Elevated caudate connectivity in cognitively normal Parkinson's disease patients.

Mild cognitive impairment (MCI) is common in Parkinson's disease patients. However, its underlying mechanism is not well understood, which has hindered new treatment discoveries specific to MCI. The aim of this study was to investigate functional connectivity changes of the caudate nucleus in cognitively impaired Parkinson's patients. We recruited 18 Parkinson's disease patients-10 PDNC [normal cognition Parkinson's disease; Montreal Cognitive Assessment (MoCA) ≥ 26], 8 PDLC (low cognition Parkinson's disease; MoCA < 26) -and 10 age-matched healthy controls. All subjects were scanned with resting-state functional magnetic resonance imaging (MRI) and perfusion MRI. We analyzed these data for graph theory metrics and Alzheimer's disease-like pattern score, respectively. A strong positive correlation was found between the functional connectivity of the right caudate nucleus and MoCA scores in Parkinson's patient groups, but not in healthy control subjects. Interestingly, PDNC's functional connectivity of the right caudate was significantly higher than both PDLC and healthy controls, while PDLC and healthy controls were not significantly different from each other. We found that Alzheimer's disease-like metabolic/perfusion pattern score correlated with MoCA scores in healthy controls, but not in Parkinson's disease. Increased caudate connectivity may be related to a compensatory mechanism found in cognitively normal patients with Parkinson's disease. Our findings support and complement the dual syndrome hypothesis.

Office-Based Screening for Dementia in Parkinson Disease: The Montreal Parkinson Risk of Dementia Scale in 4 Longitudinal Cohorts.

Importance: Parkinson disease dementia dramatically increases mortality rates, patient expenditures, hospitalization risk, and caregiver burden. Currently, predicting Parkinson disease dementia risk is difficult, particularly in an office-based setting, without extensive biomarker testing. Objective: To appraise the predictive validity of the Montreal Parkinson Risk of Dementia Scale, an office-based screening tool consisting of 8 items that are simply assessed. Design, Setting, and Participants: This multicenter study (Montreal, Canada; Tottori, Japan; and Parkinson Progression Markers Initiative sites) used 4 diverse Parkinson disease cohorts with a prospective 4.4-year follow-up. A total of 717 patients with Parkinson disease were recruited between May 2005 and June 2016. Of these, 607 were dementia-free at baseline and followed-up for 1 year or more and so were included. The association of individual baseline scale variables with eventual dementia risk was calculated. Participants were then randomly split into cohorts to investigate weighting and determine the scale's optimal cutoff point. Receiver operating characteristic curves were calculated and correlations with selected biomarkers were investigated. Main Outcomes and Measures: Dementia, as defined by Movement Disorder Society level I criteria. Results: Of the 607 patients (mean [SD] age, 63.4 [10.1]; 376 men [62%]), 70 (11.5%) converted to dementia. All 8 items of the Montreal Parkinson Risk of Dementia Scale independently predicted dementia development at the 5% significance level. The annual conversion rate to dementia in the high-risk group (score, >5) was 14.9% compared with 5.8% in the intermediate group (score, 4-5) and 0.6% in the low-risk group (score, 0-3). The weighting procedure conferred no significant advantage. Overall predictive validity by the area under the receiver operating characteristic curve was 0.877 (95% CI, 0.829-0.924) across all cohorts. A cutoff of 4 or greater yielded a sensitivity of 77.1% (95% CI, 65.6-86.3) and a specificity of 87.2% (95% CI, 84.1-89.9), with a positive predictive value (as of 4.4 years) of 43.90% (95% CI, 37.76-50.24) and a negative predictive value of 96.70% (95% CI, 95.01-97.85). Positive and negative likelihood ratios were 5.94 (95% CI, 4.08-8.65) and 0.26 (95% CI, 0.17-0.40), respectively. Scale results correlated with markers of Alzheimer pathology and neuropsychological test results. Conclusions and Relevance: Despite its simplicity, the Montreal Parkinson Risk of Dementia Scale demonstrated predictive validity equal or greater to previously described algorithms using biomarker assessments. Future studies using head-to-head comparisons or refinement of weighting would be of interest.

Caffeine as symptomatic treatment for Parkinson disease (Café-PD): A randomized trial.

