Ironically, perhaps, progress in Alzheimer's diagnosis—think CSF and amyloid PET—may boost the profile of other dementing diseases that are often misdiagnosed as AD in clinical practice. This has not gone unnoticed among researchers on frontotemporal dementias (FTDs). They are combining their newfound ability to definitively eliminate AD as a cause of a patient's symptoms with significant advances in the science of FTDs themselves.

Out comes a public-private initiative to press ahead with therapeutic trials. In June 2012  in Washington, D.C., academic and industry leaders in FTD met with scientists at the Food and Drug Administration for a one-day powwow of what's in hand versus what still needs to be done in order to launch well-designed therapy studies for these emotionally wrenching neurodegenerative diseases. The need is desperate. No single drug is approved for FTD, and the many other drugs these patients receive barely help them, experts say.