The prevalence of Parkinson's disease: a systematic review and meta-analysis

The impact of biological sex and sex hormones on cognition in a rat model of early, pre-motor Parkinson's disease

Parkinson's disease (PD) is well known for motor deficits such as bradykinesia. However, patients often experience additional deficits in working memory, behavioral selection, decision-making and other executive functions. Like other features of PD, the incidence and severity of these cognitive symptoms differ in males and females. However, preclinical models have not been used to systematically investigate the roles that sex or sex hormones may play in these complex signs. To address this, we used a Barnes maze spatial memory paradigm to compare the effects of a bilateral nigrostriatal dopamine lesion model of early PD on cognitive behaviors in adult male and female rats and in adult male rats that were gonadectomized or gonadectomized and supplemented with testosterone or estradiol. We found that dopamine lesions produced deficits in working memory and other executive operations, albeit only in male rats where circulating androgen levels were physiological. In males where androgen levels were depleted, lesions produced no additional Barnes maze deficits and attenuated those previously linked to androgen deprivation. We also found that while most measures of Barnes maze performance were unaffected by dopamine lesions in the females, lesions did induce dramatic shifts from their preferred use of thigmotactic navigation to the use of spatially guided place strategies similar to those normally preferred by males. These and other sex- and sex hormone-specific differences in the effects of nigrostriatal dopamine lesions on executive function highlight the potential of gonadal steroids as protective and/or therapeutic for the cognitive symptoms of PD. However, their complexity also indicates the need for a more thorough understanding of androgen and estrogen effects in guiding the development of hormone therapies that might effectively address these non-motor signs.

More than just dancing: experiences of people with Parkinson's disease in a therapeutic dance program

PURPOSE

To understand why individuals with Parkinson's disease (PD) participate in a community-based therapeutic dance program and to explore its influence on perceived physical, social and emotional well-being of participants.

METHODS

A qualitative descriptive design was employed using one-on-one semi-structured interviews. Individuals with PD who participated in the Dancing with Parkinson's program were recruited from two locations. Interviews were audio-recorded, transcribed, de-identified and then placed into NVivo 10 software for analysis. A content analysis approach was used with an inductive analysis method to generate a coding scheme. Group discussion facilitated development of overarching themes.

RESULTS

Ten participants' responses revealed that the dance program allows for self-improvement and regaining identity through disease self-management. Positive influences of socialization arose through the class, decreasing isolation and improving quality of life. Participants communicate through music and dance to enhance connection with others.

CONCLUSIONS

Dancing with Parkinson's classes allow for re-development of the social self, which can increase sense of enjoyment in life. Dance programs provide opportunities for social interaction, non-verbal communication and self-improvement, reestablishing self-identity and a sense of usefulness. This study provides unique insight into the experience of participating in a dance program from the perspective of individuals with PD. Implications for rehabilitation Dance is emerging as a strategy to address the physical and psychosocial effects of Parkinson's disease (PD), but little is known regarding participants' perceptions of community-based therapeutic dance programs for PD. This study found that Dancing with Parkinson's (DWP) facilitated an improvement in social participation, resulting in decreased isolation and improved quality of life. Participation in the DWP program can facilitate a positive change in perspective and attitude toward a PD diagnosis, thereby increasing feelings of self-efficacy and improving self-management of the disease. Participants of this study emphasized the multifaceted benefits of DWP, suggesting that it has great potential for addressing not only the physical challenges, but also the cognitive and emotional challenges associated with PD.

Transcranial sonography findings related to depression in parkinsonian disorders: cross-sectional study in 126 patients

Background. Transcranial sonography (TCS) has emerged as a potential diagnostic tool for Parkinson’s disease. Recent research has suggested that abnormal echogenicity of substantia nigra, raphe nuclei and third ventricle is associated with increased risk of depression among these patients. We sought to reproduce these findings in an ongoing larger study of patients with parkinsonian syndromes.

Methods. A total of 126 patients with parkinsonian symptoms underwent the Hamilton Depression Scale, and TCS of the substantia nigra (SN) (n = 126), the raphe nuclei (RN) (n = 80) and the third ventricle (n = 57). We then calculated the correlation between depression and hyper-echogenic SN, hypo-echogenic RN and a wider third ventricle.

Results. In patients with PD we found no significant difference of the SN between non-depressed and depressed patients (46% vs. 22%; p = 0.18). Non-depressed patients with other parkinsonisms more often had hyperechogenicity of the SN than depressed patients (51% vs. 0%; p = 0.01). We found no relation between depression and the echogenicity of the RN or the width of the third ventricle.

Conclusions. In patients with parkinsonian syndromes, we found no association between depression and hyper-echogenic SN, hypo-echogenic RN or a wider third ventricle, as determined by transcranial sonography.

Analysis of four scales for global severity evaluation in Parkinson's disease

Global evaluations of Parkinson’s disease (PD) severity are available, but their concordance and accuracy have not been previously tested. The present international, cross-sectional study was aimed at determining the agreement level among four global scales for PD (Hoehn and Yahr, HY; Clinical Global Impression of Severity, CGIS; Clinical Impression of Severity Index, CISI-PD; and Patient Global Impression of Severity, PGIS) and identifying which of them better correlates with itemized PD assessments. Assessments included additional scales for evaluation of the movement impairment, disability, affective disorders, and quality of life. Spearman correlation coefficients, weighted and generalized kappa, and Kendall’s concordance coefficient were used. Four hundred thirty three PD patients, 66% in HY stages 2 or 3, mean disease duration 8.8 years, were analyzed. Correlation between the global scales ranged from 0.60 (HY with PGIS) to 0.91 (CGIS with CISI-PD). Kendall’s coefficient of concordance resulted 0.76 (P<0.0001). HY and CISI-PD showed the highest association with age, disease duration, and levodopa-equivalent daily dose, and CISI-PD with measures of PD manifestations, disability, and quality of life. PGIS and CISI-PD correlated similarly with anxiety and depression scores. The lowest agreement in classifying patients as mild, moderate, or severe was observed between PGIS and HY or CISI-PD (58%) and the highest between CGIS and CISI-PD (84.3%). The four PD global severity scales agree moderately to strongly among them; clinician-based ratings estimate PD severity, as established by other measures, better than PGIS; and the CISI-PD showed the highest association with measures of impairment, disability, and quality of life.

Cognitive predictors of balance in Parkinson's disease

Postural instability is one of the most incapacitating symptoms of Parkinson's disease (PD) and appears to be related to cognitive deficits. This study aims to determine the cognitive factors that can predict deficits in static and dynamic balance in individuals with PD. A sociodemographic questionnaire characterized 52 individuals with PD for this work. The Trail Making Test, Rule Shift Cards Test, and Digit Span Test assessed the executive functions. The static balance was assessed using a plantar pressure platform, and dynamic balance was based on the Timed Up and Go Test. The results were statistically analysed using SPSS Statistics software through linear regression analysis. The results show that a statistically significant model based on cognitive outcomes was able to explain the variance of motor variables. Also, the explanatory value of the model tended to increase with the addition of individual and clinical variables, although the resulting model was not statistically significant The model explained 25-29% of the variability of the Timed Up and Go Test, while for the anteroposterior displacement it was 23-34%, and for the mediolateral displacement it was 24-39%. From the findings, we conclude that the cognitive performance, especially the executive functions, is a predictor of balance deficit in individuals with PD.

