Meditation's impact on default mode network and hippocampus in mild cognitive impairment: a pilot study

Abstract

Those with high baseline stress levels are more likely to develop mild cognitive impairment (MCI) and Alzheimer's Disease (AD). While meditation may reduce stress and alter the hippocampus and default mode network (DMN), little is known about its impact in these populations. Our objective was to conduct a "proof of concept" trial to determine whether Mindfulness Based Stress Reduction (MBSR) would improve DMN connectivity and reduce hippocampal atrophy among adults with MCI. 14 adults with MCI were randomized to MBSR vs. usual care and underwent resting state fMRI at baseline and follow-up. Seed based functional connectivity was applied using posterior cingulate cortex as seed. Brain morphometry analyses were performed using FreeSurfer. The results showed that after the intervention, MBSR participants had increased functional connectivity between the posterior cingulate cortex and bilateral medial prefrontal cortex and left hippocampus compared to controls. In addition, MBSR participants had trends of less bilateral hippocampal volume atrophy than control participants. These preliminary results indicate that in adults with MCI, MBSR may have a positive impact on the regions of the brain most related to MCI and AD. Further research with larger sample sizes and longer-follow-up are needed to further investigate the results from this pilot study.

Keywords: AD; ADAS-cog; Alzheimer's Disease; Alzheimer's Disease Assessment Scale, cognitive subscale; BIDMC; Beth Israel Deaconess Medical Center; CDR; Clinical Dementia Rating; DMN; Default mode network; Hippocampus; MBSR; MCI; MMSE; MPFC; Meditation; Mild cognitive impairment; Mindfulness Based Stress Reduction; Mini-Mental Status Exam; PCC; ROI; default mode network; fMRI; medial prefrontal cortex; mild cognitive impairment; posterior cingulate cortex; region of interest.

Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Figures

Figure 1. Resting state functional connectivity, and hippocampal volume results 1A. Resting state functional connectivity results

These images are representations of statistical results of a two sample t-test on the pre- vs. post differences between the MBSR and control groups (MBSR [pre-post] - control [pre-post]). The results showed increased functional connectivity between the Posterior Cingulate Cortex (PCC) and Medial Prefrontal Cortex (MPFC) and between the PCC and left hippocampus (hippo) after MBSR as compared with control condition. 1B. Hippocampal volume results: individual and average (bolded) hippocampal volumes from baseline to follow-up in the intervention (MBSR, Mindfulness Based Stress Reduction) and control groups