It had been thought that the most common type of dementia started in one place. The discovery opens the door to drugs that target the unique pattern of progression, say the international team, who examined the brain tissue of people with MCI (mild cognitive impairment) and full-blown Alzheimer’s as well as those of patients who had died.
Blocking the most important initial processes may stop Alzheimer’s in its tracks, they say. Co-senior author Professor Tuomas Knowles, of Cambridge University, said: “This research shows the value of working with human data instead of imperfect animal models.
“It is exciting to see the progress in this field. We are now able to study this process at the molecular level in real patients, which is an important step to one day developing treatments.”
Dementia cases worldwide are set to triple to more than 150 million by 2050 owing to ageing populations. One of the reasons medications have failed is they are prescribed too late – once Alzheimer’s has taken hold.
Plaques build up and destroy neurons and reduce grey and white matter –resulting in devastating memory loss, personality changes and confusion.
Prof Knowles said: “The key discovery is stopping the replication of aggregates [plaques].”
It was previously thought Alzheimer’s goes from one brain cell to another along linked circuits known as synapses.
The study, in Science Advances, shows it pops up spontaneously in a variety of places – with implications for potential treatments.