MAPT and Alzheimer disease: Previous works in AD have shown that higher regional brain metabolism is associated with higher tau deposition on PET and with episodic memory impairment in MCI,52 and that neuronal hyperexcitability may drive tau release, propagation, and spread at the initial phases of the disease.53,54 This phenomenon may also occur in other neurodegenerative diseases, such as Parkinson’s disease or dementia of Lewy bodies.