In November we recognize Alzheimer’s Disease Awareness Month, an opportunity to shine a light on a debilitating disease that causes memory and thinking problems often referred to as dementia. Alzheimer’s disease accounts for 60 to 80 percent of dementia cases according to the Alzheimer’s Association. But what else can cause dementia?
The Alzheimer’s Prevention Registry invited David Weidman, MD, a neurologist and associate medical director for research at the Banner Alzheimer’s Institute in Phoenix to explain some additional types of dementia.
“Dementia is a broad category of disorders with accelerated brain decline,” said Dr. Weidman. “While Alzheimer’s is the biggest piece of the pie, there are other reasons for dementia including vascular changes in the brain, Parkinson’s or Lewy Body Dementias and Frontotemporal Dementia (FTD).”
Mix of Alzheimer’s and vascular dementia
Vascular dementia is more often seen in combination with Alzheimer’s, what can be called a mixed dementia. It is not often the sole cause of dementia. It is usually caused by changes in the small vessels within the brain. Sometimes there are minor or silent strokes in areas of the brain that might affect processing speed, problem solving, and follow-through on complex tasks, with relative sparing of memory and language. Vascular dementia is more commonly encountered in people with stroke risk factors, such as hypertension, diabetes and heart disease.
Lewy Body Dementia
Lewy Bodies are deposits of protein in the nerve cells in the brain which can cause Parkinsonian features, such as stiffness and slowness in the limbs, rest tremor, along with fluctuating cognition due to wide swings in alertness and attention. The patient or family may also report visual hallucinations and a particular kind of sleep disorder, a dream enactment syndrome, during which the patient may talk and/or show complex movements, acting out what he or she is dreaming about. Lewy Bodies are also present in people with Parkinson’s disease, which puts them at risk for developing a similar form of dementia over the course of their disease.
Frontotemporal dementia (FTD)
This type of dementia encompasses a group of three different syndromes, but all are characterized by brain degeneration occurring in the front of the brain. One of these primarily affects social skills and personality; one can compromise ability to speak fluently, and a third affects ability to understand the meaning of individual words, mainly nouns. They are caused by an accumulation of abnormal proteins in the frontal and temporal lobes of the brain that control these behaviors and language functions.
Alzheimer’s vs. Dementia
The term Alzheimer’s disease and dementia are often used interchangeably, by the media. This is not correct and unfortunately can create confusion for patients and families. Alzheimer’s disease is simply the most common reason for dementia.
“Knowing the differences among the dementias and making a more specific diagnosis can help physicians and caregivers better monitor and manage symptoms, provide the right resources for patients and their families, and prepare for the future,” said Dr. Weidman. “But no matter the type of dementia, after the diagnosis is made, a patient/family-centered approach to care is essential, and thereafter, we always encourage them to partner with us to make decisions together about ongoing medical care.”