Neuropsychiatric Symptoms in Parkinson's Disease Dementia Are More Similar to Alzheimer's Disease than Dementia with Lewy Bodies: A Case-Control Study

Background and purpose

Previous studies on the clinical and pathological manifestations of Parkinson’s disease dementia (PDD) have reported findings more similar to dementia with Lewy bodies (DLB) than to Alzheimer’s disease (AD). The aim of this study was to investigate the neuropsychiatric symptoms of PDD compared to DLB and AD.

Methods

We conducted a retrospective case-control study on 125 newly diagnosed consecutive PDD patients and age- and dementia stage-matched controls with either DLB (N = 250) or AD (N = 500) who visited the same hospital over the same period. For each case and control, neuropsychiatric symptoms were assessed using the Neuropsychiatric Inventory (NPI).

Results

Overall, 513 (58.6%) patients were female and 362 (41.4%) were male. Comparisons of clinical data revealed that the PDD group, similar to the AD group, had a lower NPI total score, NPI caregiver burden score, and rate of antipsychotic use (all p < 0.001) than the DLB group. One or more psychiatric symptoms were reported in 95.2% of the PDD, 99.2% of the DLB, and 96.8% of the AD patients. The PDD group had lower subscores in the items of delusions, hallucinations, agitation, anxiety, irritation, aberrant motor behavior compared to the DLB group. Severe neuropsychiatric symptoms among all dementia patients were associated with younger age, more advanced stage, and a diagnosis of DLB.

Conclusion

Neuropsychiatric symptoms in PDD were more like those in AD than in DLB. Severe neuropsychiatric symptoms in degenerative dementia were associated with younger age, more advanced stage of dementia, and a diagnosis of DLB.

Risk of Parkinson's Disease Among Patients with Psoriasis: A Systematic Review and Meta-analysis

Background:

Patients with psoriasis might be at a higher risk of developing Parkinson's disease (PD) as a result of the detrimental effect of chronic inflammation on the neuronal tissue. This meta-analysis aimed to investigate this risk by comprehensively reviewing all available data.

Methods:

We conducted a systematic review and meta-analysis of cohort and case–control studies that reported relative risk, hazard ratio, odds ratio, or standardized incidence ratio comparing the risk of PD in patients with psoriasis versus subjects without psoriasis. Pooled risk ratio and 95% confidence interval (CI) were calculated using random-effect, generic inverse variance methods of DerSimonian and Laird.

Results:

Three retrospective studies and one case–control study met our eligibility criteria and were included in this meta-analysis. The pooled risk ratio of PD in patients with psoriasis versus participants without psoriasis was 1.38 (95% CI, 1.15–1.66). The statistical heterogeneity was low with an I² of 35%.

Conclusions:

Our meta-analysis demonstrated a statistically significant increased risk of PD among patients with psoriasis.

SIRT3 Acts as a Neuroprotective Agent in Rotenone-Induced Parkinson Cell Model

SIRT3 is a member of Sirtuins family, which belongs to NAD(+) dependent class III histone deacetylases. Emerging evidence suggests that SIRT3 plays a pivotal role in regulating mitochondrial function. Mitochondrial dysfunction is a main pathogenesis of Parkinson's disease (PD). Here, we have investigated the protective effect of SIRT3 for PD cell model. The rotenone-induced human neuroblastoma SH-SY5Y cells damage was used as PD cell model. The lentiviral vectors were used to over-expression or knockdown SIRT3 expression. The cell viability was analyzed using MTT method. The apoptosis, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were measured by flow cytometer. Superoxide dismutase (SOD) and glutathione (GSH) were detected by using automated microplate reader. The accumulation of α-synuclein was determined by immunofluorescence staining. SIRT3 knockdown significantly worsen rotenone-induced decline of cell viability (p < 0.01) and enhanced cell apoptosis (p < 0.01), exacerbated the decrease of SOD (p < 0.05) and GSH (p < 0.05), and augmented the accumulation of α-synuclein (p < 0.05). While SIRT3 overexpression dramatically increased cell viability (p < 0.01), and decreased cell apoptosis (p < 0.01), prevented the accumulation of α-synuclein (p < 0.05), suppressed the reducing of SOD (p < 0.05) and GSH (p < 0.01), decreased ROS generation (p < 0.05), and alleviated MMP collapse (p < 0.01) induced by rotenone. SIRT3 has neuroprotective effect in PD cell model and could be developed into a therapeutic agent for PD patients.

SUMO-regulated mitochondrial function in Parkinson's disease

Parkinson's disease (PD) is the second most common neurodegenerative disorder characterized by cardinal motor signs such as rigidity, bradykinesia or rest tremor that arise from a significant death of dopaminergic neurons. Non-dopaminergic degeneration also occurs and it seems to induce the deficits in olfactory, emotional, and memory functions that precede the classical motor symptoms in PD. Despite the majority of PD cases being sporadic, several genes have previously been associated with the hereditary forms of the disease. The proteins encoded by some of these genes, including α-synuclein, DJ-1, and parkin, are modified by small ubiquitin-like modifier (SUMO), a post-translational modification that regulates a variety of cellular processes. Among the several pathogenic mechanisms proposed for PD is mitochondrial dysfunction. Recent studies suggest that SUMOylation can interfere with mitochondrial dynamics, which is essential for neuronal function, and may play a pivotal role in PD pathogenesis. Here, we present an overview of recent studies on mitochondrial disturbance in PD and the potential SUMO-modified proteins and pathways involved in this process. SUMOylation, a post-translational modification, interferes with mitochondrial dynamics, and may play a pivotal role in Parkinson's disease (PD). SUMOylation maintains α-synuclein (α-syn) in a soluble form and activates DJ-1, decreasing mitochondrial oxidative stress. SUMOylation may reduce the amount of parkin available for mitochondrial recruitment and decreases mitochondrial biogenesis through suppression of peroxisomal proliferator-activated receptor-γ co-activator 1 α (PGC-1α). Mitochondrial fission can be regulated by dynamin-related protein 1 SUMO-1- or SUMO-2/3-ylation. A fine balance for the SUMOylation/deSUMOylation of these proteins is required to ensure adequate mitochondrial function in PD.

Carnosic Acid Attenuates 6-Hydroxydopamine-Induced Neurotoxicity in SH-SY5Y Cells by Inducing Autophagy Through an Enhanced Interaction of Parkin and Beclin1

Enhanced removal of abnormal protein aggregates or injured organelles through autophagy is related to neuroprotection in Parkinson's disease. In this study, we explored whether the induction of autophagy is associated with the neuroprotection of rosemary carnosic acid (CA) against 6-hydroxydopamine (6-OHDA)-induced neurotoxicity in SH-SY5Y cells. The results indicated that cells treated with CA had increased protein levels of parkin and autophagy-related markers, including phosphatidylinositol 3-kinase p100, Beclin1, autophagy-related gene 7, and microtubule-associated protein 1 light chain 3-II, as well as enhanced formation of autophagic vacuoles. Treatment of cells with 6-OHDA decreased the levels of parkin and the autophagy markers, but CA pretreatment reversed these effects. However, wortmannin (an autophagosome formation blocker) pretreatment attenuated the effect of CA. After CA pretreatment, the induction of cleaved caspase 3, cleaved poly-ADP ribose polymerase, and nuclear condensation by 6-OHDA were alleviated. Both wortmannin and bafilomycin A1 (an autophagosome-lysosome fusion blocker) inhibited the anti-apoptosis effects of CA. Additionally, we performed immunoprecipitation with anti-parkin antibody and found that the interaction of parkin and Beclin1 protein was reduced by 6-OHDA but that this effect was reversed in cells pretreated with CA. Moreover, transfection of parkin siRNA in cells inhibited the ability of CA to alleviate 6-OHDA-decreased autophagy-related markers and nuclear condensation. In conclusion, CA protects against 6-OHDA-induced apoptosis by inducing autophagy through the interaction of parkin and Beclin1. These results provide a future strategy for use of CA in the prevention of Parkinson's disease.

Self-awareness of memory impairment in Parkinson’s disease: a review of the literature

Purpose

– The purpose of this paper is to review and provide information on the small but growing body of literature that demonstrates that some people with Parkinson’s disease (PD) are unaware of the memory impairment, and this has clinical implications for how family members care for their loved one, and how clinical staff and others may interact with them on a day-to-day perspective.

Design/methodology/approach

– The approach takes the form of a general review.

Findings

– People with PD experience a variety of cognitive impairment including deficits in memory and higher level executive processes. Impairment in these areas can occur early in the disease course and result in adverse consequences including distractibility, trouble recalling information, and problems remembering to execute planned actions like adhering to medication regimes. The literature also suggests heterogeneity in both the memory performance of people with PD and in the definition of awareness used to investigate this phenomenon.

Practical implications

– Strategies for remembering may be of practical importance for people with PD, and/or caregivers should be introduced and educated to the nature of memory impairment in PD, as well as its likely course and natural progression in a non-threatening way before they are later instructed on “tips” for maximising daily functioning as more severe cognitive deficits begin to appear.

Originality/value

– This paper adds to the small body of literature that investigates patients’ awareness of memory impairment in PD and advocates for ongoing research within the area.

Glycation in Parkinson's disease and Alzheimer's disease

Glycation is a spontaneous age-dependent posttranslational modification that can impact the structure and function of several proteins. Interestingly, glycation can be detected at the periphery of Lewy bodies in the brain in Parkinson's disease. Moreover, α-synuclein can be glycated, at least under experimental conditions. In Alzheimer's disease, glycation of amyloid β peptide exacerbates its toxicity and contributes to neurodegeneration. Recent studies establish diabetes mellitus as a risk factor for several neurodegenerative disorders, including Parkinson's and Alzheimer's diseases. However, the mechanisms underlying this connection remain unclear. We hypothesize that hyperglycemia might play an important role in the development of these disorders, possibly by also inducing protein glycation and thereby dysfunction, aggregation, and deposition. Here, we explore protein glycation as a common player in Parkinson's and Alzheimer's diseases and propose it may constitute a novel target for the development of strategies for neuroprotective therapeutic interventions. © 2016 International Parkinson and Movement Disorder Society.

Clinical course and prognosis in patients with Gaucher disease and parkinsonism

Objective:

The goal of this study was to characterize the parkinsonian phenotype in patients with Gaucher disease (GD) who developed parkinsonism in order to evaluate clinical course and prognosis.

Methods:

This is a retrospective observational study conducted at the Clinical Center of the NIH, Bethesda, MD, over a period of 10 years. The study included 19 patients with GD and parkinsonism. The severity of Gaucher and parkinsonian symptoms was determined from clinical data including physical, neurologic, pathologic, and neurocognitive evaluations, family histories, imaging studies, olfactory testing, and validated questionnaires.

Results:

We found an earlier age at onset of parkinsonism and evidence of mild cognitive dysfunction in our cohort. Although the clinical course in some patients was similar to that of idiopathic Parkinson disease with a favorable levodopa response, others exhibited features characteristic of dementia with Lewy bodies. When we examined the patients as a group, we did not observe a uniformly aggressive form of parkinsonism after the initial onset of symptoms, contrary to other published reports.

Conclusions:

Appreciable clinical variation was seen in this cohort with GD and parkinsonism. Although some patients had early onset and prominent cognitive changes, others had a later, slower course, indicating that GBA1 mutations may not be a reliable prognostic indicator in Parkinson disease in clinical settings.

Reliability of the Handgrip Strength Test in Elderly Subjects With Parkinson Disease

BACKGROUND

The handgrip strength test is widely used by clinicians; however, little has been investigated about its reliability when used in subjects with Parkinson disease (PD). The purpose of this study was to investigate the test-retest reliability of the handgrip strength test for subjects with PD.

METHODS

The PD group consisted of 15 patients, and the control group consisted of 15 healthy subjects. Each patient performed 3 pain-free maximal isometric contractions on each hand on 2 occasions, 1 week apart. Intraclass correlation coefficient (ICC), standard error of measurement (SEM), and 95% limits of agreement (LOA) were calculated. The 2-way analysis of variance (ANOVA) was conducted to determine the differences between sides and groups.

RESULTS

Test-retest reliability of measurements of grip strength was excellent for dominant (ICC = 0.97; P = .001) and non-dominant (ICC = 0.98; P = .001) hand of participant with PD and (ICC = 0.99; P = .001) and (ICC = 0.99; P = .001) respectively, of healthy group.

CONCLUSIONS

The Jamar hand dynamometer had fair to excellent test-retest reliability to test grip strength in participants with PD.

New insights on the mitochondrial proteome plasticity in Parkinson's disease

Parkinson's disease (PD) is one of the most common neurodegenerative diseases whose relentless progression results in severe disability. Although PD aetiology is unknown, growing evidences point to the mitochondrial involvement in the pathobiology of this disorder. So, it seems imperative to understand the means by which the molecular pathways harboured in this organelle are regulated. With the advances in MS-based proteomics, there is a substantial expectation in the increased knowledge of mitochondrial protein dynamics. Still, few studies have been performed on mitochondrial protein profiling in the context of PD. In order to integrate data from these studies, network analyses were performed taking into consideration variables such as model of PD, cell line, or tissue origin. Overall, data retrieved from these analyses highlighted the modulation of the biological processes related with "generation of energy," "cellular metabolism," and "mitochondrial transport" in PD. However, it was noted that the impact of sample type and/or PD model on the biological processes was modulated by the disease. Moreover, technical considerations related to protein characterization using gel-based or gel-free MS approaches should be considered in data comparison among different studies. Data from the present review will help to envisage future studies targeting these mechanisms.

Oropharyngeal dysphagia in older persons - from pathophysiology to adequate intervention: a review and summary of an international expert meeting

Oropharyngeal dysphagia (OD) is a highly prevalent and growing condition in the older population. Although OD may cause very severe complications, it is often not detected, explored, and treated. Older patients are frequently unaware of their swallowing dysfunction which is one of the reasons why the consequences of OD, ie, aspiration, dehydration, and malnutrition, are regularly not attributed to dysphagia. Older patients are particularly vulnerable to dysphagia because multiple age-related changes increase the risk of dysphagia. Physicians in charge of older patients should be aware that malnutrition, dehydration, and pneumonia are frequently caused by (unrecognized) dysphagia. The diagnosis is particularly difficult in the case of silent aspiration. In addition to numerous screening tools, videofluoroscopy was the traditional gold standard of diagnosing OD. Recently, the fiberoptic endoscopic evaluation of swallowing is increasingly utilized because it has several advantages. Besides making a diagnosis, fiberoptic endoscopic evaluation of swallowing is applied to evaluate the effectiveness of therapeutic maneuvers and texture modification of food and liquids. In addition to swallowing training and nutritional interventions, newer rehabilitation approaches of stimulation techniques are showing promise and may significantly impact future treatment strategies.

The safety and efficacy of safinamide mesylate for the treatment of Parkinson's disease

Safinamide (brand name Xadago®, Zambon S.p.A) is a third-generation reversible MAO-B inhibitor, which also blocks sodium voltage-sensitive channels and modulates stimulated release of glutamate. Safinamide was recently licensed by EMA for the treatment of PD as add-on therapy to a stable dose of levodopa alone or in combination with other PD medicinal products in mid-to advanced-stage fluctuating patients. It is also under review by the US FDA. Studies in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated monkeys and 6OHDA-lesioned rats suggest antiparkinsonian efficacy and antidyskinesic effects. Randomized, double-blind, placebo-controlled trials have shown efficacy for the treatment of motor symptoms in stable PD patients on dopamine agonists and in fluctuating PD patients on levodopa. Significant improvement in daily ON time was also observed in the latter. This effect was maintained for at least 2 years in double-blind conditions and, interestingly, without significant worsening of dyskinesia. Clinical studies have not detected any specific safety issue other than those already known with MAO-B inhibitors.

Deficits in cholinergic neurotransmission and their clinical correlates in Parkinson's disease

In view of its ability to explain the most frequent motor symptoms of Parkinson’s Disease (PD), degeneration of dopaminergic neurons has been considered one of the disease’s main pathophysiological features. Several studies have shown that neurodegeneration also affects noradrenergic, serotoninergic, cholinergic and other monoaminergic neuronal populations. In this work, the characteristics of cholinergic deficits in PD and their clinical correlates are reviewed. Important neurophysiological processes at the root of several motor and cognitive functions remit to cholinergic neurotransmission at the synaptic, pathway, and circuital levels. The bulk of evidence highlights the link between cholinergic alterations and PD motor symptoms, gait dysfunction, levodopa-induced dyskinesias, cognitive deterioration, psychosis, sleep abnormalities, autonomic dysfunction, and altered olfactory function. The pathophysiology of these symptoms is related to alteration of the cholinergic tone in the striatum and/or to degeneration of cholinergic nuclei, most importantly the nucleus basalis magnocellularis and the pedunculopontine nucleus. Several results suggest the clinical usefulness of antimuscarinic drugs for treating PD motor symptoms and of inhibitors of the enzyme acetylcholinesterase for the treatment of dementia. Data also suggest that these inhibitors and pedunculopontine nucleus deep-brain stimulation might also be effective in preventing falls. Finally, several drugs acting on nicotinic receptors have proved efficacious for treating levodopa-induced dyskinesias and cognitive impairment and as neuroprotective agents in PD animal models. Results in human patients are still lacking.

Age-dependent differences in microglial responses to systemic inflammation are evident as early as middle age

Whereas age increases microglial inflammatory activities and impairs their ability to effectively regulate their immune response, it is unclear at what age these exaggerated responses begin. We tested the hypotheses that augmented microglial responses to inflammatory challenge are present as early as middle age and that repeated stimulation of primed microglia in vivo would reveal microglial senescence. Microglial gene expression was investigated in a mouse model of repeated systemic inflammation induced by intraperitoneal injection of bacterial lipopolysaccharide (LPS). Following LPS, microglia from middle-aged mice (9-10 mo) displayed larger increases in Tnfα, Il-6, and Il-1β gene expression compared with young adults (2 mo). Similar results were observed in the spleens of middle-aged mice, indicating that exaggeration of both central and peripheral immune responses are already evident at early middle age. Interestingly, despite greater proinflammatory responses to the first LPS challenge in the aged mice, there were no age-dependent differences in either microglia or spleen following a subsequent LPS dose, suggesting that animals at this age retain the ability to effectively control their immune response following repeated challenge. The exacerbated microglial immune response to systemic inflammation at early middle age suggests that the CNS may be vulnerable to age-dependent alterations earlier than previously appreciated.

Age at onset and Parkinson disease phenotype

OBJECTIVE

To explore clinical phenotype and characteristics of Parkinson disease (PD) at different ages at onset in recently diagnosed patients with untreated PD.

METHODS

We have analyzed baseline data from the Parkinson's Progression Markers Initiative database. Four hundred twenty-two patients with a diagnosis of PD confirmed by DaTSCAN imaging were divided into 4 groups according to age at onset (onset younger than 50 years, 50-59 years, 60-69 years, and 70 years or older) and investigated for differences in side, type and localization of symptoms, occurrence/severity of motor and nonmotor features, nigrostriatal function, and CSF biomarkers.

RESULTS

Older age at onset was associated with a more severe motor and nonmotor phenotype, a greater dopaminergic dysfunction on DaTSCAN, and reduction of CSF α-synuclein and total tau. The most common presentation was the combination of 2 or 3 motor symptoms (bradykinesia, resting tremor, and rigidity) with rigidity being more common in the young-onset group. In about 80% of the patients with localized onset, the arm was the most affected part of the body, with no difference across subgroups.

CONCLUSIONS

Although the presentation of PD symptoms is similar across age subgroups, the severity of motor and nonmotor features, the impairment of striatal binding, and the levels of CSF biomarkers increase with age at onset. The variability of imaging and nonimaging biomarkers in patients with PD at different ages could hamper the results of future clinical trials.

Microglia-Mediated Neuroinflammation and Neurotrophic Factor-Induced Protection in the MPTP Mouse Model of Parkinson's Disease-Lessons from Transgenic Mice

Parkinson's disease (PD) is a neurodegenerative disease characterised by histopathological and biochemical manifestations such as loss of midbrain dopaminergic (DA) neurons and decrease in dopamine levels accompanied by a concomitant neuroinflammatory response in the affected brain regions. Over the past decades, the use of toxin-based animal models has been crucial to elucidate disease pathophysiology, and to develop therapeutic approaches aimed to alleviate its motor symptoms. Analyses of transgenic mice deficient for cytokines, chemokine as well as neurotrophic factors and their respective receptors in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) model of PD have broadened the current knowledge of neuroinflammation and neurotrophic support. Here, we provide a comprehensive review that summarises the contribution of microglia-mediated neuroinflammation in MPTP-induced neurodegeneration. Moreover, we highlight the contribution of neurotrophic factors as endogenous and/or exogenous molecules to slow the progression of midbrain dopaminergic (mDA) neurons and further discuss the potential of combined therapeutic approaches employing neuroinflammation modifying agents and neurotrophic factors.

In Vitro Comparison of the Activity Requirements and Substrate Specificity of Human and Triboleum castaneum PINK1 Orthologues

Mutations in the gene encoding the mitochondrial kinase PINK1 cause early-onset familial Parkinson's disease. To understand the biological function of PINK1 and its role in the pathogenesis of Parkinson's disease, it is useful to study its kinase activity towards substrates both in vivo and in vitro. For in vitro kinase assays, a purified Triboleum castaneum PINK1 insect orthologue is often employed, because it displays higher levels of activity when compared to human PINK1. We show, however, that the activity requirements, and more importantly the substrate specificity, differ between both orthologues. While Triboleum castaneum PINK1 readily phosphorylates the PINKtide peptide and Histone H1 in vitro, neither of these non-physiological substrates is phosphorylated by human PINK1. Nonetheless, both Tc and human PINK1 phosphorylate Parkin and Ubiquitin, two physiological substrates of PINK1. Our results show that the substrate selectivity differs among PINK1 orthologues, an important consideration that should be taken into account when extrapolating findings back to human PINK1.

Quantification of the Metabolic State in Cell-Model of Parkinson's Disease by Fluorescence Lifetime Imaging Microscopy

Intracellular endogenous fluorescent co-enzymes, reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD), play a pivotal role in cellular metabolism; quantitative assessment of their presence in living cells can be exploited to monitor cellular energetics in Parkinson's disease (PD), a neurodegenerative disorder. Here, we applied two-photon fluorescence lifetime imaging microscopy (2P-FLIM) to noninvasively measure the fluorescence lifetime components of NADH and FAD, and their relative contributions in MPP(+) (1-methyl-4-phenylpyridinium) treated neuronal cells, derived from PC12 cells treated with nerve growth factor (NGF), to mimic PD conditions. A systematic FLIM data analysis showed a statistically significant (p < 0.001) decrease in the fluorescence lifetime of both free and protein-bound NADH, as well as free and protein-bound FAD in MPP(+) treated cells. On the relative contributions of the free and protein-bound NADH and FAD to the life time, however, both the free NADH contribution and the corresponding protein-bound FAD contribution increase significantly (p < 0.001) in MPP(+) treated cells, compared to control cells. These results, which indicate a shift in energy production in the MPP(+) treated cells from oxidative phosphorylation towards anaerobic glycolysis, can potentially be used as cellular metabolic metrics to assess the condition of PD at the cellular level.

Reaching Those Most in Need - A Call to Action for Advanced Parkinson's Disease

Much of the clinical and research attention for Parkinson's Disease (PD) has focused on mild to moderate stages. As the disease advances, it can become difficult for patients to attend clinical visits. These patients are often lost to follow-up, and consequently, vanish from the pool of potential research subjects who could inform our management of this understudied population. We aim to increase awareness about this population and potential interventions to improve continuity of care and foster research in advanced PD.

Cognitive Impairment Associated with Parkinson's Disease: Role of Mitochondria

Parkinson's disease (PD) is a movement disorder and is associated with some of the intellectual disabilities like cognitive dysfunctions. PD associated cognitive dysfunctions have been proved well in both preclinical and clinical set ups. Like other neurodegenerative diseases, insults to mitochondria have a significant role in the pathobiology of PD associated dementia (PDD). Neurotoxins like MPTP, mutations of the mitochondrial genes, oxidative stress, imbalanced redox mechanisms and dysregulated mitochondrial dynamics have been implicated in mitochondrial dysfunctions and have paramount importance in the pathobiology of PDD. However, the extent of contribution of mitochondrial dysfunctions towards cognitive deficits in PD has not been characterized completely. In this review we highlight on the contribution of mitochondrial dysfunction to PDD. We also highlight different behavioural tests used in nonhuman primate and rodent models for assessing cognitive deficits and some common techniques for evaluation of mitochondrial dysfunction in PDD.

Epidemiology of alpha-synucleinopathies: from Parkinson disease to dementia with Lewy bodies

The epidemiology of the diagnosis of Parkinson's disease and dementia with Lewy bodies is still based on clinical criteria and the definition of the different diseases is still a challenge for clinician and researcher. The epidemiologic estimates of prevalence and incidence are highly affected by differences in diagnostic criteria, geographic location, and methodologic limitations. Studies of prevalence and incidence show increases with advancing age and a higher rate of Parkinson's disease and dementia with Lewy bodies in men compared to women.

Cognitive and Psychiatric Effects of STN versus GPi Deep Brain Stimulation in Parkinson's Disease: A Meta-Analysis of Randomized Controlled Trials

BACKGROUND

Deep brain stimulation (DBS) of either the subthalamic nucleus (STN) or the globus pallidus interna (GPi) can reduce motor symptoms in patients with Parkinson's disease (PD) and improve their quality of life. However, the effects of STN DBS and GPi DBS on cognitive functions and their psychiatric effects remain controversial. The present meta-analysis was therefore performed to clarify these issues.

METHODS

We searched the PUBMED, EMBASE, and the Cochrane Central Register of Controlled Trials databases. Other sources, including internet-based clinical trial registries and grey literature sources, were also searched. After searching the literature, two investigators independently performed literature screens to assess the quality of the included trials and to extract the data. The outcomes included the effects of STN DBS and GPi DBS on multiple cognitive domains, depression, anxiety, and quality of life.

RESULTS

Seven articles related to four randomized controlled trials that included 521 participants were incorporated into the present meta-analysis. Compared with GPi DBS, STN DBS was associated with declines in selected cognitive domains after surgery, including attention, working memory and processing speed, phonemic fluency, learning and memory, and global cognition. However, there were no significant differences in terms of quality of life or psychiatric effects, such as depression and anxiety, between the two groups.

CONCLUSIONS

A selective decline in frontal-subcortical cognitive functions is observed after STN DBS in comparison with GPi DBS, which should not be ignored in the target selection for DBS treatment in PD patients. In addition, compared to GPi DBS, STN DBS does not affect depression, anxiety, and quality of life.

A door-to-door survey to estimate the prevalence of Parkinsonism in Pakistan

INTRODUCTION

Parkinson's disease (PD) occurs in all races and cultures, and population-related differences in frequency may provide etiological clues. The present study was designed to explore the prevalence of PD and Parkinsonism in Pakistan, the world's sixth most populous country, for which no published prevalence data are available.

