Alzheimer's 'clock' discovered in breakthrough which could help predict progression of the disease

A study undertaken by experts at Washington University saw a model developed which can forecast the onset of cognitive impairment to within three or four years, according to a paper in the Nature Medicine journal.

The tool could offer sufferers a "clock" for their symptoms, giving them information so they can live their lives to the fullest.

The model studied blood test data from two long-running research projects into the disease in the United States.

As part of the data, they found levels of a protein called p-tau217 which can be used to estimate the rate of degeneration within the brain.

Testing for heightened levels of the protein within blood plasma is already used to diagnose Alzheimer's - but the findings could significantly change patient experiences and treatments.

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Nearly 1 million Brits suffer from dementia, with Alzheimer's being the most common cause.

Symptoms vary widely between sufferers, as does the rate of degeneration.

The study may begin to help researchers figure out why the disease affects different people at varying rates.

The study's co-author, Suzanne Schindler, a dementia specialist at Washington University, called the method “substantially cheaper and more accessible” than existing estimation techniques.

To estimate the progression of the disease currently requires brain scans or spinal fluid tests.

“The kind of statistical models we’ve had in the past do not address that question. You’re positive, so you’re higher risk. But you could develop symptoms in one year, in 15 years, or never — we have no idea,” Schindler said.

“Eventually, the goal is to be able to tell individual patients when they are likely to develop symptoms, which will help them and their doctors to develop a plan to prevent or slow symptoms.”

Kellen Petersen, the study’s lead author, said: “Amyloid and tau levels are similar to tree rings — if we know how many rings a tree has, we know how many years old it is. The age they become positive strongly predicts when someone is going to develop Alzheimer’s symptoms. We found this is also true of plasma p-tau217.”

“With further refinement, these methodologies have the potential to predict symptom onset accurately enough that we could use it in individual clinical care,” Petersen said.