Cognitive impairment and dementia in Parkinson's disease: practical issues and management

Increased mean diffusivity of the caudal motor SNc identifies patients with REM sleep behaviour disorder and Parkinson's disease

Idiopathic rapid eye movement sleep behaviour disorder (iRBD)-a Parkinson's disease (PD) prodrome-might exhibit neural changes similar to those in PD. Substantia nigra pars compacta (SNc) degeneration underlies motor symptoms of PD. In iRBD and early PD (ePD), we measured diffusion MRI (dMRI) in the caudal motor SNc, which overlaps the nigrosome-1-the earliest-degenerating dopaminergic neurons in PD-and in the striatum. Nineteen iRBD, 26 ePD (1.7 ± 0.03 years), and 46 age-matched healthy controls (HCs) were scanned at Western University, and 47 iRBD, 115 ePD (0.9 ± 0.01 years), and 56 HCs were scanned through the Parkinson's Progression Markers Initiative, using 3T MRI. We segmented the SNc and striatum into subregions using automated probabilistic tractography to the cortex. We measured mean diffusivity (MD) and fractional anisotropy (FA) along white-matter bundles and subregional surfaces. We performed group-level and classification analyses. Increased caudal motor SNc surface MD was the only iRBD-HCs and ePD-HCs difference replicating across datasets (padj < 0.05). No iRBD-ePD differences emerged. Caudal motor SNc surface MD classified patient groups from HCs at the single-subject level with good-to-excellent balanced accuracy in an independent sample (0.91 iRBD and 0.86 iRBD and ePD combined), compared to fair performance for total SNc surface MD (0.72 iRBD and ePD). Caudal motor SNc surface MD correlated significantly with MDS-UPDRS-III scores in ePD patients. Using dMRI and automated segmentation, we detected changes suggesting altered microstructural integrity in iRBD and ePD in the nigrostriatal subregion known to degenerate first in PD. Surface MD of the caudal motor SNc presents a potential measure for inclusion in neuroimaging biomarkers of iRBD and PD.

How to Use the New European Academy of Neurology/Movement Disorder Society European Section Guideline for Invasive Therapies in Parkinson's Disease

BACKGROUND

The decision to choose invasive treatments for Parkinson's disease (PD) is complex and needs careful consideration.

OBJECTIVES

Although the recommendations of the European Academy of Neurology/Movement Disorder Society European Section guideline for invasive therapies of PD are useful, the different clinical profiles of people with PD who seek advice for possible invasive therapy need further attention.

METHODS AND RESULTS

Here we describe 8 clinical standard situations of people with PD unsatisfied with their current oral treatment where invasive therapies may be considered. These are PD patients presenting with the following symptoms: (1) severe motor fluctuations, (2) beginning of levodopa-responsive fluctuations, severe tremor at (3) young or (4) advanced age, (5) impulse control disorders and related behavioral disorders, (6) hallucinations and psychosis, (7) minimal cognitive impairment or mild dementia, and (8) patients in need of palliative care. For some of these conditions, evidence at lower level or simple clinical considerations exist.

CONCLUSIONS

There are no one-fits-all answers, but physician and patient should discuss each option carefully considering symptom profile, psychosocial context, availability of therapy alternatives, and many other factors. The current paper outlines our proposed approach to these circumstances.

Relationship of irisin with disease severity and dopamine uptake in Parkinson's disease patients

BACKGROUND

This study was designed to investigate the relationship of irisin with the severity of Parkinson's disease (PD) and dopamine (DOPA) uptake in patients with PD and to understand the role of irisin in PD.

METHODS

The plasma levels of irisin and α-syn were measured by enzyme-linked immunosorbent assay (ELISA). Motor and nonmotor symptoms were assessed with the relevant scales. DOPA uptake was measured with DOPA positron emission tomography (PET)/magnetic resonance imaging (MRI).

RESULTS

The plasma levels of α-syn and irisin in patients with PD gradually increased and decreased, respectively, with the progression of the disease. There was a negative correlation between plasma α-syn and irisin levels in patients with PD. The level of irisin in plasma was negatively correlated with Unified Parkinson's Disease Rating Scale (UPDRS)-III scores and positively correlated with Montreal Cognitive Assessment (MoCA) scores. The striatal/occipital lobe uptake ratios (SORs) of the ipsilateral and contralateral caudate nucleus and anterior and posterior putamen in the high-irisin group were significantly higher than those in the low-irisin group, and irisin levels in the caudate nucleus and anterior and posterior putamen contralateral to the affected limb were lower than those on the ipsilateral side. The level of irisin was positively correlated with the SORs of the ipsilateral and contralateral caudate nucleus and putamen in PD patients.

CONCLUSIONS

Irisin plays a neuroprotective role by decreasing the level of α-syn. Irisin is negatively correlated with the severity of motor symptoms and cognitive impairment. More importantly, irisin can improve DOPA uptake in the striatum of patients with PD, especially on the side contralateral to the affected limb.

Subregional analysis of striatum iron in Parkinson's disease and rapid eye movement sleep behaviour disorder

The loss of dopamine in the striatum underlies motor symptoms of Parkinson's disease (PD). Rapid eye movement sleep behaviour disorder (RBD) is considered prodromal PD and has shown similar neural changes in the striatum. Alterations in brain iron suggest neurodegeneration; however, the literature on striatal iron has been inconsistent in PD and scant in RBD. Toward clarifying pathophysiological changes in PD and RBD, and uncovering possible biomarkers, we imaged 26 early-stage PD patients, 16 RBD patients, and 39 age-matched healthy controls with 3 T MRI. We compared mean susceptibility using quantitative susceptibility mapping (QSM) in the standard striatum (caudate, putamen, and nucleus accumbens) and tractography-parcellated striatum. Diffusion MRI permitted parcellation of the striatum into seven subregions based on the cortical areas of maximal connectivity from the Tziortzi atlas. No significant differences in mean susceptibility were found in the standard striatum anatomy. For the parcellated striatum, the caudal motor subregion, the most affected region in PD, showed lower iron levels compared to healthy controls. Receiver operating characteristic curves using mean susceptibility in the caudal motor striatum showed a good diagnostic accuracy of 0.80 when classifying early-stage PD from healthy controls. This study highlights that tractography-based parcellation of the striatum could enhance sensitivity to changes in iron levels, which have not been consistent in the PD literature. The decreased caudal motor striatum iron was sufficiently sensitive to PD, but not RBD. QSM in the striatum could contribute to development of a multivariate or multimodal biomarker of early-stage PD, but further work in larger datasets is needed to confirm its utility in prodromal groups.

Exploring the feasibility of technological visuo-cognitive training in Parkinson's: Study protocol for a pilot randomised controlled trial

Visual and cognitive dysfunction are common in Parkinson's disease and relate to balance and gait impairment, as well as increased falls risk and reduced quality of life. Vision and cognition are interrelated (termed visuo-cognition) which makes intervention complex in people with Parkinson's (PwP). Non-pharmacological interventions for visuo-cognitive deficits are possible with modern technology, such as combined mobile applications and stroboscopic glasses, but evidence for their effectiveness in PwP is lacking. We aim to investigate whether technological visuo-cognitive training (TVT) can improve visuo-cognitive function in PwP. We will use a parallel group randomised controlled trial to evaluate the feasibility and acceptability of TVT versus standard care in PwP. Forty PwP who meet our inclusion criteria will be randomly assigned to one of two visuo-cognitive training interventions. Both interventions will be carried out by a qualified physiotherapist in participants own homes (1-hour sessions, twice a week, for 4 weeks). Outcome measures will be assessed on anti-parkinsonian medication at baseline and at the end of the 4-week intervention. Feasibility of the TVT intervention will be assessed in relation to safety and acceptability of the technological intervention, compliance and adherence to the intervention and usability of equipment in participants homes. Additionally, semi structured interviews will be conducted to explore participants' experience of the technology. Exploratory efficacy outcomes will include change in visual attention measured using the Trail Making Test as well as changes in balance, gait, quality of life, fear of falling and levels of activity. This pilot study will focus on the feasibility and acceptability of TVT in PwP and provide preliminary data to support the design of a larger, multi-centre randomised controlled trial. This trial is registered at isrctn.com (ISRCTN46164906).

