Decreased Brain Activity Linked to Decline in Daily Tasks Associated With Alzheimer’s
Typical daily tasks may not seem like the type that require high brain function. However, activities within our daily routine, which include paying the bills, going to appointments, and even driving — all of which are known as “instrumental activities” — are directly linked to optimal performance in specific portions of the brain that are typically diminished in Alzheimer’s patients, according to a new study.
The study, which appeared in this month’s issue of the Journal of Alzheimer’s Disease, entitled, “Decline in Daily Functioning Related to Decreased Brain Activity in Early Stages of Alzheimer’s Disease,” was conducted by researchers at Brigham and Women’s Hospital (BWH), who sought to find a link between these instrumental activities and how they directly relate to brain activity (which is measured in terms of FDG metabolism). In order to accomplish this, they accessed data from the Alzheimer’s Disease Neuroimaging Initiative database, which BWH has been compiling over the past ten years through an ongoing multi-center study.
Brain activity changes have already been measured metabolically using a unique nuclear medicine scan known as 18F-Flourodeoxy glucose (FDG) positron emission tomography (PET). In order to further associate these measured brain activity changes with the onset of cognitive decline and dementia, the researchers analyzed data taken from the BWH database, which included 104 clinically normal elderly participants, 203 participants with mild cognitive impairment, and 95 participants with mild dementia associated with Alzheimer’s disease. The data was compiled by establishing a brain activity baseline using a PET scan, followed by a series of clinical assessments that were conducted every six to twelve months for a period of up to 3 years. In addition to the participants themselves, family members or close friends also served as study partners, helping to fill out detailed questionnaires profiling the participants’ activities on a daily basis.
As a result of the study, BWH researchers discovered decreased brain activity across the frontal portions of participants’ brains. These frontal areas of the brain are largely tasked with cognitive processing and skills related to decision making. Additionally, decreased brain activity was also observed in the brain’s deep temporal and parietal (back) regions. These areas of the brain are where memories are stored and accessed. In participants with deficiencies in these regions, instrumental activities were found to be markedly impaired.
Gad Marshall, MD, with the BWH Center for Alzheimer Research and Treatment, an assistant professor of Neurology at Harvard Medical School, and the senior study author, noted that, “Impairment in activities of daily living is a major source of burden for Alzheimer’s disease patients and caregivers alike,” adding, “Therefore, detecting these important deficits early on prior to the dementia stage, along with a better understanding of how they relate to changes in the brain, can lead to more effective design of clinical trials that focus on vital patient-centered outcomes. This in turn will ultimately lead to better treatments prescribed to patients at the early stages of Alzheimer’s disease before they are robbed of their faculties and autonomy.”