A study led by Gad Marshall, MD, BWH Center for Alzheimer Research and Treatment, found that decreased glucose metabolism, indicating decreased activity, in specific brain regions demonstrated greater impairment in instrumental activities of daily living (IADL) across early stages of Alzheimer’s disease. Examples of IADL include high-level daily activities such remembering appointments and driving.
Deterioration in the ability to carry out daily activities has been associated with changes in brain activity measured as use of energy (or metabolism of sugar) with a nuclear medicine scan called 18F-Flourodeoxyglucose (FDG) positron emission tomography (PET).
Using information from the Alzheimer’s Disease Neuroimaging Initiative database, the researchers looked at data from 104 clinically older normal participants, 203 participants with amnesic mild cognitive impairment (the stage commonly preceding dementia due to Alzheimer’s disease), and 95 participants with mild Alzheimer’s disease dementia. The participants had a baseline FDG PET scan to determine brain activity and underwent clinical assessments every 6 to 12 months for up to three years. The participants’ study partners also completed questionnaires about the participants’ daily activities.
Decreased activity in frontal areas of the brain, which are responsible for cognitive processing and decision making, and deep temporal and parietal (back) areas of the brain, which are related to memory performance, were associated with greater impairment of instrumental activities of daily living initially and over time.
“Detecting these important clinical deficits early on prior to the stage of dementia, 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,” said Marshall. “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.”
The study was published August 2014 in Journal of Alzheimer’s Disease.