Association Between Parkinson's Disease and Coronary Artery Disease: A Systematic Review and Meta-Analysis

BACKGROUND

The relationship between Parkinson's disease (PD) and coronary artery disease (CAD) is unclear.

OBJECTIVE

This study aims to investigate whether PD and CAD are associated through systematic review and meta-analysis of observational studies.

METHODS

Electronic database search of PubMed, EMBASE, and Web of Science for observational studies published from 1 January 2010 to 1 August 2021 was conducted using terms related to PD and CAD. Unadjusted risk ratios (RR) and odds ratios (OR) of included cohort and case-control studies respectively were used to ascertain the association between PD and CAD. Study heterogeneity was evaluated using the I2 test.

RESULTS

Forty-one full-text studies were initially retrieved for eligibility assessment. Five studies that satisfied the inclusion criteria, consisting of three cohort and two case-control studies, were eventually included in this meta-analysis. The five studies enrolled 35,237 PD patients and 650,866 non-PD patients. PD and CAD were found to be significantly associated in cohort studies (RR = 2.23, 95% CI = 1.08-4.59, p = 0.03; Fig. 2), which held after sensitivity analysis (RR = 1.45, 95% CI = 1.31-1.60, p < 0.001; Fig. 3). Case-control studies found a trend towards association of PD and CAD approaching significance (OR = 1.47, 95% CI = 0.84-2.56, p = 0.18; Fig. 2).

CONCLUSION

Overall, this meta-analysis suggests that PD is associated with CAD. The underlying mechanisms, as well as the role of ethnicity and other comorbidities on the relationship between PD and CAD should be further explored.

Chronic Cerebral Hypoperfusion Aggravates Parkinson’s Disease Dementia-Like Symptoms and Pathology in 6-OHDA-Lesioned Rat through Interfering with Sphingolipid Metabolism

Chronic cerebral hypoperfusion (CCH) is a cardinal risk factor for Parkinson's disease dementia (PDD), but this potential causality lacks mechanistic evidence. We selected bilateral common carotid artery occlusion (BCCAO) to simulate chronic cerebral hypoperfusion in the rat model of PD induced by typical neurotoxin 6-hydroxy dopamine (6-OHDA). Four weeks after unilateral injection of 6-OHDA into the medial forebrain bundle, rats underwent BCCAO. Male Sprague-Dawley rats were divided into five groups of ten, including sham, PD+BCCAO 2 weeks, PD+BCCAO 1 week, PD, and BCCAO 2 weeks. Then, open field test (OFT) and Morris water maze test (MWM) were used to assess the PDD-like symptoms in rats. Also, the pathological manifestations and mechanisms of BCCAO impairing cognitive functions have been explored via hematoxylin-eosin staining, Nissl staining, immunohistochemistry, immunofluorescence, RNA sequencing analysis, lipidomics, and quantitative real-time polymerase chain reaction. In this study, we found that CCH could aggravate PDD-like cognitive symptoms (i.e., learning memory and spatial cognition) and PDD-like pathology (higher expression of α-Syn and Aβ in prefrontal cortex and striatum). Moreover, a potential relationship between differentially expressed mRNAs and lipid metabolism was revealed by RNA sequencing analysis. Lipidomics showed that CCH could affect the intensity of 5 lipids, including sphingomyelin (SM 9:0;2O/26:2; SM 8:1;2O/25:0; and SM 8:0;2O/28:4), cardiolipin, lysophosphatidylcholine, cholesteryl ester, and triacylglycerol. Interestingly, the KEGG pathway analysis of both RNA sequencing analysis and lipidomics suggested that CCH leaded to learning impairment by affecting sphingolipid metabolism. Finally, we found that CCH disrupts the sphingolipid metabolism by affecting the mRNA expression of SMPD1 and SMS2, leading to the accumulation of sphingomyelin in the prefrontal cortex. In summary, CCH, an independent exacerbating reason for impairment in learning and memory within the pathopoiesis of PD, aggravates Parkinson's disease dementia-like symptoms and pathology in 6-OHDA-lesioned rat through interfering with sphingolipid metabolism.

Testosterone propionate improves motor alterations and dopaminergic damage in the reserpine-induced progressive model of Parkinson's disease

Parkinson's disease (PD) is a chronic and progressive neurodegenerative disorder with a higher susceptibility to occur in men. Studies suggest that this susceptibility is related to the hormonal differences observed between men and women, being a risk factor for PD. In addition, testosterone supplementation has shown controversial results in animal models of PD and parkinsonian patients. This study evaluated the effect of chronic administration of testosterone propionate (TP) on motor behavior and neurochemical parameters in the reserpine-induced rat model of parkinsonism. Male Wistar rats received 15 injections of reserpine (RES - 0.1 mg/kg) every other day and were concomitantly treated with different doses (0.1, 1.0, or 5.0 mg/kg) of daily TP for 30 days. The rats were euthanized 48 h after the 15th injection of RES or vehicle. Brains were removed and subjected to Tyrosine hydroxylase (TH) immunohistochemistry. TP at 1.0 mg/kg reduced the damages caused by reserpine in the vacuous chewing and tong protrusion behaviors and prevented dopaminergic damage in the SNpc, VTA, and Striatum. TP at 5.0 mg/kg reduced the damages caused by reserpine in the catalepsy and tong protrusion behaviors, prevented the weight loss, and prevented dopaminergic damage in the VTA. Our results suggest that chronic administration of TP has a protective effect in a rat model of parkinsonism, improving motor alterations and dopamine depletion induced by RES.

Prevalence and clinical aspects of depression in Parkinson's disease: a systematic review and meta‑analysis of 129 studies

Depression is one of the most important non-motor symptoms in Parkinson's disease (PD), but its prevalence and related clinical characteristics are unclear. To this end, we performed a systematic review and meta-analysis based on 129 studies, including 38304 participants from 28 countries. Overall, the prevalence of depression in PD was 38%. When compared with patients without depression, those with depression had a younger age of onset, a lower education level, longer disease duration, higher UPDRS-III, higher H&Y staging scale, and lower MMSE, SE-ADL scores. We observed that depression was associated with female patients, patients carrying the GBA1 mutation, freezing of gait (FOG), apathy, anxiety and fatigue. Our results suggest that depression is an independent, frequent non-motor symptom in PD, appearing in the early stage and persisting throughout the disease duration. In addition, several clinical characteristics and motor and non-motor symptoms appeared to be associated with depression and negatively impacted on quality of life.

