 to receive oral rasagiline or placebo (NCT02359552). FDG-PET was analyzed for the presence of an AD-like pattern as an inclusion criterion and as a longitudinal outcome using prespecified regions of interest and voxel-based analyses. Tau PET was evaluated at baseline and longitudinally. Clinical outcomes were analyzed using an intention-to-treat (ITT) model.

RESULTS

Fifty patients were randomized and 43 completed treatment. The study met its primary end point, demonstrating favorable change in FDG-PET differences in rasagiline versus placebo in middle frontal (P < 0.025), anterior cingulate (P < 0.041), and striatal (P < 0.023) regions. Clinical measures showed benefit in quality of life (P < 0.04). Digit Span, verbal fluency, and Neuropsychiatric Inventory (NPI) showed non-significant directional favoring of rasagiline; no effects were observed in Alzheimer's Disease Assessment Scale-Cognitive Subscale (ADAS-cog) or activities of daily living. Rasagiline was generally well tolerated with low rates of adverse events and notably fewer neuropsychiatric symptoms in the active treatment group.

DISCUSSION

These outcomes illustrate the potential benefits of rasagiline on clinical and neuroimaging measures in patients with mild to moderate AD. Rasagiline appears to affect neuronal activity in frontostriatal pathways, with associated clinical benefit potential warranting a more fully powered trial. This study illustrated the potential benefit of therapeutic repurposing and an experimental medicine proof-of-concept design with biomarkers to characterize patient and detect treatment response.

Potential Sex-Specific Effects of Apolipoprotein E ɛ4 on Cognitive Decline in Early Parkinson's Disease

BACKGROUND/OBJECTIVE

To compare the longitudinal trajectories of cognition according to the presence of the apolipoprotein E (APOE) ɛ4 allele in male and female Parkinson's disease (PD) patients.

METHODS

This study included a total of 361 patients with recently diagnosed de novo PD (mean age [standard deviation], 61.4 [9.8] years). The patients were classified into the following groups: APOEɛ4 + /M (n = 65), APOEɛ4-/M (n = 173), APOEɛ4 + /F (n = 25), and APOEɛ4-/F (n = 98). Cognitive decline was assessed annually over 5 years of follow-up using the Montreal Cognitive Assessment (MoCA). To assess the sex-specific impacts of the APOEɛ4 status on cognitive decline, we used generalized linear mixed effects (GLME) models separately for men, women, and the two sexes combined.

RESULTS

In the sex-stratified GLME models adjusted for covariates, the interaction results showed that the males with APOEɛ4 had a steeper rate of cognitive decline than those without APOEɛ4. In contrast, there was no significant interaction between APOEɛ4 and time on longitudinal MoCA performance in the females. The main effect of APOEɛ4 on the change in the MoCA score was not significant for either men or women. When the data from both men and women were used, the APOEɛ4 + /M group exhibited a steeper rate of cognitive decline than did the APOEɛ4 + /F and APOEɛ4-/F groups. These results were consistent with those of sensitivity analyses.

CONCLUSION

Sex may be considered when APOEɛ4-related vulnerability to early cognitive decline is evaluated in PD patients.

Comparative effectiveness of dopamine agonists and monoamine oxidase type-B inhibitors for Parkinson's disease: a multiple treatment comparison meta-analysis

PURPOSE

To investigate the comparative effectiveness of dopamine agonists and monoamine oxidase type-B (MAO-B) inhibitors available for treatment of Parkinson's disease.

METHODS

We performed a systematic literature search identifying randomized controlled trials investigating 4 dopamine agonists (cabergoline, pramipexole, ropinirole, rotigotine) and 3 MAO-B inhibitors (selegiline, rasagiline, safinamide) for Parkinson's disease. We extracted and pooled data from included clinical trials in a joint model allowing both direct and indirect comparison of the seven drugs. We considered dopamine agonists and MAO-B inhibitors given as monotherapy or in combination with levodopa. Selected endpoints were change in the Unified Parkinson's Disease Rating Scale (UPDRS) score, serious adverse events and withdrawals. We estimated the relative effectiveness of each dopamine agonist and MAO-B inhibitor versus comparator drug.

