No Evidence of Sensory Neuropathy in a Traditional Mouse Model of Idiopathic Parkinson's Disease

Parkinson's disease (PD) is the second-most common neurodegenerative disorder worldwide and is diagnosed based on motor impairments. Non-motor symptoms are also well-recognised in this disorder, and peripheral neuropathy is a frequent but poorly appreciated non-motor sign. Studying how central and peripheral sensory systems are affected can contribute to the development of targeted therapies and deepen our understanding of the pathophysiology of PD. Although the cause of sporadic PD is unknown, chronic exposure to the pesticide rotenone in humans increases the risk of developing the disease. Here, we aimed to investigate whether peripheral neuropathy is present in a traditional model of PD. Mice receiving intrastriatal rotenone showed greatly reduced dopamine terminals in the striatum and a reduction in tyrosine hydroxylase-positive neurons in the Substantia nigra pars compacta and developed progressive motor impairments in hindlimb stepping and rotarod but no change in spontaneous activity. Interestingly, repeated testing using gold-standard protocols showed no change in gut motility, a well-known non-motor symptom of PD. Importantly, we did not observe any change in heat, cold, or touch sensitivity, again based upon repeated testing with well-validated protocols that were statistically well powered. Therefore, this traditional model fails to replicate PD, and our data again reiterate the importance of the periphery to the disorder.

Diagnosis of manganism and manganese neurotoxicity: A workshop report

With declining exposures to manganese (Mn) in occupational settings, there is a need for more sensitive exposure assessments and clinical diagnostic criteria for manganism and Mn neurotoxicity. To address this issue, a workshop was held on November 12-13, 2020, with international experts on Mn toxicity. The workshop discussions focused on the history of the diagnostic criteria for manganism, including those developed by the Institut de Recherche Robert-Sauvé en Santé et en Sécurité du Travail (IRSST) in Quebec in 2005 and criteria developed by the Chinese government in 2002 and updated in 2006; the utility of biomarkers of exposure; recent developments in magnetic resonance imaging (MRI) for assessing Mn accumulation in the brain and diagnosing manganism; and potential future applications of metabolomics. The suggestions of the participants for updating manganism diagnostic criteria included the consideration of: i) A history of previous occupational and environmental exposure to Mn; ii) relevant clinical symptoms such as dystonia; iii) MRI imaging to document Mn accumulation in the neural tissues, including the basal ganglia; and iv) criteria for the differential diagnosis of manganism and other neurological conditions. Important research gaps include the characterization of Mn exposure and other co-exposures, exploration of the roles of different brain regions with MRI, understanding the complexity of metal ion transporters involved in Mn homeostasis, and a need for information on other neurotransmitter systems and brain regions underlying the pathophysiology of manganism.

Dopamine pathway and Parkinson's risk variants are associated with levodopa-induced dyskinesia

Background

Levodopa-induced dyskinesia (LID) is a common adverse effect of levodopa, one of the main therapeutics used to treat the motor symptoms of Parkinson's disease (PD). Previous evidence suggests a connection between LID and a disruption of the dopaminergic system as well as genes implicated in PD, including GBA1 and LRRK2.

Objectives

To investigate the effects of genetic variants on risk and time to LID.

Methods

We performed a genome-wide association study (GWAS) and analyses focused on GBA1 and LRRK2 variants. We also calculated polygenic risk scores including risk variants for PD and variants in genes involved in the dopaminergic transmission pathway. To test the influence of genetics on LID risk we used logistic regression, and to examine its impact on time to LID we performed Cox regression including 1,612 PD patients with and 3,175 without LID.

Results

We found that GBA1 variants were associated with LID risk (OR=1.65, 95% CI=1.21-2.26, p=0.0017) and LRRK2 variants with reduced time to LID onset (HR=1.42, 95% CI=1.09-1.84, p=0.0098). The fourth quartile of the PD PRS was associated with increased LID risk (ORfourth_quartile=1.27, 95% CI=1.03-1.56, p=0.0210). The third and fourth dopamine pathway PRS quartiles were associated with a reduced time to development of LID (HRthird_quartile=1.38, 95% CI=1.07-1.79, p=0.0128; HRfourth_quartile=1.38, 95% CI=1.06-1.78, p=0.0147).

Conclusions

This study suggests that variants implicated in PD and in the dopaminergic transmission pathway play a role in the risk/time to develop LID. Further studies will be necessary to examine how these findings can inform clinical care.

Investigation of Shared Genetic Risk Factors Between Parkinson's Disease and Cancers

BACKGROUND

Epidemiological studies that examined the association between Parkinson's disease (PD) and cancers led to inconsistent results, but they face a number of methodological difficulties.

OBJECTIVE

We used results from genome-wide association studies (GWASs) to study the genetic correlation between PD and different cancers to identify common genetic risk factors.

METHODS

We used individual data for participants of European ancestry from the Courage-PD (Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in Parkinson's Disease; PD, N = 16,519) and EPITHYR (differentiated thyroid cancer, N = 3527) consortia and summary statistics of GWASs from iPDGC (International Parkinson Disease Genomics Consortium; PD, N = 482,730), Melanoma Meta-Analysis Consortium (MMAC), Breast Cancer Association Consortium (breast cancer), the Prostate Cancer Association Group to Investigate Cancer Associated Alterations in the Genome (prostate cancer), International Lung Cancer Consortium (lung cancer), and Ovarian Cancer Association Consortium (ovarian cancer) (N comprised between 36,017 and 228,951 for cancer GWASs). We estimated the genetic correlation between PD and cancers using linkage disequilibrium score regression. We studied the association between PD and polymorphisms associated with cancers, and vice versa, using cross-phenotypes polygenic risk score (PRS) analyses.

RESULTS

We confirmed a previously reported positive genetic correlation of PD with melanoma (Gcorr = 0.16 [0.04; 0.28]) and reported an additional significant positive correlation of PD with prostate cancer (Gcorr = 0.11 [0.03; 0.19]). There was a significant inverse association between the PRS for ovarian cancer and PD (odds ratio [OR] = 0.89 [0.84; 0.94]). Conversely, the PRS of PD was positively associated with breast cancer (OR = 1.08 [1.06; 1.10]) and inversely associated with ovarian cancer (OR = 0.95 [0.91; 0.99]). The association between PD and ovarian cancer was mostly driven by rs183211 located in an intron of the NSF gene (17q21.31).

CONCLUSIONS

We show evidence in favor of a contribution of pleiotropic genes to the association between PD and specific cancers. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society. This article has been contributed to by U.S. Government employees and their work is in the public domain in the USA.