METHODS

We conducted a three-phase door-to-door survey in two districts of the Khyber Pakhtunkhwa province of Pakistan, to assess the prevalence of PD and Parkinsonism in a sample of 4,000 individuals aged 50 years and above.

RESULTS

We identified 14 cases of Parkinsonism, eleven with a diagnosis of idiopathic PD. The overall prevalence estimates were 1.7/100 (95% confidence interval [CI]: 0.9-2.46) for Parkinsonism and 1.28/100 (95% CI: 0.6-1.94) for PD in persons aged 65 years and above. The age-standardized prevalence of PD (aged 65 years and above), normalized to the USA population in 2000, was 1.33/100, which is similar to that observed in other human populations. Of the total 14 cases, five were newly diagnosed and four had a family history of PD.

CONCLUSION

The estimated prevalence rates in Pakistan are similar to those observed in other human populations. The frequency of familial Parkinsonism is also equivalent to previous estimates.

Prevalence of parkinsonism estimated using the drug prescription archive: a possible method to estimate the prevalence of a chronic neurological disease?

Many surveys estimated prevalence of parkinsonism, with results varying largely. We used prescription records of medications for parkinsonism to estimate the prevalence of this condition. Retrospective survey based on Lazio (Italy) regional drugs' prescriptions registry. Cases of parkinsonism were defined as those who received a medication for parkinsonism (Dopa and dopa derivatives or Monoamine oxidase B-inhibitors) for at least 6 months in a 5-year period (2005-2009). Crude and standardized prevalence rates at June 2009 were calculated. Crude and standardized prevalence rates of parkinsonism in Lazio were, respectively, 283 per 100,000 (95 % CI 278-287), and 294 per 100,000 (95 % CI 289-298), higher in men than in women (292 per 100,000 vs. 274 per 100,000). The highest overall prevalence rate was observed among people aged 85-89 years (246 per 100,000), while the lowest in subjects aged <65 (38 per 100,000). Prevalence rates in people older than 65 and older 75 were, respectively, 1275 per 100,000 and 1912 per 100,000. Using a regional drug registry, based on currently available health information systems, may be a suitable method to estimate prevalence of parkinsonism, which is essential for public health programming, the more in presence of a demographic shift as the current one.

Neuroactive gonadal drugs for neuroprotection in male and female models of Parkinson's disease

The existence of sex differences in Parkinson's disease (PD) incidence is well documented with greater prevalence and earlier age at onset in men than in women. These reported sex differences could be related to estrogen exposure. In PD animal models, estrogen is well documented to be neuroprotective against dopaminergic neuron loss induced by neurotoxins. Using the 1-methyl 4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) mouse model, we showed that several compounds are neuroprotective on dopaminergic neurons including estrogen, the selective estrogen receptor modulator raloxifene, progesterone, dehydroepiandrosterone, the estrogen receptor alpha (ERα) agonist PPT as well as the G protein-coupled membrane estrogen receptor (GPER1) specific agonist G1. Accumulating evidence suggests that GPER1 could be implicated in the neuroprotective effects of estrogen, raloxifene and G1 in collaboration with ERα. We recently reported that the 5α-reductase inhibitor Dutasteride is also neuroprotective and could bring an alternative to estrogens for therapy in male. Additional studies are needed to optimize therapies with these gonadal drugs into safe personalized treatments according to sex for treatment of PD.

Induction of α-synuclein aggregate formation by CSF exosomes from patients with Parkinson's disease and dementia with Lewy bodies

Extracellular α-synuclein has been proposed as a crucial mechanism for induction of pathological aggregate formation in previously healthy cells. In vitro, extracellular α-synuclein is partially associated with exosomal vesicles. Recently, we have provided evidence that exosomal α-synuclein is present in the central nervous system in vivo. We hypothesized that exosomal α-synuclein species from patients with α-synuclein related neurodegeneration serve as carriers for interneuronal disease transmission. We isolated exosomes from cerebrospinal fluid from patients with Parkinson's disease, dementia with Lewy bodies, progressive supranuclear palsy as a non-α-synuclein related disorder that clinically overlaps with Parkinson's disease, and neurological controls. Cerebrospinal fluid exosome numbers, α-synuclein protein content of cerebrospinal fluid exosomes and their potential to induce oligomerization of α-synuclein were analysed. The quantification of cerebrospinal fluid exosomal α-synuclein showed distinct differences between patients with Parkinson's disease and dementia with Lewy bodies. In addition, exosomal α-synuclein levels correlated with the severity of cognitive impairment in cross-sectional samples from patients with dementia with Lewy bodies. Importantly, cerebrospinal fluid exosomes derived from Parkinson's disease and dementia with Lewy bodies induce oligomerization of α-synuclein in a reporter cell line in a dose-dependent manner. Our data suggest that cerebrospinal fluid exosomes from patients with Parkinson's disease and dementia with Lewy bodies contain a pathogenic species of α-synuclein, which could initiate oligomerization of soluble α-synuclein in target cells and confer disease pathology.

Thiazolidinediones and Parkinson Disease: A Cohort Study

Thiazolidinediones, a class of medications indicated for the treatment of type 2 diabetes mellitus, reduce inflammation and have been shown to provide a therapeutic benefit in animal models of Parkinson disease. We examined the association between treatment with thiazolidinediones and the onset of Parkinson disease in older individuals. We performed a cohort study of 29,397 Medicare patients enrolled in state pharmaceutical benefits programs who initiated treatment with thiazolidinediones or sulfonylureas during the years 1997 through 2005 and had no prior diagnosis of Parkinson disease. New users of thiazolidinediones were propensity score matched to new users of sulfonylureas and followed to determine whether they were diagnosed with Parkinson disease. We used Cox proportional hazards models to compare time to diagnosis of Parkinson disease in the propensity score-matched populations. To assess the association with duration of use, we performed several analyses that required longer continuous use of medications. In the primary analysis, thiazolidinedione users had a hazard ratio for a diagnosis of Parkinson disease of 1.09 (95% confidence interval: 0.71, 1.66) when compared with sulfonylurea users. Increasing the duration-of-use requirements to 10 months did not substantially change the association; the hazard ratios ranged from 1.00 (95% confidence interval: 0.49, 2.05) to 1.17 (95% confidence interval: 0.60, 2.25). Thiazolidinedione use was not associated with a longer time to diagnosis of Parkinson disease than was sulfonylurea use, regardless of duration of exposure.

Thinking about motor fluctuations: An examination of metacognitions in Parkinson's disease

OBJECTIVE

Motor fluctuations (characterised by a sudden increase in symptom intensity, referred to as an 'off-period') are common side effects after treatment of Parkinson's disease (PD) with dopaminergic medication. A proportion of these people find motor fluctuations highly distressing. This study aimed to identify metacognitions associated with cognitive and attentional responses to these experiences.