RESULTS

Altogether, 79 publications were included in the analysis. We found all the investigated drugs to be effective compared with placebo when given as monotherapy except safinamide. When considering combination treatment, the estimated relative effects of selegiline, pramipexole, ropinirole, rotigotine, cabergoline, rasagiline and safinamide were 2.316 (1.819, 2.951), 2.091 (1.889, 2.317), 2.037 (1.804, 2.294), 1.912 (1.716, 2.129), 1.664 (1.113, 2.418), 1.584 (1.379, 1.820) and 1.179 (1.031, 1.352), respectively, compared with joint placebo and levodopa treatment.

CONCLUSIONS

Dopamine agonists were found to be effective as treatment for Parkinson's disease, both when given as monotherapy and in combination with levodopa. Selegiline and rasagiline were also found to be effective for treating Parkinson's disease, and selegiline was the best option in combination with levodopa among all the drugs investigated.

Approach to Cognitive Impairment in Parkinson's Disease

Cognitive dysfunction is common in Parkinson's disease (PD) and predicts poor clinical outcomes. It is associated primarily with pathologic involvement of basal forebrain cholinergic and prefrontal dopaminergic systems. Impairments in executive functions, attention, and visuospatial abilities are its hallmark features with eventual involvement of memory and other domains. Subtle symptoms in the premotor and early phases of PD progress to mild cognitive impairment (MCI) which may be present at the time of diagnosis. Eventually, a large majority of PD patients develop dementia with advancing age and longer disease duration, which is usually accompanied by immobility, hallucinations/psychosis, and dysautonomia. Dopaminergic medications and deep brain stimulation help motor dysfunction, but may have potential cognitive side effects. Central acetylcholinesterase inhibitors, and possibly memantine, provide modest and temporary symptomatic relief for dementia, although there is no evidence-based treatment for MCI. There is no proven disease-modifying treatment for cognitive impairment in PD. The symptomatic and disease-modifying role of physical exercise, cognitive training, and neuromodulation on cognitive impairment in PD is under investigation. Multidisciplinary approaches to cognitive impairment with effective treatment of comorbidities, proper rehabilitation, and maintenance of good support systems in addition to pharmaceutical treatment may improve the quality of life of the patients and caregivers.

Treatment of Parkinson's Disease by MAO-B Inhibitors, New Therapies and Future Challenges - A Mini-Review

BACKGROUND

One of the most prevalent neurodegenerative diseases with increasing age is Parkinson's disease (PD). Its pathogenesis is unclear and mainly confined to glutamate toxicity and oxidative stress. The dyskinesia and motor fluctuations and neuroprotective potential are the major concerns which are still unmet in PD therapy.

OBJECTIVE

This article is a capsulization of the role of MAO-B in the treatment of PD, pharmacological properties, safety and efficiency, clinical evidence through random trials, future therapies and challenges.

CONCLUSION

MAO-B inhibitors are well tolerated for the treatment of PD because of their pharmacokinetic properties and neuroprotective action. Rasagiline and selegiline were recommended molecules for early PD and proven safe and provide a modest to significant rise in motor function, delay the use of levodopa and used in early PD. Moreover, safinamide is antiglutamatergic in action. When added to Levodopa, these molecules significantly reduce the offtime with a considerable improvement of non-motor symptoms. This review also discusses the new approaches in therapy like the use of biomarkers, neurorestorative growth factors, gene therapy, neuroimaging, neural transplantation, and nanotechnology. Clinical evidence illustrated that MAOB inhibitors are recommended as monotherapy and added on therapy to levodopa. A large study and further evidence are required in the field of future therapies to unwind the complexity of the disease.

Features and psychometric properties of the Montreal Cognitive Assessment: Review and proposal of a process-based approach version (MoCA-PA)

The current study presents a rapid review of the psychometric features of the standard Montreal Cognitive Assessment (MoCA), and the proposal for a modified version of the test, informed by the methodology of the Boston Process Approach to neuropsychological assessment. In order to aid the process of identification of the primary underlying neurocognitive mechanism responsible for defective test performance, the MoCA-Process-Based Approach (MoCA-PA) adds complementary or satellite test conditions in some of its subtests, includes "new" qualitative indices to capture the cognitive processes involved in each cognitive task, and incorporates new qualitative classifications of error subtypes. It provides concurrent assessment of multiple cognitive processes within each task, without significantly increasing administration time or placing significant additional burden upon the respondent. We present preliminary results obtained from an initial sample of 45 community-dwelling older adults attending a University program for seniors. Results suggest the usefulness of additional indices in providing additional information on cognitive deterioration that may be overlooked with the only consideration of quantitative scores. Future research will aim to collect normative data for different clinical populations using the newly developed indices in order to determine the validity and clinical utility of the relatively novel qualitative process-based methods used in the MoCA-PA.