Mitochondrial haplogroups and cognitive progression in Parkinson's disease

Mitochondria are a culprit in the onset of Parkinson's disease, but their role during disease progression is unclear. Here we used Cox proportional hazards models to exam the effect of variation in the mitochondrial genome on longitudinal cognitive and motor progression over time in 4064 patients with Parkinson's disease. Mitochondrial macro-haplogroup was associated with reduced risk of cognitive disease progression in the discovery and replication population. In the combined analysis, patients with the super macro-haplogroup J, T, U# had a 41% lower risk of cognitive progression with P = 2.42 × 10-6 compared to those with macro-haplogroup H. Exploratory analysis indicated that the common mitochondrial DNA variant, m.2706A>G, was associated with slower cognitive decline with a hazard ratio of 0.68 (95% confidence interval 0.56-0.81) and P = 2.46 × 10-5. Mitochondrial haplogroups were not appreciably linked to motor progression. This initial genetic survival study of the mitochondrial genome suggests that mitochondrial haplogroups may be associated with the pace of cognitive progression in Parkinson's disease over time.

The Interaction between HLA-DRB1 and Smoking in Parkinson's Disease Revisited

BACKGROUND

Two studies that examined the interaction between HLA-DRB1 and smoking in Parkinson's disease (PD) yielded findings in opposite directions.

OBJECTIVE

To perform a large-scale independent replication of the HLA-DRB1 × smoking interaction.

METHODS

We genotyped 182 single nucleotide polymorphism (SNPs) associated with smoking initiation in 12 424 cases and 9480 controls to perform a Mendelian randomization (MR) analysis in strata defined by HLA-DRB1.

RESULTS

At the amino acid level, a valine at position 11 (V11) in HLA-DRB1 displayed the strongest association with PD. MR showed an inverse association between genetically predicted smoking initiation and PD only in absence of V11 (odds ratio, 0.74, 95% confidence interval, 0.59-0.93, PInteraction  = 0.028). In silico predictions of the influence of V11 and smoking-induced modifications of α-synuclein on binding affinity showed findings consistent with this interaction pattern.

CONCLUSIONS

Despite being one of the most robust findings in PD research, the mechanisms underlying the inverse association between smoking and PD remain unknown. Our findings may help better understand this association. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Genome-wide Association and Meta-analysis of Age at Onset in Parkinson Disease: Evidence From the COURAGE-PD Consortium

BACKGROUND AND OBJECTIVES

Considerable heterogeneity exists in the literature concerning genetic determinants of the age at onset (AAO) of Parkinson disease (PD), which could be attributed to a lack of well-powered replication cohorts. The previous largest genome-wide association studies (GWAS) identified SNCA and TMEM175 loci on chromosome (Chr) 4 with a significant influence on the AAO of PD; these have not been independently replicated. This study aims to conduct a meta-analysis of GWAS of PD AAO and validate previously observed findings in worldwide populations.

METHODS

A meta-analysis was performed on PD AAO GWAS of 30 populations of predominantly European ancestry from the Comprehensive Unbiased Risk Factor Assessment for Genetics and Environment in Parkinson's Disease (COURAGE-PD) Consortium. This was followed by combining our study with the largest publicly available European ancestry dataset compiled by the International Parkinson Disease Genomics Consortium (IPDGC).

RESULTS

The COURAGE-PD Consortium included a cohort of 8,535 patients with PD (91.9%: Europeans and 9.1%: East Asians). The average AAO in the COURAGE-PD dataset was 58.9 years (SD = 11.6), with an underrepresentation of females (40.2%). The heritability estimate for AAO in COURAGE-PD was 0.083 (SE = 0.057). None of the loci reached genome-wide significance (p < 5 × 10-8). Nevertheless, the COURAGE-PD dataset confirmed the role of the previously published TMEM175 variant as a genetic determinant of the AAO of PD with Bonferroni-corrected nominal levels of significance (p < 0.025): (rs34311866: β(SE)COURAGE = 0.477(0.203), p COURAGE = 0.0185). The subsequent meta-analysis of COURAGE-PD and IPDGC datasets (Ntotal = 25,950) led to the identification of 2 genome-wide significant association signals on Chr 4, including the previously reported SNCA locus (rs983361: β(SE)COURAGE+IPDGC = 0.720(0.122), p COURAGE+IPDGC = 3.13 × 10-9) and a novel BST1 locus (rs4698412: β(SE)COURAGE+IPDGC = -0.526(0.096), p COURAGE+IPDGC = 4.41 × 10-8).

DISCUSSION

Our study further refines the genetic architecture of Chr 4 underlying the AAO of the PD phenotype through the identification of BST1 as a novel AAO PD locus. These findings open a new direction for the development of treatments to delay the onset of PD.

COVID-19 vaccination hesitancy among people with chronic neurological disorders: a position paper

Background and purpose

Health risks associated with SARS‐CoV‐2 infection are undisputed. Moreover, the capability of vaccination to prevent symptomatic, severe, and fatal COVID‐19 is recognized. There is also early evidence that vaccination can reduce the chance for long COVID‐19. Nonetheless, the willingness to get vaccinated and receive booster shots remains subpar among people with neurologic disorders. Vaccine scepticism not only jeopardizes collective efforts to end the COVID‐19 pandemic but puts individual lives at risk, as some chronic neurologic diseases are associated with a higher risk for an unfavorable COVID‐19 course.

Methods

In this position paper, the NeuroCOVID‐19 Task Force of the European Academy of Neurology (EAN) summarizes the current knowledge on the prognosis of COVID‐19 among patients with neurologic disease, elucidates potential barriers to vaccination coverage, and formulates strategies to overcome vaccination hesitancy. A survey among the Task Force members on the phenomenon of vaccination hesitancy among people with neurologic disease supports the lines of argumentation.

Results

The study revealed that people with multiple sclerosis and other nervous system autoimmune disorders are most skeptical of SARS‐CoV‐2 vaccination. The prevailing concerns included the chance of worsening the pre‐existing neurological condition, vaccination‐related adverse events, and drug interaction.

Conclusions

The EAN NeuroCOVID‐19 Task Force reinforces the key role of neurologists as advocates of COVID‐19 vaccination. Neurologists need to argue in the interest of their patients about the overwhelming individual and global benefits of COVID‐19 vaccination. Moreover, they need to keep on eye on this vulnerable patient group, its concerns, and the emergence of potential safety signals.

Dairy Intake and Parkinson's Disease: A Mendelian Randomization Study

BACKGROUND

Previous prospective studies highlighted dairy intake as a risk factor for Parkinson's disease (PD), particularly in men. It is unclear whether this association is causal or explained by reverse causation or confounding.

OBJECTIVE

The aim is to examine the association between genetically predicted dairy intake and PD using two-sample Mendelian randomization (MR).

METHODS

We genotyped a well-established instrumental variable for dairy intake located in the lactase gene (rs4988235) within the Courage-PD consortium (23 studies; 9823 patients and 8376 controls of European ancestry).

RESULTS

Based on a dominant model, there was an association between genetic predisposition toward higher dairy intake and PD (odds ratio [OR] per one serving per day = 1.70, 95% confidence interval = 1.12-2.60, P = 0.013) that was restricted to men (OR = 2.50 [1.37-4.56], P = 0.003; P-difference with women = 0.029).

