03 Rarer types of dementia
Around 5% of dementia diagnoses are rarer types of dementia
At only approximately 5%, rarer types of dementia account for a small percentage of dementia diagnoses. These rarer types of dementia are usually more common under 65 years of age.
Creutzfeldt-Jakob Disease (CJD)
CJD is unlike most other forms of dementia because it can be contracted in different ways. CJD is caused by an abnormally shaped protein called a prion infecting the brain which damages the nerve cells, inhibiting their ability to communicate information around the brain and body, causing them to die. A recent discovery in CJD research* identified a new form which is contracted by eating meat from cattle infected with bovine spongiform encephalopathy (BSE). This typically affected younger adults.
Symptoms of Creutzfeldt-Jakob Disease
In the early stages of CJD, symptoms can often be associated with the symptoms of Alzheimer’s including minor lapses of memory, mood changes and loss of interest. CJD typically progresses quickly, and symptoms such as clumsiness, confusion and impaired motor skills such as walking or talking can occur within weeks. Symptoms in the later stages of CJD progress to jerky movements, shakiness, stiffness of limbs, incontinence and loss of the ability to move or speak.
Alcohol-related brain damage
As the name suggests, alcohol-related brain damage (ARBD) is caused by regularly drinking too much alcohol over a sustained period of time, usually several years. The term ARBD includes several different conditions including Wernicke-Korsakoff syndrome and alcoholic dementia. None of these are actually a type of dementia, but they share similar symptoms.
- The most common form of ARBD is alcoholic dementia which may also be called alcohol-related dementia. Excessive and sustained consumption of alcohol damages the nerve cells in the brain because not only is alcohol a toxin, but alcohol also interferes with the body’s ability to absorb vitamin B1 (thiamine). Thiamine is an important vitamin which provides the body with energy, and since the brain is the organ in the body which uses the most energy, a deficiency in thiamine causes a decline in the brain’s ability to function.
- There are two stages in the development of Wernicke-Korsakoff syndrome. The first is Wernicke’s encephalopathy, which usually develops suddenly after abrupt alcohol withdrawal where thiamine levels plummet. Wernicke’s encephalopathy requires immediate treatment with intravenous thiamine, but if left untrteated, Korsakoff’s syndrome usually develops. Korsakoff’s syndrome causes damage in several areas deep within the brain. These structures are responsible for short-term day-to-day memory.
Symptoms of ARBD
The symptoms of dementia caused by ARBD largely reflect the areas in the person’s brain that are damaged. Symptoms include memory loss (particularly short-term memory), difficulty in planning, making decisions and judgements, impulsive behaviours such difficulty controlling emotions, problems with attention and a lack of sensitivity.
There are a number of conditions which can cause or mimic symptoms of dementia such as Parkinson’s, Corticobasal Degeneration (CBD), Huntington’s, Normal Pressure Hydrocephalus and Progressive Supranuclear Palsy (PSP). Each condition may cause different types of dementia and symptoms to develop. You can find out more in the ‘dementia-related conditions’ section.
Anyone living with dementia who is under 65 years of age is described as having early-onset or young-onset dementia and it is estimated that 42,000 younger people (under 65 years of age) are living with dementia in the UK. There are many types of young-onset dementia, ranging from more common types to rarer types. You can find out more in the ‘young-onset dementia’ section.