Did you know that dementia is not one disease, but a name for many different brain diseases?
Before the late 1800s, dementia was an umbrella term for many types of unrelated mental illnesses, and there was very little medical understanding from ancient times. The haphazard developments in medical knowledge in this field are why we have many different conditions, lumped under one word. It is an unfortunate legacy, especially when combined with the social stigma and the wrongful association with natural aging.
Today, medical research endeavor to unravel the intricate web of dementia so we can have a better understanding of these diseases, in the hope of prevention and one day – a cure. Though there are many types of dementia, the most common ones are Alzheimer’s and vascular dementia, according to the Alzheimer’s Disease Association.
1. Alzheimer’s disease
Alzheimer’s is a “type of dementia that causes problems with memory, thinking, behavioral and other intellectual abilities serious enough to interfere with daily life”, according to Alzheimer’s Association. Alzheimer’s disease makes up some 50%-70% of dementia cases – there is a clear organic process of deterioration. The early symptoms of Alzheimer’s are difficulty remembering recent conversations, names or events, as well as apathy and depression. As it progresses, symptoms include impaired communication, poor judgment, disorientation, confusion, behavior changes and difficulty speaking, swallowing and walking.
2. Vascular dementia/ Multi-infarct dementia
Previously known as post-stroke or multi-infarct dementia, vascular dementia is caused by problems in the brain’s blood supply, often after a series of strokes or bleeding in the brain. The location, number, and size of the brain injury determine how the individual’s thinking and physical functioning are affected. The early symptoms of vascular dementia are impaired judgment or ability to make decisions, plan or organize. Memory loss is not a common initial-stage symptom in people with vascular dementia as it is in people with Alzheimer’s.
3. Dementia with Lewy Bodies (DLB)
DLB is a type of “progressive dementia that leads to a decline in thinking, reasoning and independent function because of abnormal microscopic deposits that damage brain cells over time”, as per Alzheimer’s Association. Medical science doesn’t know what causes DLB, but it is specific enough – there is cognitive decline and can only be confirmed by a post-mortem brain histology that shows Lewy bodies in the neurons. People with DLB often have early symptoms such as sleep disturbances, well-formed visual hallucinations, slowness, gait imbalance or other parkinsonian movement traits. Memory loss and thinking problems are also common symptoms in DLB as it is in Alzheimer’s.
4. Parkinson’s disease dementia/ Mixed Dementia
Alzheimer’s Association explains Parkinson’s disease dementia as an “impairment in thinking and reasoning that begins in a region that plays a key role in movement”. Changes in the brain gradually spread and initially affect mental functions, including memory and the ability to pay attention, make sound judgments and plan the steps needed to complete a task. An estimated 50 to 80 percent of those with Parkinson’s eventually experience dementia as their disease progresses, according to Alzheimer’s Association. The average time from onset of Parkinson’s to developing dementia is about 10 years. If dementia develops, symptoms are often similar to dementia with Lewy bodies.
Mentioned above are only some of the common types of dementia, and up-to-date there are over nine types discovered. As different types of dementia can have similar overlapping symptoms, it may be difficult to diagnose dementia just by the symptoms alone. Take note of the signs and early symptoms of dementia. People with deterioration in cognition and personality should seek medical help upon the onset of symptoms. Alzheimer’s Disease Association offers help through programs and support services for patients and their families.