Basal ganglia atrophy-associated causal structural network degeneration in Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disease characterized by both motor and non-motor symptoms. A convergent pathophysiological hallmark of PD is an early selective vulnerability within the basal ganglia circuit. However, the causal interactions between basal ganglia atrophy and progressive structural network alterations in PD remain unaddressed. Here, we adopted voxel-based morphometry method to measure gray matter (GM) volume for each participant (n = 84 PD patients and n = 70 matched healthy controls). Patients were first divided into three stages according to the Hoehn and Yahr (H&Y) and the Part III of Unified Parkinson's Disease Rating Scale scores respectively to analyze the stage-specific GM atrophy patterns. Then, the modulation of early caudate atrophy over other brain structures was evaluated using the whole-brain voxel-wise and region-of-interest-wise causal structural covariance network approaches. We found that GM atrophy progressively expands from the basal ganglia to the angular gyrus, temporal areas, and eventually spreads through the subcortical-cortical networks as PD progresses. Notably, we identified a shared caudate-associated degeneration network including the basal ganglia, thalamus, cerebellum, sensorimotor cortex, and cortical association areas with the PD progressive factors. These findings suggest that the early structural vulnerability of basal ganglia in PD may play a pivotal role in the modulation of motor and non-motor circuits at the structural level. Our work provides evidence for a novel mechanism of network degeneration that underlies the pathology of PD and may have potential clinical applications in the development of early predictors of PD onset and progress.

Gamified Dual-Task Training for Individuals with Parkinson Disease: An Exploratory Study on Feasibility, Safety, and Efficacy

Objectives: The feasibility and safety of the use of neurorehabilitation technology (SMARTfit^® Trainer system) by physical therapists in implementing a gamified physical-cognitive dual-task training (DTT) paradigm for individuals with Parkinson disease (IWPD) was examined. Additionally, the efficacy of this gamified DTT was compared to physical single-task training (STT), both of which were optimized using physio-motivational factors, on changes in motor and cognitive outcomes, and self-assessed disability in activities of daily living. Methods: Using a cross-over study design, eight participants with mild-to-moderate idiopathic PD (including one with mild cognitive impairment) completed both training conditions (i.e., gamified DTT and STT). For each training condition, the participants attended 2–3 sessions per week over 8.8 weeks on average, with the total amount of training being equivalent to 24 1 h sessions. A washout period averaging 11.5 weeks was inserted between training conditions. STT consisted of task-oriented training involving the practice of functional tasks, whereas for gamified DTT, the same task-oriented training was implemented simultaneously with varied cognitive games using an interactive training system (SMARTfit^®). Both training conditions were optimized through continual adaptation to ensure the use of challenging tasks and to provide autonomy support. Training hours, heart rate, and adverse events were measured to assess the feasibility and safety of the gamified DTT protocol. Motor and cognitive function as well as perceived disability were assessed before and after each training condition. Results: Gamified DTT was feasible and safe for this cohort. Across participants, significant improvements were achieved in more outcome measures after gamified DTT than they were after STT. Individually, participants with specific demographic and clinical characteristics responded differently to the two training conditions. Conclusion: Physical therapists’ utilization of technology with versatile hardware configurations and customizable software application selections was feasible and safe for implementing a tailor-made intervention and for adapting it in real-time to meet the individualized, evolving training needs of IWPD. Specifically in comparison to optimized STT, there was a preliminary signal of efficacy for gamified DTT in improving motor and cognitive function as well as perceived disability in IWPD.

Mechanistic insights into the pathogenesis of neurodegenerative diseases: towards the development of effective therapy

Neurodegeneration is a prevalent and one of the emerging reasons for morbidity, mortality, and cognitive impairment in aging. Dementia is one of such conditions of neurodegeneration, partially manageable, irreversible, and worsens over time. This review is focused on biological and psychosocial risk factors associated with Alzheimer's and Parkinson's diseases, highlighting the value of cognitive decline. We further emphasized on current therapeutic strategies from pharmacological and non-pharmacological perspectives focusing on their effects on cognitive impairment, protein aggregation, tau pathology, and improving the quality of life. Deeper mechanistic insights into the multifactorial neurodegeneration could offer the design and development of promising diagnostic and therapeutic strategies.

Association Between REM Sleep Behavior Disorder and Cognitive Dysfunctions in Parkinson's Disease: A Systematic Review and Meta-Analysis of Observational Studies

Background: Rapid eye movement sleep behavior disorder (RBD) is thought to be a prodromal symptom of Parkinson's disease (PD). RBD is also thought to be involved in cognitive decline and dementia in PD. In PD, although the relationship between RBD and cognitive dysfunctions was confirmed by considerable studies, whether RBD was associated with distinct types of cognitive defects is worth of study. Objectives: This systematic review summarizes the evidence relating to cognitive dysfunction in PD patients with RBD (PD-RBD) and those without and explores their specificity to cognitive domains. Methods: A meta-analysis using a random-effects model was performed for 16 different cognitive domains, including global cognitive function, memory (long-term verbal recall, long-term verbal recognition, long-term visual recall, short-term spatial recall, and short-term verbal recall), executive function (general, fluid reasoning, generativity, shifting, inhibition, and updating), language, processing speed/complex attention/working memory, visuospatial/constructional ability, and psychomotor ability. The cognitive difference between the groups of patients was measured as a standardized mean difference (SMD, Cohen's d). PD-RBD patients were classified into Confirmed-RBD (definite diagnosis with polysomnography, PSG) and Probable-RBD (without PSG re-confirmation). In some domains, RBD patients could not be analyzed separately due to the exiguity of primary studies; this analysis refers to such RBD patients as "Mixed-RBD." Results: Thirty-nine studies with 6,695 PD subjects were finally included. Confirmed-RBD patients showed worse performance than those without in global cognitive function, long-term verbal recall, long-term verbal recognition, generativity, inhibition, shifting, language, and visuospatial/constructional ability; Probable-RBD, in global cognitive function and shifting; and Mixed-RBD, in long-term visual recall, short-term spatial recall, general executive function, and processing speed/complex attention/working memory. Conclusion: This meta-analysis strongly suggests a relationship between RBD, Confirmed-RBD in particular, and cognitive dysfunctions in PD patients. Early and routine screening by sensitive and targeted cognitive tasks is necessary for all PD-RBD patients because it may offer the therapeutic time window before they evolve to irreversible dementia.

Approach to Cognitive Impairment in Parkinson's Disease

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

Evaluating a frontostriatal working-memory updating-training paradigm in Parkinson's disease: the iPARK trial, a double-blinded randomized controlled trial

BACKGROUND

Cognitive decline and dementia are common in Parkinson's disease (PD). Cognitive deficits have been linked to the depletion of dopamine in the nigrostriatal pathway, but pharmacological treatments for PD have little evidence of improving or delaying cognitive decline. Therefore, exploring non-pharmacological treatment options is important. There have been some promising results of cognitive training interventions in PD, especially for improvements in working memory and executive functions. Yet, existing studies are often underpowered, lacking appropriate control condition, long term follow-up, a thorough description of the intervention and characteristics of the participants. Working memory updating training has previously shown to increase striatal activation in healthy young and old participants as well as dopaminergic neurotransmission in healthy young participants. In the light of dopamine dysfunction in PD, with negative effects on both motor and cognitive functions it is of interest to study if an impaired striatal system can be responsive to a non-invasive, non-pharmacological intervention.

METHODS AND DESIGN

The iPARK trial is a double-blinded, randomized controlled trial with a parallel-group design that aims to recruit 80 patients with PD (during the period 02/2017-02/2023). Included patients need to have PD, Hoehn and Yahr staging I-III, be between 45 to 75 years of age and not have a diagnosis of dementia. All patients will undergo 30 sessions (6-8 weeks) of web-based cognitive training performed from home. The target intervention is a process-based training program targeting working memory updating. The placebo program is a low dose short-term memory program. A battery of neuropsychological tests and questionnaires will be performed before training, directly after training, and 16 weeks after training.

DISCUSSION

We expect that the iPARK trial will provide novel and clinically useful information on whether updating training is an effective cognitive training paradigm in PD. Further, it will hopefully contribute to a better understanding of cognitive function in PD and provide answers regarding cognitive plasticity as well as determining critical factors for a responsive striatal system.

