Rapid onset dementia Important information for families

Rapid onset dementia: Important information for families

5 min read

If you're noticing changes in your loved one’s cognitive function, you may be worried about rapid onset dementia.

Rapid onset (or rapidly progressive dementia) describes a disease that progresses much faster than other dementias.

This diagnosis can be distressing for the person with dementia as well as their loved ones supporting them.

This article will cover everything you need to know about rapid onset dementia and provide important information for families.

Here’s a summary of what we’ll cover:

  • Rapid onset dementia is more accurately known as rapidly progressive dementia. 
  • It can be caused by a stroke, infections, and autoimmune or neurological diseases amongst other factors which are known through the VITAMIN mnemonic. 
  • Rapid onset dementia is diagnosed only when doctors have ruled out other conditions that could cause similar symptoms.
  • Families should discuss appropriate care options and understand that care needs may change rapidly.
What is rapid onset dementia 

What is rapid onset dementia? 

Rapid onset dementia is the unofficial but commonly used term for rapidly progressive dementia.

As the name suggests, people with this diagnosis will experience a very fast onset of symptoms.

The name refers to a number of conditions which cause severe cognitive decline and loss of independence in a short space of time.

How does RPD differ from other types of dementia?

There are different types of dementia which affect the brain and body differently, though cognitive decline is a common symptom. 

RPD is different from Alzheimer’s or other types of dementia due to the way it progresses rapidly over a course of weeks or months. 

The normal progression of dementia symptoms is much slower, but this always depends on age and other health factors. 

Here’s more information about the difference between dementia and Alzheimer’s and the dementia life expectancy over 80.

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What are the symptoms of rapidly progressive dementia?

As with many conditions, symptoms can vary between individuals.

The symptoms of this rapid onset condition are very similar to those of other dementias. 

They just appear in a shorter amount of time, causing a greater severity of cognitive decline that affects multiple parts of life. 

Symptoms are neurological and physical, the combination of which can render your loved one unable to live independently.

What causes rapidly progressive or rapid onset dementia?

Researchers working on the causes of rapid onset dementia (RPD) have determined a mnemonic outlining the key factors.

They use VITAMINS to outline the main factors which are:


When blood flow to the brain is disrupted, for example in the event of a stroke. 

Strokes can cause vascular dementia which can also have a rapidly progressive form. 


Viral infections in the body or brain can be a cause of rapid onset dementia. 

This includes brain damage caused by HIV, Lyme disease or other parasitic infections.


Toxic metabolic conditions caused by vitamin excess or deficiency, nutrition or drugs can lead to rapid onset dementia. 


Some autoimmune conditions produce antibodies that cause the body to attack the brain cells and nerve tissue. 


Disorders of the mitochondria which cause chronic, genetic disorders caused by mitochondria failing to produce sufficient energy for the body to function properly.

Metastasis is the spread of cancer cells from their original location to another part of the body.


Some medical interventions can lead to rapidly progressive dementia due to side effects or complications. 


Neurodegenerative diseases are those that affect the brain and nervous system such as dementia, Parkinson’s or Huntington’s. 


People who have more seizures experience cognitive decline at a faster rate than those who don’t experience them. 


How is rapidly progressive dementia diagnosed

How is rapidly progressive dementia diagnosed?

RPD or rapid onset dementia can, like other types of dementia, be hard to diagnose. 

Without specific testing available, doctors have to rely on their evaluation of people presenting with these symptoms. 

Plus, they must rule out any other possible causes for dementia-like symptoms, which can be caused by an infection. 

This is because confusion and delirium can be caused by a number of things, which we look at in our article can dehydration cause confusion.

What can you expect after rapidly progressive dementia is diagnosed?

Coming to terms with the diagnosis can be difficult for the person with the disease as well as their families. 

The fast onset and rapid progression of symptoms is likely to cause your loved one to deteriorate quickly. 

This can range from a few weeks or months to around three years at most – a much shorter timeframe than more common dementia conditions. 

Their behaviour can drastically change as they begin to struggle with regular tasks and lose their independence. 

What can you expect after rapidly progressive dementia is diagnosed

What are the treatment options for rapid onset dementia?

The treatment that your loved one receives for rapidly progressive dementia depends on any associated health conditions

If they have RPD with cancer or an autoimmune disease, they can be treated for that to help manage secondary dementia symptoms. 

Another priority treatment is to ensure that they are comfortable without distress or pain to improve quality of life. 

What care is available for rapid onset dementia?

Maintaining the best quality of life possible is important for people living with RPD as well as their families. 

This can be achieved through getting the right care, whether that’s through home care visits, live in care or in a residential nursing home. 

There are also specialist homes or EMI nursing units for dementia care – to find more information about what is an EMI unit go here.

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Important information for families of people with rapidly progressive dementia

Seeing your loved one deteriorate is never going to be easy, but there are some things you can do to support them.

Talk to your loved one about the future

Find out from your loved one about what care they want to receive and where they would feel most comfortable living. 

This may include having an understanding that they will receive a certain type of care if specific conditions are met. 

It may be a difficult conversation, but it’s certainly a practical one that will help everyone later down the line.

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Organise the right care

Whether they were already receiving care or not, the right support is essential for people with RPD as their condition changes rapidly. 

They may go from being able to look after themselves at home to needing support with personal care in a matter of weeks. 

Or they may become very distressed at home, especially if they are alone or at night – which could mean hiring carers who sleep overnight

Create a lasting power of attorney

If your loved one still has the mental capacity to do so, it’s advisable to set up a lasting power of attorney for both their health and finances. 

This legal document gives a trusted individual the power to make decisions on behalf of someone who no longer has the capacity to do so. 

In the case of severe cognitive decline, this could involve making decisions for their care or managing financial matters.

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If you found this guide useful then you might like to check out these guides on:

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Find your stress-free care solution

We know that finding care for your loved one isn’t an easy task, especially when it’s on the list with 100 other things. 

Whether it’s filling forms, contacting providers or trying to manage diaries, the process can feel complicated before it’s even started. 

Thankfully, with the Sweet Pea app, you can find and manage care in just a few stress-free clicks. 

Enter your loved ones care needs and you’ll be matched with top quality providers with availability when you need it. 

Just click below to get started.