[Eagles6]

I think it can only be definitively diagnosed by autopsy.

Whatever the cause, dementia is horrific.

[steve86]

A variety of novel imaging procedures — not available everywhere — can diagnose it and provide a differential diagnosis vs. lewy body, etc.

[allendale]

Sadly autopsies, which are the best learning and teaching tool for physicians, are rarely performed these days. There are many reasons. Dementia is rarely verifiably diagnosed.