Logopenic, mixed, or Alzheimer-related aphasia?

Objective:This study tested the hypothesis that patients with primary progressive aphasia (PPA) who do not meet the proposed criteria for any of the recognized subtypes would have the atrophy pattern reported in the past for logopenic variant PPA (lvPPA), in turn suggesting that the PPA of likely Alzheimer disease origin is more variable than that captured in the current lvPPA diagnostic recommendations.Methods:MRI gray matter volumes from 14 patients with mixed PPA who failed to meet the diagnostic recommendations for any recognized variant were compared with those of 25 matched control participants via voxel-based morphometry.Results:The mixed PPA group had left temporoparietal atrophy with a pattern identical to that in previously reported lvPPA cohorts.Conclusion:Patients with PPA who did not meet the criteria for any recognized PPA variant at their initial assessment had the group-level atrophy pattern previously reported as the hallmark of lvPPA. We suggest that the specific language features proposed for lvPPA are too narrow to characterize the language impairments arising from likely Alzheimer pathology.