This article explains the definition of dementia, and what the different causes and symptoms are of dementia.
The term ‘dementia’ is used to describe a wide range of clinical memory related diseases that have their root cause in some neurological dysfunction in the brain. The main symptoms include memory loss, difficulties with thinking, difficulties with concentration for problem-solving and difficulties with language.
Someone who suffers from dementia might also find himself experiencing sudden changes in mood, emotions and behaviour.
The symptoms of dementia vary and depend on the parts of the brain that are damaged and the exact disease that causes the dementia.
There are many types of dementia, and the different dementia types are explained further in this article.
How many types of dementia are there?
There are actually over 400 different types of dementia! Some of them, like Alzherimer’s disease or Vascular dementia are very common and well known, while some are more rare and difficult to diagnose.
Common types of dementia
The most common types of dementia are Alzheimer’s disease, Vascular dementia, Lewy Body disease and Fronto-temporal dementia.
Dementia and Down syndrome
It is also very common for people who suffer from Down syndrome to develop dementia, usually in the form of Alzheimer’s disease, although this is not always the case. This is because there are some similarities in the brain abnormalities among people with Down syndrome, and people who suffer from Alzheimer’s disease.
Studies show that around the age of 40, people who suffer from Down syndrome are very likely to also have significant levels of the beta-amyloid plaques and tau tangles in their brains – the main cause of Alzheimer’s disease.
Despite this fact, not all patients who have the presence of these abnormal protein deposits develop the symptoms of Alzheimer’s disease.
Symptoms of dementia
Different people are affected in different ways by dementia, especially in the early stages of dementia. The main symptoms of dementia have to do with thinking, concentration, focusing and memory.
The most common symptoms of dementia are:
- Difficulty recalling events that happened very recently (where the person was yesterday, etc.)
- Difficulties making decisions, solving basic problems or carrying out a sequence of tasks, like cooking a meal.
- Difficulties with language – for example, struggling to find the right words.
- Orientation problems – difficulties assessing distance and eye-body coordination.
- Confusion – suddenly forgetting where you are or which day it is, what’s the context of the situation you are in, etc.
- In the more extreme cases of dementia, a person with dementia might also experience severe emotional swings – they might become very anxious, irritable, apathetic or upset for no apparent reason. Some people might even experience visual hallucinations and delusions.
Dementia is a progressive disease, meaning that, in most cases, the symptoms get worse over time. The speed of the deterioration differs from person to person. As dementia develops, the person might seem different to his family and friends, and start to behave in strange and unusual ways. Common behaviors include asking the same question again and again, feeling very anxious, restless or agitated.
In the later stages of dementia, a person might have physical symptoms like lack of sleep, weakness in the muscles and weight loss.
Causes of dementia
Dementia is caused by neurological problems in the brain. The different types of dementia have different root causes.
In the case of Alzheimer’s disease, the most common type of dementia, the root cause is a gradual build-up (which takes years till the first external symptoms are shown) of abnormal clumps of protein in the brain (beta-amyloid plaques and tau tangles). These clumps damage the nerve cells in the brain, and interfere with the functioning of memory and cognitive related areas in the brain.
In the case of Vascular dementia, what happens is that there is a narrowing in the blood vessels in the brain, sometimes even complete blockages. This causes insufficient blood supply to certain areas in the brain, and then the cells that are not receiving sufficient blood are severely damaged. Unlike Alzheimer’s disease (which is progressive and slowly built up), vascular dementia symptoms can also appear suddenly.
Fronto-temporal dementia is a more severe type of dementia that has a wider effect than just memory loss. Fronto-temporal dementia affects the whole front section of the brain, as well as the temporal lobes, which are located over the ears.
When the main damage is in the frontal lobes, the person will suffer from severe difficulties in planning, organizing and constructing tasks, as well as with regulating their emotions and socially appropriate behavior.
When the main damage is in the temporal lobes, the person will have difficulties with language – speaking, listening, comprehending what people are saying. Those who suffer from severe damage in the temporal lobes will find it difficult to participate in a conversation and communicate.