Rasagiline combined with levodopa therapy versus levodopa monotherapy for patients with Parkinson's disease: a systematic review

OBJECTIVE

The aim of this report was to systematically evaluate the efficacy and safety of rasagiline (R) plus levodopa (L) (R + L) for the treatment of Parkinson's disease (PD) compared with that of L monotherapy, in order to provide a reference resource for rational drug use.

METHODS

Randomized controlled trials (RCTs) of R + L for PD published up to September 2018 were searched. Sensitivity analyses were also performed.

RESULTS

Fourteen RCTs with 2531 participants were included. Compared with L monotherapy, the pooled effects of R + L combination therapy on unified Parkinson's disease rating scale (UPDRS) score were (SMD - 0.50, 95% CI - 0.70 to - 0.30, P < 0.00001) for UPDRS motor score, (SMD - 0.59, 95% CI - 0.79 to - 0.39, P < 0.00001) for UPDRS activities of daily living (ADL) score, (SMD - 0.65, 95% CI - 0.81 to - 0.49, P < 0.00001) for UPDRS total score. R + L combination therapy was better than L monotherapy in reducing daily off-time (SMD - 1.15, 95% CI - 2.13 to - 0.17, P = 0.02), but there was a statistically nonsignificant result in daily on-time increase (SMD 1.39, 95% CI - 0.69 to 3.48, P = 0.19). There were no statistical differences in number of adverse events (OR 1.33, 95% CI 0.97 to 1.82, P = 0.07) and number of dropout (OR 0.88, 95% CI 0.65 to 1.19, P = 0.39) between R + L combination therapy and L monotherapy.

CONCLUSIONS

R + L combination therapy was superior to L monotherapy for improvement of UPDRS scores and off-time in PD patients. Moreover, R + L combination therapy and L monotherapy were similar in terms of safety and tolerability.

A Stage-Based Approach to Therapy in Parkinson's Disease

Parkinson’s disease (PD) is a neurodegenerative disorder that features progressive, disabling motor symptoms, such as bradykinesia, rigidity, and resting tremor. Nevertheless, some non-motor symptoms, including depression, REM sleep behavior disorder, and olfactive impairment, are even earlier features of PD. At later stages, apathy, impulse control disorder, neuropsychiatric disturbances, and cognitive impairment can present, and they often become a heavy burden for both patients and caregivers. Indeed, PD increasingly compromises activities of daily life, even though a high variability in clinical presentation can be observed among people affected. Nowadays, symptomatic drugs and non-pharmaceutical treatments represent the best therapeutic options to improve quality of life in PD patients. The aim of the present review is to provide a practical, stage-based guide to pharmacological management of both motor and non-motor symptoms of PD. Furthermore, warning about drug side effects, contraindications, as well as dosage and methods of administration, are highlighted here, to help the physician in yielding the best therapeutic strategies for each symptom and condition in patients with PD.

Selegiline Recovers Synaptic Plasticity in the Medial Prefrontal Cortex and Improves Corresponding Depression-Like Behavior in a Mouse Model of Parkinson's Disease

