Cognitive impairment in Parkinson's disease: Associations between subjective and objective cognitive decline in a large longitudinal study.

Background: Cognitive decline creates substantial morbidity and cost in Parkinson's disease (PD) and clinicians have limited tools for counseling patients on prognosis. We aimed to use data from a randomized, controlled trial of isradipine in Parkinson's disease (STEADY-PD III) to determine which objective cognitive domain deficits drive patient complaints of cognitive symptoms.

Methods: Neuro-Quality of Life (Neuro-QoL) Cognition: General Concerns (GC), and Cognition: Executive Function (EF) (subjective measures), were administered at baseline, 1, 2, and 3 years in 324 people with PD.

Assessing Retinal Structure in Patients with Parkinson's Disease.

Objective: The retina is an extension of the central nervous system (CNS), and ocular symptoms can precede manifestations of CNS disorders. Given that several neurodegenerative conditions that affect the brain exhibit ocular symptoms, the retina may be an accessible biomarker to monitor disease progression. Dopamine, the key neurotransmitter related to Parkinson's disease (PD), is contained in amacrine and interplexiform cells, which reside in specific retinal layers.

Consensus-Based Attributes for Identifying Patients With Spasmodic Dysphonia and Other Voice Disorders.

Importance: A roadblock for research on adductor spasmodic dysphonia (ADSD), abductor SD (ABSD), voice tremor (VT), and muscular tension dysphonia (MTD) is the lack of criteria for selecting patients with these disorders.

Objective: To determine the agreement among experts not using standard guidelines to classify patients with ABSD, ADSD, VT, and MTD, and develop expert consensus attributes for classifying patients for research.

Design, Setting And Participants: From 2011 to 2016, a multicenter observational study examined agreement among blinded experts when classifying patients with ADSD, ABSD, VT or MTD (first study).

Effect of Deutetrabenazine on Chorea Among Patients With Huntington Disease: A Randomized Clinical Trial.

Importance: Deutetrabenazine is a novel molecule containing deuterium, which attenuates CYP2D6 metabolism and increases active metabolite half-lives and may therefore lead to stable systemic exposure while preserving key pharmacological activity.

Objective: To evaluate efficacy and safety of deutetrabenazine treatment to control chorea associated with Huntington disease.

Design, Setting, And Participants: Ninety ambulatory adults diagnosed with manifest Huntington disease and a baseline total maximal chorea score of 8 or higher (range, 0-28; lower score indicates less chorea) were enrolled from August 2013 to August 2014 and randomized to receive deutetrabenazine (n = 45) or placebo (n = 45) in a double-blind fashion at 34 Huntington Study Group sites.

Clinical-Genetic Associations in the Prospective Huntington at Risk Observational Study (PHAROS): Implications for Clinical Trials.

Importance: Identifying measures that are associated with the cytosine-adenine-guanine (CAG) expansion in individuals before diagnosis of Huntington disease (HD) has implications for designing clinical trials.

Objective: To identify the earliest features associated with the motor diagnosis of HD in the Prospective Huntington at Risk Observational Study (PHAROS).

Design, Setting, And Participants: A prospective, multicenter, longitudinal cohort study was conducted at 43 US and Canadian Huntington Study Group research sites from July 9, 1999, through December 17, 2009.

A randomized clinical trial of high-dosage coenzyme Q10 in early Parkinson disease: no evidence of benefit.

Importance: Coenzyme Q10 (CoQ10), an antioxidant that supports mitochondrial function, has been shown in preclinical Parkinson disease (PD) models to reduce the loss of dopamine neurons, and was safe and well tolerated in early-phase human studies. A previous phase II study suggested possible clinical benefit.

Objective: To examine whether CoQ10 could slow disease progression in early PD.

Where is the action? Action sentence processing in Parkinson's disease.

According to an influential view of conceptual representation, action concepts are understood through motoric simulations, involving motor networks of the brain. A stronger version of this embodied account suggests that even figurative uses of action words (e.g.

Parkinson's disease disrupts both automatic and controlled processing of action verbs.

The problem of how word meaning is processed in the brain has been a topic of intense investigation in cognitive neuroscience. While considerable correlational evidence exists for the involvement of sensory-motor systems in conceptual processing, it is still unclear whether they play a causal role. We investigated this issue by comparing the performance of patients with Parkinson's disease (PD) with that of age-matched controls when processing action and abstract verbs.

Effects of tyramine administration in Parkinson's disease patients treated with selective MAO-B inhibitor rasagiline.

Rasagiline is a novel, potent, and selective MAO-B inhibitor shown to be effective for Parkinson's disease. Traditional nonselective MAO inhibitors have been associated with dietary tyramine interactions that can induce hypertensive reactions. To test safety, tyramine challenges (50-75 mg) were performed in 72 rasagiline-treated and 38 placebo-treated Parkinson's disease (PD) patients at the end of two double-blind placebo-controlled trials of rasagiline.

A randomized controlled trial of etilevodopa in patients with Parkinson disease who have motor fluctuations.

Background: Motor fluctuations are a common complication in patients with Parkinson disease (PD) receiving long-term levodopa therapy. Slowed gastric emptying and poor solubility of levodopa in the gastrointestinal tract may delay the onset of drug benefit after dosing. Etilevodopa is an ethyl-ester prodrug of levodopa that has greater gastric solubility, passes quickly into the small intestine, is rapidly hydrolyzed to levodopa, and has a shortened time to maximum levodopa concentration.

Rasagiline improves quality of life in patients with early Parkinson's disease.

The objective of this study was to determine the effects of rasagiline as monotherapy on quality of life (QOL) in patients with early Parkinson's disease (PD). Rasagiline, a potent, second-generation, irreversible, selective monoamine oxidase B inhibitor improves PD symptoms in patients with early PD. Patients with early untreated PD were randomly assigned to once-daily rasagiline 1 mg/day, rasagiline 2 mg/day, or placebo in a 6-month, double-blind trial (n=404).

Neural basis for impaired time reproduction in Parkinson's disease: an fMRI study.

Studies involving brain-lesioned subjects have used the paced finger tapping (PFT) task to investigate the neural systems that govern motor timing. Patients with Parkinson's disease (PD), for example, demonstrate abnormal performance on the PFT, characterized by decreased accuracy and variability changes, suggesting that the basal ganglia may play a critical role in motor timing. Consistent with this hypothesis, an fMRI study of healthy participants demonstrated that the medial frontostriatal circuit (dorsal putamen, ventrolateral thalamus, SMA) correlated with explicit time-dependent components of the PFT task.

Test-retest reliability of the unified Parkinson's disease rating scale in patients with early Parkinson's disease: results from a multicenter clinical trial.

Our objective was to assess the test-retest reliability of the Unified Parkinson's Disease Rating Scale (UPDRS). The UPDRS is the most widely used instrument for measuring severity of parkinsonian symptoms in clinical research and in practice. The validity and inter-rater reliability of this scale have been previously studied.