OBJECTIVE: To assess effects of caffeine on Parkinson disease (PD). METHODS: In this multicenter parallel-group controlled trial, patients with PD with 1-8 years disease duration, Hoehn & Yahr stages I-III, on stable symptomatic therapy were randomized to caffeine 200 mg BID vs matching placebo capsules for 6-18 months. The primary research question was whether objective motor scores would differ at 6 months (Movement Disorder Society-sponsored Unified Parkinson's Disease Rating Scale [MDS-UPDRS]-III, Class I evidence). Secondary outcomes included safety and tolerability, motor symptoms (MDS-UPDRS-II), motor fluctuations, sleep, nonmotor symptoms (MDS-UPDRS-I), cognition (Montreal Cognitive Assessment), and quality of life. RESULTS: Sixty patients received caffeine and 61 placebo. Caffeine was well-tolerated with similar prevalence of side effects as placebo. There was no improvement in motor parkinsonism (the primary outcome) with caffeine treatment compared to placebo (difference between groups -0.48 [95% confidence interval -3.21 to 2.25] points on MDS-UPDRS-III). Similarly, on secondary outcomes, there was no change in motor signs or motor symptoms (MDS-UPDRS-II) at any time point, and no difference on quality of life. There was a slight improvement in somnolence over the first 6 months, which attenuated over time. There was a slight increase in dyskinesia with caffeine (MDS-UPDRS-4.1+4.2 = 0.25 points higher), and caffeine was associated with worse cognitive testing scores (average Montreal Cognitive Assessment = 0.66 [0.01, 1.32] worse than placebo). CONCLUSION: Caffeine did not provide clinically important improvement of motor manifestations of PD (Class I evidence). Epidemiologic links between caffeine and lower PD risk do not appear to be explained by symptomatic effects. CLINICALTRIALSGOV IDENTIFIER: NCT01738178. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that for patients with PD, caffeine does not significantly improve motor manifestations.

Dementia Predictors in Parkinson Disease: A Validation Study.

In a prospective study, we recently discovered 8 clinical predictors of dementia in Parkinson's disease. Here, we validate these dementia predictors using two additional prospective cohorts (n = 134). After a 3.6-year follow-up, 35/134 developed dementia (7.2% per year). When confirming individual variables, 5/8 were significantly associated with dementia in the validation cohort. These included age, male sex, baseline RBD, orthostatic hypotension, and MCI. Bilateral onset, hallucinations and falls/freezing did not significantly predict dementia; however, point estimates of OR were all >1. In all cohorts, the strongest determinant for dementia development was the co-existence of RBD, MCI and orthostatic hypotension at baseline.

New Clinical Subtypes of Parkinson Disease and Their Longitudinal Progression: A Prospective Cohort Comparison With Other Phenotypes.

IMPORTANCE: There is increasing evidence that Parkinson disease (PD) is heterogeneous in its clinical presentation and prognosis. Defining subtypes of PD is needed to better understand underlying mechanisms, predict disease course, and eventually design more efficient personalized management strategies. OBJECTIVES: To identify clinical subtypes of PD, compare the prognosis and progression rate between PD phenotypes, and compare the ability to predict prognosis in our subtypes and those from previously published clustering solutions. DESIGN, SETTING, AND PARTICIPANTS: Prospective cohort study. The cohorts were from 2 movement disorders clinics in Montreal, Quebec, Canada (patients were enrolled during the period from 2005 to 2013). A total of 113 patients with idiopathic PD were enrolled. A comprehensive spectrum of motor and nonmotor features (motor severity, motor complications, motor subtypes, quantitative motor tests, autonomic and psychiatric manifestations, olfaction, color vision, sleep parameters, and neurocognitive testing) were assessed at baseline. After a mean follow-up time of 4.5 years, 76 patients were reassessed. In addition to reanalysis of baseline variables, a global composite outcome was created by merging standardized scores for motor symptoms, motor signs, cognitive function, and other nonmotor manifestations. MAIN OUTCOMES AND MEASURES: Changes in the quintiles of the global composite outcome and its components were compared between different subtypes. RESULTS: The best cluster solution found was based on orthostatic hypotension, mild cognitive impairment, rapid eye movement sleep behavior disorder (RBD), depression, anxiety, and Unified Parkinson's Disease Rating Scale Part II and Part III scores at baseline. Three subtypes were defined as mainly motor/slow progression, diffuse/malignant, and intermediate. Despite similar age and disease duration, patients with the diffuse/malignant phenotype were more likely to have mild cognitive impairment, orthostatic hypotension, and RBD at baseline, and at prospective follow-up, they showed a more rapid progression in cognition (odds ratio [OR], 8.7 [95% CI, 4.0-18.7]; P < .001), other nonmotor symptoms (OR, 10.0 [95% CI, 4.3-23.2]; P < .001), motor signs (OR, 4.1 [95% CI, 1.8-9.1]; P = .001), motor symptoms (OR, 2.9 [95% CI, 1.3-6.2]; P < .01), and the global composite outcome (OR, 8.0 [95% CI, 3.7-17.7]; P < .001). CONCLUSIONS AND RELEVANCE: It is recommended to screen patients with PD for mild cognitive impairment, orthostatic hypotension, and RBD even at baseline visits. These nonmotor features identify a diffuse/malignant subgroup of patients with PD for whom the most rapid progression rate could be expected.

