My wife has "logopenic Primary Progressive Dementia" - a subtype of frontotemporal aphasia. I understand it is usually progresses to late-onset Alzheimer's. However, her initial and continuing symptom is an inability to find the proper word to say thus resulting in long pauses in what she is saying. Her care is directed by the Center for Healthy Aging in the Seattle Swedish Medical system. I suspect the neurologist overseeing her case would make an excellent interviewee.