Different Types of Dementia: More Than Just Alzheimer’s
Alzheimer’s is usually the first thing that comes to mind when people think of dementia, but it’s more than that: it’s a cognitive decline that’s not part of the natural aging process. It’s also not a single disease the way Alzheimer’s is, but a collection of signs and symptoms, depending on what part of the brain is affected.
Alzheimer’s is characterized by the death of brain neurons in both the cortical and subcortical tissue, as well as more-than-normal amounts of plaques (beta amyloid protein) and tangles (tau protein). As nerve cells die off, there’s less available space for signals to be sent. This form of dementia is the most common, consisting of anywhere from half to three-quarters of all dementia cases.
This type is the second most common form of dementia after Alzheimer’s, and accounts for about 2% of all cases; interestingly, it’s the most common form of dementia in Japan (50%). There are however great homecare services so your loved one can stay at home and receive the help they need. It’s caused by disruptions in blood flow to the brain, such as during a major stroke or series of smaller ones. Because the main purpose of hemoglobin in the blood is to transport oxygen throughout the vessels, vascular dementia is brain damage caused by being starved of oxygen, blood, and blood glucose. Compared with Alzheimer’s patients, those with vascular dementia are better able to memorize a list of words and freely recall any of them.
Dementia with Lewy Bodies
Protein in the body is normal, but when it gathers in large amounts inside nerve cells, DLB can occur. Because it shares many similarities with Parkinson’s, DLB can be referred to either as “dementia with Lewy bodies” or “Parkinson’s dementia”. It’s not a terribly common form of dementia in the United States, affecting about 1.3 million people. When it does strike, it causes cognitive decline, but mainly with executive functions (e.g. reasoning, planning, problem solving). One of the strongest characteristics of DLB is repeated visual hallucinations, which affects about three-quarters of sufferers.
One of the more vicious forms of dementia, Huntington’s disease is progressive, hereditary, and affects the middle part of the brain that controls mood, movement, and thinking. There’s no cure or abatement for it, only treatments to reduce the severity of other symptoms (irritability, obsessive-compulsive thoughts, chorea–involuntary movements).
This dementia is slangily known as the human version of bovine spongiform encephalopathy (BSE), even though it shares nothing with it but stereotypical symptoms. CJD is a rare and fatal form of dementia in humans, usually starts earlier in life, and is caused by protein having gone mutant by folding itself improperly.
The name points right to where in the brain the dementia occurs, and the two lobes are responsible for a variety of symptoms and variants of dementia: lethargy, aspontaneity, binge eating, compulsive behaviors, progressive nonfluent aphasia, and semantic dementia. Pick’s disease is the most common disease with this dementia, with behavior and personality changes usually arriving before memory loss.
This type is so called because more than one dementia is present and causing signs and symptoms, usually Alzheimer’s plus another one (typically vascular dementia). In most cases, abnormal amounts of protein are linked with blood vessel abnormalities, but Lewy bodies can also be present. However, it’s not possible to concretely diagnose until a posthumous autopsy.
There are several other types of dementia, with many of them closely linked to the ones above (normal pressure hydrocephalus, Wernicke-Korsakoff Syndrome, mild cognitive impairment [MCI], and others).