Madhukar Dwivedi received his MS in Computer Science and Engineering (CSE). His research work was supervised by Prof. S Bapi Raju. Here’s a summary of his research work on Investigation of the longitudinal changes in the structure of the brain in mild cognitive impairment (MCI) and Alzheimer’s disease (AD):
Dementia is a neurological disease that affects people starting around the age of 45. The most common symptom of dementia includes memory difficulties, impaired judgment-making capacity, difficulty in performing daily living activities, mind wandering, and disorientation (WHO 2022). Researchers have been looking into the causes, rate of progression, and potential remedies for many years. However, there is as yet no cure for dementia. As a result, researchers have been investigating the efficacy of alternative therapeutic methods such as regular exercise, therapies, meditation, etc.
The present thesis has focused on investigating dementia Alzheimer’s type and its early phases. It includes an overview of Alzheimer’s disease and potential research gaps related to atrophy rates in
selected regions of interest, such as the hippocampal subfields and the effects of meditation as adjuvant therapy. We used longitudinal structural and functional MRI datasets from humans to address these two research topics in the thesis.
We have explored the nature of atrophy in the hippocampal subfields during the distinct phases of
Alzheimer’s disease. This research hypothesized that hippocampal subfields in Alzheimer’s disease patients would have the highest gray matter volume atrophy rate compared to other groups (control, early MCI, and late MCI). We have also proposed that the subfields being involved in memory encoding and decoding would deteriorate faster in the late MCI or AD groups. The analysis used structural MRI data available at two-time points (separated by a year) from a cohort of 196 participants in the publicly available ADNI dataset. We have estimated the gray matter volume (as the cortical thickness is irrelevant here in the subcortical region) and compared it across the four groups. Subfields that are mainly involved in the process of memory encoding, consolidation, and decoding, such as the dentate gyrus, CA3, CA1, and subiculum, have shown a higher atrophy rate in Alzheimer’s disease and late MCI groups as compared to early MCI or healthy controls over a one-year time period.
We have also investigated the long-term effects of meditation techniques (one of the alternative therapy approaches) in early MCI or Alzheimer’s disease patients over the course of six months. This study hypothesized that simple long-term daily meditation would have a facilitatory effect on the brain regions related to attention and executive control in patients with early MCI or Alzheimer’s disease. In his study, we have used a dataset collected by our collaborators on a cohort of dementia patients from Kolkata, India. In this longitudinal study, we compared the meditation and non-meditation groups on two structural brain measures: cortical thickness (CT) and gray matter volume (GMV). Our results indicate that long-term daily meditation led to substantial improvements in cortical thickness and gray matter volume in the regions responsible for attention and executive control in the prefrontal and inferior parietal cortex.
In summary, the thesis presents results from two longitudinal studies. One study characterized the
atrophy rate differences among aged controls and early-to-late-stage dementia patients. The other
study investigated the efficacy of meditation in arresting the structural decline in some critical
brain regions. It is hoped that these studies are useful for the clinical management of dementia.