Changes in sight, hearing, taste, touch and balance are little-known dementia signs  that can strike years before more well-known symptoms, experts have warned.

Dementia, a condition which blights the lives of millions, famously causes problems with patients’ memory, language and mood.

Medics, using tools like memory tests and interviews, assess these when diagnosing the condition. 

But now scientists say there is substantial evidence that dementia starts to impair the senses many years before a patient shows the classic signs. 

This they say, offers hope that sensory changes can be used as an early warning sign and help patients be diagnosed far sooner.

They have now called for such changes to be included in standard dementia diagnostic tests which have predominantly focused on recording memory difficulties. 

An early diagnosis for dementia is considered critical as, while the condition is incurable, treatments can combat symptoms and sometimes slow progression.

The team includes three dementia experts in Professor Andrea Tales, of Swansea University, Dr Emma Richards of Public Health Wales and Professor Jan Kremláček of Charles University in Prague. 

Changes in sight, hearing, taste, touch and balance are little-known dementia signs that can strike years before more well-known symptoms, experts have warned

Many warning signs of dementia are often confused with normal aging. Common early symptoms include forgetfulness, repeating themselves, sudden changes in mood, inability to speak, and personality changes

‘Broadening the diagnostic approach beyond memory testing raised the potential to identify dementia at preclinical stages when therapies and life modifications may be most effective,’ Professor Kremláček explained.

Dr Richards added: ‘Many patients report experiencing these sensory changes years before receiving a diagnosis, but these symptoms may be overlooked during standard cognitive assessments.

‘Understanding and addressing these issues, and providing support earlier could be transformative, enabling health care providers to offer the vital emotional and social support patients need at a potentially confusing and distressing time.

‘In addition to this, understanding changes in a person’s senses can help support a clinician in determining a dementia diagnosis.’

Dementia, and particularly early signs of the condition, has been linked to changes in sensory perception before. 

As the condition is neurodegenerative, meaning it causes continuous brain atrophy, loss of brain tissue and volume, over time, this is believed to have an impact on how our senses function, even in the early stages. 

Earlier this year neurologists highlighted that a loss of sense of smell could be an early sign of dementia and strike 10-years before better-known symptoms. 

It isn’t just smell—vision disturbances and problems with balance are some of the earliest, but often dismissed, signs, especially in younger patients. 

More than 944,000 people in the UK are thought to be living with dementia, while the figure is thought to be around seven million in the US

Writing for The Conversation earlier this year, Molly Murray, an expert in young-onset dementia from the University of West Scotland, said for many patients the first sign of the condition is a problem with their eyes.

‘Research shows that for around one third of people with young-onset Alzheimer’s disease [the most common form of dementia] , the earliest symptoms they had were problems with coordination and vision changes,’ she wrote.

Experts have also warned that problems with spatial awareness such as standing too close to people are also potential dementia warning signs which can occur up to twenty years before the classic symptoms.

More than 944,000 people in the UK are thought to be living with dementia, while the figure is thought to be around seven million in the US. 

Recent analysis by the Alzheimer’s Society estimated the overall annual cost of the dementia to the UK is £42billion a year, with families bearing the brunt. 

An ageing population means these costs—which include lost earnings of unpaid carers—are set to soar to £90billion in the next 15 years. 

A separate Alzheimer’s Research UK analysis found 74,261 people died from dementia in 2022 compared with 69,178 a year earlier, making it the country’s biggest killer.