CONCLUSIONS

Using MR, our findings provide further support for a causal relationship between dairy intake and higher PD risk, not biased by confounding or reverse causation. Further studies are needed to elucidate the underlying mechanisms. © 2022 International Parkinson and Movement Disorder Society.

Structured guideline-based physiotherapy reduces difficulties in activities of daily living in Parkinson's disease

BACKGROUND

In the long term, Parkinson's disease (PD) leads to the development of difficulties in daily functional tasks. There remains a paucity of evidence on the effectiveness of physiotherapy on patient-perceived difficulties regarding basic activities of daily living (ADL).

OBJECTIVES

To assess an effect of a versatile physiotherapy intervention on patient-perceived difficulties in basic ADL.

METHODS

The study sample included 24 patients (10 men and 14 women) with PD. Participants were randomly assigned into intervention (IG) and control groups (CG). Two assessments were performed with a gap of 10 weeks. Following first assessment, during an 8-week period, IG participants attended sixteen physiotherapy 60-minutes sessions in groups that were divided into five parts to address the core areas recommended by the European Physiotherapy Guideline for PD (EPGPD): gait, transfers, balance, physical capacity, and manual activities. The main assessment tool was the Modified Patients Specific Functional Scale (ModPSFS), which represents a self-assessment rating on difficulties perceived in 17 different commonly occurring activities.

RESULTS

IG members reported a significant reduction in self-perceived difficulties as assessed by ModPSFS (effect size 1.39; 95%CI 5.1, 26.6 points, p = 0.005).

CONCLUSIONS

2-months conventional physiotherapy with incorporated core areas recommended in EPGPD for PD reduced patient-perceived difficulties in basic ADL.

A plea for equitable global access to COVID-19 diagnostics, vaccination and therapy: The NeuroCOVID-19 Task Force of the European Academy of Neurology

Coronavirus disease 2019 (COVID-19), a multi-organ disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), continues to challenge health and care systems around the globe. The pandemic has disrupted acute neurology services and routine patient care and has impacted the clinical course in patients with chronic neurological disease. COVID-19 appears to have exposed inequalities of societies and healthcare systems and had a disproportionate impact on already vulnerable communities. The next challenge will be to set up initiatives to stop disparities in all aspects related to COVID-19. From the medical perspective, there is a need to consider inequalities in prevention, treatment and long-term consequences. Some of the issues of direct relevance to neurologists are summarised. With this appraisal, the European Academy of Neurology NeuroCOVID-19 Task Force intends to raise awareness of the potential impact of COVID-19 on inequalities in healthcare and calls for action to prevent disparity at individual, national and supranational levels.

Education on palliative care for Parkinson patients: development of the "Best care for people with late-stage Parkinson's disease" curriculum toolkit

BACKGROUND

Palliative care education among all stakeholders involved in the care of patients with late-stage Parkinson's disease is not adequate. In fact, there are many unmet educational and training needs as confirmed with a targeted, narrative literature review.

METHODS

To address these needs we have developed the "Best Care for People with Late-Stage Parkinson's Disease" curriculum toolkit. The toolkit is based on recommendations and guidelines for training clinicians and other healthcare professionals involved in palliative care, educational material developed in recent research efforts for patients and caregivers with PD and consensus meetings of leading experts in the field. The final version of the proposed toolkit was drafted after an evaluation by external experts with an online survey, the feedback of which was statistically analysed with the chi-square test of independence to assess experts' views on the relevance and importance of the topics. A sentiment analysis was also done to complement statistics and assess the experts positive and negative sentiments for the curriculum topics based on their free text feedback.

RESULTS

The toolkit is compliant with Kern's foundational framework for curriculum development, recently adapted to online learning. The statistical analysis of the online survey, aiming at toolkit evaluation from external experts (27 in total), confirms that all but one (nutrition in advanced Parkinson's disease) topics included, as well as their objectives and content, are highly relevant and useful.

CONCLUSIONS

In this paper, the methods for the development of the toolkit, its stepwise evolution, as well as the toolkit implementation as a Massive Open Online Course (MOOC), are presented. The "Best Care for People with Late-Stage Parkinson' s disease" curriculum toolkit can provide high-quality and equitable education, delivered by an interdisciplinary team of educators. The toolkit can improve communication about palliative care in neurological conditions at international and multidisciplinary level. It can also offer continuing medical education for healthcare providers.

Mendelian Randomisation Study of Smoking, Alcohol, and Coffee Drinking in Relation to Parkinson's Disease

BACKGROUND

Previous studies showed that lifestyle behaviors (cigarette smoking, alcohol, coffee) are inversely associated with Parkinson's disease (PD). The prodromal phase of PD raises the possibility that these associations may be explained by reverse causation.

OBJECTIVE

To examine associations of lifestyle behaviors with PD using two-sample Mendelian randomisation (MR) and the potential for survival and incidence-prevalence biases.

METHODS

We used summary statistics from publicly available studies to estimate the association of genetic polymorphisms with lifestyle behaviors, and from Courage-PD (7,369 cases, 7,018 controls; European ancestry) to estimate the association of these variants with PD. We used the inverse-variance weighted method to compute odds ratios (ORIVW) of PD and 95%confidence intervals (CI). Significance was determined using a Bonferroni-corrected significance threshold (p = 0.017).

RESULTS

We found a significant inverse association between smoking initiation and PD (ORIVW per 1-SD increase in the prevalence of ever smoking = 0.74, 95%CI = 0.60-0.93, p = 0.009) without significant directional pleiotropy. Associations in participants ≤67 years old and cases with disease duration ≤7 years were of a similar size. No significant associations were observed for alcohol and coffee drinking. In reverse MR, genetic liability toward PD was not associated with smoking or coffee drinking but was positively associated with alcohol drinking.

CONCLUSION

Our findings are in favor of an inverse association between smoking and PD that is not explained by reverse causation, confounding, and survival or incidence-prevalence biases. Genetic liability toward PD was positively associated with alcohol drinking. Conclusions on the association of alcohol and coffee drinking with PD are hampered by insufficient statistical power.

Advance Care Planning and Care Coordination for People With Parkinson's Disease and Their Family Caregivers-Study Protocol for a Multicentre, Randomized Controlled Trial

Background: Parkinson's disease (PD) is a progressive neurodegenerative disease with motor- and non-motor symptoms. When the disease progresses, symptom burden increases. Consequently, additional care demands develop, the complexity of treatment increases, and the patient's quality of life is progressively threatened. To address these challenges, there is growing awareness of the potential benefits of palliative care for people with PD. This includes communication about end-of-life issues, such as Advance Care Planning (ACP), which helps to elicit patient's needs and preferences on issues related to future treatment and care. In this study, we will assess the impact and feasibility of a nurse-led palliative care intervention for people with PD across diverse European care settings.

