The hippocampus, a part of the limbic system of the brain, is the keeper of our life stories and is the seat of short-term memory.
Everything we hear, feel, touch, smell and taste first processes through the hippocampus, where it is sorted and sent to long-term storage areas in other parts of the brain. The hippocampus is the first area to be damaged by Alzheimer's disease, so when it malfunctions, or the data gets interrupted and is not sent to the long-term storage areas of the brain, then information is basically erased. Therefore, this information gets lost in just a few moments (short-term memory) and it is as if the information never existed.
The temporal lobe, situated in the front part of the brain, or frontal lobe, is like a dictionary. It helps the individual decide on what to say and to find words to express the thought. The damage to the brain in someone with Alzheimer's typically moves from the hippocampus to the temporal lobe, and this causes problems in communication and word finding. For instance, the affected individual would have difficulty naming common items such as a cup or watch or car keys.
Working with numbers, knowing the date, reading a map, putting things in patterns — these skills are housed in the parietal lobe of the brain. It affects the thinking and visual-spatial skills of someone with Alzheimer's disease. If damage from the disease is occurring in the parietal lobe, they will have trouble with day and time orientation, difficulty in following directions and become lost in familiar and unfamiliar places. Additionally, they will have difficulty following sequences in projects or recipes.
The frontal lobe is responsible for judgment and planning and is the seat of our personality. This is the "executive function" headquarters, so to speak, which includes making good decisions, initiating activities and having appropriate dialogue in social settings. When the frontal lobe is damaged, the affected individual loses that filtering system, meaning he or she can start cursing, saying the wrong things in social situations or undressing in public. Additionally, the affected individual will become more apathetic and irritable.
The amygdala, located next to the hippocampus, is said to be the part of the brain that never sleeps and is also referred as the "emotional" part of the brain. It can alert for dangers so that the individual can act quickly for protection, and gives life its emotional content such as joy, sadness and anger. As the amygdala is damaged through the progression of the disease, the individual will experience anger and agitation over the smallest and least consequential incidents.
Acting as a "damper switch" for the amygdala is the prefrontal cortex, which is located between the amygdala and the frontal lobe, and often called the seat of “social and moral cognition." This area of the brain slows down the immediate, strong emotional reaction in which the amygdala sets up and allows the reasoning ability to decide whether a first reaction is socially appropriate. For an affected individual, damage to the prefrontal cortex can leave altered social cognitive abilities, and the individual may behave inappropriately in public or use offensive language to others, yet feel no remorse or empathy about it.
Alzheimer's disease damages parts of the brain differently in each individual. Yet, it helps to understand the workings of the various parts of the brain and how they are affected by the disease.
Questions about Alzheimer's disease or a related disorder can be sent to Dana Territo, the Memory Whisperer, director of services at Alzheimer's Services of the Capital Area at email@example.com or visit the organization at 3772 North Blvd., Baton Rouge....Read more