Not all forms of primary progressive aphasia (PPA) are caused by the same disease pathology with logopenic variant PPA (lvPPA) capable of being associated with either FTD or Alzheimer’s disease. This distinction was recently highlighted by the journey of lauded playwright Christopher Durang, who passed away from complications of lvPPA on April 2.

Durang made a name for himself as a playwright with his sharp comedic wit; he laced his plays with satire and absurdism. Over his career, Durang gained widespread acclaim and won numerous awards, including a Tony and three Obies. As previously shared by Durang’s husband, John Augustine, he began to experience difficulties from the onset of symptoms in 2012; he was having difficulty finding words and struggled to understand lengthy sentences. Durang was diagnosed with lvPPA in 2016.

“If people come up to you and start talking quickly in Spanish and want you to answer or explain something technical to them, you know what that feeling is,” Augustine told Broadway News of his husband’s difficulties at the time. “You’re not out to lunch. You know what you want to say; you just don’t know the words. If people interrupt you or try to answer for you, that throws you off.”

Always active in the production of his plays, Durang was forced to step back as his symptoms progressed. Durang also resigned from his position at Julliard, having served as the co-chair of the playwriting program since its inception in 1994. Augustine and other members of Durang’s family publicly announced his diagnosis in 2022.

How is lvPPA Related to FTD?

PPA disorders are the FTD disorders most associated with language difficulties, which may have some asking: why is lvPPA not always considered an FTD disorder?

People living with any type of PPA and their families share very similar experiences of diagnosis, care and support needs, and benefit from similar resources. There are distinct symptoms and features of PPA subtypes that can differentiate them; In terms of symptoms, lvPPA has a pattern of language deficits that are similar to nfvPPA, with experts noting subtle differences in these deficits and specific MRI features as characteristics that can distinguish between lvPPA and other PPA disorders.
Yet, there is a further underlying distinction between FTD-related PPA disorders svPPA and nfvPPA, and lvPPA caused by Alzheimer’s; the pathology of the disease. In terms of diseases like FTD and Alzheimer’s, pathology refers to the underlying biological features that characterize these neurodegenerative conditions.

While FTD and Alzheimer’s disease can develop as tauopathies (with 40% of FTD cases associated with tau), different types of tau are associated with each, and it is often Alzheimer’s tau that is found in lvPPA, unlike the FTD-tau found in many cases of nfvPPA. The language deficits caused by lvPPA associated with Alzheimer’s tau can also be caused by TDP-43, which is associated with FTD. While these distinctions are known by scientists, there are still many other pathological mechanisms that are much less understood.

Identifying the pathology at work will be helpful as researchers work towards identifying drug targets and developing medications for FTD. While identifying a pathology does not have much clinical significance currently, those whose lvPPA is identified as Alzheimer’s can be prescribed medications approved for the disease.

Regardless of the pathology, whether it’s FTD or Alzheimer’s, AFTD is here for families affected by PPA. The AFTD HelpLine has answers and guidance for anyone uncertain about PPA; contact the HelpLine at 1-866-507-7222 or info@theaftd.org.