Mom (64f) has had a 1 & 1/2 year history of word-finding difficulties, semantic and phonemic paraphasias, periodic slurring of speech, mispronouncing words, and stuttering/hesitance in speech. concerned about ppa. what would be the differential dx?

Just base on those speech problems without a neurologic exam and brain imaging results, the different diagnosis will be tough. I assume your mom has been thoroughly evaluated by a neurologist or a neurology team. If you have doubt, you can request a second opinion. Good luck to your mom.

If specifically involving speech with no other deficits definitely suggesting a condition from the primary progressive aphasia spectrum. A neuro exam with testing (imaging) may help in better differentiating from other poorly differentiated progressive neurodegenerative disorders. Ccf.org has reliable information regarding PPA.

If this occurred suddenly, this would likely be due to a stroke, or an association with hypertension. A gradual steady deterioration would raise concerns of Frontal Temporal Dementia or Alzheimer's. Obtain a second neurological opinion.