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Statistically and clinically significant cognitive declines are observed in a small subset of individuals with Parkinson's Disease (PD) following treatment with Deep Brain Stimulation (DBS).We examine the association between multi-domain cognitive decline (MCD) and demographic and baseline clinical variables and the incidence of serious adverse events (SAE) arising within a six-month interval following DBS for PD.Study participants with PD who displayed MCD at 6-month follow-up evaluation after DBS (n = 18) were contrasted with individuals with PD from the same study who did not show cognitive decline after DBS (n = 146). Logistic regression analyses were employed to assess relationship between predictors, including age (70 years old), pre-DBS cognitive screening test performance, SAE, and MCD. MCD+ and MCD-groups were also compared on other baseline clinical and demographic variables.MCD showed modest association with older age and lower baseline neurocognitive screening performance, whereas the groups did not differ on most other baseline clinical and demographic variables. SAEs during the study interval were the most robust predictor of MCD in the DBS group. A variety of SAEs were documented in study participants experiencing MCD after DBS surgery, including, but not limited to, infections and small intracranial hemorrhages.Older age and lower baseline cognition measured prior to treatment are associated with MCD measured at six-months after DBS. SAE occurring following DBS surgery are also predictive of MCD. These predictors may reflect aspects of "frailty" in advanced PD. Risk factors for SAE warrant careful consideration in clinical trials.

BackgroundParkinson’s disease (PD) is the second most common neurodegenerative disorder among older adults worldwide. Currently, studies of PD progression rely primarily on White non-Latino (WNL) patients. Here, we compare clinical profiles and PD progression in Latino and WNL patients enrolled in a community-based study in rural Central California.MethodPD patients within 5 years of diagnosis were identified from 3 counties between 2001 and 2015. During up to 3 visits, participants were examined by movement disorders specialists and interviewed. We analyzed cross-sectional differences in PD clinical features severity at each study visit and used linear mixed models and Cox proportional hazards models to compare motor, nonmotor, and disability progression longitudinally and to assess time to death in Latinos compared to WNL patients.ResultsOf 775 patients included, 138 (18%) self-identified as Latino and presented with earlier age at diagnosis (63.6 vs 68.9) and death (78.6 vs 81.5) than WNL. Motor (hazard ratio [HR] = 1.17 [0.71, 1.94]) and nonmotor symptoms did not progress faster in Latino versus WNL patients after accounting for differences in baseline symptom severity. However, Latino patients progressed to disability stages according to Hoehn and Yahr faster than WNL (HR = 1.81 [1.11, 2.96]). Motor and nonmotor symptoms in Latino patients were also medically managed less well than in WNL.ConclusionsOur PD study with a large proportion of Latino enrollees and progression data reveals disparities in clinical features and progression by ethnicity that may reflect healthcare access and structural socioeconomic disadvantages in Latino patients with PD.

BackgroundParaquat dichloride is currently among the most widely used commercial herbicides in the United States. Exposure has been broadly linked to Parkinson’s disease (PD) through experimental and epidemiologic research. In the current study, we provide further epidemiologic assessment of ambient paraquat exposure and Parkinson’s risk in a large population-based study of PD in agricultural regions of Central California.MethodsBased on 829 PD patients and 824 community controls, we assessed associations between ambient paraquat dichloride exposure and PD. We estimated residential and workplace proximity to commercial agricultural applications in three California counties since 1974 using the CA pesticide use reporting (PUR) data and land use maps. We evaluated any, duration, and average intensity (pounds per acre per year) of exposure to paraquat in four time-windows prior to PD diagnosis or interview for controls.ResultsAmbient paraquat exposure assessed at both residence and workplace was associated with PD based on all three exposure measures, indicating that PD patients lived and worked near agricultural facilities that applied greater amounts of the herbicide than community controls. For workplace proximity to commercial applications since 1974, any exposure (yes/no, OR=1.25, 95% CI=1.00, 1.57), duration of exposure (per SD, OR=1.26, 95% CI=1.10, 1.44), and long-term average intensity of exposure (per SD, OR=1.30, 95% CI=1.10, 1.53) increased the odds of PD. Similar associations were observed for residential proximity (duration of exposure: OR=1.23 per SD, 95% CI=1.07,1.40; long-term average exposure: OR=1.22 per SD, 95% CI=1.03, 1.46). Risk estimates were comparable for men and women and the strongest odds were observed for those diagnosed ≤60 years of age.ConclusionThis study provides further evidence that paraquat dichloride exposure increases the risk of Parkinson’s disease.