Methods: The intervention will be evaluated in a multicentre, open-label randomized controlled trial, with a parallel group design in seven European countries (Austria, Estonia, Germany, Greece, Italy, Sweden and United Kingdom). The “PD_Pal intervention” comprises (1) several consultations with a trained nurse who will perform ACP conversations and support care coordination and (2) use of a patient-directed “Parkinson Support Plan-workbook”. The primary endpoint is defined as the percentage of participants with documented ACP-decisions assessed at 6 months after baseline (t1). Secondary endpoints include patients' and family caregivers' quality of life, perceived care coordination, patients' symptom burden, and cost-effectiveness. In parallel, we will perform a process evaluation, to understand the feasibility of the intervention. Assessments are scheduled at baseline (t0), 6 months (t1), and 12 months (t2). Statistical analysis will be performed by means of Mantel–Haenszel methods and multilevel logistic regression models, correcting for multiple testing.

Discussion: This study will contribute to the current knowledge gap on the application of palliative care interventions for people with Parkinson's disease aimed at ameliorating quality of life and managing end-of-life perspectives. Studying the impact and feasibility of the intervention in seven European countries, each with their own cultural and organisational characteristics, will allow us to create a broad perspective on palliative care interventions for people with Parkinson's disease across settings.

Clinical Trial Registration:www.trialregister.nl, NL8180.

Genome-wide survival study identifies a novel synaptic locus and polygenic score for cognitive progression in Parkinson's disease

A key driver of patients' well-being and clinical trials for Parkinson's disease (PD) is the course that the disease takes over time (progression and prognosis). To assess how genetic variation influences the progression of PD over time to dementia, a major determinant for quality of life, we performed a longitudinal genome-wide survival study of 11.2 million variants in 3,821 patients with PD over 31,053 visits. We discover RIMS2 as a progression locus and confirm this in a replicate population (hazard ratio (HR) = 4.77, P = 2.78 × 10-11), identify suggestive evidence for TMEM108 (HR = 2.86, P = 2.09 × 10-8) and WWOX (HR = 2.12, P = 2.37 × 10-8) as progression loci, and confirm associations for GBA (HR = 1.93, P = 0.0002) and APOE (HR = 1.48, P = 0.001). Polygenic progression scores exhibit a substantial aggregate association with dementia risk, while polygenic susceptibility scores are not predictive. This study identifies a novel synaptic locus and polygenic score for cognitive disease progression in PD and proposes diverging genetic architectures of progression and susceptibility.

Transcriptomic profiles in Parkinson's disease

Transcriptomics in Parkinson's disease offers insights into the pathogenesis of Parkinson's disease but obtaining brain tissue has limitations. In order to bypass this issue, we profile and compare differentially expressed genes and enriched pathways (KEGG) in two peripheral tissues (blood and skin) of 12 Parkinson's disease patients and 12 healthy controls using RNA-sequencing technique and validation with RT-qPCR. Furthermore, we compare our results to previous Parkinson's disease post mortem brain tissue and blood results using the robust rank aggregation method. The results show no overlapping differentially expressed genes or enriched pathways in blood vs. skin in our sample sets (25 vs. 1068 differentially expressed genes with an FDR ≤ 0.05; 1 vs. 9 pathways in blood and skin, respectively). A meta-analysis from previous transcriptomic sample sets using either microarrays or RNA-Seq yields a robust rank aggregation list of cortical gene expression changes with 43 differentially expressed genes; a list of substantia nigra changes with 2 differentially expressed genes and a list of blood changes with 1 differentially expressed gene being statistically significant at FDR ≤ 0.05. In cortex 1, KEGG pathway was enriched, four in substantia nigra and two in blood. None of the differentially expressed genes or pathways overlap between these tissues. When comparing our previously published skin transcription analysis, two differentially expressed genes between the cortex robust rank aggregation and skin overlap. In this study, for the first time a meta-analysis is applied on transcriptomic sample sets in Parkinson's disease. Simultaneously, it explores the notion that Parkinson's disease is not just a neuronal tissue disease by exploring peripheral tissues. The comparison of different Parkinson's disease tissues yields surprisingly few significant differentially expressed genes and pathways, suggesting that divergent gene expression profiles in distinct cell lineages, metabolic and possibly iatrogenic effects create too much transcriptomic noise for detecting significant signal. On the other hand, there are signs that point towards Parkinson's disease-specific changes in non-neuronal peripheral tissues in Parkinson's disease, indicating that Parkinson's disease might be a multisystem disorder.

Community-based genetic study of Parkinson's disease in Estonia

OBJECTIVE

To examine the genetic variability of Estonian Parkinson's disease (PD) patients using an ongoing epidemiological study in combination with a genetic analysis.

METHODS

This study was a community-based genetic screening study of 189 PD patients, and 158 age- and sex-matched controls screened for potential mutations in 9 PD genes using next-generation sequencing and multiplex ligation-dependent probe amplification method. Different clinimetric scales and questionnaires were used to examine PD patients and assess clinical characteristics and severity of the disease.

RESULTS

The overall frequency of pathogenic PD-causing variants was 1.1% (2/189), and any rare genetic variant was present in 21.2% (40/189) of the patients and in 8.2% (13/158) of the controls (P < .05). Variants of unknown significance accounted for 10.6% (20/189). Frequency of any GBA variant among PD patients was 10.1% (19/189) and in controls 3.8% (6/158). The frequency of any GBA variant in PD compared to controls was significantly higher (P = .035; OR 2.82; CI 95% 1.05-8.87). Burden of rare variants was not different between patients and controls. Also, a novel GBA pathogenic variant p.E10X was detected.

CONCLUSION

Among different genetic variants identified in Estonian PD patients, GBA variants are the most common, while an overall pathogenic variant frequency was 1.1%.

EAN consensus statement for management of patients with neurological diseases during the COVID-19 pandemic

BACKGROUND AND PURPOSE

The recent SARS-CoV-2 pandemic has posed multiple challenges to the practice of clinical neurology including recognition of emerging neurological complications and management of coexistent neurological diseases. In a fast-evolving pandemic, evidence-based studies are lacking in many areas. This paper presents European Academy of Neurology (EAN) expert consensus statements to guide neurologists caring for patients with COVID-19.

METHODS

A refined Delphi methodology was applied. In round 1, statements were provided by EAN scientific panels (SPs). In round 2, these statements were circulated to SP members not involved in writing them, asking for agreement/disagreement. Items with agreement >70% were retained for round 3, in which SP co-chairs rated importance on a five-point Likert scale. Results were graded by importance and reported as consensus statements.

RESULTS

In round one, 70 statements were provided by 23 SPs. In round two, 259/1061 SP member responses were received. Fifty-nine statements obtained >70% agreement and were retained. In round three, responses were received from 55 co-chairs of 29 SPs. Whilst general recommendations related to prevention of COVID-19 transmission had high levels of agreement and importance, opinion was more varied concerning statements related to therapy.

CONCLUSION

This is the first structured consensus statement on good clinical practice in patients with neurological disease during the COVID-19 pandemic that provides immediate guidance for neurologists. In this fast-evolving pandemic, a rapid response using refined Delphi methodology is possible, but guidance may be subject to change as further evidence emerges.