TRIAL REGISTRATION

Clinicaltrials.gov registry number: NCT03680170 , registry name: "Cognitive Training in Parkinson's Disease: the iPARK study", retrospectively registered on the 21st of September 2018. The inclusion of the first participant was the 1st of February 2017.

Altered awareness of motor symptoms in Parkinson's disease and Dementia with Lewy Bodies: A systematic review

OBJECTIVES

Altered awareness of motor symptoms is reported in people with Parkinson's disease and Dementia with Lewy Bodies, and may adversely affect quality of life and medication concordance. How symptom awareness is influenced by motor and cognitive disease severity, age and medication use is not fully understood. We carried out a systematic review of the literature on motor symptom awareness in Parkinson's disease and Dementia with Lewy Bodies.

METHODS

Pubmed and Wed of Science were searched for relevant articles published in or prior to March 2019. Data regarding participant demographics, diagnosis, cognitive status, method of assessing awareness and study findings were extracted from relevant publications.

RESULTS

Sixteen relevant publications were identified. Motor symptom awareness appears to decline over the course of Parkinson's disease. Imaging studies implicate the prefrontal cortex, with different mechanisms involved in hypokinesia and dyskinesia awareness. The hypothesis that people with right hemisphere based disease would have more severely reduced awareness is only weakly supported. Most studies focused on cognitively intact individuals, and on awareness of dyskinesia rather than hypokinesia.

CONCLUSIONS

Whilst reduced awareness of dyskinesia and to a lesser extent hypokinesia is common, there is a lack of longitudinal data on how awareness changes over time, and how it interacts with global cognitive changes. Motor symptom awareness in Dementia with Lewy Bodies is understudied. Future studies of symptom awareness should include robust assessment of overall cognitive functioning, and use a longitudinal design to elucidate how awareness changes over time. J Am Geriatr Soc 68:-, 2020.

Vascular risk factors, white matter lesions and cognitive impairment in Parkinson's disease: the PACOS longitudinal study

Background

Vascular risk factors (VRFs) may be associated with cognitive decline in early Parkinson’s disease (PD) but results are inconclusive. The identification of modifiable risk factors is relevant for prevention and treatment.

Methods

Parkinson’s disease (PD) patients of the PACOS cohort who underwent a baseline and follow-up neuropsychological evaluation were enrolled in the study. PD with Mild Cognitive Impairment (MCI) and dementia (PDD) were diagnosed according to the MDS criteria. A Baseline 1.5 T brain MRI was used to calculate the white matter lesions (WMLs) burden using the Wahlund visual scale. Laboratory data, presence of hypertension, diabetes and use of anti-hypertensive drugs were collected and the Framingham Risk (FR) score was calculated. VRFs predicting PD-MCI and PDD were evaluated using Cox proportional hazard regression model.

Results

Out of 139 enrolled patients, 84 (60.4%) were classified as normal cognition (NC) and 55 (39.6%) as MCI at baseline. At follow-up 28 (33.3%) PD-NC developed MCI and 4 (4.8%) PDD (follow-up time 23.5 ± 10.3 months). Out of 55 PD-MCI patients at baseline, 14 (25.4%) converted to PDD. At multivariate analysis among PD-NC a systolic blood pressure (SBP) > 140 mmHg was the stronger predictor of MCI (adjHR 4.04; 95% CI 1.41–11.3) while the presence of MCI at baseline (adj HR 7.55; 95% CI 1.76–32.3) and a severe WMLs burden (adj HR 2.80; 95% CI 0.86–9.04) were the strongest predictors of PDD, even if this latter association has a trend towards significance.

Conclusion

Hypertension represents the most important modifiable risk factor for PD-MCI in the PACOS cohort, increasing the risk of about four times.

Elevated Plasma Melatonin Levels Are Correlated With the Non-motor Symptoms in Parkinson's Disease: A Cross-Sectional Study

OBJECTIVE

Melatonin is the major hormone produced and secreted at night by the pineal gland into the cerebrospinal fluid (CSF) and circulation. The relationship between plasma melatonin levels and Parkinson's disease is not clear. The aim of the current study was to assess plasma melatonin levels in Parkinson's disease (PD) patients and to analysis the relationship between plasma melatonin levels and non-motor symptoms.

PARTICIPANTS AND METHODS

In this cross-sectional study, we evaluated 61 patients with idiopathic PD [males n = 30 (49.2%), average age 62.4 years (range: 46-73 years)] and a total of 58 healthy volunteers [males n = 30 (51.7%), average age 64.3 years (range: 45-70 years)] who participated in the study. Plasma melatonin levels were measured using an enzyme-linked immunosorbent assay. The severity of disease in PD patients was scored by the Unified Parkinson's Disease Rating Scale and the Hoehn and Yahr Staging scale. The quality of life in PD patients was assessed by the 39-item Parkinson's Disease Questionnaire. The non-motor symptoms were assessed by the 14-item Hamilton Anxiety Rating Scale, the 24-item Hamilton Depression Rating Scale, the Parkinson Disease Sleep Scale, the Epworth Sleepiness Scale and the Non-Motor Symptoms Scale for PD.

RESULTS

Compared with the healthy controls, the plasma melatonin levels were significantly higher in PD patients (12.82 ± 4.85 vs. 19.40 ± 4.23, P < 0.001). Plasma melatonin levels were significantly associated with the levodopa equivalent daily dose (r = -0.262, P < 0.05, n = 61). Higher plasma melatonin concentrations were detected in the negative cardiovascular symptom group than in the cardiovascular symptom group (20.13 ± 3.74 vs. 16.93 ± 3.74, P < 0.05). Higher plasma melatonin concentrations were detected in the non-sleep-disorders group than in the sleep disorders group (22.12 ± 5.93 vs. 18.86 ± 3.66, P < 0.05). In addition, the plasma melatonin concentration was higher in the group without gastrointestinal dysfunction than in the gastrointestinal dysfunction group (21.71 ± 4.44 vs. 18.35 ± 3.74, P < 0.05).

CONCLUSION

This study revealed that the plasma melatonin levels in PD patients were significantly higher than those in healthy controls. Non-motor symptoms that were significantly negatively correlated with plasma melatonin levels were cardiovascular symptoms, sleep disorders, and gastrointestinal dysfunction. Plasma melatonin levels have the closest relationship with sleep disorders. There was a correlation between plasma melatonin levels and sleep quality in patients with PD. The remaining non-motor symptoms were not related to plasma melatonin levels.

Risk Factors for Cognitive Impairment in Patients with Type 2 Diabetes

OBJECTIVES

To investigate the risk factors for cognitive impairment in Chinese type 2 diabetes mellitus (T2DM) patients of advanced age and to identify effective biomarkers of mild cognitive impairment (MCI) in these patients.

METHODS

Chinese T2DM patients (n = 120) aged 50-70 years were divided into groups with impaired (mild, moderate, and severe) and normal cognitive function based on Montreal Cognitive Assessment and Mini-Mental State Examination scores. Data regarding demographic characteristics, clinical features of diabetes, biochemical markers, and metabolomics were collected.

RESULTS

Age, educational level, duration of diabetes, fasting blood glucose (FBG), HbA1c, total cholesterol (TC), triglyceride (TG), and 24-hour urine protein were significantly associated with cognitive impairment in T2DM patients of advanced age. The severity of fundus retinopathy and the incidence of macrovascular disease also differed significantly among the groups (P < 0.05). Metabolomics analysis suggested that increased levels of glutamate (Glu), phenylalanine (Phe), tyrosine (Tyr), proline (Pro), and homocysteine (Hcy) and a decreased level of glutamine (Gln) were significantly associated with cognitive impairment in the T2DM patients (P < 0.05). Receiver operating characteristic curve analysis demonstrated that Glu, Gln, Phe, and Pro levels were significant predictors of cognitive impairment in the T2DM patients.

