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Dementia is a collective term for conditions causing a decline in cognitive function. Although Alzheimer’s is the most common form of dementia, there are many different types of dementia and each type has its own pattern of progression, with symptoms and signs attributed to different stages of the journey. Understanding the early signs of dementia is important when it comes to managing the condition.
Of the 850,000+ people currently living with dementia in the UK, each individual will experience dementia – and dementia symptoms – in their own unique way. While the type and progression of dementia vary, a general guide to the stages of dementia will help you understand what to expect and plan for the future.
There are two main ways of measuring the progression of dementia: the three-stage model and the seven-stage model. The seven-stage model is most appropriate for identifying the stages of Alzheimer’s, and the three-stage model can be used for most other types of dementia.
Stages of Alzheimer’s
The changes in the brain may begin 25 years or more before a formal diagnosis, and the rate of progression of Alzheimer’s varies greatly. The abnormal proteins (plaques and tangles) build-up in structures of the brain and usually spread throughout the brain in a predictable pattern. In the earliest stages, before dementia symptoms can be detected with current tests, plaques and tangles begin to form in brain areas involved in learning & memory (image 2) and thinking & planning (image 3). In the mild to moderate stages, plaques and tangles spread and begin to affect thinking and planning, (image 4), language & speech (image 5) and spatial awareness (image 6) which begin to interfere with everyday life. In the advanced stages of dementia (image 7), the cortex becomes significantly damaged and the brain reduces in size as the cells deteriorate. As the proteins spread to different brain structures, the different functions of those structures become affected.
Alzheimer’s and dementia stages
The seven-stage progression of Alzheimer’s
Stage 1 – No cognitive decline
In this stage, the person functions normally, with normal cognitive function, no memory loss and generally good mental health. People with stage 1 have no dementia.
Stage 2 – Very mild cognitive decline
General forgetfulness as a general part of ageing is associated with stage 2. Forgetfulness is mild and unnoticed by loved ones and medical professionals.
Stage 3 – Mild cognitive decline
At this stage, loved ones may begin to notice signs of cognitive decline, such as forgetfulness and slight difficulty concentrating which begin to impact on daily life. A person at stage 3 may also become disorientated, lost and have difficulty in finding the right words. On average, a person is at stage 3 approximately 7 years before the onset of dementia.
Stage 4 – Moderate cognitive decline
Symptoms at stage 4, the impact on daily life becomes increasingly significant. Stage 4 dementia can be identified by symptoms including significant difficulty concentrating, memory loss, disorientation and inability to travel alone to new locations. As communication problems develop, someone living with stage 4 dementia may start withdrawing from loved ones and avoiding interaction. The average duration of stage 4 dementia is 2 years.
Stage 5 – Moderately severe cognitive decline
Those living with stage 5 dementia will need assistance to complete their daily activities (dressing, bathing, preparing meals). Memory loss will become more severe and may affect the ability to recall major relevant aspects of life such as address or phone number and someone living with stage 5 dementia may not know the time or day or where they are. The average duration of stage 5 is 1.5 years.
Stage 6 – Severe cognitive decline
Someone living with stage 6 dementia will require extensive support with daily life including continence care as control over the bladder and bowel declines. The names of close family members and memories of both recent events and details of early life will fade. Stage 6 can also be identified by personality changes (such as delusions, compulsive behaviour, anxiety and agitation), difficulty in speaking, counting down from 10 and finishing basic tasks. The average duration of stage 6 is 2.5 years.
Stage 7 – Very severe cognitive decline
Stage 7 dementia has the most significant impact on someone’s life. People in this stage typically demonstrate minimal ability to speak or communicate and they will require extensive support with all aspects of daily life including continence care and personal care due to the loss of psychomotor skills (the ability to control movement). The average duration of stage 7 is 2.5 years.
The three-stage progression of other types of dementia
Vascular dementia stages
The symptoms of vascular dementia can occur suddenly, following one large stroke or they can develop over time, after a series of smaller strokes. The progression of stroke-related or vascular dementia symptoms usually follows a ‘stepped’ pattern, with a combination of longer periods of time when symptoms are stable and periods when symptoms change rapidly.