Lack of Accredited Clinical Training in Movement Disorders in Europe, Egypt, and Tunisia

BACKGROUND

Little information is available on the official postgraduate and subspecialty training programs in movement disorders (MD) in Europe and North Africa.

OBJECTIVE

To survey the accessible MD clinical training in these regions.

METHODS

We designed a survey on clinical training in MD in different medical fields, at postgraduate and specialized levels. We assessed the characteristics of the participants and the facilities for MD care in their respective countries. We examined whether there are structured, or even accredited postgraduate, or subspecialty MD training programs in neurology, neurosurgery, internal medicine, geriatrics, neuroradiology, neuropediatrics, and general practice. Participants also shared their suggestions and needs.

RESULTS

The survey was completed in 31/49 countries. Structured postgraduate MD programs in neurology exist in 20 countries; structured neurology subspecialty training exists in 14 countries and is being developed in two additional countries. Certified neurology subspecialty training was reported to exist in 7 countries. Recommended reading lists, printed books, and other materials are the most popular educational tools, while courses, lectures, webinars, and case presentations are the most popular learning formats. Mandatory activities and skills to be certified were not defined in 15/31 countries. Most participants expressed their need for a mandatory postgraduate MD program and for certified MD sub-specialization programs in neurology.

CONCLUSION

Certified postgraduate and subspecialty training exists only in a minority of European countries and was not found in the surveyed Egypt and Tunisia. MD training should be improved in many countries.

The international European Academy of Neurology survey on neurological symptoms in patients with COVID-19 infection

Background and purpose

Although the main clinical features of COVID‐19 infection are pulmonary, several associated neurological signs, symptoms and diseases are emerging. The incidence and characteristics of neurological complications are unclear. For this reason, the European Academy of Neurology (EAN) core COVID‐19 Task Force initiated a survey on neurological symptoms observed in patients with COVID‐19 infection.

Methods

A 17‐question online survey was made available on the EAN website and distributed to EAN members and other worldwide physicians starting on 9 April 2020.

Results

By 27 April 2020, proper data were collected from 2343 responders (out of 4199), of whom 82.0% were neurologists, mostly from Europe. Most responders (74.7%) consulted patients with COVID‐19 mainly in emergency rooms and in COVID‐19 units. The majority (67.0%) had evaluated fewer than 10 patients with neurological manifestations of COVID‐19 (neuro COVID‐19). The most frequently reported neurological findings were headache (61.9%), myalgia (50.4%), anosmia (49.2%), ageusia (39.8%), impaired consciousness (29.3%) and psychomotor agitation (26.7%). Encephalopathy and acute cerebrovascular disorders were reported at 21.0%. Neurological manifestations were generally interpreted as being possibly related to COVID‐19; they were most commonly recognized in patients with multiple general symptoms and occurred at any time during infection.

Conclusion

Neurologists are currently and actively involved in the management of neurological issues related to the COVID‐19 pandemic. This survey justifies setting up a prospective registry to better capture the prevalence of patients with neuro COVID‐19, neurological disease characteristics and the contribution of neurological manifestations to outcome.

A systematic review of neurological manifestations of SARS-CoV-2 infection: the devil is hidden in the details

Background and purpose

We systematically reviewed available evidence for reports of neurological signs and symptoms in patients with COVID‐19 to identify cases with severe acute respiratory syndrome coronavirus (SARS‐CoV)‐2 infection or immune‐mediated reaction in the nervous system.

Methods

We followed PRISMA guidelines and used the MEDLINE, EMBASE, Google Scholar, MedRxiv and ChinaXiv databases to search for articles on COVID‐19 and nervous system involvement that were published from 1 January to 24 April 2020. Data on design, sample size, neurological assessment and related work‐up were extracted. Biases were assessed with the Newcastle–Ottawa scale.

Results

We analysed 27 publications on potential neuroinvasive or parainfectious neurological complications of COVID‐19. The reports focused on smell and taste (n = 5) and evaluation of neurological symptoms and signs in cohorts (n = 5). There were cases of Guillain‐Barré syndrome/Miller‐Fisher syndrome/cranial neuropathy (seven cases), meningitis/encephalitis (nine cases) and various other conditions (five cases). The number of patients with examination of cerebrospinal fluid and, in particular, SARS‐CoV‐2 polymerase chain reaction was negligible. Two had a positive SARS‐CoV‐2 polymerase chain reaction examination of cerebrospinal fluid specimen. Study of potential parenchymal involvement with magnetic resonance imaging was rare. Only four reports received a rating of the highest quality standards.

Conclusions

This systematic review failed to establish comprehensive insights into nervous system manifestations of COVID‐19 beyond immune‐mediated complications in the aftermath of respiratory symptoms. The authors therefore provide guidance for more careful clinical, diagnostic and epidemiological studies to characterize the manifestations and burden of neurological disease caused by SARS‐CoV‐2 on behalf of the Infectious Disease Panel of the European Academy of Neurology.

Parkinson's Disease and Symptomatic Osteoarthritis Are Independent Risk Factors of Falls in the Elderly

Objectives:

Deteriorating functionality and loss of mobility, resulting from Parkinson’s disease, may be worsened by osteoarthritis, which is the most common form of joint disease causing pain and functional impairment. We assessed the association between symptomatic hip or knee osteoarthritis, falls, and the ability to walk among patients with Parkinson’s disease compared to a control group.

Methods:

A total of 136 patients with Parkinson’s disease in Southern Estonia and 142 controls with an average age of 76.8 and 76.3 years, respectively, were enrolled in a retrospective case-control study. Information on falls and related fractures during the previous year was collected from the patients with Parkinson’s disease and controls. Covariates included gender, age, mobility, duration of Parkinson’s disease, and fractures.

Results:

Patients with Parkinson’s disease were at an increased risk of falls compared to the control group, and for the higher risk of fractures. Symptomatic knee or hip osteoarthritis was a significant independent predictor of falls in both patients with Parkinson’s disease and controls. The higher risk for fractures during the previous year was demonstrated in symptomatic osteoarthritis. Risk factors for falls included also female gender, use of sleep pills, and the inability to walk 500 m.

Conclusions:

Symptomatic hip and knee osteoarthritis are risk factors for falls and related fractures among the elderly population with and without Parkinson’s disease. The inability to walk 500 m could be used as a simple predictive factor for the increased risk of falls among elderly populations.

Cognitive profile of patients with manganese-methcathinone encephalopathy

Manganese-methcathinone encephalopathy (MME) is a rare parkinsonian syndrome described in drug addicts who have self-injected a home-made mixture containing methcathinone and manganese. We assessed 14 patients with MME and compared their results with 14 matched control subjects. The patients had a parkinsonian syndrome with symmetrical bradykinesia, dystonias, and postural, gait and speech impairment, with moderate restrictions in activities of daily living. Their cognitive status was assessed with the Russian version of the Wechsler Adult Intelligence Scale (WAIS) and with tests of attention (Trail Making Test, Bourdon-Wiersma Dot Cancellation Test), memory (Auditory Verbal Learning Test, Rey-Osterrieth Complex Figure), motor skills (Grooved Pegboard), visuospatial skills (Money Road Map Test, Benton Judgment of Line Orientation), and executive abilities (Verbal Fluency, 5-Point Test, Wisconsin Card Sorting Test). Only a few significant differences emerged. After controlling for multiple comparisons, the results in the WAIS Object Assembly subtest, the Grooved Pegboard test (dominant and nondominant hand) and the Verbal Fluency test remained significant.