CONCLUSIONS

Age, educational level, duration of diabetes, and the levels of FBG, HbA1c, TC, TG, and 24-hour urine protein were considered as independent risk factors for cognitive impairment in older T2DM patients. Macrovascular and microvascular diseases also were closely associated with cognitive impairment in these patients. Together, Glu and Gln levels may represent a good predictive biomarker for the early diagnosis of cognitive impairment in T2DM patients.

A computer-based cognitive training in Mild Cognitive Impairment in Parkinson's Disease

BACKGROUND

There is no successful pharmacological treatment for cognitive impairment in Parkinson's Disease, therefore treatments capable of slowing down the progression of cognitive dysfunction are needed.

OBJECTIVE

To evaluate the effectiveness of a cognitive training, supported by the CoRe computerized tool, in patients with Parkinson's Disease Mild Cognitive Impairment.

METHODS

This is a prospective, open-unblinded, randomized, controlled study. After baseline cognitive assessment (T0), enrolled patients were randomized to receive motor rehabilitation plus cognitive intervention (G1) or motor rehabilitation only (G2). Follow-up assessments were scheduled 4 weeks (T1) and 6 months after (T2). Global cognitive functioning scores (MOCA and MMSE) were considered as primary outcome. Outcome measures at T0, T1 and T2 were compared within- and between-groups. A percentage change score between T0 and next assessments was calculated to identify patients who improved, remain stable or worsened.

RESULTS

Differently from G2, G1 showed a medium/large effect size improvement in primary (MoCA) and secondary outcome, both between T0 and T1 and T0 and T2. Moreover, within G1, most patients improved their cognitive state compared to the baseline.

CONCLUSIONS

Patients trained with CoRe showed a better evolution of cognitive decline, while untreated patients tended to get worse over time.

Physical activity sustains memory retrieval in dopamine-depleted mice previously treated with L-Dopa

The neurodegenerative disorder Parkinson's disease affects motor abilities as well as cognition. The gold standard therapy is L-Dopa, which mainly restores motor skills. Therefore, we require additional interventions to sustain cognitive functions in Parkinson's disease. The lifestyle intervention "physical activity" improves adult hippocampal neurogenesis and memory but so far, its impact has not been investigated in rodent models for Parkinson's disease previously treated with the standard therapy. We hereby asked whether physical activity serves as a pro-neurogenic and -cognitive stimulus in dopamine-depleted mice previously treated with L-Dopa. Therefore, we injected dopamine-depleted mice with L-Dopa/Benserazide followed either by exercise or by a sedentary lifestyle. We analysed adult hippocampal neurogenesis histologically and assessed spatial memory in the Morris water maze. Furthermore, we investigated the hippocampal and striatal monoaminergic cross-talk. Physical activity prevented memory decline and was linked to a slower dopamine turnover but did not enhance neurogenesis in dopamine-depleted mice previously treated with L-Dopa. In conclusion, physical activity did not develop its full pro-neurogenic potential in mice previously treated with L-Dopa but sustained spatial cognition in Parkinson's disease.

An efficacy evaluation method for non-normal outcomes in randomized controlled trials

Randomized controlled trials (RCT) are widely used in clinical efficacy evaluation studies. Linear regression is a general method to evaluate treatment efficacy considering the existence of confounding variables. However, when residuals are not normally distributed, parameter estimation based on ordinary least squares (OLS) is inefficient. This study introduces an exponential squared loss (ESL) model to evaluate treatment effect. The proposed method provides robust estimation for non-normal data. Simulation results show that it outperforms ordinary least squares regression with contaminated data. In the mild cognitive impairment (MCI) efficacy evaluation study with traditional Chinese medicine, our method is applied to construct a linear efficacy evaluation model for the difference in Alzheimer's disease assessment scale-cognitive (ADAS-cog) scores between the final and baseline records (ADASFA), with the existence of confounding factors and non- normal residuals. The results coincide with existing medical literatures. This proposed method overcomes the limitation of confounding variables and non-normal residuals in RCT efficacy studies. It outperforms OLS on estimation efficiency in situations where the percentage of non-normal contamination reaches 30%. These advantages make it a good method for real-world clinical studies.

Electrocortical networks in Parkinson's disease patients with Mild Cognitive Impairment. The PaCoS study

INTRODUCTION

Parkinson's Disease (PD) is frequently associated with cognitive dysfunction ranging from Mild Cognitive Impairment (PD-MCI) to dementia. Few electrophysiological studies are available evaluating potential pathogenetic mechanisms linked to cognitive impairment in PD since its initial phases. The objective of the study is to analyze electrocortical networks related with cognitive decline in PD-MCI for identifying possible early electrophysiological markers of cognitive impairment in PD.

METHODS

From the PaCoS (Parkinson's disease Cognitive impairment Study) cohort, a sample of 102 subjects including 46 PD-MCI and 56 PD with normal cognition (PD-NC) was selected based on the presence of a neuropsychological assessment and at least one EEG recording. EEG signal epochs were analysed using Independent Component Analysis LORETA and spectral analysis by computing the Power Spectral Density (PSD) of site-specific signal epochs.

RESULTS

LORETA analysis revealed significant differences in PD-MCI patients compared to PD-NC, with a decreased network involving alpha activity over the occipital lobe, an increased network involving beta activity over the frontal lobe associated with a reduction over the parietal lobe, an increased network involving theta and delta activity over the frontal lobe and a reduction of networks involving theta and delta activity in the parietal lobe. Quantitative EEG analysis showed a significant decrease of alpha PSD over the occipital regions and an increase of delta PSD over the left temporal region in PD-MCI as compared to PD-NC.

CONCLUSION

Electrocortical abnormalities detected in PD-MCI patients may represent the instrumental counterpart of early cognitive decline in PD.

Ambroxol as a novel disease-modifying treatment for Parkinson's disease dementia: protocol for a single-centre, randomized, double-blind, placebo-controlled trial

BACKGROUND

Currently there are no disease-modifying treatments for Parkinson's disease dementia (PDD), a condition linked to aggregation of the protein α-synuclein in subcortical and cortical brain areas. One of the leading genetic risk factors for Parkinson's disease is being a carrier in the gene for β-Glucocerebrosidase (GCase; gene name GBA1). Studies in cell culture and animal models have shown that raising the levels of GCase can decrease levels of α-synuclein. Ambroxol is a pharmacological chaperone for GCase and is able to raise the levels of GCase and could therefore be a disease-modifying treatment for PDD. The aims of this trial are to determine if Ambroxol is safe and well-tolerated by individuals with PDD and if Ambroxol affects cognitive, biochemical, and neuroimaging measures.

METHODS

This is a phase II, single-centre, double-blind, randomized placebo-controlled trial involving 75 individuals with mild to moderate PDD. Participants will be randomized into Ambroxol high-dose (1050 mg/day), low-dose (525 mg/day), or placebo treatment arms. Assessments will be undertaken at baseline, 6-months, and 12-months follow up times. Primary outcome measures will be the Alzheimer's disease Assessment Scale-cognitive subscale (ADAS-Cog) and the ADCS Clinician's Global Impression of Change (CGIC). Secondary measures will include the Parkinson's disease Cognitive Rating Scale, Clinical Dementia Rating, Trail Making Test, Stroop Test, Unified Parkinson's disease Rating Scale, Purdue Pegboard, Timed Up and Go, and gait kinematics. Markers of neurodegeneration will include MRI and CSF measures. Pharmacokinetics and pharmacodynamics of Ambroxol will be examined through plasma levels during dose titration phase and evaluation of GCase activity in lymphocytes.