METHODS

Ten individuals with PD who experience motor fluctuations were interviewed for this study using an adapted metacognitive profiling schedule. Participants were asked about their metacognitions, and the cognitive processes and attentional strategies activated in response to a distressing off-period.

RESULTS

Metacognitions identified were more often related to conceptual thinking about symptoms rather than symptom focus and data suggested trends for increased depressive symptoms among individuals with stronger metacognitive beliefs.

CONCLUSION

Metacognitions may play a role in determining or maintaining off-period distress in PD.

Altered Neuronal Firing Pattern of the Basal Ganglia Nucleus Plays a Role in Levodopa-Induced Dyskinesia in Patients with Parkinson's Disease

BACKGROUND

Levodopa therapy alleviates the symptoms of Parkinson's disease (PD), but long-term treatment often leads to motor complications such as levodopa-induced dyskinesia (LID).

AIM

To explore the neuronal activity in the basal ganglia nuclei in patients with PD and LID.

METHODS

Thirty patients with idiopathic PD (age, 55.1 ± 11.0 years; disease duration, 8.7 ± 5.6 years) were enrolled between August 2006 and August 2013 at the Xuanwu Hospital, Capital Medical University, China. Their Hoehn and Yahr (1967) scores ranged from 2-4 and their UPDRS III scores were 28.5 ± 5.2. Fifteen of them had severe LID (UPDRS IV scores of 6.7 ± 1.6). Microelectrode recording was performed in the globus pallidus internus (GPi) and subthalamic nucleus (STN) during pallidotomy (n = 12) or STN deep brain stimulation (DBS; bilateral, n = 12; unilateral, n = 6). The firing patterns and frequencies of various cell types were analyzed by assessing single cell interspike intervals (ISIs) and the corresponding coefficient of variation (CV).

RESULTS

A total of 295 neurons were identified from the GPi (n = 12) and STN (n = 18). These included 26 (8.8%) highly grouped discharge, 30 (10.2%) low frequency firing, 78 (26.4%) rapid tonic discharge, 103 (34.9%) irregular activity, and 58 (19.7%) tremor-related activity. There were significant differences between the two groups (p < 0.05) for neurons with irregular firing, highly irregular cluster-like firing, and low-frequency firing.

CONCLUSION

Altered neuronal activity was observed in the basal ganglia nucleus of GPi and STN, and may play important roles in the pathophysiology of PD and LID.

A Systematic Review and Meta-analysis on the Epidemiology of the Muscular Dystrophies

Background: The muscular dystrophies are a heterogeneous group of genetic muscle diseases with variable distribution of weakness and mode of inheritance.Methods: We previously performed a systematic review of worldwide population-based studies on Duchenne and Becker muscular dystrophies; the current study focused on the epidemiology of other muscular dystrophies using Medline and EMBASE databases. Two reviewers independently reviewed all abstracts, full-text articles, and abstracted data from 1985 to 2011. Pooling of prevalence estimates was performed using random-effect models.Results: A total of 1104 abstracts and 167 full-text articles were reviewed. Thirty-one studies met all eligibility criteria and were included in the final analysis. The overall pooled prevalence of combined muscular dystrophies was 16.14 (confidence interval [CI], 11.21-23.23) per 100,000. The prevalence estimates per 100,000 were 8.26 (CI, 4.99-13.68) for myotonic dystrophy, 3.95 (CI, 2.89-5.40) for facioscapulohumeral dystrophy, 1.63 (CI, 0.94-2.81) for limb girdle muscular dystrophy, and 0.99 (CI, 0.62-1.57) for congenital muscular dystrophies.Conclusions: The studies differed widely in their approaches to case ascertainment, and substantial gaps remain in the global estimates of many other types of muscular dystrophies. Additional epidemiological studies using standardized diagnostic criteria as well as multiple sources of case ascertainment will help address the economic impact and health care burden of muscular dystrophies worldwide.

Dysphagia in Parkinson's Disease

More than 80 % of patients with Parkinson's disease (PD) develop dysphagia during the course of their disease. Swallowing impairment reduces quality of life, complicates medication intake and leads to malnutrition and aspiration pneumonia, which is a major cause of death in PD. Although the underlying pathophysiology is poorly understood, it has been shown that dopaminergic and non-dopaminergic mechanisms are involved in the development of dysphagia in PD. Clinical assessment of dysphagia in PD patients is challenging and often delivers unreliable results. A modified water test assessing maximum swallowing volume is recommended to uncover oropharyngeal dysphagia in PD. PD-specific questionnaires may also be useful to identify patients at risk for swallowing impairment. Fiberoptic endoscopic evaluation of swallowing and videofluoroscopic swallowing study are both considered to be the gold standard for evaluation of PD-related dysphagia. In addition, high-resolution manometry may be a helpful tool. These instrumental methods allow a reliable detection of aspiration events. Furthermore, typical patterns of impairment during the oral, pharyngeal and/or esophageal swallowing phase of PD patients can be identified. Therapy of dysphagia in PD consists of pharmacological interventions and swallowing treatment by speech and language therapists (SLTs). Fluctuating dysphagia with deterioration during the off-state should be treated by optimizing dopaminergic medication. The methods used during swallowing treatment by SLTs shall be selected according to the individual dysphagia pattern of each PD patient. A promising novel method is an intensive training of expiratory muscle strength. Deep brain stimulation does not seem to have a clinical relevant effect on swallowing function in PD. The goal of this review is giving an overview on current stages of epidemiology, pathophysiology, diagnosis, and treatment of PD-associated dysphagia, which might be helpful for neurologists, speech-language therapists, and other clinicians in their daily work with PD patients and associated swallowing difficulties. Furthermore areas with an urgent need for future clinical research are identified.

Lumbar Spine Surgery in Patients with Parkinson Disease

BACKGROUND

Parkinson disease is the second most common neurodegenerative condition. The literature on patients with Parkinson disease and spine surgery is limited, but increased complications have been reported.

METHODS

All patients with Parkinson disease undergoing lumbar spine surgery between 2002 and 2012 were identified. Patients' charts, radiographs, and outcome questionnaires were reviewed. Parkinson disease severity was assessed with use of the modified Hoehn and Yahr staging scale. Complications and subsequent surgeries were analyzed. Risk for reoperation was assessed.

RESULTS

Ninety-six patients underwent lumbar spine surgery. The mean patient age was 63.0 years. The mean follow-up duration was 30.1 months. The Parkinson disease severity stage was <2 in thirteen patients, 2 in thirty patients, 2.5 in twenty-three patients, and ≥3 in thirty patients. The primary indication for surgery was spinal stenosis in seventy-two patients, spondylolisthesis in seventeen patients, and coronal and/or sagittal deformity in seven patients. There were nineteen early complications, including postoperative infections requiring surgical irrigation and debridement and long-term antibiotics in ten patients. The visual analog scale for back pain improved from 7.4 cm preoperatively to 1.8 cm postoperatively (p < 0.001). The visual analog scale for lower-limb pain improved from 7.7 cm preoperatively to 2.3 cm postoperatively (p < 0.001). The Oswestry Disability Index score dropped from 54.1 points to 17.7 points at the time of the latest follow-up (p < 0.001). The Short Form-12 Physical Component Summary score improved from 26.6 points preoperatively to 30.5 points postoperatively (p < 0.05). Twenty patients required revision surgery. Risks for further surgery included a Parkinson disease severity stage of ≥3 (p < 0.05), a history of diabetes mellitus, treatment for osteoporosis, and a combined anterior and posterior approach.