Pesticide exposure has consistently been associated with Parkinson's disease (PD) onset. Yet, fewer epidemiologic studies have examined whether pesticides influence PD motor and non-motor symptom progression.Using a geographic information system tool that integrates agricultural pesticide use reports and land use records to derive ambient exposures at residences and workplaces, we assessed associations between specific pesticides previously related to PD onset with PD symptom progression in two PD patient cohorts living in agricultural regions of California.We calculated the pounds of pesticide applied agriculturally near each participant's residential or occupational addresses from 1974 to the year of PD diagnosis, using a geographic information system tool that links the California Pesticide Use Reports database to land use data. We examined 53 pesticides selected a priori as they have previously been associated with PD onset. We longitudinally followed two PD patient cohorts (PEG1 N = 242, PEG2 N = 259) for an average of 5.0 years (SD ± 3.5) and 2.7 years (SD ± 1.6) respectively and assessed PD symptoms using the movement disorder specialist-administered Unified Parkinson's disease Rating Scale part III (UPDRS), Mini-Mental State Examination (MMSE), and Geriatric Depression Scale (GDS). Weighted time-to-event regression models were implemented to estimate effects.Ten agricultural pesticides, including copper sulfate (pentahydrate), 2-methyl-4-chlorophenoxyacetic acid (MCPA) dimethylamine salt, tribufos, sodium cacodylate, methamidophos, ethephon, propargite, bromoxynil octanoate, monosodium methanearsonate (MSMA), and dicamba, were associated with faster symptom progression. Among these pesticides, residential or workplace proximity to higher amounts of copper sulfate (pentahydrate) and MCPA (dimethylamine salt) was associated with all three progression endpoints (copper sulfate: HRs = 1.22-1.36, 95 % CIs = 1.03-1.73; MCPA: HRs = 1.27-1.35, 95 % CIs = 1.02-1.70).Our findings suggest that pesticide exposure may not only be relevant for PD onset but also PD progression phenotypes. We have implicated ten specific pesticide active ingredients in faster PD motor and non-motor decline.

Deep brain stimulation is an accepted treatment for advanced Parkinson disease (PD), although there are few randomized trials comparing treatments, and most studies exclude older patients.To compare 6-month outcomes for patients with PD who received deep brain stimulation or best medical therapy.Randomized controlled trial of patients who received either deep brain stimulation or best medical therapy, stratified by study site and patient age (70 years vsor = 70 years) at 7 Veterans Affairs and 6 university hospitals between May 2002 and October 2005. A total of 255 patients with PD (Hoehn and Yahr stageor = 2 while not taking medications) were enrolled; 25% were aged 70 years or older. The final 6-month follow-up visit occurred in May 2006.Bilateral deep brain stimulation of the subthalamic nucleus (n = 60) or globus pallidus (n = 61). Patients receiving best medical therapy (n = 134) were actively managed by movement disorder neurologists.The primary outcome was time spent in the "on" state (good motor control with unimpeded motor function) without troubling dyskinesia, using motor diaries. Other outcomes included motor function, quality of life, neurocognitive function, and adverse events.Patients who received deep brain stimulation gained a mean of 4.6 h/d of on time without troubling dyskinesia compared with 0 h/d for patients who received best medical therapy (between group mean difference, 4.5 h/d [95% CI, 3.7-5.4 h/d]; P.001). Motor function improved significantly (P.001) with deep brain stimulation vs best medical therapy, such that 71% of deep brain stimulation patients and 32% of best medical therapy patients experienced clinically meaningful motor function improvements (or = 5 points). Compared with the best medical therapy group, the deep brain stimulation group experienced significant improvements in the summary measure of quality of life and on 7 of 8 PD quality-of-life scores (P.001). Neurocognitive testing revealed small decrements in some areas of information processing for patients receiving deep brain stimulation vs best medical therapy. At least 1 serious adverse event occurred in 49 deep brain stimulation patients and 15 best medical therapy patients (P.001), including 39 adverse events related to the surgical procedure and 1 death secondary to cerebral hemorrhage.In this randomized controlled trial of patients with advanced PD, deep brain stimulation was more effective than best medical therapy in improving on time without troubling dyskinesias, motor function, and quality of life at 6 months, but was associated with an increased risk of serious adverse events.clinicaltrials.gov Identifier: NCT00056563.

The brain uptake of phenobarbital during prolonged status epilepticus (3 h) was studied in paralyzed, ventilated sheep. The first 30 min of status epilepticus was characterized by systemic hypertension, increased CBF, increased peripheral vascular resistance, a fall in brain pH, and an elevation in brain lactate concentrations. Subsequently, hemodynamic factors normalized and brain acidosis persisted. Phenobarbital administered during the early phase of status epilepticus produced higher levels of brain phenobarbital concentration, which was greatest at the earliest sample time (5 min following infusion), compared to nonseizure controls. This elevation persisted for the first 3 h following the infusion. Phenobarbital administration during the established phase of status epilepticus, when systemic blood pressure, peripheral vascular resistance, and CBF had returned to preseizure values, resulted in attenuated brain uptake not different from controls for the first 30 min. These results are explained by disruption of the blood-brain barrier to phenobarbital during the early (hypertensive) phase of status epilepticus.