DISCUSSION

If found effective and safe, Ambroxol will be one of the first disease-modifying treatments for PDD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT02914366, 26 Sep 2016/retrospectively registered.

Computer-Based Driving in Dementia Decision Tool With Mail Support: Cluster Randomized Controlled Trial

Background

Physicians often find significant challenges in assessing automobile driving in persons with mild cognitive impairment and mild dementia and deciding when to report to transportation administrators. Care must be taken to balance the safety of patients and other road users with potential negative effects of issuing such reports.

Objective

The aim of this study was to assess whether a computer-based Driving in Dementia Decision Tool (DD-DT) increased appropriate reporting of patients with mild dementia or mild cognitive impairment to transportation administrators.

Methods

The study used a parallel-group cluster nonblinded randomized controlled trial design to test a multifaceted knowledge translation intervention. The intervention included a computer-based decision support system activated by the physician-user, which provides a recommendation about whether to report patients with mild dementia or mild cognitive impairment to transportation administrators, based on an algorithm derived from earlier work. The intervention also included a mailed educational package and Web-based specialized reporting forms. Specialists and family physicians with expertise in dementia or care of the elderly were stratified by sex and randomized to either use the DD-DT or a control version of the tool that required identical data input as the intervention group, but instead generated a generic reminder about the reporting legislation in Ontario, Canada. The trial ran from September 9, 2014 to January 29, 2016, and the primary outcome was the number of reports made to the transportation administrators concordant with the algorithm.

Results

A total of 69 participating physicians were randomized, and 36 of these used the DD-DT; 20 of the 35 randomized to the intervention group used DD-DT with 114 patients, and 16 of the 34 randomized to the control group used it with 103 patients. The proportion of all assessed patients reported to the transportation administrators concordant with recommendation did not differ between the intervention and the control groups (50% vs 49%; Z=−0.19, P=.85). Two variables predicted algorithm-based reporting—caregiver concern (odds ratio [OR]=5.8, 95% CI 2.5-13.6, P<.001) and abnormal clock drawing (OR 6.1, 95% CI 3.1-11.8, P<.001).

Conclusions

On the basis of this quantitative analysis, in-office abnormal clock drawing and expressions of concern about driving from caregivers substantially influenced physicians to report patients with mild dementia or mild cognitive impairment to transportation administrators, but the DD-DT tool itself did not increase such reports among these expert physicians.

Trial Registration

ClinicalTrials.gov NCT02036099; https://clinicaltrials.gov/ct2/show/NCT02036099 (Archived by WebCite at http://www.webcitation.org/6zGMF1ky8)

An International Approach to Enhancing a National Guideline on Driving and Dementia

PURPOSE OF REVIEW

The purpose of this study was to update a national guideline on assessing drivers with dementia, addressing limitations of previous versions which included a lack of developmental rigor and stakeholder involvement.

METHODS

An international multidisciplinary team reviewed 104 different recommendations from 12 previous guidelines on assessing drivers with dementia in light of a recent review of the literature. Revised guideline recommendations were drafted by consensus. A preliminary draft was sent to specialist physician and occupational therapy groups for feedback, using an a priori definition of 90% agreement as consensus.

RECENT FINDINGS

The research team drafted 23 guideline recommendations, and responses were received from 145 stakeholders. No recommendation was endorsed by less than 80% of respondents, and 14 (61%) of the recommendations were endorsed by more than 90%.The recommendations are presented in the manuscript. The revised guideline incorporates the perspectives of consensus of an expert group as well as front-line clinicians who regularly assess drivers with dementia. The majority of the recommendations were based on evidence at the level of expert opinion, revealing gaps in the evidence and future directions for research.

Weight Loss and Malnutrition in Patients with Parkinson's Disease: Current Knowledge and Future Prospects

Parkinson's Disease (PD) is currently considered a systemic neurodegenerative disease manifested with not only motor but also non-motor symptoms. In particular, weight loss and malnutrition, a set of frequently neglected non-motor symptoms, are indeed negatively associated with the life quality of PD patients. Moreover, comorbidity of weight loss and malnutrition may impact disease progression, giving rise to dyskinesia, cognitive decline and orthostatic hypotension, and even resulting in disability and mortality. Nevertheless, the underlying mechanism of weight loss and malnutrition in PD remains obscure and possibly involving multitudinous, exogenous or endogenous, factors. What is more, there still does not exist any weight loss and malnutrition appraision standards and management strategies. Given this, here in this review, we elaborate the weight loss and malnutrition study status in PD and summarize potential determinants and mechanisms as well. In conclusion, we present current knowledge and future prospects of weight loss and malnutrition in the context of PD, aiming to appeal clinicians and researchers to pay a closer attention to this phenomena and enable better management and therapeutic strategies in future clinical practice.

Alzheimer's Disease-Related Dementias Summit 2016: National research priorities

Goal 1 of the National Plan to Address Alzheimer's Disease is to prevent and effectively treat Alzheimer disease and Alzheimer disease-related dementias by 2025. To help inform the research agenda toward achieving this goal, the NIH hosts periodic summits that set and refine relevant research priorities for the subsequent 5 to 10 years. This proceedings article summarizes the 2016 Alzheimer's Disease-Related Dementias Summit, including discussion of scientific progress, challenges, and opportunities in major areas of dementia research, including mixed-etiology dementias, Lewy body dementia, frontotemporal degeneration, vascular contributions to cognitive impairment and dementia, dementia disparities, and dementia nomenclature.

The implication of neuronimmunoendocrine (NIE) modulatory network in the pathophysiologic process of Parkinson's disease

Parkinson's disease (PD) is a progressive neurodegenerative disorder implicitly marked by the substantia nigra dopaminergic neuron degeneration and explicitly characterized by the motor and non-motor symptom complexes. Apart from the nigrostriatal dopamine depletion, the immune and endocrine study findings are also frequently reported, which, in fact, have helped to broaden the symptom spectrum and better explain the pathogenesis and progression of PD. Nevertheless, based on the neural, immune, and endocrine findings presented above, it is still difficult to fully recapitulate the pathophysiologic process of PD. Therefore, here, in this review, we have proposed the neuroimmunoendocrine (NIE) modulatory network in PD, aiming to achieve a more comprehensive interpretation of the pathogenesis and progression of this disease. As a matter of fact, in addition to the classical motor symptoms, NIE modulatory network can also underlie the non-motor symptoms such as gastrointestinal, neuropsychiatric, circadian rhythm, and sleep disorders in PD. Moreover, the dopamine (DA)-melatonin imbalance in the retino-diencephalic/mesencephalic-pineal axis also provides an alternative explanation for the motor complications in the process of DA replacement therapy. In conclusion, the NIE network can be expected to deepen our understanding and facilitate the multi-dimensional management and therapy of PD in future clinical practice.