Early-stage vascular dementia can often share symptoms with Alzheimer’s, with the key difference being that mild vascular dementia symptoms are usually associated with difficulties in planning, decision-making, and following instructions rather than memory loss. Other early symptoms include:
- A reduction in speed of thought
- Difficulty in concentrating
- Loss of bladder control is common with early subcortical vascular dementia
- Symptoms attributed to the stroke
As vascular dementia progresses, the earlier symptoms will become increasingly evident. Since vascular dementia affects various aspects of thought processes such as problem-solving, concentrating, reasoning and communication, someone living with moderate vascular dementia may experience:
- Periods of sustained confusion
- Memory loss
- The development of unusual behaviours
- In the later stages of vascular dementia, the individual may:
- Become decreasingly aware of what is happening around them
- Experience delusions and hallucinations.
- Someone living with vascular dementia will become increasingly dependent on the support of medical professionals and care providers to assist them with most aspects of everyday life such as eating, bathing and dressing.
Stages of frontotemporal dementia
The rate at which FTD progresses varies greatly and research has found that the differences between different types of FTD become less obvious as dementia progresses. Those who originally exhibited symptoms of behavioural variants may eventually experience language difficulties and similarly, a person originally diagnosed with a language variant of FTD will typically develop behavioural problems. The symptoms and signs of behavioural variant frontotemporal dementia are generally unaware of their behaviour and will rely on their loved ones to identify new and unusual characteristics.
Unlike Alzheimer’s, the early stage of frontotemporal dementia doesn’t usually affect memory or cognitive functioning. Someone with FTD may go walking without obvious purpose but, unlike someone with Alzheimer’s, will return home without getting lost.
During the early stages of behavioural FTD, changes to personality and behaviour become noticeable. Typical behavioural changes include:
- Becoming uncharacteristically selfish or apathetic
- Acting impulsively
- Developing obsessive or compulsive behaviours
- With language variants of frontotemporal dementia, difficulties with language become apparent slowly.
- Semantic dementia primarily affects the ability to understand language
- Aphasia affects the ability to produce fluent speech
- The earlier symptoms of frontotemporal dementia will become increasingly evident.
With behavioural variants:
Inappropriate behaviours will become more frequent and more intense.
With language variants:
Aphasia will continue to implicate speech production and signs of moderate aphasia may include:
- Grammatical errors
- Impaired understanding
- Semantic dementia causes:
- Vocabulary to decline
- Confusion regarding the meaning of familiar words,
- Difficulty in finding the right word
- Difficulty with recognising familiar objects
In the later stages of all types of FTD, more structures of the brain become damaged. Someone living with later stages of FTD usually experiences symptoms that are similar to the later stages of Alzheimer’s disease such as:
- A disinterest in their surroundings
- Difficulties in communication
- Inability to recognise loved ones
- Behavioural changes may cause increased aggression or agitation.
- At this late stage, full-time care will be needed to meet the needs of the individual and maximise their ability to access an enriched life wherever possible.
Dementia with Lewy bodies
Each person living with dementia with Lewy bodies will have a different experience, but like all types of dementia, DLB is progressive and the abnormal proteins responsible for the causing damage to brain cells (Lewy bodies) will continue to build up in structures of the brain. The spread and density of the Lewy bodies will vary with each individual. This means that the symptoms each individual will experience is also unique to each person because the Lewy bodies will affect different parts of the brain which have different functions.
Dementia with Lewy bodies also shares symptoms with Alzheimer’s in the early stage, and symptoms include:
- Problems with attention and awareness, which can fluctuate significantly daily and even from moment to moment.
- Difficulty in judging distances
- Disorientation can lead to falls and fainting
- Sleeping becomes disrupted
- Ability to plan and organise becomes affected
- Recurrent visual and auditory hallucinations can lead to distorted perceptions and delusions of persecution
The earlier symptoms of dementia with Lewy bodies will become increasingly noticeable and signs that someone living with dementia with Lewy bodies has reached a moderate stage include:
- Noticeable decline in motor skills which cause difficulties with movement.
- Slow movements
- Loss of balance or coordination
- As dementia with Lewy bodies progresses into the ‘severe’ stage, symptoms include:
- Frequent and sustained confusion about days, times and places
- Significant memory decline which may include forgetting events, names and faces
- Communication problems become increasingly evident and speech can become challenging
- Behavioural changes such as compulsive rituals, repetition and agitation
- Slow movements
- Difficulties in swallowing and eating – often causing weight loss
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