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There are multiple types of dementia – each related to cognitive decline and critical mental functions. Most impact older adults over 65, but not all. Although age is a risk factor for developing many forms of dementia, aging itself does not directly cause dementia, says Dr. David Irwin

“It’s possible to live to be over 100 years old without significant cognitive deficits.”

What are the types? How do they differ from a normal aging brain? Are there cognitive conditions that emulate dementia but simply require time or treatment? Let’s take a look at some of the more common forms.


The most common type of dementia, Alzheimer’s disease, is an irreversible, progressive brain disorder that erodes thinking and memory skills. It can be early-onset Alzheimer’s appearing in those as young as 30 years of age, which is rare, or the common late-onset Alzheimer’s disease appearing in those 65 years of age and older.

Alzheimer’s disease accounts for 60 to 80 percent of dementia cases. Click here to learn about the seven stages of Alzheimer’s.

Are you recently diagnosed with dementia or a caregiver of a person with dementia?

Sun Health offers Memory Care Navigator, a program offered at no cost to you or your insurance.

We will create a customized, individual plan of care that leverages community resources and professional support to assist families/caregivers who care for someone with a memory issue.


Caused by vascular (blood flow) problems that impair circulation or cause bleeding, such as stroke, diabetes, high blood pressure and head trauma or injury, vascular dementia can cause significant changes to memory, thinking and behavior as the result of damaged areas in the brain.

Post-stroke dementia is an example of vascular dementia occurring as a result of stroke damage to the brain. It may be temporary or permanent, depending on the cause and other factors. Damage can occure from a major stroke, or multiple small ones called TIAs.


Also a fairly common dementia, Lewy Body Dementia is caused by abnormal protein deposits along nerve cells that can cause loss in thinking, memory and movement abilities. It also may include symptoms similar to Parkinson’s disease, such as rigid muscles, tremors and slow movement. The same protein is associated with both Lewy Body Dementia and Parkinson’s, and those with the protein in their brains often have brain changes associated with Alzheimer’s disease.

A note on Parkinson’s disease…

While Parkinson’s disease is not considered dementia, it’s interesting to note that it shares certain characteristics with Lewy Body dementia. Both are cognitive diseases of “protein misfolding,” according to a recent Michael J. Fox Foundation webinar. There is a difference in the timing of cognitive problems between the two conditions, however. Patients who have Parkinson’s disease with motor problems for one year or more before developing dementia are classified as Parkinson’s disease, and those with the onset of cognitive impairments within a year of the onset of motor difficulties or before are diagnosed with Lewy Body Dementia.

Frontotemporal Dementia

This type of dementia has an unknown cause, although mutations in specific genes are found in many patients diagnosed with frontotemporal dementia.

Those with frontotemporal dementia typically show abnormalities in the brain on MRI scans, and it can be difficult to distinguish from Alzheimer’s disease or occur in conjunction with it. It’s not uncommon for a group of cognitive disorders to be collectively labeled as frontotemporal dementia, according to the National Institute on Aging (NIH).

Depending on how the damage occurs and other factors, some people with frontotemporal dementia can decline rapidly or show only minor changes for a decade or longer. It’s more unpredictable in its progression than Alzheimer’s and most other forms of dementia.


While dementias are forms of progressive brain deterioration, symptoms from other medical conditions or causes can mimic dementia. According to NIH, these include the following:

  • Side effects of certain medication
  • Emotional health issues, such as stress, anxiety or depression
  • Certain vitamin deficiencies
  • Alcoholic beverages or recreational drug use
  • Blood clots, tumors or infections in the brain
  • Delirium
  • Head injury
  • Thyroid, kidney or liver problems
  • Certain other medical conditions

It’s fairly common for those over the age of 65 to experience some form of memory loss, but it becomes more significant and progressive with dementia.  Difficulty finding the right word can be normal aging, but frequent pauses and substitutions when finding words can be a sign of dementia, according to one Alzheimer Society.

Progressively worsening spatial issues that make driving difficult are another sign of dementia, and one that substantially increases a risk of falling. Unlike vision difficulties that may cause a driver to ride their brakes and drive slowly, driving impacted by dementia may include an inability to park in a standard space, inability to react at intersections and a failure to remain in their correct lane.

Normal aging might result in someone forgetting the name of someone they met some time ago, where someone with dementia may not remember the name of a family member or recognize a best friend.

If you have concerns about dementia or are seeking resources to help with a diagnosis, Sun Health offers resources for dementia, including a support group for caregivers, the no-cost Memory Care Navigator program, classes to keep the brain fit and more. Visit our website https://sunhealthwellbeing.org/memory-care to learn more.


(Originally published Sept. 19, 2018; last updated Jan. 6, 2019.)

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