Association of Physical Exercise With Structural Brain Changes and Cognitive Decline in Patients With Early Parkinson Disease.

Background And Objectives: Accumulating evidence suggests that physical activity is associated with a better clinical and cognitive course in Parkinson disease (PD), yet whether these effects are subserved by structural brain alterations are largely unexplored. The aim of this study was to investigate whether regular physical activity associates with a reduced longitudinal rate of neurodegeneration and slower cognitive decline in PD.

Methods: In this longitudinal, observational cohort study, we used data from the Parkinson's Progression Markers Initiative.

The effect of Lewy body (co-)pathology on the clinical and imaging phenotype of amnestic patients.

Lewy body (LB) pathology is present as a co-pathology in ∼50% of patients with Alzheimer's disease (AD) and may even represent the main neuropathologic substrate in a subset of patients with amnestic impairments. However, the degree to which LB pathology affects regional neurodegeneration patterns and clinical trajectories among amnestic patients is not well understood. We studied 865 patients from the Alzheimer's Disease Neuroimaging Initiative cohort with clinical diagnoses of amnestic mild cognitive impairment (n = 661) or AD dementia (n = 211), who had CSF and FDG-PET data available.

Imaging biomarkers of cortical neurodegeneration underlying cognitive impairment in Parkinson's disease.

Purpose: Imaging biomarkers bear great promise for improving the diagnosis and prognosis of cognitive impairment in Parkinson's disease (PD). We compared the ability of three commonly used neuroimaging modalities to detect cortical changes in PD patients with mild cognitive impairment (PD-MCI) and dementia (PDD).

Methods: 53 cognitively normal PD patients (PD-CN), 32 PD-MCI, and 35 PDD underwent concurrent structural MRI (sMRI), diffusion-weighted MRI (dMRI), and [F]FDG PET.

Cortical hypometabolism in Parkinson's disease is linked to cholinergic basal forebrain atrophy.

Cortical hypometabolism on FDG-PET is a well-established neuroimaging biomarker of cognitive impairment in Parkinson's disease (PD), but its pathophysiologic origins are incompletely understood. Cholinergic basal forebrain (cBF) degeneration is a prominent pathological feature of PD-related cognitive impairment and may contribute to cortical hypometabolism through cholinergic denervation of cortical projection areas. Here, we investigated in-vivo associations between subregional cBF volumes on 3T-MRI, cortical hypometabolism on [F]FDG-PET, and cognitive deficits in a cohort of 95 PD participants with varying degrees of cognitive impairment.

Peripheral Inflammation Is Associated with Dopaminergic Degeneration in Parkinson's Disease.

Background: Peripheral inflammatory immune responses are suggested to play a major role in dopaminergic degeneration in Parkinson's disease (PD). The neutrophil-to-lymphocyte ratio (NLR) is a well-established biomarker of systemic inflammation in PD. Degeneration of the nigrostriatal dopaminergic system can be assessed in vivo using [ I]FP-CIT single photon emission computed tomography imaging of striatal dopamine transporter (DAT) density.