What is meant by rapidly progressive dementia (RPD)?
Although there is no universally agreed definition for rapidly progressive dementia (RPD), it usually indicates a very fast cognitive decline, where the person affected can develop symptoms of dementia over a matter of weeks or months.
What happens in RPD?
The presentation and progress of RPD will vary between individuals. People affected will usually develop problems with their memory, thought processes and communication. Many people also have personality or behavioural changes and mood disturbance, as well as movement changes that can occur as a result of brain damage. These cognitive and behavioural changes can make it difficult to complete everyday tasks such as managing medications, dressing and bathing independently.
How does RPD differ from other types of dementia?
By dementia, we mean somebody who is impaired in one or more cognitive abilities, such as memory, language, organising, planning, multitasking and so forth. In other words, they can no longer function the way they could before their condition. In general, dementia is a progressive condition, meaning that it gets steadily worse over time. However, the speed of deterioration often differs between individuals depending on age, general health status, and the underlying cause of dementia.
Dementia, especially of Alzheimer’s type, typically develops slowly over many years and is often diagnosed in the late stages of the illness. RPD, on the other hand, is different as it progresses much more quickly. However, compared to Alzheimer’s disease and vascular dementia, RPD tends to be rare, often challenging to diagnose, and can develop at a greater rate.
The course of RPD is variable and depends on the cause. For example, the average age of onset of sporadic Creutzfeldt-Jakob disease (or CJD which is rare, degenerative, fatal brain disorder) is 60–70 years. Those affected may initially experience fatigue, sleep disturbances, and decreased appetite, all of which may occur weeks before the onset of nervous system dysfunction. Behavioural changes can also be an early sign of disease.
As shown below, a number of conditions in addition to CJD can cause RPD and functionally impair a person at a faster rate than other forms of dementia.
What causes dementia to progress quickly?
There are many causes of RPD. The word VITAMINS is a useful mnemonic in which each letter refers to a group of causes of RPD:
- V Disturbed blood flow to the brain, including strokes, can cause more sudden and severe vascular dementia.
- I These might involve secondary effects of a COVID-19 infection or direct brain damage from other infections (e.g. HIV, Lyme disease etc).
- Toxic metabolic. Due to vitamin excesses, vitamin deficiencies, disorders of nutrition, or abuse or side effects of drugs etc.
- A In some autoimmune conditions, antibodies are produced which can attack brain or nerve tissue.
- Mitochondrial disease and metastasis. For example, neurodegenerative conditions may be underpinned by disorders of the mitochondria (often referred to as the powerhouses of the cell). Also, a cancer may spread to the brain (metastasis).
- I This indicates RPD caused by medical interventions, usually because of side effects of medications or other treatments.
- Neurodegenerative conditions and neoplasm. For example, unusual presentations of common causes of dementia may also induce RPD. Rarely, Alzheimer’s, Parkinson’s, frontotemporal dementia, and dementia with Lewy bodies can become established more quickly and have an accelerated progression. Although human prion diseases, including Creutzfeldt-Jakob disease (CJD), constitute a rare form of neurodegenerative diseases caused by abnormally folded proteins in the brain, they are a leading cause of RPD. Cancer can also have a degenerative effect on the brain.
- Seizures, systemic diseases, and structural problems. Individuals may experience seizures or live with disorders that affect the whole body, such as rheumatologic or cardiovascular diseases. Tumours or cysts in the brain may also affect normal function by interfering with the flow of spinal fluid or impinging on parts of the brain.
RPD is often a challenging condition to diagnose. Despite this, it is critical to perform an evaluation as early as possible, usually in a hospital setting, following a structured approach to diagnosis. The initial step in this process may be to evaluate for delirium and perform tests to attempt to rule out infections, autoimmune disorder, cancer, vascular disease, and toxic-metabolic disorders.
Among older adults in particular, most cases of sudden confusion and RPD are caused by delirium from an infection – especially urinary infections and pneumonia – that can cause people to be incoherent, muddled, and disorientated. Agitation, aggression, and odd behaviour are also common. If the infection is properly treated, however, the symptoms of delirium can be managed and reversed.
After ruling out delirium, further tests like viral PCR or CT body scans or serum vitamins B12 and E tests may be ordered. Additional specific clinical and imaging features can, in some cases, steer the specialist clinician directly to a particular diagnosis.
A thorough physical examination and detailed personal history will also help rule out or confirm a diagnosis of RPD. For example, there may be family history of neurological or psychiatric disease, but relatives may have been misdiagnosed. A genetic prion disease may have been mistaken for other neurological or psychiatric disorders, including Alzheimer’s and Parkinson’s disease. Furthermore, an assessment of the person’s ability to complete different everyday activities can help assess how far the RPD has progressed.
What is the treatment of RPD?
Some forms of RPD are treatable, particularly if they are detected at an early stage. The potential for treatment depends on the type of RPD that is diagnosed. For example, for RPD caused by cancer, hormone imbalance or vascular disease, treatment of the underlying cause may help treat the dementia symptoms also. For some cases of RPD, particularly due to CJD, there are treatments available which are effective in reducing distress, maintaining comfort, and improving quality of life.
Familiarity with surroundings and enhanced levels of accessibility can help someone with dementia to continue living independently. You can find out more about making a home dementia-friendly here. Moreover, specific guides to RPD for both healthcare providers and affected individuals have been developed that contain key information and links to additional resources and media [see references below].
How Helping Hands can support those with dementia and their families?
When you or someone you love is living with dementia it can be difficult to understand all the changes that are taking place. Helping Hands’ dedicated and compassionate carers will ensure that you are fully cared for in the home you love, while making sure that your loved ones also receive the emotional support they need.
When receiving dementia care it can be highly beneficial to remain in your own home, as being in familiar surroundings – amongst precious people, pets and possessions – can help to reduce confusion and anxiety and help you to live well with your condition. We have been supporting people living with dementia in their own homes for over 30 years, meaning that we’re highly experienced in how best to care for people with Alzheimer’s, Vascular, Lewy Body or one of the other over 100 different types of dementia.
Helping Hands are regulated by the Care Quality Commission and Care Inspectorate Wales and thanks to our fully managed service you can always have confidence in us to consistently deliver the very highest standards of care.
About the author
This article has been written especially for Helping Hands and comes from Snorri Rafnsson’s work at the Geller Institute of Ageing and Memory, School of Biomedical Sciences at the University of West London.
Dr. Snorri Bjorn Rafnsson BSc (Hons.), MSc (Edin), PhD (Edin), PGCHE, FHEA, FRSPH (UK) currently serves as Associate Professor of Ageing and Dementia in the Geller Institute of Ageing and Memory, School of Biomedical Sciences at the University of West London.
His research combines an interest in epidemiology and social gerontology.
References and further information
Page reviewed by Snorri Rafnsson, Associate Professor of Ageing and Dementia in the Geller Institute of Ageing and Memory on October 27, 2021