Tango for treatment of motor and non-motor manifestations in Parkinson's disease: a randomized control study.

OBJECTIVE: To determine effects of Argentine tango on motor and non-motor manifestations of Parkinson's disease. DESIGN: Randomized control trial. PARTICIPANTS: Forty patients with idiopathic Parkinson's disease. SETTING: Movement disorder clinic and dance studio. INTERVENTION: Two randomized groups: group (N=18) with 24 partnered tango classes, and control self-directed exercise group (N=15). MAIN OUTCOMES MEASURES: The primary outcome was overall motor severity. Secondary outcomes included other motor measures, balance, cognition, fatigue, apathy, depression and quality of life. RESULTS: On the primary intention-to-treat analysis there was no difference in motor severity between groups MDS-UPDRS-3 (1.6 vs.1.2-point reduction, p=0.85). Patient-rated clinical global impression of change did not differ (p=0.33), however examiner rating improved in favor of tango (p=0.02). Mini-BESTest improved in the tango group compared to controls (0.7±2.2 vs. -2.7±5.9, p=0.032). Among individual items, tango improved in both simple TUG time (-1.3±1.6s vs. 0.1±2.3, p=0.042) and TUG Dual Task score (0.4±0.9 vs. -0.2±0.4, p=0.012), with borderline improvement in walk with pivot turns (0.2±0.5 vs. -0.1±0.5, p=0.066). MoCa (0.4±1.6 vs. -0.6±1.5, p=0.080) and FSS (-3.6±10.5 vs. 2.5±6.2, p=0.057) showed a non-significant trend toward improvement in the tango group. Tango participants found the activity more enjoyable (p<0.001) and felt more "overall" treatment satisfaction (p<0.001). We found no significant differences in other outcomes or adverse events. CONCLUSION: Argentine tango can improve balance, and functional mobility, and may have modest benefits upon cognition and fatigue in Parkinson's disease. These findings must be confirmed in longer-term trials explicitly powered for cognition and fatigue.

Predictors of dementia in Parkinson disease: a prospective cohort study.

OBJECTIVE: We investigated an array of possible markers of early dementia in Parkinson disease. METHODS: We performed a comprehensive assessment of autonomic, sleep, psychiatric, visual, olfactory, and motor manifestations in 80 patients with Parkinson disease who were dementia-free at baseline. After 4.4 years' follow-up, patients were evaluated for dementia. Predictive variables were assessed using logistic regression adjusting for disease duration, follow-up duration, age, and sex. RESULTS: Of 80 patients, 27 (34%) developed dementia. Patients destined to develop dementia were older and more often male (odds ratio [OR] = 3.64, p = 0.023). Those with baseline mild cognitive impairment had increased dementia risk (OR = 22.5, p < 0.001). REM sleep behavior disorder at baseline dramatically increased dementia risk (OR = 49.7, p = 0.001); however, neither daytime sleepiness nor insomnia predicted dementia. Higher baseline blood pressure increased dementia risk (OR = 1.37 per 10 mm Hg, p = 0.032). Orthostatic blood pressure drop was strongly associated with dementia risk (OR = 1.84 per 10 mm Hg, p < 0.001); having a systolic drop of >10 mm Hg increased dementia odds 7-fold (OR = 7.3, p = 0.002). Abnormal color vision increased dementia risk (OR = 3.3, p = 0.014), but olfactory dysfunction did not. Among baseline motor variables, proportion of gait involvement (OR = 1.12, p = 0.023), falls (OR = 3.02, p = 0.042), and freezing (OR = 2.63, p = 0.013), as well as the Purdue Pegboard Test (OR = 0.67, p = 0.049) and alternate tap test (OR = 0.97, p = 0.033) predicted dementia. CONCLUSION: Cardiovascular autonomic dysfunction, REM sleep behavior disorder, color discrimination ability, and gait dysfunction strongly predict development of dementia in Parkinson disease.