PNI Study Links Muscular Strength, Mobility, and Brain Health in Alzheimer’s Patients

Santa Monica, Calif. — January 2023 — A new clinical study published in the Journal of Alzheimer’s Disease reveals a strong correlation between muscular strength, mobility, and brain volume in individuals with Alzheimer’s disease. The research, led by scientists at the Pacific Neuroscience Institute (PNI) and partner institutions, highlights the role of frailty-related factors as modifiable risks for brain health.

Using Neuroreader® volumetric MRI software, researchers demonstrated that stronger grip strength and better walking endurance were directly linked to larger brain volumes in regions critical to memory and cognition.

Study Overview

• Participants: 38 individuals with Alzheimer’s disease dementia confirmed through amyloid biomarkers and cognitive impairment testing.
• Measurements:
  • Handgrip strength (dominant & non-dominant hand)
  • Handgrip asymmetry (calculated difference between hands)
  • Two-minute walk test (2MWT) for mobility
• Brain Imaging: Regional brain volumes quantified with Neuroreader® volumetric MRI.
• Analysis: Regression and covariance models adjusted for age, sex, education, BMI, head size, and handedness.

Key Findings

• Non-dominant handgrip strength → larger hippocampal volumes (p = 0.02).
• Dominant handgrip strength → larger frontal lobe volumes (p = 0.02).
• 2MWT performance → larger hippocampal, frontal, temporal, parietal, and occipital lobe volumes.
• Frailty → associated with reduced volumes in the frontal, temporal, and parietal lobes.

In short, patients with stronger grip and better mobility had healthier brain volumes across multiple regions tied to cognition.

Expert Perspectives

“Our study shows that participants who were not frail had larger brain volumes, and we were able to measure this precisely with volumetric MRI,” said Dr. Cyrus A. Raji, Assistant Professor of Radiology at Washington University in St. Louis and study co-author.

Lead author Dr. Somayeh Meysami, Assistant Professor of Neurosciences at Saint John’s Cancer Institute and clinical research scientist at the Pacific Brain Health Center at PNI, added:

“These results suggest that frailty-related factors are modifiable risk factors for brain health. Strength and mobility are directly linked to the brain regions that support cognition.”

Dr. David Merrill, Director of the Pacific Brain Health Center and co-senior author, emphasized the clinical impact:

“We aim to translate these findings into larger patient care strategies, combining diagnostics, cognitive training, and lifestyle interventions to improve resilience and brain health in Alzheimer’s patients.”

Clinical Significance

• Up to 50% of Alzheimer’s risk is linked to modifiable risk factors, including frailty.
• This study supports the growing evidence that physical strength and mobility can influence brain health.
• Findings could inform early interventions for patients at risk of dementia, as well as treatment strategies for those already diagnosed.

Publication Details

• Published: December 14, 2022, in the Journal of Alzheimer’s Disease.
• DOI: 10.3233/JAD-220886
• Will also appear in the 2023 JAD Handbook on Dementia Prevention.
• Authors: Somayeh Meysami, Cyrus A. Raji, Ryan M. Glatt, Emily S. Popa, Aarthi S. Ganapathi, Tess Bookheimer, Colby B. Slyapich, Kyron P. Pierce, Casey J. Richards, Melanie G. Lampa, Jaya M. Gill, Molly K. Rapozo, John F. Hodes, Ynez M. Tongson, Claudia L. Wong, Mihae Kim, Verna R. Porter, Scott A. Kaiser, Stella E. Panos, Richelin V. Dye, Karen J. Miller, Susan Y. Bookheimer, Neil A. Martin, Santosh Kesari, Daniel F. Kelly, Jennifer E. Bramen, Prabha Siddarth, and David A. Merrill.

Read the full study on PubMed