A groundbreaking brain scan could spot the first signs of Alzheimer's years before symptoms strike.

Until now, diagnosing the cruel, memory robbing condition has often relied on questionnaires to spot issues with memory as well as MRI scans to track loss of brain volume. 

But it means many are only diagnosed with Alzheimer's once it has progressed. 

Now, British scientists found a new 'world first' technique that spots subtle changes to the cortical region, the outer layer of the brain, responsible for functions, including memory and decision-making. 

The series of scans—that analyse the cell structure of the brain—means medics could see changes to the brain far earlier, at a level normally only possible via a post-mortem examination. 

Experts said the 'breakthrough' device could herald a new era in fighting the disease.

Although not yet offered to patients suspected of having the disease in the UK, Oxford Brain Diagnostics which developed the technique, said it was in talks with private health providers. 

It was also approved by medicines regulator the Food and Drug Administration for use in the US back in January. 

Oxford Brain Diagnostics, a spinout company from the University of Oxford, was founded by Dr Steven Chance, former associate professor of neuroscience at Oxford, and Professor Mark Jenkinson, a leading expert in brain imaging. 

The technique, called cortical disarray measurement, uses advanced software which analyses MRI scans to pinpoint more subtle signs of neurodegeneration. 

Dr Chance said: 'The core technology is founded on my background, looking at the microscopic structure of brains at autopsy for many years. You couldn't do that with a living patient and this is what we needed.

'More than 20 per cent of those over 50 have Alzheimer's-type changes, small-scale changes that would be otherwise invisible. 

'These breakthroughs open up a whole new way of monitoring brain health.'

The technology, he added, could eventually have a 'transformative' impact, bringing hope to 'millions of people who are seeking a non-invasive, precision diagnostic tool to reveal the truth about their brain health'.

David Thomas, head of policy at Alzheimer's Research UK, also said: 'Dementia is caused by diseases that often begin years before symptoms appear, and so finding new ways to detect these diseases earlier is vital. 

'There is a huge amount of progress happening in this space and it's encouraging to see UK companies contributing to that.

'While this technology shows promise for diagnosing dementia earlier, so far it has only been validated in research settings. 

'We're still some way off it being used within the NHS and we would need to see much more real-world clinical data to fully understand its potential.

'Improving early and accurate diagnosis is crucial—not only to give people clarity about their condition but also to ensure they can access the right support and, in future, new treatments as they become available.'

It comes as two Alzheimer's treatments were last year approved by medicines regulator, the Medicines and Healthcare products Regulatory Agency (MHRA).

Lecanemab and donanemab were hailed as 'the beginning of the end' of dementia last year, after studies showed the drugs slowed the progression of memory-robbing illness in its early stages by up to 35 per cent.  

But draft guidance by the NHS spending watchdog last year ruled the benefits of both drugs were 'too small' to justify the estimated £1bn a year roll-out cost.

Experts have also repeatedly raised concerns over the drug's rare side effects such as 'swelling' and 'potential bleedings in the brain'. 

It means lecanemab and donanemab are currently only available to patients who can afford to pay about £60,000 privately every year at select clinics.

Alzheimer's Disease is the most common form of dementia and affects 982,000 people in the UK. 

It is thought to be caused by a build-up of amyloid and tau in the brain, which clump together and from plaques and tangles that make it harder for the brain to work properly. 

Eventually, the brain struggles to cope with this damage and dementia symptoms develop.

Memory problems, thinking and reasoning difficulties and language problems are common early symptoms of the condition, which then worsen over time.

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.