05 Young-onset dementia

Types of young-onset dementia & early-onset dementia

Anyone living with dementia who is under 65 years of age is described as having early-onset or young-onset dementia. The age of retirement has historically been 65, and the term ‘young-onset’ refers to dementia occurring before the traditional retirement age. It is estimated that 42,000 younger people (under 65 years of age) are living with dementia in the UK. 10% of all young-onset dementia diagnoses indicate that the condition has been inherited from a parent, which suggests that young-onset dementia is more likely to be hereditary than other forms of dementia. The causes of young-onset dementia are similar to other forms of dementia, but there are some important differences.

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Young-onset Alzheimer’s

As with ‘late-onset’ Alzheimer’s, this type of dementia is caused by the formation of abnormal proteins called plaques and tangles in the brain which implicate the nerve cells’ ability to communicate. Alzheimer’s is the most common type of dementia in both older and younger people, but younger people are more likely to have an ‘atypical’ (unusual) form of Alzheimer’s. Unlike Alzheimer’s typically experienced by older people, the initial symptoms of Atypical Alzheimer’s is not memory loss, but problems with vision, speech or planning, decision-making and behaviour.

Young-onset vascular dementia

As with ‘late-onset’ vascular dementia, this type of ‘young-onset’ dementia is caused by restricted bloodflow to the brain, starving the brain cells of oxygen. Vascular dementia is closely linked to diabetes and to cardiovascular diseases in younger people. Symptoms of vascular dementia may vary and younger people are more likely to experience problems with thought processing than memory loss.

Vascular dementia can also be hereditary, and this genetic form of vascular dementia known as CADASIL (cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy) is most common in people aged 30 to 50. Symptoms of CADASIL include migraines, repeated strokes, fits, low mood and progressive loss of mental abilities.

Young-onset frontotemporal dementia

As with late-onset frontotemporal dementia, the build-up of abnormal proteins inside the nerve cells in the front and side areas of the brain interrupt the communication between cells. Whilst frontotemporal dementia is somewhat rare in older people, the percentage of younger people living with frontotemporal dementia is significantly higher at around 10-15%. Medical research has established notable evidence to suggest that frontotemporal dementia is genetic in approximately 1 in 3 occasions.

Young-onset alcohol-related brain damage

Alcohol-related brain damage includes Wernicke Korsakoff’s syndrome and alcoholic (or alcohol-related) dementia. ARBD is caused by a lack of thiamine (vitamin B1), direct damage to nerve cells from alcohol which is a toxin, head injuries and a poor diet. This type of dementia occurs most often in younger people who are often diagnosed in their 50s. At least 10% of people living with alcohol-related dementias are classed as younger people. Symptoms of ARBD are dependent on the area of the brain that is damaged. Symptoms include memory loss, difficulty in planning, making decisions and judgements, impulsive behaviours such difficulty controlling emotions, problems with attention and a lack of sensitivity.

Rarer forms of young-onset dementia

A significantly higher proportion of younger people than older people develop rarer types of dementia (around 20-25%). Neurological conditions such as Huntington’s disease, progressive supranuclear palsy, corticobasal degeneration and Creutzfeldt-Jakob disease (CJD) cause progressive damage to the nervous system and these degenerative neurological conditions are known to cause dementia. Metabolic disorders such as Gaucher’s disease, Tay Sach’s disease and Niemann-Pick’s disease are also known causes of young-onset dementia because they typically develop in childhood or adolescence. Hormone disorders such as thyroid problems, vitamin deficiencies, inflammatory conditions such as multiple sclerosis and infections such as HIV are also known causes of dementia – particularly in younger people.