Clinical and neuroimaging characteristics of clinically unclassifiable primary progressive aphasia

Rene L. Utianski, Hugo Botha, Peter R. Martin, Christopher G. Schwarz, Joseph R. Duffy, Heather M. Clark, Mary M. Machulda, Alissa M. Butts, V. J. Lowe, Clifford R. Jack, Matthew L. Senjem, Anthony J. Spychalla, Jennifer L. Whitwell, Keith A. Josephs

Research output: Contribution to journalArticlepeer-review

9 Scopus citations


Many patients who meet core/root criteria for Primary Progressive Aphasia (PPA) are not classifiable as a recognized variant and are often excluded from neuroimaging studies. Here, we detail neurological, neuropsychological, speech and language assessments, and anatomic and molecular neuroimaging (MRI, PiB-PET, and FDG-PET) for fifteen (8 female) clinically unclassifiable PPA patients. Median age of onset was 64 years old with median 3 years disease duration at exam. Three patients were amyloid positive on PiB-PET. 14/15 patients had abnormal FDG-PETs with left predominant hypometabolism, affecting frontal, temporal, parietal, and even occipital lobes. Patients had mild to severe clinical presentations. Visualization of the FDG-PETs principal component analysis revealed patterns of hypometabolism similar to those seen in the PPA variants and suggests the brain regions affected in unclassifiable PPA patients are no different from those who are more easily classifiable. These findings may inform future modifications to the diagnostic criteria to improve diagnostic classification.

Original languageEnglish (US)
Article number104676
JournalBrain and Language
StatePublished - Oct 2019


  • Amyloid imaging
  • Frontotemporal dementia
  • Hypometabolism
  • PET imaging
  • Primary progressive aphasia

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Language and Linguistics
  • Linguistics and Language
  • Cognitive Neuroscience
  • Speech and Hearing


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