Acute effects of methcathinone and manganese in mice: A dose response study

An intravenously injectable illicit drug made by mixing pseudoephedrine, potassium permanganate, vinegar and water, yielding methcathinone (Mcat) and manganese (Mn), induces an extrapyramidal syndrome with parkinsonism, dystonia, gait and balance disorders similar to manganism. Although the cause of the syndrome is largely attributed to Mn, the interaction of the drug's individual components is not known and the role of Mcat is possibly underestimated. Aim of the present study was to analyze dose-dependent behavioral effects of the mixture and its two main active components Mcat and Mn in an acute setting and determine the lethal doses of each substance.

Three groups of C57BL/6 mice were injected intraperitoneally with (1) the drug mixture containing 10, 25, 50, 100 or 150 mg of Mcat and respectively 1.6, 3.8, 6.9, 17.1 and 22.6 mg of Mn per kilogram of body weight; (2) 10, 25, 50, 100, 150, 200 or 300 mg of racemic Mcat/kg of body weight; (3) MnCl₂ 10, 25 or 50 mg/kg of body weight. Locomotor activity of the animals, various signs and time of death were recorded.

Lower doses (10 and 25 mg/kg) of Mcat had a clear motor activity stimulating effect and this was clearly dose-dependent. High doses of Mcat produced epileptic seizures in 74% of the animals and became lethal with the highest doses. Similarly, the mixture had a clear dose-dependent stimulating effect and the higher doses became lethal. The LD₅₀ of the pseudoephedrine mixture was 110.2 mg of Mcat/kg and for pure Mcat 201.7 mg/kg. Mn did not prove to be lethal in doses up to 50 mg/kg, but had a strong dose dependent inhibitory effect on the animals’ behavior. Our data reveal that both Mn and Mcat have a significant role in the toxicity of the mixture.

Increased Serum Levels of Mesencephalic Astrocyte-Derived Neurotrophic Factor in Subjects With Parkinson's Disease

Background

Mesencephalic astrocyte-derived neurotrophic factor (MANF) and cerebral dopamine neurotrophic factor (CDNF) promote the survival of midbrain dopamine neurons in animal models of Parkinson’s disease (PD). However, little is known about endogenous concentrations of MANF and CDNF in human PD patients, and their relation to PD pathogenesis. Our main objective was to study whether circulating concentrations of MANF and CDNF differ between PD patients and controls, and if they correlate with clinical parameters. Levels of circulating CDNF were studied for the first time.

Methods

MANF and CDNF levels were measured from serum samples of 34 PD patients and 35 controls using validated in-lab-designed enzyme-linked immunosorbent assay (ELISAs). MANF and CDNF mRNA levels in whole blood samples of 60 PD patients and 30 controls were measured by quantitative real time polymerase chain reaction (qRT-PCR). MANF concentrations in different blood cell types were measured by ELISA.

Results

Circulating MANF concentrations were significantly higher in PD patients compared to controls (P < 0.001) and were positively correlated with Beck Depression Inventory (BDI) depression rating. MANF protein was present in blood cells, however, MANF mRNA levels in the blood did not differ between PD patients and controls (P = 0.44). The mean concentration of serum CDNF was 33 pg/ml in the controls. CDNF levels were not altered in PD patients (P = 0.25).

Conclusion

MANF but not CDNF level was increased in the blood of PD patients. It would be interesting to examine the blood level of MANF from early stage PD patients in future studies to test whether MANF can be used as a clinical marker of PD.

Versatile guideline-based physiotherapy intervention in groups to improve gait speed in Parkinson's disease patients

BACKGROUND:

Gait function is known to be impaired by Parkinson’s disease (PD). The effect of exercise to improve gait has been widely examined, often with special intervention. However, in clinical settings, physiotherapy rarely consists only of gait training.

OBJECTIVE:

To examine whether versatile physiotherapy intervention conducted in accordance with European Physiotherapy Guideline for Parkinson’s Disease (EPGPD) is sufficient to increase gait speed (GS).

METHODS:

Participants (24) with idiopathic PD were randomly enrolled into intervention (IG) and control groups (CG) (n = 12, 7 females and 5 males in each group). Sixteen one-hour therapy sessions (twice per week) were conducted for IG. Each session focused on core areas recommended in EPGPD. Participants were assessed twice with 10 weeks between assessments. GS was calculated based on a gait test of Short Physical Performance Battery. Dominant side hip flexion and abduction range of motion (HFLEX & HABD) were measured and Freezing of Gait questionnaire (FOG) was administered.

RESULTS:

Versatile intervention in groups resulted in increase of GS (ES –0.9 [CI{0.1}–{0.4}] m/s) and HFLEX (ES–0.6 [CI{5.9}–{16.6°}]. FOG was reduced (ES –0.41 [CI {–2.8}{–5.5}]). Re-evaluation HABD differed between groups and indicated large ES (r = –0.5).

CONCLUSIONS:

Versatile physiotherapy is sufficient to improve GS, range of motion and reduce FOG.

Incidence and Mortality of Parkinson's Disease in Estonia

BACKGROUND

There is lack of data on the incidence of Parkinson's disease (PD) based on repeat studies. Mortality rates of PD in Estonia have never been studied before.

OBJECTIVES

To estimate the incidence and mortality rates of PD in -Estonia, to compare current incidence rates with those of the prior epidemiological study in Estonia, and to examine the reported causes of death of the study population.

METHODS

Eligible subjects were identified from multiple case-finding sources. Subjects were subsequently tracked on the Electronic-Health Record until either the end of the study, or their death. Incidence rates and standardized mortality ratios (SMR) were calculated. Causes of death were identified, based on the data from death certificates.

RESULTS

In the current study, the overall age-adjusted incidence rate was 28.0/100,000 person-years (95% CI 25.2-30.8). Compared with the previous study, the age-adjusted incidence rate inEstonia has not significantly changed (rate ratio 1.11; p = 0.19). Overall SMR for the inception cohort of PD cases with a median follow-up time of 5 years was 1.12 (95% CI 0.88-1.36; p = 0.3). For those deceased subjects known to have had clinically diagnosed PD, this was mentioned on 46.8% of death certificates.

CONCLUSIONS

Over the last 20 years, the overall incidence of PD in Estonia has remained comparatively stable. The data did not show an excess mortality in PD patients (vs. general population) in the first 5 years of the disease.

