Having several family members that struggle with Alzheimer’s as well as dementia, there’s one question that seems to constantly circulate in my mind which I never quite get an answer to: “What exactly is the difference between Alzheimer’s and dementia?” I’ve received answers such as, “Alzheimer’s is where a person can’t remember important long term memory things like who their family members are, while dementia is where a person can’t remember short term memory things like what they ate for lunch.” I’ve also been told that “dementia is what naturally happens to the mind as you age.” So eventually we’ll all get dementia? Needless to say, I’ve been left scratching my head and not quite understanding much of anything when it comes to Alzheimer’s and dementia.
To get some clarity, let’s take a look at Merriam-Webster’s definitions of each:
Dementia – a progressive condition marked by deteriorated cognitive functioning often with emotional apathy.
In other words, an impairment of thinking and memory that interferes with a person’s ability to do things which he or she previously was able to do caused by physical changes in the brain. And NO – it’s not something everyone develops as they age!
Alzheimer’s -a degenerative brain disease of unknown cause, that is the most common form of dementia, that usually starts in late middle age or in old age, that results in progressive memory loss, impaired thinking, disorientation, and changes in personality and mood, and that is marked histologically by the degeneration of brain neurons especially in the cerebral cortex and by the presence of neurofibrillary tangles and plaques containing beta-amyloid.
So, Alzheimer’s is an actual disease while dementia is a condition. Alzheimer’s disease is, by definition, a type of dementia as well as the most common cause of dementia. It accounts for 50-80% of dementia cases. However, there are many other causes of dementia. Furthermore, a diagnosis of dementia does not always indicate Alzheimer’s disease. Thoroughly confused yet? My brain is still a little foggy. Maybe discussing other causes of dementia can clear it up.
Here’s a list of other types and causes of dementia:
Vascular Dementia – also known as “post-stroke” dementia because it typically occurs after blood flow is blocked from the brain during a stroke. Vascular is the second most common type of dementia.
Mixed Dementia – when vascular and Alzheimer’s disease occur at the same time. According to brain autopsies, up to 45% of people with dementia have signs of both Alzheimer’s and vascular disease, making mixed dementia more common than previously thought.
Dementia with Lewy Bodies – named after the scientist who first described them, Lewy bodies are abnormal deposits of protein inside the brain’s nerve cells found in multiple brain disorders such as Parkinson’s, some cases of Alzheimer’s and of course dementia with Lewy Bodies.
Frontotemporal Dementia – a rare dementia that affects the front and side lobes of the brain.
Normal Pressure Hydrocephalus – also a rare dementia where fluid surrounding the brain and spinal cord is not able to drain normally causing enlarged ventricles and damaged tissue. During a spinal tap the pressure will appear normal making it hard to detect; thus, the ‘normal’ in the name.
Parkinson’s Disease – a disease where Lewy Bodies are present in the brain and movement is affected such as tremors, stiffness, shakiness, and lack of muscle control. In some cases, dementia occurs in the later stages of the disease.
Huntington’s Disease – a rare and fatal disease caused by inherited changes in a single gene that leads to the destruction of nerve cells in the brain.
Creutzfeldt-Jakob Disease – a very rare disease where prion protein in the brain begins to assume an abnormal three-dimensional shape triggering the other brain protein to do the same, resulting in destruction of brain cells.
Wernicke-Korsakoff Syndrome – caused by a deficiency of vitamin B-1, brains cells are unable to generate enough energy to function properly. Typically associated with AIDS, high levels of thyroid hormone and cancers that have spread throughout the body.
Since Alzheimer’s disease is a specific type of dementia with specific microscopic brain abnormalities, just like Parkinson’s Disease or Vascular Dementia, it requires a doctor’s exam and a CT or MRI scan to properly diagnose.
Assuming severe memory impairment is natural with age and ignoring developing symptoms can be dangerous. Treatment in the form of medication, as well as lifestyle changes, may help slow the progression of the disease. Consult with a doctor if you or your loved one is experiencing memory impairment so a correct diagnosis can be determined and proper treatment can begin immediately to ensure a better quality of life for all involved.
Carrie Robertson
Research & Community Education
