A new type of dementia has been indentified - and it may be part of the reason there is no cure yet

According to researchers writing in the science journal Brain, a new type of dementia has been identified.

The strand, which is being called limbic-predominant age-related TDP-43 encephalopathy - or Late, for short - is apparently a distinct disease different from Alzheimer's, although it may have been misdiagnosed as the latter for years now.

A group of international scientists have claimed that Late appears to affect much older people the most, e.g: people over the age of 80.

Reportedly, Late will cause a more gradual decline in memory, unlike Alzheimer's.

But while the two are different, they can co-exist within a person's brain, according to the researchers.

While Late appears to come about as a result of an accumulation of the protein TDP-43 in the brain, Alzheimer's is linked to two different proteins.

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Researchers have said that the discovery of the new form of dementia may well mean that better treatment options could be on the way, now that research into a cure can be more focused.

Lead author of the study, Dr Pete Nelson, from the University of Kentucky, said to BBC News, "It's been there all along obviously but we are just first recognising it.

"Alzheimer's disease is something that everyone knows about - it's a way of getting dementia - but there are different diseases as well and this disease we are calling Late is one of the most common, and so it is sort of an exciting time to begin and do research and trying to optimise and develop therapies.

"There is a lot of work to be done. This is more of a starting point than a finish point."

Dr Pete also explained that many people over the years who had been told they had Alzheimer's may in fact have been experiencing this other form of dementia.

He said, "There's no doubt that many people who were previously called Alzheimer's, in fact, did not have Alzheimer's."

Dr James Pickett, Head of Research at Alzheimer’s Society, also commented on the news, explaining that the findings may indicate why research into a dementia cure has not been successful so far.

He said, "This type of research is the first step towards more precise diagnosis and personalised treatment for dementia, much as we’ve started to see in other serious diseases such as breast cancer.

“This evidence may also go some way to help us understand why some recent clinical trials testing treatment for Alzheimer’s disease have failed – participants may have had slightly different brain diseases. But, more research into LATE is required to clarify specific symptoms, identify biomarkers, understand risk factors and develop treatments."