Rarer Types of Dementia

Written by Active Minds on Friday the 19th of January 2018.


Dementia can be caused by a variety of diseases and conditions, with Alzheimer’s being the most common, and thus the most recognised. However, there are some rarer, less-well known diseases that can cause dementia, which make up about 5% of dementia cases in the UK.


In this blog, we take a look at some of these less-common types of dementia:


Huntington’s Disease

Huntington’s disease causes problems with coordination and abnormal movements, as well as problems regulating mood and cognitive impairment. Dementia can occur in any stage of the illness and manifests itself as difficultly concentrating and planning. Short-term memory loss may also develop. However, unlike Alzheimer’s, a person living with Huntington’s disease will be able to recognise people and places in the later stages of the illness.


Posterior Cortical Atrophy

Posterior cortical atrophy (PCA) is a rare variant of Alzheimer’s disease, where damage has occurred to the posterior region (back part) of the brain. The symptoms are slow to develop, but will generally begin with tasks that are controlled by the back part of the brain, such as issues with sight and difficulty recognising faces. They may also experience problems with literacy and numeracy. As the damage to the brain spreads, symptoms like confusion and memory loss may develop.


Corticobasal Degeneration

Corticolbasal degeneration (CBD) is where parts of the brain, more specifically the cortex and the basal ganglia, become damaged and start to shrink.  CBD usually affects people between 60 and 80, and whilst there is no known cause, it is thought that producing too much of a specific protein (tau) may be part of the reason the disease develops. People with CBD start to develop problems with movement, including failure to control hand movements on one side, as well as loss of balance and co-ordination. They may also experience symptoms of dementia, such as problems with memory and thinking.


Niemann-Pick Disease Type C

This disease is inherited and mainly affects school-age children. It is caused by an inherited inability to process fats, leading to an accumulation of them in cells all over the body, including the brain. The symptoms of the disease manifest themselves as loss of movement and problems with swallowing and walking. Dementia can also develop as part of the disease, causing confusion and memory problems.


Parkinson’s Disease

Parkinson’s disease brings with it a higher than average risk of developing dementia in the later stages of the disease, though it is important to note that around two thirds of people are unaffected. Symptoms vary but they will often include memory loss, the inability to carry out everyday tasks and to think quickly. A person with dementia associated with Parkinson’s may also lose the ability to control their emotions, experiencing sudden bursts of anger or anxiety. There are also certain drugs that are prescribed for people living with Parkinson’s that may exacerbate their dementia symptoms, but generally this can be rectified with some medicine adjustments.


Normal Pressure Hydrocephalus

This disease occurs when excess fluid accumulates in the brain. Whilst often the causes for the excess fluid is unknown, in some cases it can be caused by a head injury, a bleed in the brain or meningitis.  Symptoms include difficulties in walking, as well as urinary incontinence and dementia.