In patients with Parkinson’s disease (PD), non-motor symptoms (NMS) including depression and anxiety are often recognized before motor symptoms develop. Monoamine oxidase (MAO)-B inhibitors are therapeutically effective for motor symptoms; however, their effects on NMS in PD are yet to be fully assessed. Here, we aimed to explore the antidepressant-like effects of propargyl MAO-B inhibitors, selegiline and rasagiline, in mice treated with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) as a PD model, and to elucidate the mechanisms underlying these effects. Four repeated intraperitoneal injections of MPTP at 17.5 mg/kg to C57BL/6 mice led to a partial reduction in the number of nigrostriatal tyrosine hydroxylase-positive neurons and to the extension of immobility time during the tail suspension test (TST), without any obvious induction of motor deficits. A single subcutaneous administration of selegiline at 10 mg/kg shortened the extended immobility time of MPTP mice in the TST, without any increase in motor activities, suggesting that selegiline exerts antidepressant-like effects. In this test, rasagiline did not produce antidepressant-like effects, although the inhibitory effect of 3 mg/kg rasagiline on brain MAO activity was comparable to that of 10 mg/kg selegiline. The shortened immobility time in the TST correlated with reduced cortical dopamine (DA) turnover rates in MPTP mice treated with selegiline, but not in MPTP mice treated with rasagiline. These results suggest that MAO inhibition does not entirely account for the antidepressant-like effects of selegiline. Administration of selegiline (10 mg/kg), but not rasagiline (1 mg/kg), to MPTP mice restored the impaired long-term potentiation induced by high-frequency stimulation in the medial prefrontal cortex (mPFC), and normalized the reduced phosphorylation of Ca²⁺/calmodulin-dependent protein kinase IIα, which is known to be involved in neuroplasticity, in the frontal cortex. In MPTP mice, the antiparkinsonian drug pramipexole (0.3 mg/kg), a DA D₂ and D₃ receptor agonist, that has been shown to be effective in treating depression in PD, ameliorated depression-like behavior and synaptic dysfunction in the mPFC. Taken together, the antidepressant-like effects of selegiline in MPTP mice are attributable to the restoration of impaired synaptic plasticity in the mPFC, suggesting its potential for treating depression in early PD.

Update on treatments for nonmotor symptoms of Parkinson's disease-an evidence-based medicine review

OBJECTIVE

To update evidence-based medicine recommendations for treating nonmotor symptoms in Parkinson's disease (PD).

BACKGROUND

The International Parkinson and Movement Disorder Society Evidence-Based Medicine Committee's recommendations for treatments of PD were first published in 2002, updated in 2011, and now updated again through December 31, 2016.

METHODS

Level I studies testing pharmacological, surgical, or nonpharmacological interventions for the treatment of nonmotor symptoms in PD were reviewed. Criteria for inclusion and quality scoring were as previously reported. The disorders covered were a range of neuropsychiatric symptoms, autonomic dysfunction, disorders of sleep and wakefulness, pain, fatigue, impaired olfaction, and ophthalmologic dysfunction. Clinical efficacy, implications for clinical practice, and safety conclusions are reported.

RESULTS

A total of 37 new studies qualified for review. There were no randomized controlled trials that met inclusion criteria for the treatment of anxiety disorders, rapid eye movement sleep behavior disorder, excessive sweating, impaired olfaction, or ophthalmologic dysfunction. We identified clinically useful or possibly useful interventions for the treatment of depression, apathy, impulse control and related disorders, dementia, psychosis, insomnia, daytime sleepiness, drooling, orthostatic hypotension, gastrointestinal dysfunction, urinary dysfunction, erectile dysfunction, fatigue, and pain. There were no clinically useful interventions identified to treat non-dementia-level cognitive impairment.

CONCLUSIONS

The evidence base for treating a range of nonmotor symptoms in PD has grown substantially in recent years. However, treatment options overall remain limited given the high prevalence and adverse impact of these disorders, so the development and testing of new treatments for nonmotor symptoms in PD remains a top priority. © 2019 International Parkinson and Movement Disorder Society.

Factors associated with depression in patients with Parkinson's disease A multicenter study in Lima, Peru

The diagnosis and treatment of depression in patients with Parkinson's disease (PD) is inadequate, often contributing to a reduced quality of life, rapid disease progression, higher cognitive impairment, and an increased burden of care for family members of patients with PD.

OBJECTIVE

To determine the factors associated with depression in PD and to examine the frequency of depressive symptoms among patients with PD.

METHODS

This study was an observational, analytical, multicenter study of a cross-sectional cohort, conducted between July 2016 and May 2017. PD patients were recruited from neurology clinics in Lima, Peru. All statistical analyses were performed using descriptive statistics. Bivariate and multivariate logistic regression analyses were calculated using STATA.

