Dementia due to Alzheimer’s Disease
Dementia due to Alzheimer’s Disease (AD) is the most common type of dementia, accounting for 60-80 % of all cases.
Dementia of the Alzheimer’s Type (now called Major Neurocognitive Disorder due to Alzheimer’s Disease) presntas with gradual and progressive cognitive decline. Early clinical presentation is typically difficulty remembering names and recent events. Mood changes, such as apathy and depression are also common early symptoms. Later symptoms include impaired judgment, disorientation, confusion, behavior changes and difficulty speaking, swallowing and walking. New criteria and guidelines for diagnosing Alzheimer’s were published in 2011 recommending that AD be considered a disease with three stages, beginning well before the development of symptoms. Therefore, a category of amnestic Mild Cognitive Impairment (MCI, now known as Minor Neurocognitive Disorder) often precedes Alzheimer’s dementia.
Biologically, the brains of individuals with AD have abnormal deposits of the protein fragment beta-amyloid (plaques) and twisted strands of the protein tau (tangles) as well as evidence of nerve cell damage and death in the brain.
The greatest known risk factor for AD is aging. Most individuals with the AD are age 65 or older. The likelihood of developing Alzheimer’s doubles about every five years after age 65 (!). After age 85, the risk reaches nearly 50 percent.
Patient’s often ask whether family history plays a role in developing AD. Individuals who have a parent, brother, sister or child with AD are at higher risk than individuals with no family history. This risk increases if more than one family member has the illness. However, individuals with a family history of AD may never get the disorders. Whereas, individuals with no known family history may spontaneously develop the disorder. Who will and will not get the disorder is still a mystery. There are no known tests to predict who will get AD.
There are ways to lessen risk for, or delay, development of AD. These includes a lifestyle that includes frequent exercising (which increases brain tissue), eating a diet rich in antioxidants and low in sugar, social interaction, and challenging mental stimulation (increases communications within the brain). It is also important to protect your brain with helmets and wear seatbelts to prevent brain injury; head trauma is a leading risk for future development of AD, or AD-like disorders.