85,000 patients suffering from ‘new dementia’

A NEW form of dementia identified yesterday is thought to affect 85,000 people in Britain.

One in ten dementia patients are now believed to have the LATE form of the disease. The discovery transforms the way scientists understand the neurological condition.

British experts last night described the US findings as a ‘genuine breakthrough’. Most of the 85,000 sufferers have been told they have Alzheimer’s disease which leads to rapid decline in memory and cognition. But a major study published last night suggests 17 per cent of people with Alzheimer’s – 10 per cent of all people with dementia – actually have the LATE sub-type, which works in a different way.

The breakthrough could explain the failure of so many promising drug trials for the disease. It gives new hope for the discovery of drugs for Alzheimer’s and LATE.

Research leader Dr Pete Nelson, of the University of Kentucky, said: ‘LATE disease probably responds to different treatments than Alzheimer’s. We recently performed an autopsy on an individual diagnosed during life with Alzheimer’s. It turned out he didn’t have Alzheimer’s at all – he had LATE instead.’

Dr Nelson added: ‘Now that the scientific community is on the same page about LATE, further research into the “how” and “why” can help us develop disease-specific drugs that target the right patients.’ A total of 850,000 people in the UK have dementia, including 500,000 thought to have Alzheimer’s in which toxic plaques of a substance called amyloid clog up the brain. But researchers found in postmortem examinations in the US many ‘Alzheimer’s’ patients had no sign of amyloid build- up. Instead 17 per cent had signs of a protein called TDP-43, which was ‘misfolded’ into strange shapes in the hippocampus – the part of the brain that deals with learning and memory. The neurologists believe misfolded TDP-43 is the key driver of LATE.

They said LATE ‘mimics’ Alzheimer’s – arriving late in life, usually after 80, and leading to confusion and memory loss.

But patients with LATE tend to decline more slowly. When LATE occurs in combination with Alzheimer’s – which is common – it can cause a more rapid decline than either condition would alone.

Professor Robert Howard, a dementia specialist at University College London, said the findings were a ‘genuine breakthrough’.

He added: ‘This is probably the most important paper to be published in the field of dementia in the last five years. LATE has clearly been an under-recognised contributor to dementia, particularly in people over the age of 80.

‘Those of us who work in dementia have long been puzzled by our patients who have all the symptoms of Alzheimer’s disease, but whose brains do not contain the pathological features of the condition. We have also been puzzled by a group of often very old patients whose dementia does not progress as rapidly as we would expect with Alzheimer’s disease.

‘We now know that these puzzling patients are probably suffering from LATE and not Alzheimer’s disease and that LATE may be “mimicking” Alzheimer’s in about 20 per cent of cases.’

Dr James Pickett, of the Alzheimer’s Society, hailed the study as ‘the first step towards more precise diagnosis and personalised treatment for dementia’.

But Dr Carol Routledge, of Alzheimer’s Research UK, said: ‘This isn’t yet something doctors will be able to diagnose in the clinic. Multiple processes are often underway at the same time.

‘It can be difficult to say where one disease starts and the next one stops.’

‘This is a genuine breakthrough’