Written by Josh Horsman
When we talk about Dementia, most people think first of Alzheimer's Disease (AD). The usual connotations are memory-loss, and a steady decline in brain function affecting older people in later life. These are understandable thoughts given that Alzheimer's is the most common type of Dementia and that memory-loss is a key characteristic shared by the associated diseases which come under the umbrella term - Dementia.
Dementia is used to describe and refer to several different conditions which all impair the brain and cognitive function but differ significantly in their symptoms, causes and who they affect. Here's a guide to help you understand each of the different types:
Alzheimer’s Disease [40-70% of cases]
Alzheimer's Disease (AD) is the most common form of dementia, affecting memory and thinking skills and changes in behavior. It is an age-related condition with the risk of developing AD increasing as you get older. Indeed 1 in 14 people over the age of 65 live with AD and that figure more than doubles to 1 in 6 for those over 80.
Alzheimer’s is most commonly associated with short-term memory-loss, and this is normally the first symptom to manifest, however other symptoms include:
Alzheimer’s disease is a progressive condition which means that symptoms are mild at first, but developing to a moderate and severe state over a number of years (sometimes even just months) to the point where the patient is unable to interact with their environment or hold a conversation.
Unfortunately, there is no cure to reverse the effects of Alzheimer’s at the moment. Nevertheless, modern medication has proven effective at easing some Alzheimer’s symptoms, such as depression and behavioral changes. Recent studies have also suggested Alzheimer's may also be linked to lifestyle factors, with the groundbreaking ‘FINGER study’ concluding that following a healthy lifestyle comprising of regular exercise, a healthy diet, social interaction and brain training could significantly reduce your risk of developing AD.
Vascular Dementia [15-25% of cases]
Vascular Dementia (VD) is usually evident, in its early stages, through a decline in the ability to plan, make sound decisions and follow simple instructions. An affected person may also demonstrate a decline in their speed of thought and confusion. As the condition progresses, the patient is eventually likely to experience the kind of memory-loss associated with other forms of Dementia. Vascular Dementia may also cause symptoms mood-swings, symptoms of agitation and even aggression in some cases.
Vascular Dementia is caused by reduced blood-flow to the brain, which deprives it of the oxygen it needs to function effectively. In many cases this results from a stroke, but high blood-pressure, heart conditions and diabetes are also significant risk factors for VD. The fact that many of these conditions are triggered by unhealthy lifestyles means that it is possible to significantly reduce your risk of VD by making healthy lifestyle choices. Factors which can help prevent VD include: Not smoking, a healthy diet and regular exercise.
Lewy Body Dementia [2-20% of cases]
Lewy Body Dementia, or ‘Dementia with Lewy Bodies (DLB)’ is the third most common form of Dementia. Similarly to Alzheimer’s, people with DLB typically display problems with reasoning, processing information and judgement as well as confusion. However memory is usually less affected by DLB than Alzheimer’s.
Other common symptoms of DLB include: alternating periods of alertness and confusion, disrupted sleep, hallucinations, tremors (uncontrollable shaking) and dizzy spells or unsteadiness.
DLB is named because it is caused by build-ups of protein forming inside brain-cells which are thought to affect the brain’s ability to send and receive signals internally. The deposits of protein are known as ‘Lewy Bodies' and it is not yet known what causes them. However, DLB is not thought to be a genetic condition and there are very few cases where the condition has been seen to be passed-down through family members.
Frontotemporal Dementia [2-4% of cases]
Frontotemporal Dementia (FTD), also known as ‘Pick’s disease’ or ‘Frontal Lobe Dementia’, refers to damage to the frontal lobes of the brain which results in Dementia symptoms.
The frontal area of the brain is responsible for behaviour, the control of emotions, problem-solving and planning, and so these are the main cognitive functions affected by FTD, rather than the memory-loss associated with Alzheimer’s and other types of Dementia. In fact, FTD can affect people in different ways and the symptoms experienced can be displayed in two distinguishable ways:
In contrast to other forms of Dementia, FTD primarily affects younger people, with the majority of diagnoses reported in those aged between 45-65. This means that FTD is not linked with aging in the same way as, for example, Alzheimer’s. Instead, examples of FTD running in families and affecting several generations is far higher than with other types of Dementias, with around 10-15% of those diagnosed having a family history of the condition. Unfortunately, it is not currently known what causes the frontal lobes of the brain to become damaged, causing FTD symptoms.
Having an understanding of the different types of Dementia is crucial to building awareness, enabling symptoms to be recognized and diagnoses to be made earlier. If you or a loved-one are experiencing any of the symptoms above, it's important not to panic. Often simple signs of normal aging can be mistaken for symptoms of Dementia. If you are in any doubt, your first port of call should always be your Doctor who will be able to provide reassurance, explain your symptoms and help to arrange any further care you may need.