The effect of AD co‐pathology on cognitive phenotype and FDG‐PET patterns in Parkinson’s disease with cognitive impairment.

Background: Co‐morbid Alzheimer’s disease (AD) pathology is a major risk factor for cognitive impairment (CI) in PD, but whether and how AD co‐pathology affects the clinical phenotype of PD‐CI is incompletely understood. Recently validated plasma biomarkers for AD pathology, such as ptau217, hold great promise to revolutionize the diagnosis of neurodegenerative diseases. Here, we used plasma ptau217 to detect AD co‐pathology in a well‐characterized cohort of PD patients with CI and examine its associations with APOE4 genotype, cognitive profile, and cerebral hypometabolism on 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.

Addressing the sources of inter-subject variability in E-field parameters in anodal tDCS stimulation over motor cortical network.

Although transcranial direct current stimulation constitutes a non-invasive neuromodulation technique with promising results in a great variety of applications, its clinical implementation is compromised by the high inter-subject variability reported. This study aims to analyze the inter-subject variability in electric fields (E-fields) over regions of the cortical motor network under two electrode montages: the classical C3Fp2 and an alternative P3F3, which confines more the E-field over this region.Computational models of the head of 98 healthy subjects were developed to simulate the E-field under both montages.

In vivo cholinergic basal forebrain degeneration and cognition in Parkinson's disease: Imaging results from the COPPADIS study.

Introduction: We aimed to assess associations between multimodal neuroimaging measures of cholinergic basal forebrain (CBF) integrity and cognition in Parkinson's disease (PD) without dementia.

Methods: The study included a total of 180 non-demented PD patients and 45 healthy controls, who underwent structural MRI acquisitions and standardized neurocognitive assessment through the PD-Cognitive Rating Scale (PD-CRS) within the multicentric COPPADIS-2015 study. A subset of 73 patients also had Diffusion Tensor Imaging (DTI) acquisitions.