Association between Motor Signs and Cognitive Performance in Cognitively Unimpaired Older Adults: A Cross-Sectional Study Using the NACC Database

Abstract

Aiming to examine whether specific motor signs are associated with worse performance in specific cognitive domains among cognitively unimpaired (CU) individuals, we performed a cross-sectional analysis of data from the baseline evaluations of older, CU participants from the National Alzheimer’s Coordinating Center (NACC) Uniform Data Set. In total, 8149 CU (≥60 years) participants were included. Of these, 905 individuals scored ≥ 2 on at least one of the motor domains of the Unified Parkinson’s Disease Rating Scale part III (UPDRSIII). Cognitively impaired individuals, participants with psychiatric disorders and/or under treatment with antipsychotic, anxiolytic, sedative or hypnotic agents were excluded. Nine motor signs were examined: hypophonia, masked facies, resting tremor, action/postural tremor, rigidity, bradykinesia, impaired chair rise, impaired posture/gait and postural instability. Their association with performance on episodic memory, semantic memory, language, attention, processing speed or executive function was assessed using crude and adjusted linear regression models. Individuals with impaired chair rise had worse episodic memory, semantic memory, processing speed and executive function, while those with bradykinesia had worse language, processing speed and executive function. Sensitivity analyses, by excluding participants with cerebrovascular disease or PD, or other Parkinsonism, produced similar results with the exception of the relationship between bradykinesia and language performance.

Learned Irrelevance, Perseveration, and Cognitive Aging: A Cross-Sectional Study of Cognitively Unimpaired Older Adults

“…It has been shown that after a dopaminergic drug switch, patients with PD begin to handle PE errors better, while LI errors do not improve. This falls in line with the Dual Syndrome Hypothesis [ 54 ], which provides an explanation for the clinical heterogeneity observed in PD [ 55 ]. Specifically, it is suspected that two separate mechanisms tied to dopaminergic and cholinergic activity affect the manifestations of cognitive disorders in PD.…”

Associations between neuropsychiatric symptoms and incident Alzheimer’s dementia in men versus women

“…Therefore, more thorough assessment protocols might capture additional associations. Moreover, although we adjusted analyses for several factors, our findings may have been driven by residual confounding (it would not be possible to capture the effect of every potential confounder [ 43 , 44 ]) or the non-trivial proportion of missing data. Another limitation of this study is its observational nature.…”

Cognitive Performance and Incident Alzheimer’s Dementia in Men Versus Women

“…Chronological age at the beginning of the monitoring, years of formal education and body-mass index (BMI) were treated as scale variables. Sex, race (Caucasian, African American, American Indian or Alaska Native, Native Hawaiian or Pacific Islander, Asian and multiracial) and the following comorbidities, medications and daily habits were treated as categorical variables: history of traumatic brain injury (TBI), Parkinson’s disease (PD), seizures, cerebrovascular (CEVD) and cardiovascular disease (CAVD), atrial fibrillation (AF), hypertension, diabetes mellitus (DM), dyslipidaemia, smoking, alcohol or other substance abuse (with clinically significant impairment occurring over a 12-month period manifested in one of the following areas: work, driving, legal, or social) or vitamin B12 deficiency, and reported use of antidepressants, antipsychotics or anxiolytic/sedative/hypnotic agents ( 42 , 43 ). These variables were evaluated based on subject or co-participant reporting (co-participants usually belonged to one of the following categories: spouse, partner, companion – child, sibling or other relative – friend, neighbour, colleague – paid caregiver) ( 44 ).…”