WASHINGTON (AP) — A toxic duo of plaques and tangles interact to drive Alzheimer’s disease, and now researchers say it’s the tangles that may better predict early symptoms.

It’s not clear exactly what causes Alzheimer’s. Sticky amyloid that builds into plaques coating the brain increases people’s risk. But they can harbor a lot of that gunk before losing memories.

Wednesday, researchers who used brain scans for a closer look said tangles of a protein named “tau” are a better marker of the decline into Alzheimer’s than amyloid alone. It’s a small study that won’t affect routine patient care. But the findings have important implications for creating better treatments, as researchers hunt for drugs to block both amyloid and tau buildup.

The research was reported in Science Translational Medicine.

Join our Newsletter for the latest news right to your inbox