Neuropsychological effects of occupational exposure to polychlorinated biphenyls

In the context of a health surveillance program for former PCB-exposed workers of a transformer and capacitor recycling company in Germany, their family members, employees of surrounding companies and area residents a broad range of cognitive functions covering attention, executive processing, reasoning, memory and motor performance was examined. The study aimed at identifying potential adverse effects of PCB load on cognitive functions. Detailed analysis of PCB burden of the participants revealed rather high correlations of lower and higher chlorinated as well as dioxin-like PCBs. Nearly one half of the participants exhibited increased burden in all three PCB classes whereas only 33 out of 237 participants did not show any increased PCB burden. Thus, data analysis followed a two-fold strategy: (1) Based on studies providing data on PCB exposure of the German general population the PCB burden of every participant was classified as normal (percentile rank PR <95) or increased (PR ≥95). Increased burden with respect to lower (LPCBs) and higher chlorinated (HPCBs) as well as dioxin-like (dlPCBs) PCBs was assumed if a participant showed at least one congener surpassing the PR95 criterion for the respective congener class and (2) Overall plasma PCB level per congener class was used as measure of PCB load. In a multivariate approach using structural equation modelling and multiple regression analysis we found a significant impact of PCBs on word fluency and sensorimotor processing irrespective of the measure of PCB burden (PR95 criterion or overall plasma level). However, no effect of PCB burden on memory, attention, and cognitive flexibility could be demonstrated. Particularly, an increase of LPCBs was associated with an overall reduction of verbal fluency of letter and semantic word generation as well as word production based on a single or two alternating criteria. In addition, participants with increased burden of LPCBs exhibited a time-on-task effect in terms of a stronger decline of performance with increasing duration of the verbal fluency task. Moreover, we found adverse effects of HPCBs on Aiming and of dlPCBs on Line Tracking. Results are discussed in terms of (1) a decrease of cerebral dopamine (DA) with non-coplanar PCBs resulting in an impact on fronto-striatal cerebral structures subserving verbal fluency and motor processing, (2) a PCB-induced reduction of norepinephrine leading to the time-on-task effect with verbal fluency, and (3) adverse effects of PCBs on dopaminergic receptors in the cerebellum resulting in impaired fine motor function.

Serum Butyrylcholinesterase Activity: A Biomarker for Parkinson's Disease and Related Dementia

Objective

This study aim to determine changes of serum butyrylcholinesterase (BChE) activity in PD patients and related dementia.

Patients and Methods

Consecutive PD patients and healthy controls were included and clinical data were collected. Fast serum BChE activity was determined and compared between healthy controls and PD patients. Independent risk factors were performed for BChE activity, PD, and related dementia. The relationship between BChE activity and disease severity was also evaluated. Receiver operating characteristic (ROC) curves were obtained to explore serum BChE activity in distinguishing PD patients and related dementia.

Results

Serum BChE activity mainly independently correlated with gender, albumin, triglyceride, body mass index, and PD. Serum BChE activity decreased in PD patients compared with healthy controls. Based on the ROC curve, the optimal cut-off point was 6864.08 IU/L for distinguishing PD patients, and the sensitivity and specificity values were 61.8% and 72.1%. It inversely correlated with Unified Parkinson's Disease Rating Scale score. BChE activity decreased in PD-related dementia compared with those without dementia. The sensitivity and specificity values were 70.6% and 76.3%, respectively, with an optimal cut-off point of 6550.00 IU/L.

Conclusions

Serum BChE activity can be regarded as a biomarker for PD and related dementia.

Non-motor features of Parkinson disease

Many of the motor symptoms of Parkinson disease (PD) can be preceded, sometimes for several years, by non-motor symptoms that include hyposmia, sleep disorders, depression and constipation. These non-motor features appear across the spectrum of patients with PD, including individuals with genetic causes of PD. The neuroanatomical and neuropharmacological bases of non-motor abnormalities in PD remain largely undefined. Here, we discuss recent advances that have helped to establish the presence, severity and effect on the quality of life of non-motor symptoms in PD, and the neuroanatomical and neuropharmacological mechanisms involved. We also discuss the potential for the non-motor features to define a prodrome that may enable the early diagnosis of PD.

Normalization of timed neuropsychological tests with the PATA rate and nine-hole pegboard tests

INTRODUCTION

Despite neurological patients show frequent physical impairment, timed neuropsychological tests do not take this into account during scoring procedures.

OBJECTIVE

We propose a normalization method based on the PATA Rate Task (PRT) and on the nine-hole pegboard test (9HPT) as a measure of dysarthria and upper limb dysfunction.

METHODS

We tested 65 healthy controls on timed neuropsychological tests (Attentional Matrices [AM], Trail Making Test, Symbol Digit Modalities Test, Verbal Fluencies) to determine the time spent on phonation or on hand movement during test execution. We developed correction formulas to normalize test times considering the patient's PRT/9HPT, their normality limits, and the test timing. We tested the method on 24 patients with Friedreich Ataxia (FRDA), as a model of motor and speech impairment.

RESULTS

In healthy controls, phonation or hand movement is 13.5-61.7% of total test time. In FRDA patients, the effect of normalization improved all test results (range: 0.51-48.4%; p < .001). FRDA patients had worst scores in all tests when compared to controls, and the difference remained significant after correction except for the AM. At the individual level, the normalization method improved equivalent scores with fever patients showing impaired scores after correction.

CONCLUSIONS

We propose an innovative normalization method to reduce the impact of neurological disability on timed neuropsychological tests. This could be easily integrated in a clinical setting, as it requires a simple preliminary test with the PRT and 9HPT.

Medical Management of Parkinson's Disease after Initiation of Deep Brain Stimulation

In this review, we have gathered all the available evidence to guide medication management after deep brain stimulation (DBS) in Parkinson's disease (PD). Surprisingly, we found that almost no study addressed drug-based management in the postoperative period. Dopaminergic medications are usually reduced, but whether the levodopa or dopamine agonist is to be reduced is left to the personal preference of the treating physician. We have summarized the pros and cons of both approaches. No study on the management of cognitive problems after DBS has been done, and only a few studies have explored the pharmacological management of such DBS-resistant symptoms as voice (amantadine), balance (donepezil) or gait disorders (amantadine, methylphenidate). As for the psychiatric problems so frequently reported in PD patients, researchers have directed their attention to the complex interplay between stimulation and reduction of dopaminergic drugs only recently. In conclusion, studies addressing medical management following DBS are still needed and will certainly contribute to the ultimate success of DBS procedures.

Parkinson's Disease: Cognitive Impairment

Cognitive deficits are important and emerging clinical targets for psychiatrists caring for patients with Parkinson's disease (PD), a neurodegenerative disorder commonly accompanied by mood and psychotic disturbances and identified by its progressive motor abnormalities. Over the course of the disease and across all its stages, virtually every individual with PD experiences some degree of cognitive deficit, ranging from mild cognitive impairment to dementia. Across this spectrum, cognitive impairments affect functioning and quality of life, often more than motor aspects of the disease. Advances in treatments for motor deficits in PD now render the clinical significance of cognitive dysfunction more obvious, including its impact on psychiatric presentations and their treatment. Since cognitive dysfunction is underdetected and undertreated in clinical practice, holistic psychiatric care of PD patients warrants appreciation of the clinical presentation, biopsychosocial features, and treatment of cognitive impairment. Future directions for research and clinical care also discussed.

The role of deep brain stimulation in Parkinson's disease: an overview and update on new developments

Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by the loss of neuronal dopamine production in the brain. Oral therapies primarily augment the dopaminergic pathway. As the disease progresses, more continuous delivery of therapy is commonly needed. Deep brain stimulation (DBS) has become an effective therapy option for several different neurologic and psychiatric conditions, including PD. It currently has US Food and Drug Administration approval for PD and essential tremor, as well as a humanitarian device exception for dystonia and obsessive-compulsive disorder. For PD treatment, it is currently approved specifically for those patients suffering from complications of pharmacotherapy, including motor fluctuations or dyskinesias, and a disease process of at least 4 years of duration. Studies have demonstrated superiority of DBS and medical management compared to medical management alone in selected PD patients. Optimal patient selection criteria, choice of target, and programming methods for PD and the other indications for DBS are important topics that continue to be explored and remain works in progress. In addition, new hardware options, such as different types of leads, and different software options have recently become available, increasing the potential for greater efficacy and/or reduced side effects. This review gives an overview of therapeutic management in PD, specifically highlighting DBS and some of the recent changes with surgical therapy.

