Innovative Research on Alzheimer’s Disease and Working Memory Loss
Overview of Alzheimer’s Disease and Dementia
Dementia refers to a decline in memory and other cognitive abilities that significantly impacts daily life. Unlike cognitive changes related to normal aging, dementia results in serious impairments. Alzheimer’s disease, the most prevalent form of dementia, affects over 560,000 Canadians. Early symptoms include mild memory loss, but as the disease advances, individuals may undergo personality changes and struggle with everyday tasks such as driving, managing finances, or cooking. Additionally, they may repeat questions, become disoriented, or find simple activities confusing.
Currently, there is no cure for Alzheimer’s disease or dementia, prompting treatment and research efforts to focus on slowing symptom progression and enhancing the quality of life for both patients and caregivers.
Brain Changes Associated with Dementia
Dementia is characterized by specific brain changes, including the presence of amyloid plaques—abnormal clumps of protein—and tau tangles, which are twisted fibers. A significant aspect of dementia is the loss of connections between nerve cells. Initially, damage occurs primarily in the hippocampus, the brain region responsible for memory, spatial navigation, and emotional regulation. As the disease progresses, damage becomes widespread, leading to significant brain tissue shrinkage.
Recently, a study published in JAMA Psychiatry by researchers from Toronto has identified a new area of exploration regarding brain changes that may lead to treatments aimed at slowing or preventing Alzheimer’s disease.
Exploring Brain Plasticity and Working Memory
The study involved 32 participants diagnosed with Alzheimer’s disease and 16 healthy individuals, all aged 65 or older. Each participant wore a 64-node cap for scalp electroencephalography (EEG) to measure the electrical activity generated by the frontal lobes in response to stimulation. The researchers monitored changes in brain signals before and after stimulation as indicators of brain plasticity, which is the brain’s capacity to adapt and change.
The focus on the frontal lobes was intentional, as this area is crucial for complex cognitive functions and working memory, which is essential for storing and manipulating information over time. Healthy plasticity in the frontal lobes is believed to counterbalance deficits in other brain regions that contribute to dementia.
The findings revealed that although all participants exhibited some level of brain plasticity, those with Alzheimer’s disease demonstrated significantly reduced plasticity. Furthermore, participants with impaired plasticity performed worse on memory tests.
These results suggest that deficits in brain plasticity within the frontal lobes may contribute to working memory impairments in individuals with early Alzheimer’s disease. Dr. Kumar, the lead author, noted the significance of these findings, stating, “Impaired brain plasticity may be a future target for treatment or prevention of dementia, for which no effective treatments currently exist.”
Reference
Kumar S, Zomorrodi R, Ghazala Z, et al. Extent of dorsolateral prefrontal cortex plasticity and its association with working memory in patients with Alzheimer disease. JAMA Psychiatry. 2017;74(12):1266-1274. doi:10.1001/jamapsychiatry.2017.3292