RESULTS

Out of 124 patients (average age: 68.7 years; 58% males) included in the study 60.5% (75/124) presented with symptoms of depression; only 20% (25/124) received antidepressants. Factors associated with depression in PD included: unemployment, falls, freezing of gait, involuntary movements micrographia, stooped posture, hyposmia, movement disorders in sleep, rapid disease progression, and the use of MAOIs. Furthermore, statistically significant differences were found in disease duration, UPDRS and MMSE scores, Hoehn and Yahr (HY) stage, and length of time taking L-dopa between PD patients with and without depressive symptoms.

CONCLUSION

Factors associated with depressive symptoms in patients with PD were hyposmia, rapid progression of the disease, the use of L-dopa, and use of MAOIs. The frequency of depressive symptoms in patients with PD is high; early diagnosis and prompt treatment are needed to improve their quality of life and the family environment.

A multiple treatment comparison meta-analysis of monoamine oxidase type B inhibitors for Parkinson's disease

AIMS

To the best of our knowledge, there are no systematic reviews or meta-analyses that compare rasagiline, selegiline and safinamide. Therefore, we aimed to perform a drug class review comparing all available monoamine oxidase type B (MAO-B) inhibitors in a multiple treatment comparison.

METHODS

We performed a systematic literature search to identify randomized controlled trials assessing the efficacy of MAO-B inhibitors in patients with Parkinson's disease. MAO-B inhibitors were evaluated either as monotherapy or in combination with levodopa or dopamine agonists. Endpoints of interest were change in the Unified Parkinson's Disease Rating Scale (UPDRS) score and serious adverse events. We estimated the relative effect of each MAO-B inhibitor versus the comparator drug by creating three networks of direct and indirect comparisons. For each of the networks, we considered a joint model.

RESULTS

The systematic literature search and study selection process identified 27 publications eligible for our three network analyses. We found the relative effects of rasagiline, safinamide and selegiline treatment given alone and compared to placebo in a model without explanatory variables to be 1.560 (1.409, 1.734), 1.449 (0.873, 2.413) and 1.532 (1.337, 1.757) respectively. We also found all MAO-B inhibitors to be efficient when given together with levodopa. When ranking the MAO-B inhibitors given in combination with levodopa, selegiline was the most effective and rasagiline was the second best.

CONCLUSIONS

All of the included MAO-B inhibitors were effective compared to placebo when given as monotherapy. Combination therapy with MAO-B inhibitors and levodopa showed that all three MAO-B inhibitors were effective compared to placebo, but selegiline was the most effective drug.

Impaired serial ordering in nondemented patients with mild Parkinson's disease

The ability to arrange thoughts and actions in an appropriate serial order (the problem of serial order) is essential to complex behaviors such as language, reasoning and cognitive planning. Patients with Parkinson’s disease (PD) perform poorly in tasks that rely on the successful rearrangement of working memory representations. We hypothesized that serial ordering is impaired in nondemented patients with mild PD. We recruited 49 patients with mild idiopathic PD (Hoehn and Yahr Scale 1–2.5) and 51 matched healthy adults. Nineteen patients had normal global cognition (PD-NC, Montreal Cognitive Assessment, MoCA≥26/30) and thirty patients had mild cognitive impairment (PD-MCI, 21≤MoCA≤25). All participants underwent three working memory assessments: two experimental tests that require reordering random digits following a particular rule (adaptive digit ordering test and digit span backward test) and a control test that requires maintaining but no reordering (digit span forward test). PD-NC and PD-MCI patients performed significantly worse (with lower test scores and larger ordering costs) than healthy controls in both digit ordering and backward tests, although they performed normally in the forward test. The ordering cost increased as a function of age across groups, indicating an aging-related decline in the ability of serial ordering. However, individual patients’ task performances were not correlated with their severity or duration of motor symptoms, or daily exposure to dopaminergic drugs. These results suggested that serial ordering deficits exist in early stages of PD, prior to subtle changes in global cognition and in parallel with motor symptoms.

Effects of Antiparkinson Medication on Cognition in Parkinson's Disease: A Systematic Review

OBJECTIVE

This study aimed to systematically review the effects of currently prescribed antiparkinson medication on cognition in patients with mild-to-moderate Parkinson's disease (PD) who were either cognitively intact or mildly impaired.

