Cognitive and motor function in long-duration PARKIN-associated Parkinson disease.

Importance: Data on the long-term cognitive outcomes of patients with PARKIN-associated Parkinson disease (PD) are unknown but may be useful when counseling these patients.

Objective: Among patients with early-onset PD of long duration, we assessed cognitive and motor performances, comparing homozygotes and compound heterozygotes who carry 2 PARKIN mutations with noncarriers.

Design, Setting, And Participants: Cross-sectional study of 44 participants at 17 different movement disorder centers who were in the Consortium on Risk for Early-Onset PD study with a duration of PD greater than the median duration (>14 years): 4 homozygotes and 17 compound heterozygotes (hereafter referred to as carriers) and 23 noncarriers.

Neuropsychological Profile of Parkin Mutation Carriers with and without Parkinson Disease: The CORE-PD Study.

The cognitive profile of early onset Parkinson's disease (EOPD) has not been clearly defined. Mutations in the parkin gene are the most common genetic risk factor for EOPD and may offer information about the neuropsychological pattern of performance in both symptomatic and asymptomatic mutation carriers. EOPD probands and their first-degree relatives who did not have Parkinson's disease (PD) were genotyped for mutations in the parkin gene and administered a comprehensive neuropsychological battery.

A pilot study of gene/gene and gene/environment interactions in Alzheimer disease.

Background: Although some genes associated with increased risk of Alzheimer Disease (AD) have been identified, few data exist related to gene/gene and gene/environment risk of AD. The purpose of this pilot study was to explore gene/gene and gene/environment associations in AD and to obtain data for sample size estimates for larger, more definitive studies of AD.

Methods: The effect of gene/gene and gene/environment interaction related to late onset Alzheimer Disease (LOAD) was investigated in 153 subjects with LOAD and 302 gender matched controls enrolled in the Personalized Medicine Research Project, a population-based bio-repository.

Predictors of parkin mutations in early-onset Parkinson disease: the consortium on risk for early-onset Parkinson disease study.

Background: Mutations in the parkin gene are the most common genetic cause of early-onset Parkinson disease (PD). Results from a multicenter study of patients with PD systematically sampled by age at onset have not been reported to date.

Objective: To determine risk factors associated with carrying parkin mutations.

Self-report of cognitive impairment and mini-mental state examination performance in PRKN, LRRK2, and GBA carriers with early onset Parkinson's disease.

While little is known about risk factors for cognitive impairment in early onset Parkinson disease (EOPD), postmortem studies have shown an association between dementia with Lewy bodies (DLB) and glucocerebrosidase (GBA) mutation. We compared Mini-Mental State Examination (MMSE) performance and self-reported cognitive impairment in 699 EOPD participants genotyped for mutations in parkin (PRKN), leucine-rich repeat kinase-2 (LRRK2), and GBA. Logistic regression was used to assess the association between reported cognitive impairment and MMSE score, as well as between GBA group membership and self-reported impairment and MMSE.

Motor phenotype of LRRK2 G2019S carriers in early-onset Parkinson disease.

Objective: To determine the motor phenotype of LRRK2 G2019S mutation carriers. LRRK2 mutation carriers were previously reported to manifest the tremor dominant motor phenotype, which has been associated with slower motor progression and less cognitive impairment compared with the postural instability and gait difficulty (PIGD) phenotype.

Design: Cross-sectional observational study.

Predictors of nursing home admission and/or death in incident Alzheimer's disease and other dementia cases compared to controls: a population-based study.

This research elucidates the risk of institutional care and/or death of patients with Alzheimer's disease (AD) or other dementia (OD) compared with noncases. Community dwelling incident cases of AD (n = 240) or OD (n = 208) and age-matched noncases (n = 363) living in an enumerated population were included. The adjusted hazard ratio (HR) of being admitted to a nursing home compared with controls was 5.

Alzheimer's disease or other dementia and medical care utilization.

Purpose: Recent findings on medical care utilization among people with Alzheimer's disease (AD) or other dementia (OD) are conflicting. A population-based case-control study was designed to determine if patients with clinically diagnosed AD or OD have different medical care utilization patterns before and after diagnosis compared to age-matched controls.

Methods: All community dwelling incident cases of AD (n = 240) or OD (n = 208) diagnosed between July 1, 1992 and June 30, 1997, and age-matched controls (n = 363) living in an enumerated population, were included.