Creutzfeldt-Jakob disease (CJD) is caused by an abnormally shaped protein called a prion infecting the brain.
The causes of young-onset dementia are different from that in older people. The young-onset of some of the most common types of dementia are described on this page.
Here you will find a list of other useful organisations that may be able to provide you with further information about rarer types of dementia.
Progressive supranuclear palsy (PSP) is a rare progressive movement disorder, sometimes known as Steele-Richardson-Olszewski syndrome.
Posterior cortical atrophy (PCA), also known as Benson's syndrome, is a rare degenerative condition in which damage occurs at the back (posterior region) of the brain. In the vast majority of people, the cause of PCA is Alzheimer's disease.
Parkinson's disease dementia accounts for around 2 per cent of all cases of dementia in the UK.
Normal pressure hydrocephalus occurs when excess fluid accumulates in the brain, but without causing pressure to build up in the brain tissue.
Niemann-Pick disease type C is one of a group of rare inherited disorders. It is not related to frontotemporal dementia, which is also sometimes called Pick's disease.
Some people with multiple sclerosis (MS) experience a loss of some of their mental abilities. This happens if damage caused by the MS occurs in certain parts of the brain.
Huntington's disease is an inherited disease causing abnormal movements and problems with coordination.