Neural correlates of perceived physical and mental fatigability in older adults: A pilot study

• Published in: Experimental gerontology Vol. 115; pp. 139 - 147
• Main Authors: Wasson, Emily, Rosso, Andrea L., Santanasto, Adam J., Rosano, Caterina, Butters, Meryl A., Rejeski, W. Jack, Boudreau, Robert M., Aizenstein, Howard, Gmelin, Theresa, Glynn, Nancy W.
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01-01-2019
• Subjects: Aged; Aged, 80 and over; Aging; Basal Ganglia - pathology; Fatigue; Fatigue - diagnosis; Female; Geriatric Assessment - methods; Gray Matter - pathology; Grey matter volumes; Humans; Logistic Models; Magnetic Resonance Imaging; Male; Pilot Projects; Sedentary Behavior; Walking - physiology; Aging; Grey matter volumes; Fatigue; Magnetic resonance imaging
• ISSN: 0531-5565; 1873-6815
• DOI: 10.1016/j.exger.2018.12.003

This pilot work examined associations of brain grey matter volumes (GMV) with perceived fatigability in older adults to elucidate disablement mechanisms. A subsample (n = 29; age = 77.2 ± 5.5; 86% female) of participants from the Lifestyle Interventions and Independence for Elders (LIFE) Study was utilized to quantify GMV for regions of interest in the basal ganglia and limbic system normalized to intracranial volume. The Pittsburgh Fatigability Scale measured physical and mental fatigability (score 0–50; higher physical fatigability ≥ 15; higher mental fatigability ≥ 13). We used an exploratory alpha level of p < 0.1. Nineteen (66%) participants had higher physical fatigability, 19 (66%) had higher mental fatigability, of these, 17 (57%) had both. Right hippocampal volumes/ICV were smaller in participants with higher verses lower physical fatigability (0.261 ± 0.039 vs. 0.273 ± 0.022, p = 0.07); associations were similar for right putamen and bilateral thalamus. Higher mental fatigability was associated with smaller right hippocampus, thalamus, and posterior cingulum and bilateral amygdala. Higher fatigability in older adults may be associated with smaller volumes of the basal ganglia and limbic system, indicating mechanisms for further exploration.
•Provides initial evidence that fatigability in aging has a neurobiological component•Specific regions in the basal ganglia and limbic system may be related to fatigability.•Regions were similar for physical and mental, but more regions associated with mental fatigability.