CONCLUSIONS

Despite a higher rate of complications than in the general population, the overall outcome of spine surgery in patients with mild to moderate Parkinson disease is good, with improvement of spine-related pain. A larger prospective study is warranted.

Neuroinflammation in Parkinson's disease and its potential as therapeutic target

Parkinson’s disease (PD), the second most common age-associated neurodegenerative disorder, is characterized by the loss of dopaminergic (DA) neurons and the presence of α-synuclein-containing aggregates in the substantia nigra pars compacta (SNpc). Chronic neuroinflammation is one of the hallmarks of PD pathophysiology. Post-mortem analyses of human PD patients and experimental animal studies indicate that activation of glial cells and increases in pro-inflammatory factor levels are common features of the PD brain. Chronic release of pro-inflammatory cytokines by activated astrocytes and microglia leads to the exacerbation of DA neuron degeneration in the SNpc. Besides, peripheral immune system is also implicated in the pathogenesis of PD. Infiltration and accumulation of immune cells from the periphery are detected in and around the affected brain regions of PD patients. Moreover, inflammatory processes have been suggested as promising interventional targets for PD and even other neurodegenerative diseases. A better understanding of the role of inflammation in PD will provide new insights into the pathological processes and help to establish effective therapeutic strategies. In this review, we will summarize recent progresses in the neuroimmune aspects of PD and highlight the potential therapeutic interventions targeting neuroinflammation.

"Short term surgical complications after subthalamic deep brain stimulation for Parkinson's disease: does old age matter?"

Background

Patients aged 65 years and older are not traditionally considered optimal candidates for subthalamic deep brain stimulation (STN-DBS), mainly for their presumed increased incidence of surgical complications. The aim of this study was to assess STN-DBS surgery safety in relation to age.

Methods

A total of 107 consecutive patients undergoing bilateral STN-DBS at our institution between 2002 and 2014 were retrospectively stratified according to age in two groups (Young group < 65 years old; Elderly group ≥ 65 years old;). Rate of short-term surgical complications (within 90 days) was reviewed and compared between the two groups.

Results

Pre-operative baseline data were comparable between the two groups. The 90-days post-operative mortality rate was 0%. Overall incidence of complications related to surgery was 6,54%. In the Elderly group we observed 3 post-operative intra-cerebral haematomas (7,89%), 1 requiring urgent surgical evacuation. In the Young group we observed 2 post-operative asymptomatic intra-cerebral haematomas (2,89%) and 2 wound infections (2,89%), 1 requiring system removal. No others surgical complications were noticed in both groups.

Conclusions

Chronological age ≥ 65 years old should not be considered alone as exclusion criteria to STN-DBS surgery.

Parkinson's disease

Parkinson's disease is a neurological disorder with evolving layers of complexity. It has long been characterised by the classical motor features of parkinsonism associated with Lewy bodies and loss of dopaminergic neurons in the substantia nigra. However, the symptomatology of Parkinson's disease is now recognised as heterogeneous, with clinically significant non-motor features. Similarly, its pathology involves extensive regions of the nervous system, various neurotransmitters, and protein aggregates other than just Lewy bodies. The cause of Parkinson's disease remains unknown, but risk of developing Parkinson's disease is no longer viewed as primarily due to environmental factors. Instead, Parkinson's disease seems to result from a complicated interplay of genetic and environmental factors affecting numerous fundamental cellular processes. The complexity of Parkinson's disease is accompanied by clinical challenges, including an inability to make a definitive diagnosis at the earliest stages of the disease and difficulties in the management of symptoms at later stages. Furthermore, there are no treatments that slow the neurodegenerative process. In this Seminar, we review these complexities and challenges of Parkinson's disease.

Gout is not associated with a lower risk of Parkinson's disease: A systematic review and meta-analysis

BACKGROUND

Uratic acid is a potent anti-oxidant and hyperuricemia is well-linked to a lower risk of Parkinson's disease (PD), one of the most common neurodegenerative disorders. However, data on gout, the major complication of hyperuricemia, remain unclear.

METHODS

Two investigators independently searched published studies indexed in MEDLINE, and EMBASE from inception to April 2015 using the terms for gout combined with the terms for PD. The inclusion criteria were as follows: (1) cohort or case-control study evaluating the risk of PD among patients with gout (2) odds ratio, relative risk, hazard ratio or standardized incidence ratio were provided (3) subjects without gout and subjects with PD were used as controls in cohort and case-control study, respectively. RevMan 5.3 software was used to perform the statistical analysis. Point estimates and standard errors were extracted from individual studies and were combined by generic inverse variance method of DerSimonian and Laird. Statistical heterogeneity was assessed using the Cochran's Q test and I(2) statistics.

RESULTS

Three case-control studies and two cohort studies were identified and included in the data analysis. The pooled risk ratio of PD in patients with gout was 0.93 (95% CI, 0.79 to 1.09). The statistical heterogeneity was high with an I(2) of 87%. The results were not significantly different between males and females (RR 0.89; 95% CI, 0.57 to 1.39 and RR 0.95; 95% CI, 0.76 to 1.19, respectively).

CONCLUSION

This study did not provide support for an inverse relationship between gout and risk of PD.

Opposite Effects of Visual Cueing During Writing-Like Movements of Different Amplitudes in Parkinson's Disease

BACKGROUND

Handwriting is often impaired in Parkinson's disease (PD). Several studies have shown that writing in PD benefits from the use of cues. However, this was typically studied with writing and drawing sizes that are usually not used in daily life.

OBJECTIVE

This study examines the effect of visual cueing on a prewriting task at small amplitudes (≤1.0 cm) in PD patients and healthy controls to better understand the working action of cueing for writing.

METHODS

A total of 15 PD patients and 15 healthy, age-matched controls performed a prewriting task at 0.6 cm and 1.0 cm in the presence and absence of visual cues (target lines). Writing amplitude, variability of amplitude, and speed were chosen as dependent variables, measured using a newly developed touch-sensitive tablet.

RESULTS

Cueing led to immediate improvements in writing size, variability of writing size, and speed in both groups in the 1.0 cm condition. However, when writing at 0.6 cm with cues, a decrease in writing size was apparent in both groups (P < .001) and the difference in variability of amplitude between cued and uncued writing disappeared. In addition, the writing speed of controls decreased when the cue was present.

CONCLUSIONS

Visual target lines of 1.0 cm improved the writing of sequential loops in contrast to lines spaced at 0.6 cm. These results illustrate that, unlike for gait, visual cueing for fine-motor tasks requires a differentiated approach, taking into account the possible increases of accuracy constraints imposed by cueing.