Dementia is a syndrome associated with an ongoing decline in brain functioning. It tends to affect people over the age of 65, although early-onset dementia can affect people as young as 40.
To ensure accuracy we have referenced the NHS site, where you will find greater detail and many links to other, useful websites, depending on your particular needs.
People with dementia tend to lose the ability to remember events or fully understand their environment or situations.
They may lose interest in their usual activities and struggle with their emotions, often finding social situations challenging. Some aspects of their personality may change; for instance, they may lose their natural empathy with other people and their situations. Some people with the condition also see or hear things that others do not.
As dementia affects a person's mental abilities, they may find planning and organising difficult. Staying independent becomes more of a challenge too, so a person with dementia will increasingly need support from friends or relatives, including help with making decisions, as they become increasingly confused.
It may surprise you to know that dementia is not a disease itself but a collection of symptoms that result from damage to the brain caused by different diseases, such as Alzheimer's.
There are many different types of dementia (described further on) and the symptoms of each vary according to the part of the brain that is damaged.
However, there are some common early symptoms that may appear some time before a diagnosis of dementia, such as:
These symptoms are often mild and may develop only very gradually.
“Mild cognitive impairment" (MCI) is the term used for this condition where the symptoms are not severe enough to be diagnosed as dementia. It may be that you don’t notice the symptoms initially and neither do your family or friends, and in some people, they will remain the same and not worsen. But others with MCI will go on to develop dementia.
Dementia is not a natural part of ageing and should not be dismissed as such, which is why you should talk to your GP sooner rather than later if you're at all worried about memory problems or other symptoms. If possible, someone who knows you well should be with you as they can help describe any changes or problems they have noticed.
If it is someone else you are worried about, encourage them to make an appointment and perhaps suggest that you go along with them.
There are many of strains of dementia, each with its own characteristics. Here we are looking at the four that most frequently present in the UK, typically (but not exclusively) amongst people over 65. Again, please note, that to ensure accuracy we have referenced organisations that are experts in dementia.
The most common cause of dementia is Alzheimer's disease. Though not yet fully understood, scientists know that it begins many years before the symptoms become evident. Its development is driven by the abnormal build-up of deposits from two particular proteins: Amyloid which forms plaques around the brain cells, and Tau which forms tangles within the brain cells.
As brain cells become affected, there's also a decrease in chemical messengers (called neurotransmitters) involved in sending messages, or signals, between brain cells.
Over time, different areas of the brain shrink. The first areas usually affected are responsible for memories. Alzheimer's disease is a progressive condition, meaning the symptoms develop gradually over many years and eventually become more severe. It affects multiple brain functions.
Early symptoms include:
Numerous factors are thought to increase our risk of developing the condition, including:
This is a common type of dementia, and affects around 150,000 people in the UK. It is caused by reduced blood flow to the brain. Nerve cells in the brain need oxygen and nutrients from blood to survive so when the blood supply to the brain is reduced, the nerve cells cannot function properly and eventually die.
Reduced blood flow can be caused by:
Symptoms can include:
Lewy bodies are tiny clumps of a protein called alpha-synuclein that can develop inside brain cells. They affect the way the cells work and communicate with each other, and the cells eventually die.
Dementia with Lewy bodies is closely related to, and has some of the same symptoms as Parkinson's disease, including difficulty with movement and a higher risk of falls.
It also has many of the features of Alzheimer's disease. Obvious symptoms include:
These problems make daily activities increasingly difficult.
Although Alzheimer's disease is still the most common type of dementia in people under 65, a higher percentage of people in this age group may develop frontotemporal dementia than older people. Most cases are diagnosed in people aged 45-65.
It's caused by an abnormal clumping of proteins, including tau, in the frontal and temporal lobes at the front and sides of the brain. These proteins damages nerve cells in the frontal and temporal lobes, causing brain cells to die, which in turn leads to these areas of the brain shrinking.
Frontotemporal dementia is more likely to run in families and have a genetic link than other, more common causes of dementia.
Early symptoms may include:
As dementia progresses, memory loss and difficulties with communication often become severe. In the later stages, the person is likely to neglect their own health, and require constant care and attention.
The most common symptoms of advanced dementia include:
Sadly, there is no known cure for dementia - yet. However, early diagnosis can slow the progression of the condition and provides the opportunity to learn to live with it – for the person concerned and also their family and friends.