Serum Amyloid Alpha Is Downregulated in Peripheral Tissues of Parkinson's Disease Patients

We report the changed levels of serum amyloid alpha, an immunologically active protein, in Parkinson’s disease (PD) patients’ peripheral tissues. We have previously shown that Saa-1 and -2 (serum amyloid alpha-1,-2, genes) were among the top downregulated genes in PD patients’ skin, using whole-genome RNA sequencing. In the current study, we characterized the gene and protein expression profiles of skin and blood samples from patients with confirmed PD diagnosis and age/sex matched controls. qRT-PCR analysis of PD skin demonstrated downregulation of Saa-1 and -2 genes in PD patients. However, the lowered amount of protein could not be visualized using immunohistochemistry, due to low quantity of SAA (Serum Amyloid Alpha, protein) in skin. Saa-1 and -2 expression levels in whole blood were below detection threshold based on RNA sequencing, however significantly lowered protein levels of SAA1/2 in PD patients’ serum were shown with ELISA, implying that SAA is secreted into the blood. These results show that SAA is differentially expressed in the peripheral tissues of PD patients.

Effect of Age on Substantia Nigra Hyper-echogenicity in Parkinson's Disease Patients and Healthy Controls

Substantia nigra (SN) hyper-echogenicity (SN+) describes an enlargement (>90th percentile) of the area of echogenicity at the anatomic site of the SN in the midbrain detected by transcranial sonography. This ultrasound sign has proven to be a valuable marker supporting the clinical diagnosis of Parkinson's disease (PD). Although there is considerable variation in the extent of echogenic signals at the anatomic site of the SN among PD patients, previous work suggests that SN+ is a stable marker throughout the course of the disease. The present study focused on two aspects: (i) determining whether SN+ values differ between the sides, mirroring the asymmetric character of the disease; and (ii) determining whether age has an influence on SN echogenicity. This cross-sectional study included 300 PD patients and 200 healthy controls. SN+ was measured planimetrically by transcranial sonography. Echogenicity was analyzed separately for onset and non-onset sides, with onset side defined as the SN contralateral to the side of the body that first manifested PD-related motor impairment. Age of the patients and healthy controls at study time was used for correlation. We found that the onset SN+ contralateral to the side of initial motor symptoms was on average 17.6% larger than its counterpart. However, we also found that contrary to the control group, where an increase in age was associated with an increase in size of SN+, age of PD patients was associated with a decline in size of the onset SN+. Furthermore, SN measured at the onset side of PD patients correlated significantly with patient age and Hoehn and Yahr stage, a scale that grades PD severity, although this was not the case for the non-onset side. The present study indicates that changes in SN echogenicity have a different dynamic depending on the onset side of the disease. The age at study time had a significantly negative effect on the size of onset SN+, the effect on the non-onset side was non-significant. We conclude that for appropriate PD analysis, onset SN+ is a more important marker than the average of both sides of SN. Furthermore, we found that among healthy controls, the size of SN+ increases with age.

Adaption and validation of the Mississippi Aphasia Screening Test to Estonian speakers with aphasia

OBJECTIVES

The Mississippi Aphasia Screening Test (MAST) is a brief screening tool for assessing the expressive and receptive language abilities of patients with aphasia. The goal of this study was to adapt and validate the MAST into the Estonian language. The discriminant validity and internal consistency of the test were examined, as well as its sensitivity and specificity.

METHODS

The MASTest was administered in 50 left hemisphere stroke patients with aphasia (LHA+ group) in the acute phase after the stroke and 126 healthy volunteers in a control group (CG), stratified by age and level of education. Nonparametric tests were used to get normative values, compare the values of the MASTest scores between the LHA+ group and the CG, and to assess the discriminant validity, internal consistency, sensitivity, and specificity of the MASTest.

RESULTS

The summary scores: total score (MASTest-T), expressive score (MASTest-E), and receptive score (MASTest-R) correlated with age and educational level, and the normative values were adjusted accordingly. The LHA+ group showed more impairment than the CG in all subtests and summary scores. The internal reliability of the MASTest was high for the whole sample and LHA+ group. The sensitivity and specificity of the MASTest using the 5th percentile were 74% and 94%, respectively, but using receiver operating characteristic (ROC) analysis, it was 89% and 80%.

CONCLUSION

The MASTest is a valid screening tool for evaluating expressive and receptive language abilities in Estonian patients with aphasia in early stroke. The MASTest is the first validated aphasia screening test for Estonian-speaking people, who number less than one million worldwide.

The increasing prevalence of Parkinson's disease in Estonia

OBJECTIVES

A previous epidemiological study of Parkinson's disease (PD) in the county of Tartu, Estonia, found an adjusted prevalence rate of 152/100 000 persons. We aimed to determine PD prevalence almost 20 years later, as well as evaluate any dynamic changes in disease frequency compared to the first study.

METHODS

A cross-sectional, community-based study was conducted over 2010-2016 in the county of Tartu, Estonia. Multiple case-finding sources, including information from neurologists, family doctors, the local PD Society, nursing institutions, and the database of the Estonian Health Insurance Fund were used to identify patients with PD of all ages.

RESULTS

Total crude PD prevalence was 283 and age-adjusted prevalence (standardized to the 2014 age structure of the Estonian population) 314/100 000. No significant differences in age-adjusted prevalence rates were found between men and women, nor people living in urban and rural areas. After adjustment to the same standard population used in the previous prevalence study, the overall age-adjusted prevalence rate was 197/100 000. Patients in the current study were older and often had a more severe form of PD and a longer disease duration, compared to those reported in the first epidemiological study 20 years ago.

CONCLUSIONS

The age-specific crude rates in oldest age-groups have risen substantially, and the age-adjusted prevalence has moderately increased compared to 20 years ago in Estonia. We hypothesize that the increased life expectancy of the Estonian population and improved diagnosis of PD contributed most to the increase in disease frequency.

Relationship between the MDS-UPDRS and Quality of Life: A large multicenter study of 3206 patients

BACKGROUND

The relationship between Health-Related Quality of Life (HRQoL) and MDS-UPDRS has not been fully studied so far. The aim of this study was to evaluate the relationship between all MDS-UPDRS components and HRQoL in a representative international cohort of PD patients.

METHODS

We collected demographic and disease-related data as well as MDS-UPDRS and PDQ8 scales. Data were analyzed using correlations between PDQ8 and all MDS-UPDRS items, subsequently two hierarchical multiple regressions were performed, first between the scores of the MDS-UPDRS Parts and PDQ8 and second between individual items from those Parts demonstrating significant relationship to PDQ8 scores in the first regression. LASSO regression analyses were performed to evaluate the relationship between PDQ8 and all individual MDS-UPDRS items.

RESULTS

A total of 3206 PD patients were included in the study. In the first regression analysis, PDQ8 was significantly related to MDS-UPDRS parts I and II, but not to III and IV. In the second regression model, significant contributions to PDQ8 were found for Part I items Fatigue, Pain, Depressed mood, Apathy; and Part II items Dressing, Doing hobbies, Freezing, Speech and Tremor. In the LASSO analysis, six Part I, seven Part II, three Part III and one Part IV items contributed to PDQ8 scores. The five items most significantly related to the model were Depressed mood, Dressing, Apathy, Pain and Fatigue.

