3.1 Introduction and types of dementia

3.1.1. Introduction

Reviewing dementia rates published by the WHO in 2020, we can see that 50 million of people worldwide are actually affected by dementia and 60% of these people live in low- or middle-income countries. Every year 10 million of new cases are registered.

According to estimations, between 5% and 8% of people whose age comprise 60 years or more have dementia at some point.

Estimations also show that in 2030 there will be 82 million of people worldwide with dementia, and this number will continue growing until 152 million in 2050. In short, number is increasing very fast.

But what are we talking about? What is dementia?

Although dementia mainly affects older people, it is not a natural and inevitable consequence of ageing. Dementia is a syndrome or a collective term for the state of a number of diseases, characterized by impairment of cognitive function. In other words, even if the risk of developing dementia increases with the age, it is not due to the age but it is caused by different diseases that affects the brain. Generally, dementia involves the impairment of memory, thinking, orientation, comprehension, calculation, learning ability, language and judgement.

As mentioned above, the number of people with dementia is increasing rapidly and it is important to highlight that this is one of the main causes of disability and dependency among older people worldwide.

3.1.2. General symptoms of dementia

Dementia affects in a different way each individual; it depends on their personality and the impact of disease. In general terms we can stand out the following symptoms according to three stages of dementia:

Early stage: start of dementia, in some cases it is not known that the individual is at this stage.

• Memory impairment: people with dementia at this stage tent to forget some things.
• Temporal disorientation: loss of the sense of time.
• Spatial disorientation: they can feel lost even in known places.

Middle stage: at this stage the symptoms become more evident and limits more individual’s life.

• Memory impairment: they start forgetting current facts or events, also people’s names.
• Spatial disorientation: increase of spatial disorientation, also in their own houses.
• Communication problems.
• Assistance: they need help with personal care.
• Experience some behavioral changes.

Late stage: this last stage of dementia stand out for dependency and inactivity of individuals. Cognitive impairment and physical capacity changes are severe.

• Severe temporal and spatial disorientation
• Difficulty recognising family and friends
• Increasing need for personal care and general assistance
• Mobility problems
• Behavioral changes

In addition, people with dementia also experience psychological changes as: anxiety, nervousness, paranoia or depression.

After this general review of some of the most common symptoms of dementia, diseases related to dementia are set our below.

3.1.3. Common forms of dementia

There are many different forms or diseases that causes dementia or cognitive impairment. Repairing the information published by the WHO in 2020, Alzheimer disease is the most common (60% or 70% of cases). However, there are other frequent dementia forms that are explained bellow:

Neurodegenerative diseases are those that affect the central nervous system, characterized by a progressive and often slow breakdown of the brain and its functions. This category would include: Alzheimer’s dementia, Lewy Body dementia and Frontotemporal dementia.

Alzheimer’s dementia

As it is mentioned above, Alzheimer’s disease is the most common dementia forms worldwide. It causes memory, thinking, behavior and social abilities impairment that affects individuals’ capacity to life in an autonomous way.

It is a progressive disease and symptoms become more severe as time goes on. At first stages, this disease affects the parts of the brain that control thought, memory and language. People with Alzheimer’s dementia tend to forget some details (for example: events, conversations or nouns). Short term memory impairment is normally followed by other symptoms as impairment on solving problems, judgment and disorganization. As the disease develops, people with Alzheimer ends with serious memory problems, losing the ability to make daily living activities by their own and suffering behavioral changes (for example: bad humor). Finally, they need total or full-time care which can be very stressing for family members that will probably need external or professional support.

The causes of this disease are not known but researchers have identified some risk factors, for example: age or family background and genetic. Currently, there is no cure for this disease but there are some treatments that could reduce some symptoms of Alzheimer’s dementia.

Lewy Body dementia

This is another of the most common causes of dementia in older people. Lewy Body dementia affects the ability to think, as Alzheimer’s disease. It later causes other problems such as movement symptoms, visual hallucinations and certain sleep disturbances.

Development of this dementia is caused by the accumulation of Lewy bodies in areas of the brain that control memory, thinking and movement. At this moment, the reason of this accumulation is unknown.

Lewy Body dementia is also a progressive disease, at first stages symptoms are slight and get worse over time. Symptoms include: loss of mental functions, concentration and attention changes, visual hallucinations, problems with movements and posture, sleep disturbances and changes in behaviour and patients’ mood.

There is no cure for this type of dementia but there are some treatments that can reduce or help with the symptoms, for example: physiotherapy, occupational therapy, certain pharmacological treatments, etc.

Frontotemporal dementia

It is a less common form of dementia, similar to Alzheimer’s disease but with the different that it only affects some areas of the brain.

People with Frontotemporal dementia experience behaviour changes, speaking difficulties and thinking impairment. What is more, early behavioural changes can help to distinguish this disease from Alzheimer’s disease. People with frontotemporal dementia tend to behave incorrectly in different social environments or circumstances, for example: impulsive actions, problems with personal hygiene, mood changes, difficulties finding certain words, decreased ability to read or write, etc.

There is no specific treatment for this disease but there are certain pharmacological treatments to deal with some symptoms, as well as other methods such as support groups. Usually, patients with this disorder can live between 8 and 10 years.

Vascular dementia

Vascular dementia, after Alzheimer’s dementia, is the second most common cause of dementia in elderly over 65 years old. It happens because of a series of small strokes over a long time period. A stroke or a cerebrovascular accident is an interruption or blockage of the blood supply to any part of the brain. If the blood flow stops a few seconds, the brain cannot obtain oxygen and the cells can die. This fact causes a permanent damage in the brain and this leads to symptoms.

First symptoms are: difficulty with easy activities, loss of interest in activities you once enjoyed, language problems, etc. Later more symptoms appear: changes in sleep patterns, agitation, forget current facts or events, not recognising yourself or who you are among others.

There is no treatment that can repair the damage caused by strokes, the only thing that can be done to improve patients live is: control the symptoms and pay attention to risk factors. Risk factors include: diabetes, smoking, heart diseases, hypertension, etc. Also is recommend to pay attention to healthy diets or not drinking more than 2 alcohol drinks per day for example.

Other diseases

There are other diseases and disorders that have a direct or indirect influence on brain function and cause cognitive impairment, for example:

• Huntington’s disease: It is a genetic disorder in which neurons at some parts of the brain tend to wear down. It is inherited from parents to children.
  Normally this disease appears in adulthood but it can occur also in childhood (less cases).

• Multiple sclerosis: It is an autoimmune disease that affects the brain and the spinal cord. There are multiple symptoms, it depends on the location and size of the attack.

• Parkinson: Parkinson disease causes the death of certain cells of the brain where is the control of movements and coordination. Over the years, progression of this disease can end with dementia.

• Creutzfeldt-Jokob: it is a rare brain degenerative disorder. The symptoms start over 60 years old: memory impairment, behavioural changes, visual problems and bad coordination.

Occasionally reversible cases

There are some special cases or disorders that could cause dementia but can be reversed if they are detected on time. Check the following list to know what are those exceptions:

• Some brain injuries
• Some brain tumours
• Alcoholism
• Some brain infections
• Low levels of B12 vitamin
• Level changes of blood sugar, calcium and sodium