"These individuals are often excluded because they don't have memory deficits, but they share the same disease [Alzheimer's] that's causing their symptoms."
According to Dr Rogalski, your symptoms and type of Alzheimer's will depend on what part of the brain is affected.
And a doctor cannot know for sure where a person's disease is rooted until after their death during a post-mortem examination.
However, there are some key markers of PPA that we may not immediately recognise as symptoms.
1. Unusual confidence
Lack of inhibitions can be the case for many types of Alzheimer's, including PPA.
"Someone who was very shy may go up to a grocery store clerk - who is a stranger - and try to give her a hug or a kiss," Dr Rogalski said.
2. Language issues
This symptom presents most clearly in patients with PPA.
Primary progressive aphasia is a form of dementia that impacts our ability to process speech and articulate words.
Patients may have delayed or halting speech, decreased vocabulary, and misuse of words.
3. Writing difficulties
A person who may have had no problems with spelling words may begin to struggle.
They may also struggle with simple writing tasks, like a cheque or signing a birthday card.
4. Struggling to read
It can become problematic to follow sentences through to the end, or to digest a full paragraph.