METHODS

English- and French-language studies published between 1969 and 2017 were accessed via MedLine, PsychNET, EMBASE and EBSCO databases. Methodological quality (MQ) was evaluated with the quality assessment instrument of the Cochrane Collaboration Depression, Anxiety and Neurosis Review (scores from 0% to 44% indicate very low quality; scores from 45% to 64% indicate low quality; scores from 65% to 84% indicate medium quality; and scores from 85% to 100% indicate high quality). Hedges' g and Student's t-test were performed on all cognitive outcome measures reported.

RESULTS

In total, 14 studies assessed the cognitive effects of levodopa (L-D), pramipexole (PRX), selegiline (SEL) and rasagiline (RAS) in mild-to-moderate non-demented PD patients. The MQ was overall low, with an average score of 49.1%. Results for L-D showed deleterious effects on a test of cognitive inhibition, as well as benefits on tests of attention/processing speed/working memory, executive functions and episodic memory. Pramipexole was associated with a worsening of episodic memory and impulse control. Results on SEL indicated a deterioration of global cognition over time and of concept formation. Rasagiline had some benefits on working memory and verbal fluency.

CONCLUSION

Antiparkinson medications can have deleterious (L-D; PRX; SEL) and beneficial (L-D; RAS) effects on cognition. However, randomized double-blind placebo-controlled trials with larger sample sizes are required to better elucidate this issue.

Strengths and challenges in conducting clinical trials in Parkinson's disease mild cognitive impairment

Treatments to slow the progression of cognitive dysfunction to dementia and improve the quality of life of persons with Parkinson's disease (PD) are desperately needed. Because PD mild cognitive impairment is considered a transitional stage before dementia, it opens a window to timely intervention. This article critically reviews the strengths and challenges of pharmacologic and nonpharmacologic clinical therapeutic trials in PD mild cognitive impairment conducted during the past 5 years, including ongoing trials. Relatively few high-quality trials have been conducted, and some important factors in designing future clinical trials are discussed. © 2018 International Parkinson and Movement Disorder Society.

Rasagiline for dysexecutive symptoms during wearing-off in Parkinson's disease: a pilot study

Wearing-off refers to the predictable worsening of motor and sometimes non-motor symptoms of Parkinson's disease occurring at the end of levodopa dose that improves with the next drug dose. Here, we investigated the efficacy of rasagiline on executive functions at the end of levodopa dose in patients displaying symptoms of wearing-off. Rasagiline was well-tolerated and produced a significant improvement at the Frontal Assessment Battery, together with improvement of motor symptoms at the end of levodopa dose. These results suggest that treatment of motor symptoms of wearing-off with rasagiline may be accompanied by improvement of executive functions, and further support the need for optimizing dopamine replacement therapy in fluctuating Parkinson's disease patients.

Efficacy of rasagiline for the treatment of Parkinson's disease: an updated meta-analysis

OBJECTIVE

Rasagiline is a second-generation potent selective inhibitor of monoamine oxidase-B. The aim of the study was to analyze the effectiveness of rasagiline in treatment of Parkinson's disease (PD), both as monotherapy and combination therapy.

METHODS

Medline, Cochrane, EMBASE, and Google Scholar databases were searched until 9 March 2016 using the keywords: Rasagiline, Azilect, Parkinson's disease. Randomized controlled trials of patients with PD who were randomized to treatment with rasagiline or placebo were included. Outcomes were unified Parkinson's disease rating scale (UPDRS) and the three subscales.

RESULTS

Ten studies fulfilled the inclusion criteria and 2709 patients were evaluated. The overall analysis revealed a significant improvement in change of total UPDRS scores in 1 mg/day and 2 mg/day rasagiline groups compared to placebo. Significant improvement in Part I (Mentation) of UPDRS scores was observed in 1 mg/day, but not in 2 mg/day rasagiline treatment group. Part II (ADL) and Part III (Motor) subscales significantly improved with both doses of rasagiline. Both monotherapy and combination therapy significantly improved total UPDRS scores.

CONCLUSIONS

Our results confirm the efficacy of rasagiline in PD. Further studies are required to establish the optimal dose of rasagiline, as well as to determine its effectiveness in different combination therapy protocols. KEY MESSAGES Rasagiline treatment was associated with significant improvement of UPDRS scores and the scores of the subscales. Both monotherapy and combination therapy significantly improved total UPDRS scores. Effect of rasagiline on total UPDRS scores was not dose-dependent.

Nonmotor Effects of Conventional and Transdermal Dopaminergic Therapies in Parkinson's Disease

Nonmotor symptoms (NMS) are an integral component of Parkinson's disease (PD). Because the burden and range of NMS are key determinants of quality of life for patients and caregivers, their management is a crucial issue in clinical practice. Although a range of NMS have a dopaminergic pathophysiological basis, this fact is underrecognized, and thus, they are often regarded as dopamine unresponsive symptoms. However, substantial evidence indicates that many NMS respond to oral and transdermal dopaminergic therapies. In contrast, certain NMS are exacerbated or even precipitated by dopaminergic drugs and these unwanted effects may be seriously dangerous. Therefore, a dopaminergic strategy for NMS should be based on a consideration of the benefits vs the risks in individual patients with PD.

Comparison for Efficacy and Tolerability among Ten Drugs for Treatment of Parkinson's Disease: A Network Meta-Analysis

Parkinson’s disease (PD) is a long term disorder affects the central nervous system and we aim to determine the relative efficacy of the current available drugs used in PD. Firstly, we performed a systematic review in current literature and eligible studies were retrieved from online databases, relevant data were extracted. Efficacy of these medications was assessed by different Unified Parkinson’s Disease Rating Scales (UPDRS). Mean difference (MD) and odds ratio (OR) were produced by pairwise or network meta-analysis (NMA). Finally, we performed a cluster analysis for the included medications with respect to their surface under the cumulative ranking curve (SUCRA). Pairwise meta-analysis suggests that selegiline had a higher ranking in UPDRS II, UPDRS III and UPDRS total than bromocriptine and levodopa. Selegiline was more tolerable than bromocriptine (OR = 0.62, CI: 0.39 to 0.98) and pramipexole was less tolerable than levodopa (OR = 1.43, CI = 1.00 to 2.04). Results of NMA indicate that patients with levodopa, pramipexole, ropinirole and selegiline exhibited a significantly improved UPDRS III than those with lazabemide. To sum up, levodopa, selegiline, ropinirole and rotigotine were recommended for PD patients as they appeared relatively high efficacy and tolerability.

Neuropsychiatric Issues in Parkinson's Disease

Cognitive and neuropsychiatric symptoms are common in Parkinson's Disease and may surpass motor symptoms as the major factors impacting patient quality of life. The symptoms may be broadly separated into those associated with the disease process and those that represent adverse effects of treatment. Symptoms attributed to the disease arise from pathologic changes within multiple brain regions and are not restricted to dysfunction in the dopaminergic system. Mood symptoms such as depression, anxiety, and apathy are common and may precede the development of motor symptoms by years, while other neuropsychiatric symptoms such as cognitive impairment, dementia, and psychosis are more common in later stages of the disease. Neuropsychiatric symptoms attributed to treatment include impulse control disorders, pathologic use of dopaminergic medications, and psychosis. This manuscript will review the current understanding of neuropsychiatric symptoms in Parkinson's Disease.

Patterns and predictors of freezing of gait improvement following rasagiline therapy: A pilot study

OBJECTIVES

Freezing of gait (FoG) is a challenging clinical symptom in Parkinson's disease with variable improvements in FoG with rasagiline. In this prospective, uncontrolled, pre-/post- treatment pilot study, we explore the clinical variables that contribute to this variability and those that predict improvement.

PATIENTS AND METHODS

Frequency and duration of FoG, along with other standardized scales, were evaluated in 18 optimally medicated PD participants with intractable FoG, prior to and after completion of a 90-day course of 1mg daily rasagiline. Gait tasks were video-recorded and analyzed by two independent reviewers. After evaluating the simple main effect, hierarchical cluster analysis was used to identify subgroups for treatment responsiveness. Bidirectional elimination stepwise regression analysis was conducted to identify which clinical variables predicted reduction in frequency of FoG events post-treatment.

