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.

Correlation Between Amyloid PET Imaging and Discordant Cerebrospinal Fluid Biomarkers Results in Patients with Suspected Alzheimer's Disease.

Background: Although the concordance between cerebrospinal fluid (CSF) Alzheimer's disease (AD) biomarkers and amyloid-PET findings is well known, there are no data regarding the concordance of amyloid-PET with inconclusive CSF values of amyloid-β (Aβ)1 - 42 and p-tau for the diagnosis of AD.

Objective: To investigate the relationship between the amyloid-PET results with discordant AD biomarkers values in CSF (Aβ1 - 42+/p-tau-or Aβ1 - 42-/p-tau+).

Methods: An observational retrospective study, including 62 patients with mild cognitive impairment (32/62) or dementia (30/62), suspicious of AD who had undergone a lumbar puncture to determine CSF AD biomarkers, and presented discordant values in CSF between Aβ1 - 42 and p-tau (Aβ1 - 42+/p-tau-or Aβ1 - 42-/p-tau+).

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.

TMA-93 Validation by Alzheimer's Disease Biomarkers: A Comparison with the Free and Cued Selective Reminding Test on a Biobank Sample.

Background: The Memory Associative Test TMA-93 examines visual relational binding, characteristically affected in early-AD stages.

Objective: We aim to validate the TMA-93 by biomarkers determination and compare its diagnostic characteristics with the Free and Cued Selective Reminding Test (FCSRT).

Methods: Retrospective analysis of a Biobank database.