How Do Dementia and Alzheimer's Relate and Differ?
There’s a lot of confusion around dementia and Alzheimer’s disease. Many people believe them to be the same thing and most don’t know what the differences between the two are.
This is because dementia and Alzheimer's disease do share many of the same symptoms. They are not, however, different names for the same condition.
To avoid making this common mistake, here’s what you need to know about the variations between Alzheimer’s and dementia.
Syndrome Versus Disease
Dementia is not a specific disease — it’s a syndrome. This is a group of symptoms that always occur together.
The word ‘dementia’ describes a set of symptoms that can include issues with language, memory loss and difficulty thinking or problem-solving, caused when damage occurs to the brain cells. Alzheimer’s is an actual disease that destroys the brain, and therefore it is one of the most common causes of dementia.
As many as 50 to 70 percent of all dementia cases are caused by Alzheimer’s; however, there are also other conditions that can cause dementia, such as Creutzfeldt-Jakob disease and Parkinson’s disease.
Dementia is often incorrectly described as ‘senility’ or ‘senile dementia.’ These terms come from a time when it was widely believed that serious mental decline was a normal part of aging, which is not the case.
Symptoms of Dementia
Different types of dementia are associated with different types of brain damage. For this reason, the symptoms of dementia can vary greatly.
But some of the symptoms you should prepare to experience if you have been diagnosed with dementia are:
- Trouble with visual perception
- Loss of the ability to focus
- A reduction in your attention span
- Difficulties with reasoning and judgment
- Communication and language problems
- Memory loss
In addition, The Alzheimer’s Society reported that an estimated 10 percent of people with dementia suffer from more than one type at the same time. The most common combination of this being Alzheimer's disease with vascular dementia.
Alzheimer’s As a Form of Dementia
The Alzheimer’s Association says that Alzheimer’s disease is, in fact, a specific form of dementia.
It is caused when high levels of particular proteins inside and outside of the brain cells make it difficult for the cells to stay healthy and to communicate with each other. This leads to the connections being lost between nerve cells, and ultimately to the death of the nerve cells and loss of brain tissue.
The foremost difference between Alzheimer’s disease and dementia is that when an individual is diagnosed with dementia, they are diagnosed based on the symptoms they are experiencing without necessarily knowing what is causing these symptoms.
In Alzheimer’s disease, the exact cause of the symptoms is known. Additionally, Alzheimer's disease is not reversible, where some types of dementia, such as those caused by a drug interaction or nutritional problems, can be reversed.
Other Forms of Dementia
While Alzheimer’s disease is the most prevalent cause of dementia, many other conditions can lead to the syndrome. Some of the disorders are more common than others, some are extremely rare, but with each disorder the cause of the symptoms is known. This is important so that the best plan for treatment and management can be found.
Vascular Dementia
This is the second most common form of dementia and occurs when there is poor blood flow to the brain. This deprives the brain cells of the oxygen and nutrients that they to be able to function correctly.
Vascular dementia can be a result of any number of conditions that narrow the blood vessels. These include diabetes, stroke and hypertension.
Mixed Dementia
Mixed dementia is the term used to describe the condition when it has more than one underlying cause. The most common form of mixed dementia is a combination of Alzheimer's disease and vascular dementia.
Dementia with Lewy Bodies (DLB)
You may hear this referred to as Lewy Body Disease. This type of dementia is caused when abnormal protein deposits called Lewy bodies appear in the nerve cells of the brain stem.
The Lewy bodies disrupt the normal functioning of the brain, which impairs cognition and behavior. An individual with DLB might also suffer from tremors. This condition is not reversible and has no known cure.
Parkinson's Disease Dementia (PDD)
Parkinson's disease is a chronic and progressive neurological condition, but not all people with PDD will go on to develop dementia. In the advanced stages of the disease, cognitive functioning can be affected.
When dementia does develop due to Parkinson's it is also a Lewy body dementia. The symptoms of dementia which occur with PDD include muscle stiffness, tremors and speech problems. Memory, reasoning and judgment are also usually affected.
Frontotemporal Dementia
Pick's disease is the most common of the frontotemporal dementia types. It is a rare condition that causes damage to the brain cells in the frontal and temporal lobes.
Pick's disease usually affects the individual's personality considerably. There will often be a decline in social skills and emotional apathy. In Pick's disease, you will typically experience changes in behavior and personality before memory loss and speech problems occur. In this way, Pick’s disease differs from all other forms of dementia.
Creutzfeldt-Jacob Dementia (CJD)
CJD is sometimes also referred to as mad cow disease. It is a degenerative neurological disorder. It only occurs in around one in a million people, so it is extremely rare. There is no known cure for CJD.
