Parkinson's Disease and Other Alzheimer's Disease and Related Dementia Pathologies and the Progression of Parkinsonism in Older Adults.

Background: The interrelationship of parkinsonism, Parkinson's disease (PD) and other Alzheimer's disease (AD) and Alzheimer's disease and related dementias (ADRD) pathologies is unclear.

Objective: We examined the progression of parkinsonian signs in adults with and without parkinsonism, and their underlying brain pathologies.

Methods: Annual parkinsonian signs were based on a modified Unified Parkinson's Disease Rating Scale.

Alzheimer's Disease Pathology Outside of the Cerebrum Is Related to a Higher Odds of Dementia.

Background: Assessments of Alzheimer's disease pathology do not routinely include lower brainstem, olfactory bulb, and spinal cord.

Objective: Test if amyloid-β (Aβ) and paired helical filament (PHF) tau-tangles outside the cerebrum are associated with the odds of dementia.

Methods: Autopsies were obtained in decedents with cognitive testing (n = 300).

Contrasting walking styles map to discrete neural substrates in the mouse brainstem.

Walking is a slow gait which is particularly adaptable to meet internal or external needs and is prone to maladaptive alterations that lead to gait disorders. Alterations can affect speed, but also style (the way one walks). While slowed speed may signify the presence of a problem, style represents the hallmark essential for clinical classification of gait disorders.

Stereotaxic Surgical Approach to Microinject the Caudal Brainstem and Upper Cervical Spinal Cord via the Cisterna Magna in Mice.

Stereotaxic surgery to target brain sites in mice is commonly guided by skull landmarks. Access is then obtained via burr holes drilled through the skull. This standard approach can be challenging for targets in the caudal brainstem and upper cervical cord due to specific anatomical challenges as these sites are remote from skull landmarks, leading to imprecision.

Brain β-Amyloid Links the Association of Change in Body Mass Index With Cognitive Decline in Community-Dwelling Older Adults.

Background: We tested the hypothesis that indices of Alzheimer's disease and related dementia (ADRD) pathologies may explain associations between change in body mass index (BMI) and cognitive decline in old age.

Method: We used data from 436 older decedents participating in a prospective longitudinal cohort study who had undergone annual cognitive and BMI assessments and postmortem collection of indices of 12 brain pathologies. We identified ADRD brain pathologies associated with BMI range, a previously published metric of change in BMI.