Before understanding the causes of dementia, one must first understand how the brain works. The adult brain weighs approximately 3.3 pounds and contains about 86 billion nerve cells, called neurons, that are responsible for sending messages throughout the brain to the rest of the body. The brain is also split up into two hemispheres, consisting of a total of four lobes: frontal, occipital, temporal and parietal.

The frontal lobe is positioned at the front of each hemisphere and is the part of the brain where higher mental functions are processed, such as planning and reasoning. It is also used in speech, movement and emotions. The parietal lobe is involved with movement, but also helps with processing stimulations of your senses. The temporal lobe controls memory, processing of sound and hearing, as well as the ability to understand speech and language. This lobe is often the first to be affected by dementia. The occipital lobe controls vision.

When interference begins to occur with the functioning of brain cells, dementia happens. Dementia prevents the brain cells from communicating with each other and therefore stops them from carrying out their normal jobs. Two types of major injury occur with brain cells during dementia: brain cells die off or protein deposits form and inhibit the ability of the brain cells to function properly.

The popular question among families with a person diagnosed with Alzheimer’s is “will we get it.” Unfortunately, the answer is not as straight forward as a yes or no answer given there are so many different types of dementia. Typically, early on-set Alzheimer’s disease is hereditary; however, there is no link between late-onset and heredity. There is no proven genetic risk for vascular dementia; however, frontotemporal dementia does pose a risk to families. There is no clear answer as to whether or not Lewy body dementia is hereditary. All of that being said, dementia does not discriminate. It affects people of all ethnic backgrounds, socio-economic standings, and religions.

The positive point of all this? Taking out the few with predisposed genetic risks, several risk factors have been identified in the diagnosis of dementia that can be prevented! See the “Preventative Risks of Dementia” section for more information.