CJD is caused by viruses that interrupt the brain's normal functioning. Dementia resulting from CJD progresses very quickly.
Symptoms include speech impairment, memory loss, confusion, muscle stiffness and twitching. A lack of coordination can also be experienced which makes the individual susceptible to falls. Blurred vision and hallucinations have also been associated with the condition occasionally.
Normal Pressure Hydrocephalus (NPH)
Normal pressure hydrocephalus occurs when cerebrospinal fluid accumulates in the brain's cavities. The build-up results from impaired drainage and causes additional pressure to be placed on the brain.
This leaves the brain unable to function normally. Individuals with dementia caused by NPH often experience problems with mobility, balance and bladder control. They also suffer from cognitive impairment affecting their speech, memory and problem-solving abilities.
Huntington's Disease
Huntington's disease is an inherited condition that causes progressive dementia. The condition affects the individual's behavior, movement and cognition.
Individual’s with Huntington’s disease often suffer from impaired judgment, memory problems, depression, mood swings and speech problems – particularly slurred speech. Delusions and hallucinations may also be experienced. There can also be difficulty walking and uncontrollable jerking movements of the face and body.
Wernicke-Korsakoff Syndrome
Wernicke-Korsakoff syndrome is caused by a deficiency in Vitamin B1. It often occurs in people who are alcohol dependent, but it can also result from malnutrition or cancers that have spread in the body.
Abnormally high thyroid hormone levels, long-term dialysis, and long-term diuretic therapy can also result in this deficiency. The symptoms of Wernicke-Korsakoff syndrome include confusion, permanent gaps in memory, impaired short-term memory and hallucinations.
Mild Cognitive Impairment (MCI)
Dementia can also be caused by medical illness, medications and a range of other treatable causes. With MCI, an individual will experience memory loss, sometimes with impaired judgment and speech, but they will usually be aware of their decline. These symptoms are mild and don’t often interfere with the normal activities of daily living.
People with mild cognitive impairment can also experience behavioral changes including anxiety, depression, emotional apathy, and aggression. These can be due to the awareness of their condition and the frustration that brings and aren’t necessarily direct symptoms of the disorder.
How Will You Know Which Type of Dementia You Have?
Diagnosing the specific form of dementia that a person is suffering from can be tricky and requires a full review of your health care, family and medical history.
This will include first evaluating whether you might be suffering from anything which could be causing the symptoms of dementia such as depression, substance abuse, nutrition, anemia, vitamin deficiency, diabetes, kidney or liver disease, thyroid disease, infections, cardiovascular and pulmonary problems.
Once these causes have been ruled out, your doctors can go on to further investigate what the cause of dementia may be.
Usually, a physical exam and blood tests will be needed to determine which types of dementia you may have.
You’ll need to find a doctor who is familiar with the complexities of dementia diagnosis. No single test proves Alzheimer's disease, but it is possible to diagnose with around 90% accuracy.
It can be challenging to diagnose the exact type of dementia in people who only show mild and early symptoms of the syndrome. As the condition progresses, a diagnosis often becomes clear.
Your doctors may use many different approaches to determine which type of dementia you have.
Mini-Mental State Evaluation (MMSE)
This is a very brief evaluation of your cognitive status that is used in diagnosing dementia types.
You will be asked to identify the time, date and place where the test is taking place, to count backward, identify objects previously known to you, to repeat common phrases, perform basic skills involving math, language use, and comprehension and to demonstrate basic motor skills.
Mini-Cog
The mini-cog takes only a few minutes to carry out and is used as an initial screening for different types of dementia.
You will be asked to identify three objects in the office, then draw the face of a clock in its entirety from memory, and finally to recall the three items you identified earlier.
Imaging Tests: CTs, MRIs, and Pet Scans
Doctors can study the structure of your brain by using imaging tests to see if there are any growths, abnormalities or general shrinkage.
Brain function can be studied using a PET scan and a special form of MRI. This can confirm the diagnosis of the specific type of dementia and raise the accuracy of the diagnosis to 90 percent.
The Bottom Line
Whether you have been diagnosed with Alzheimer’s disease or dementia, coming to terms with your diagnosis may take a long time. You might experience a range of emotions, including anger, shock, and fear, but you might even feel relief at having your symptoms explained.
This is completely normal, and your feelings may change from one day to the next. Your friends and family are also likely to experience a range of emotions and have their difficulties coming to terms with what is happening.
The good news is that these days you can access a wealth of information and support regarding both conditions. This helps you to understand what is happening, find ways to cope and continue to enjoy your life.