RESULTS

There were no overall pre-/post- treatment improvements, a result driven by a heterogeneous response to treatment. Three subgroups were identified: improved (n=6) with a 136% and 162% reduction in FoG count and duration; worsened (n=5) with 154% and 141% increase in FoG count and duration; and no change (n=3). The final predictive model had good explanatory power (adjusted-R²=0.9898, p<0.01), explaining 99% of the variance between the improved and worsened groups. In this model, lower UPDRS gait scores, higher LEDD dose, lower anxiety scores, lower FOG-Q scores, and higher UPDRS scores for lower extremity rigidity and rise from chair, predicted FoG-related rasagiline benefit.

CONCLUSION

Using both objective and subjective measures for FoG, the current pilot study identified a set of clinical variables that may elucidate the heterogeneous FoG-responsiveness following rasagiline treatment and aid in predicting improvement.

Rasagiline for mild cognitive impairment in Parkinson's disease: A placebo-controlled trial

BACKGROUND

This study's aims were to determine the efficacy and tolerability of rasagiline, a selective monoamine oxidase inhibitor B, for PD patients with mild cognitive impairment.

METHODS

Patients on stable dopaminergic therapy were randomized to adjunct rasagiline 1 mg/day or placebo in this 24-week, double-blind, placebo-controlled, multisite study. The primary endpoint was mean change from baseline to week 24 on the Scales for Outcomes of Parkinson's Disease-Cognition total score. Key secondary measures included changes in cognition, activities of daily living, motor scores, and Clinical Global Impression of Change, as well as safety and tolerability measures.

RESULTS

Of the 170 patients randomized, 151 (88.2%) completed the study. Change in Scales for Outcomes of Parkinson's Disease-Cognition scores were not significantly different in the rasagiline and placebo groups (adjusted mean: 1.6 [standard error {SE} = 0.5] vs. 0.8 [SE = 0.5] points; LS means difference = 0.8; 95% confidence interval: -0.48, 2.05; P = 0.22). There were no between-group differences in change in the MoCA (p=0.84) or Penn Daily Activities Questionnaire (P = 0.48) scores or in the distribution of Alzheimer's Disease Cooperative Study-Clinical Global Impression of Change modified for mild cognitive impairment (P = 0.1). Changes in motor (UPDRS part III; P = 0.02) and activities of daily living (UPDRS part II; P < 0.001) scores favored rasagiline. Rasagiline was well tolerated; the most common adverse events in both groups were falls and dizziness.

CONCLUSIONS

Rasagiline treatment in PD patients with mild cognitive impairment was not associated with cognitive improvement. Rasagiline did not worsen cognition, improved motor symptoms and activities of daily living, and was well tolerated in elderly cognitively impaired patients. © 2016 International Parkinson and Movement Disorder Society.

Current Treatment Options for Alzheimer's Disease and Parkinson's Disease Dementia

Alzheimer's disease (AD) and Parkinson's disease (PD) are the two most common neurodegenerative disorders encountered in clinical practice. Whilst dementia has long been synonymous with AD, it is becoming more widely accepted as part of the clinical spectrum in PD (PDD). Neuropsychiatric complications, including psychosis, mood and anxiety disorders, and sleep disorders also frequently co-exist with cognitive dysfunctions in AD and PDD patients. The incidence of such symptoms is often a significant source of disability, and may aggravate pre-existing cognitive deficits. Management of AD and PDD involves both pharmacological and non-pharmacological measures. Although research on pharmacological therapies for AD and PDD has so far had some success in terms of developing symptomatic treatments, the benefits are often marginal and non-sustained. These shortcomings have led to the investigation of non-pharmacological and novel treatments for both AD and PD. Furthermore, in light of the diverse constellation of other neuropsychiatric, physical, and behavioural symptoms that often occur in AD and PD, consideration needs to be given to the potential side effects of pharmacological treatments where improving one symptom may lead to the worsening of another, rendering the clinical management of these patients challenging. Therefore, the present article will critically review the evidence for both pharmacological and non-pharmacological treatments for cognitive impairment in AD and PD patients. Treatment options for other concomitant neuropsychiatric and behavioural symptoms, as well as novel treatment strategies will also be discussed.