CONCLUSIONS

This is so far the largest study related to HRQoL issues in PD. Restrictions in activities of daily living and non-motor symptoms significantly contribute to HRQoL in PD.

Prevalence of depressive symptoms and their association with brainstem raphe echogenicity in patients with Parkinson's disease and non-PD controls

Despite advances in diagnostics and clinical recognition, depressive symptoms in Parkinson's disease (PD) exceeding normal limits remain effectively untreated. In this study, we report on the prevalence and severity of depressive symptoms as well as their association with brainstem raphe echogenicity in patients with PD and non-PD controls. The study included 266 Estonian PD patients and 168 age- and education-matched controls. Demographic and clinical data was documented. Brainstem raphe (BR) was visualized by transcranial sonography (TCS). The prevalence of depressive symptoms in the patient sample was found to be significantly higher than in controls. BR echogenicity in both patients and controls was directly related to their total BDI score, although we found a significantly greater reduction of BR echogenicity in patients with PD and depressive symptoms compared to depressed non-PD controls. The present results corroborate the hypothesis that morphological alteration of the BR is involved in the pathogenesis of depressive disorders. TCS of BR could be used as a non-invasive biomarker to improve detection of depressive symptoms in early PD stages where clinicians may not recognize affective disturbances in the context of PD phenomena.

Factors associated with motor complications in Parkinson's disease

OBJECTIVES

Levodopa is the most effective therapy for treating Parkinson's disease (PD); however, side effects such as dyskinesias and motor fluctuations may occur after some years of its usage. The aims of this study were to assess the frequency of and factors associated with motor complications among PD patients on levodopa treatment.

METHODS

In a cross-sectional study carried out in 2010-2013, clinical data and treatment details were collected. Logistic regression expressed by odd ratios (OR) and 95% confidence intervals (CI) was conducted to examine the effects of several independent variables on the occurrence of motor complications.

RESULTS

A total of 455 patients were enrolled, among whom 374 were on levodopa. Analysis was performed in 328 patients whose exact duration of levodopa treatment was known. Among patients included in the analysis, 25.9% experienced motor complications; of these, 21% had dyskinesias and 20.1% had motor fluctuations. Based on logistic regression, statistically significant factors associated with the occurrence of motor complications were younger age at onset of the disease, higher levodopa equivalent daily dose (LEDD), shorter time to levodopa initiation, and akinetic-rigid dominant phenotype of PD.

CONCLUSIONS

This study suggests that postponing the start of levodopa therapy and maintaining low daily doses of levodopa might reduce the risk of motor complications. Our results confirm that due to higher risk of motor complications, effectively treating patients with akinetic-rigid dominant phenotype of PD might be more challenging than for patients whose dominant symptom is tremor.

Dissociation of reward and effort sensitivity in methcathinone-induced Parkinsonism

Methcathinone‐induced Parkinsonism is a recently described extrapyramidal syndrome characterized by globus pallidus and substantia nigra lesions, which provides a unique model of basal ganglia dysfunction. We assessed motivated behaviour in this condition using a novel cost‐benefit decision‐making task, in which participants decided whether it was worth investing effort for reward. Patients showed a dissociation between reward and effort sensitivity, such that pallidonigral complex dysfunction caused them to become less sensitive to rewards, while normal sensitivity to effort costs was maintained.

Differences in MDS-UPDRS Scores Based on Hoehn and Yahr Stage and Disease Duration

Background

The Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS) is a newly developed tool to assess Parkinson's disease (PD). Changes in scores on the scale over the course of PD, including increasing disease duration and Hoehn and Yahr (HY) stages, have not been described. The objectives of this study were to analyze MDS-UPDRS scores on Parts I through IV and their differences based on HY stage and disease duration in a large cohort of patients with PD.

Methods

For this cross-sectional study, demographic data and MDS-UPDRS scores were collected, including HY stage. Subscores on MDS-UPDRS Parts I through IV were analyzed using 1-way analyses of variance for each HY stage and in 5-year increments of disease duration. Part III (motor assessment) scores were analyzed separately for on and off states.

Results

The mean age of the 3206 patients was 65.8 ± 10.6 years, 53.3% were men, the mean disease duration was 11.5 ± 4.6 years, and the median HY stage was 2 (range, 0-5); 2156 patients were examined in an on state and 987 were examined in an off state. Scores for all MDS-UPDRS parts increased significantly through HY stages 1 through 5, with an average increase of 3.8, 7.7, 14.6, and 2.0 points consecutively for parts I through IV, respectively. For the 5-year increments of disease duration, MDS-UPDRS subscores increased by an average of 1.6, 3.3, 4.2, and 1.4 points consecutively for parts I through IV, respectively. This increase was significant only during the first 15 years of disease for all 4 parts, including part III scores evaluated in both on and off states.

Conclusions

MDS-UPDRS scores for all 4 parts increase significantly with every HY stage and also with 5-year increments of disease duration in the first 15 years of the disease.

Looking beyond the brain to improve the pathogenic understanding of Parkinson's disease: implications of whole transcriptome profiling of Patients' skin

BACKGROUND

Parkinson's Disease is a progressive neurodegenerative disease, characterized by symptoms of motor impairment, resulting from the loss of dopaminergic neurons in the midbrain, however non-neuronal symptoms are also common. Although great advances have been made in the pathogenic understanding of Parkinson's Disease in the nervous system, little is known about the molecular alterations occurring in other non-neuronal organ systems. In addition, a higher rate of melanoma and non-melanoma skin cancer has been observed in the Parkinson's Disease population, indicating crosstalk between these diseases.

METHODS

To understand the molecular pathogenesis and gene expression alterations of Parkinson's Disease in peripheral tissues, and in order to explore the possible link between skin cancer and neurodegeneration, whole transcriptomic profiling of patients' skin was performed. Skin biopsies from 12 patients and matched controls were collected, and processed with high-throughput RNA-sequencing analysis.

RESULTS

This analysis resulted in a large collection of over 1000 differentially expressed genes, among which clear biological and functional networks could be distinguished. The central functional processes altered in patients skin can be grouped into six broad categories: impaired cellular metabolism and mitochondrial dysfunction, defective protein metabolism, disturbed skin homeostasis, dysfunctional nuclear processes, altered signalling and tumour pathways, as well as disordered immune regulation.

CONCLUSIONS

These results demonstrate that the molecular alterations leading to neurodegeneration in the CNS are systemic and manifest also in peripheral tissues, thereby indicating the presence of "skin-brain" crosstalk in Parkinson's Disease. In addition, the extensive homeostatic imbalance and basal stress can lead to increased susceptibility to external and internal mutagenic hazards in these patients, and thus provide a possible molecular link for the crosstalk between skin cancer and Parkinson's Disease.