You notice an older person is forgetting words or daily tasks more than usual and displaying personality changes. Should you be worried? Is it dementia? Alzheimer’s? And what’s the difference? We’ll help you unravel these similar, but different terms.
There is often misunderstanding about the difference between Alzheimer’s and dementia, but good treatment depends on having an in-depth knowledge of these conditions.
Alzheimer’s Disease Is A Form Of Dementia
Dementia is not a specific disease. It’s an umbrella term, describing a wide range of symptoms. Alzheimer’s, by contrast, is a disease. It’s one type of dementia — in fact, it happens to be the most common one — but it’s not the only one. Not everyone with dementia has Alzheimer’s disease.
There Are Multiple Types Of Dementia
The National Institutes on Aging estimates that four to five million Americans currently have some form of dementia, and those forms include:
- Alzheimer’s Disease – 70-80% of people who have dementia have Alzheimer’s. It’s a progressive condition that usually affects people older than 65. There’s currently no cure. It happens when proteins called plaques, and fibers called tangles, build up in the brain, block nerve signals and destroy brain cells. As brain cells degenerate and die, there’s a corresponding decline in memory and mental function.
- Vascular Dementia – 20-30% who have dementia have vascular dementia. It happens when there’s not enough blood going to the brain, caused by damage to blood vessels or blockages that lead to mini-strokes or brain bleeding. There are several forms of vascular dementia, so symptoms may vary. In general, people with vascular dementia may show more problems with attention, organization, processing speed.
- Lewy Body Dementia – Up to 10-20% of those with dementia have this form. Lewy bodies are abnormal clumps of a protein called alpha-synuclein which build up in the cortex of the brain (the part that handles learning and memory). It causes problems with attention, sleeping issues, hallucinations, and unbalanced movements, similar to Parkinson’s disease symptoms. Memory loss tends to show up later with this kind of dementia.
- Frontotemporal Dementia – Up to 10% of those with dementia have this form, which involves the loss of nerve cells in the front and side areas (frontal and temporal lobes) of the brain. Symptoms include personality and behavior changes, inattention, memory problems, executive functioning difficulties (for example, problems planning, sequencing steps, doing multiple things at once), and trouble with language. Some people also have a hard time with writing and comprehension. Symptoms usually show up around age 60—earlier than they usually start with Alzheimer’s disease.
- Creutzfeldt-Jakob Disease (CJD) – This rare form of dementia happens when proteins called prions fold into an abnormal shape, damaging brain cells and triggering quick mental decline. People with CJD may also have mood changes, jerky movements, and trouble walking.
- Huntington’s Disease Dementia – A genetic issue, it affects the central part of the brain—the area that helps us think, move, and show emotion.
- Mixed Dementia – Sometimes, a person has brain impairments caused by more than one type of dementia. For example, they may have blocked or damaged blood vessels (vascular dementia) and brain plaques and tangles (Alzheimer’s disease) at the same time.
To diagnose dementia, physicians look for a person to be having a hard time with at least two of the following cognitive functions and behaviors:
2. Communication & Speech
3. Focus & Concentration
4. Reasoning & Judgment
5. Visual Perception
A Deeper, Clinical Dive Into Alzheimer’s Disease
Although younger people can and do get Alzheimer’s (known as early-onset Alzheimer’s disease), the symptoms generally begin after age 60. Scientists believe that for most people, Alzheimer’s is caused by a combination of genetics, lifestyle and environmental factors that affect the brain over time.
When Alzheimer’s brain tissue is examined under a microscope, two types of abnormalities emerge that are indications of the disease. These abnormalities aren’t seen in brains without the disease.
- Plaques – clumps of a protein, called beta-amyloid, that may damage and destroy brain cells in several ways, including interfering with cell-to-cell communication.
- Tangles – twisted threads of a protein, called tau, that get into abnormal tangles inside brain cells leading to failure of the internal cell “transport system” that normally carries nutrients and other essential materials throughout the cells.
Symptoms Specific To Alzheimer’s
While both dementia and Alzheimer’s have some common symptoms, including a decline in the ability to process information, memory and communication impairment, symptoms specific to Alzheimer’s include:
- Difficulty Remembering Recent Events Or Conversations
- Impaired Judgment
- Behavioral Changes
- Difficulty Speaking, Swallowing, Or Walking (in advanced stages of the disease)
Diagnosing Alzheimer’s Is Often A Guessing Game
When it comes to diagnosing Alzheimer’s, a doctor can’t say that a person has Alzheimer’s with absolute certainty, but there are things to test to be reasonably sure. These include attention, memory, language, and vision tests, and typically an MRI to look for changes in brain tissue.
Alzheimer’s is not curable, but with early detection, patients can explore treatments that may provide some relief of symptoms and help maintain a level of independence longer. There may also be opportunities to participate in clinical drug trials that help advance research.
Long-Term Outlook For Dementia & Alzheimer’s
On the good news front, scientists are continually investigating ways to stave off and/or treat dementia including Alzheimer’s. Current research looks at factors that might influence the development of dementia, including:
- Genetic Factors
- Inflammation Reduction
- Tau, The Protein Found In Neurons That Can Twist Into Tangles
- Oxidative Stress, Or Chemical Reactions That Can Damage Proteins, DNA, and Lipids Inside Cells
Dementia in all its forms takes a toll on public health and so is a priority for NIH-supported research.
More Resources On Dementia & Alzheimer’s