About Dementia
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Dementia is the medical term used for any impairment of brain function. Alzheimer's Disease is the most common cause, but there are many others.
The physical effects of dementia
The symptom everyone associates with dementia is loss of short-term memory. Whilst that's usually the first brain function noticeably affected, others follow over time. Dementia is a progressive condition, although the rate of change can vary widely between different people, and in the absence of other health issues cutting its progression short, every brain function is likely to be affected eventually.
Dementia is often described as a fog that slowly envelops - barely noticeable at first, imperceptibly increasing over time, but eventually you realise that things that could be seen before no longer can be.
It should be borne in mind that life with dementia can still be happy, with care and support - people with dementia can still smile, laugh, love and feel loved.
There's no absolute set order in which brain functions are affected, but they can include:
- memory - both short-term (what's happened that day), and then long-term (for example, routines or names)
- general cognitive ability and speed - thinking, comprehension and reasoning
- sleep patterns - sleep disruption at night (including failing to recognise that it's time for sleep), and sleepiness during the day (which isn't necessarily boredom)
- slowness in reaction and poor balance
- language - speaking (finding the required word, through to forming even short sentences or any speech), and understanding speech - though it's important to note that someone who can no longer speak may still be able to understand speech, so lack of response shouldn't be taken as lack of understanding
- perception - the reduced ability to recognise an object and what it does ('agnosia'), since the brain must process the image from two eyes and then look up each object in memory
- hallucination - which can be purely aural, for example occasionally thinking the doorbell has rung
- difficulty in coordinating swallowing (which involves a series of muscles and moving the epiglottis so that it prevents food going down the windpipe, and sensing where food or drink is)
- ultimately the ability to recognise hunger or thirst.
These reduced abilities can lead to difficulty in performing complex tasks, as track is lost of what the overall task is and how far through they are. They can also lead to disorientation, from poor recognition of surroundings or cues such as darkness at night, and from disconnect from normal triggers such as time from a clock or memory of what is normally done at that time.
The effects on behaviour
Not surprisingly, at times the above difficulties can be very upsetting to the person with dementia (and to their loved ones of course). They may become anxious, agitated or frustrated as a result. They may also be unable to express pain clearly.
They may become anxious at their inabilities and the feeling they don't know what to do. They may become agitated as a result of a misconception about the situation - for example, someone in a care home may think the other residents have been visiting them in their own home and are now overstaying their welcome. Sleeping poorly, of course, affects anyone's mood.
Another important effect to be mindful of is that communication difficulties can lead to inability to express pain or discomfort clearly, or where it is - and this may come out as behavioural issues. See our section on pain assessment.
Other examples are the person may become frustrated at not being able to or allowed to do something, or bored from the lack of things they would choose to do. They may become depressed or withdrawn.
All of the physical and consequential effects may combine to cause changes in behaviour and personality. Our section on interpreting behaviour aims to show how you can look for clues in their patterns of behaviour as to how their wellbeing can be improved. We also cover commonly occurring behaviour themes and helpful techniques to use.
Causes of dementia
The term 'disease' doesn't imply it's caused by bacteria or a virus. A lot more research is needed to investigate the causes of dementia, but it seems fair to say that the brain's health depends on a supply of blood carrying oxygen and nutrients and taking away waste products, and that exercising the brain helps retain its strength just as exercise does for muscles. It's thought that health in middle age affects the appearance of the disease in old age.
There can be a genetic slight increase in the risk of getting dementia, but this doesn't appear to be the significant factor in most cases that arise in old age (a rarer form of dementia that affects younger people does appear to be quite strongly genetic).
More information is available on the Alzheimer's Society website section about dementia risk.
Cognitive assessment
Several alternative tools have been developed for use by health professionals for assessment of cognitive impairment in those with dementia. These are used as part of initial diagnosis, in addition to physical investigations and a review of the medications being taken which may affect cognitive ability, and are also re-used periodically in assessment of progression of the disease over time. For more information see our section on cognitive assessment.
Treatments for dementia
There are two categories of medication that are used to slow the progression of the disease, and these may also help settle the person. These are outlined within our section on common medicines, but we do ask that you read its introduction first, regarding medical information you find on websites.
How to reduce your risk
The following advice is mostly aimed at people without dementia, to reduce your risk of getting the disease in later life.
A lot more research is needed but some things are known, and if you have a poor diet and lifestyle then making some improvements could halve your risk of getting dementia.
General health improvers
The same things that reduce the risk of other health problems such as heart disease and cancer also reduce the risk of dementia:
- eat plenty of fruit and vegetables
- exercise sufficiently
- if you're overweight then gradually reduce weight (diabetes is a significant influence)
- stop or at least reduce smoking
- limit or stop alcohol consumption
- limit the amount of red meat and heavily processed food you eat.
More details are given in the NHS website Health A-Z for Alzheimer's disease prevention.
See our note on alcohol, and note that cigarettes are a fire hazard and are best only used supervised.
Particular measures
Research indicates that some things have a particular influence in reducing the risk of dementia:
- get enough sleep, especially deep sleep (to enable waste products to be cleared from the brain)
- eat fish (oily or white; NB the lowest levels of mercury are found in salmon, followed by haddock, Atlantic mackerel, cod and then tuna)
- eat eggs (it's the yolk that contains the nutrients needed; NB the latest information is that most cholesterol in your body is made out of the fatty food you eat, rather than coming from eggs, so that isn't a concern).
Vitamins
Also see our note on vitamin d and others.
Avoid cannabis
Finally, since a few misguided states have legalised recreational cannabis, we recommend you to avoid it at all costs. Medical research is limited because of the generally illegal nature of cannabis, but there is evidence to indicate that long-term use can permanently damage memory in particular, but also other brain functions. If you damage your brain you won't be given another one!