Vascular Risk Factors and Cognition in Parkinson's Disease

Vascular risk factors have been associated with cognitive deficits and incident dementia in the general population, but their role on cognitive dysfunction in Parkinson's disease (PD) is still unclear. The present study addresses the single and cumulative effect of vascular risk factors on cognition in PD patients, taking clinical confounders into account. Standardized neuropsychological assessment was performed in 238 consecutive PD patients. We evaluated the association of single and cumulative vascular risk factors (smoking, diabetes, hypercholesterolemia, hypertension, and heart disease), with the diagnosis of PD normal cognition (PDNC, n = 94), mild cognitive impairment (PD-MCI, n = 111), and dementia (PDD, n = 33). The association between single neuropsychological tests and vascular risk factors was evaluated with covariance analyses adjusted for age at onset, educational levels, gender, disease duration, and motor performance. Age, educational levels, disease duration, and motor function were significantly different between PDNC, PD-MCI, and PDD. Heart disease was the only vascular factor significantly more prevalent in PDD compared with PDNC in adjusted analyses. Performance of tests assessing executive and attention functions were significantly worse in patients with hypertension, heart disease, and/or diabetes (p <  0.05). Heart disease is associated with dementia in PD, suggesting a potential window of intervention. Vascular risk factors act especially on attention and executive functions in PD. Vascular risk stratification may be useful in order to identify PD patients with a greater risk of developing dementia. These findings need to be verified in longitudinal studies.

Pharmacotherapies for Parkinson's disease symptoms related to cholinergic degeneration

INTRODUCTION

Dopamine depletion is one of the most important features of Parkinson's Disease (PD). However, insufficient response to dopaminergic replacement therapy suggests the involvement of other neurotransmitter systems in the pathophysiology of PD. Cholinergic degeneration contributes to gait impairments, cognitive impairment, psychosis, and REM-sleep disturbances, among other symptoms. Areas covered: In this review, we explore the idea that enhancing cholinergic tone by pharmacological or neurosurgical procedures could be a first-line therapeutic strategy for the treatment of symptoms derived from cholinergic degeneration in PD. Expert opinion: Rivastigmine, a drug that increases cholinergic tone by inhibiting the enzyme cholinesterase, is effective for dementia, whereas the use of Donepezil is still in the realm of investigation. Interesting results suggest the efficacy of these drugs in the treatment of gait dysfunction. Evidence on the clinical effects of these drugs for psychosis and REM-sleep disturbances is still weak. Stimulation of the pedunculo-pontine tegmental nuclei (which provide cholinergic innervation to the brain stem and subcortical nuclei) has also been used with some success for the treatment of gait dysfunction. Anticholinergic drugs should be used with caution in PD, as they may aggravate cholinergic symptoms. Notwithstanding, in some patients they might help control parkinsonian motor symptoms.

A Personalized Approach to Parkinson's Disease Patients Based on Founder Mutation Analysis

While the phenotype of Parkinson disease (PD) is heterogeneous, treatment approaches are mostly uniform. Personalized medicine aims to treat diseases with targeted therapies based on cumulative variables, including genotype. We believe that sufficient evidence has accumulated to warrant the initiation of personalized medicine in PD based on subjects genotype and provide examples for our reasoning from observations of GBA and LRRK2 mutations carriers. While PD patients who carry the G2019S mutation in the LRRK2 gene seem to develop relatively mild disease with more frequent postural instability gait disturbance phenotype, carriers of mutations in the GBA gene tend to have an early onset, rapidly deteriorating disease, with more pronounced cognitive and autonomic impairments. These characteristics have significant implications for treatment and outcome and should be addressed from an early stage in the attempt to improve the patient's quality of life.

Treatment patterns and characteristics of older antipsychotic users in Germany

The aim of this study was to investigate the characteristics and treatment patterns of older antipsychotic (AP) users in Germany. We carried out a cohort study in the German Pharmacoepidemiological Research Database and identified new AP users aged at least 65 years between 2005 and 2011. Possible indications, comedication, and information on persistence and adherence, concurrent multiple use, and switch of APs were assessed. Overall, 298,847 individuals were included in the cohort. Almost 70% entered the cohort with a typical antipsychotic (TAP). Melperone (23.4%) was used most frequently, followed by promethazine (18.3%), sulpiride (11.0%), and risperidone (10.3%). AP users had a low prevalence of schizophrenia and bipolar disorders in contrast to dementia. Initiators of atypical antipsychotics had more treatment episodes compared with TAPs (median 3 vs. 2), but lower median persistence (14 vs. 22 days). Persistence was also lower in patients with, rather than without, dementia. The overall percentage of concurrent multiple use and switch to other APs was low with 5.6%, but higher in patients with, rather than without, dementia. In conclusion, APs were used for a broad range of indications, mostly other than schizophrenia and bipolar disorders. Low persistence and a high number of treatment episodes suggest frequent 'as-needed' treatment, especially in dementia patients.

Drugs with potential cardiac adverse effects: Retrospective study in a large cohort of parkinsonian patients

INTRODUCTION/OBJECTIVE

Drugs with potential cardiac adverse effects are commonly prescribed in Parkinson's disease (PD). To describe demographic and clinical characteristics in a group of PD patients with cardiac events and to evaluate risk factors.

PATIENTS AND METHODS

We sampled 506 consecutive PD patients (211 women/295 men), median age 68.3±10.6 years (range 36-95) and median disease duration 11.2±6.5 years (range 1-49). Medications with potential cardiac effects, i.e. QT prolongation (citalopram, escitalopram, venlafaxine, sertraline, domperidone, amantadine, solifenacin), ventricular arrhythmia (rivastigmine, clozapine, midodrine, sildenafil, tadalafil) and ischemic heart disease (rasagiline, entacapone, tadalafil) were recorded. Demographic and clinical data were collected prospectively; cardiac events were obtained retrospectively.

RESULTS

Twenty-four patients (4.7%) (9 women/15 men) presented a cardiac event. Fifteen (62.5%) patients had dysautonomia, 4 (16.6%) a history of heart disease and 8 (33.3%) were taking one or more drugs with a definite potential cardiac adverse effect. Age (75.9±6.6 yr vs. 67.8±11 yr), disease duration (14.7±3.6 yr vs. 11±6.5 yr), dysautonomia (62.5% vs. 24.5%) and dementia associated with PD (37.5% vs. 14.6%) were significantly higher in the group with cardiac events (P<0.05). Cofactors increasing the risk for cardiovascular events were age and dysautonomia.

DISCUSSION/CONCLUSION

Our results indicate that the neurodegenerative process in Parkinson's disease is associated with a higher risk of cardiovascular complications.

Gait in Parkinson's disease: A visuo-cognitive challenge

Vision and cognition have both been related to gait impairment in Parkinson's disease (PD) through separate strands of research. The cumulative and interactive effect of both (which we term visuo-cognition) has not been previously investigated and little is known about the influence of cognition on vision with respect to gait. Understanding the role of vision, cognition and visuo-cognition in gait in PD is critical for data interpretation and to infer and test underlying mechanisms. The purpose of this comprehensive narrative review was to examine the interdependent and interactive role of cognition and vision in gait in PD and older adults. Evidence from a broad range of research disciplines was reviewed and summarised. A key finding was that attention appears to play a pivotal role in mediating gait, cognition and vision, and should be considered emphatically in future research in this field.