Study shows how tau spreads to four distinct patterns leading to different Alzheimer's symptoms Alzheimer's disease is characterized by the abnormal accumulation and spread of the tau protein in the brain. An international study can now show how tau spreads according to four distinct patterns that lead to different symptoms with different prognoses of the affected individuals. The study was published in Nature Medicine. In contrast to how we have so far interpreted the spread of tau in the brain, these findings indicate that tau pathology in the brain varies according to at least four distinct patterns. This would suggest that Alzheimer's is an even more heterogeneous disease than previously thought. We now have reason to reevaluate the concept of typical Alzheimer's, and in the long run also the methods we use to assess the progression of the disease."