Here’s an excerpt from a wonderful article in Forbes about professor Joanne Douglas who has primary progressive aphasia, a subtype of frontotemporal degeneration:
Before her interview, Joanne Douglas spends the day in silence. Hers is not a spiritual practice, but a cerebral one: Joanne needs to conserve her word supply, which she says runs out over the course of the day, leaving her virtually speechless by its end. Joanne has a form of the brain disease frontotemporal degeneration (FTD) known as primary progressive aphasia (PPA), which affects about 20% of FTD patients, and is what makes her often unable to retrieve the words she once produced with ease. Eventually she’ll lose the ability to produce speech completely.
Here’s a link to the full article: