posted on 2018-03-01, 22:14authored bySarah Grace Hudspeth Dalton, Christine Shultz, Maya L. Henry, Argye E. Hillis, Jessica D. Richardson
Purpose: The purpose of this study was to describe the linguistic environment of phonological paraphasias in 3 variants of primary progressive aphasia (semantic, logopenic, and nonfluent) and to describe the profiles of paraphasia production for each of these variants.
Method: Discourse samples of 26 individuals diagnosed with primary progressive aphasia were investigated for phonological paraphasias using the criteria established for the Philadelphia Naming Test (Moss Rehabilitation Research Institute, 2013). Phonological paraphasias were coded for paraphasia type, part of speech of the target word, target word frequency, type of segment in error, word position of consonant errors, type of error, and degree of change in consonant errors.
Results: Eighteen individuals across the 3 variants produced phonological paraphasias. Most paraphasias were nonword, followed by formal, and then mixed, with errors primarily occurring on nouns and verbs, with relatively few on function words. Most errors were substitutions, followed by addition and deletion errors, and few sequencing errors. Errors were evenly distributed across vowels, consonant singletons, and clusters, with more errors occurring in initial and medial positions of words than in the final position of words. Most consonant errors consisted of only a single-feature change, with few 2- or 3-feature changes. Importantly, paraphasia productions by variant differed from these aggregate results, with unique production patterns for each variant.
Conclusions: These results suggest that a system where paraphasias are coded as present versus absent may be insufficient to adequately distinguish between the 3 subtypes of PPA. The 3 variants demonstrate patterns that may be used to improve phenotyping and diagnostic sensitivity. These results should be integrated with recent findings on phonological processing and speech rate. Future research should attempt to replicate these results in a larger sample of participants with longer speech samples and varied elicitation tasks.
Supplemental Material S1. Results for participants who produced paraphasias.
Supplemental Material S2. Average target frequency.
Supplemental Material S3. Median target frequency.
Supplemental Material S4. Average target frequency, including outlier.
Supplemental Material S5. Motor speech and speech sample characteristics of participants who produced paraphasias.
Dalton, S. G. H., Shultz, C., Henry, M. L., Hillis, A. E., & Richardson, J. D. (2018). Describing phonological paraphasias in three variants of primary progressive aphasia. American Journal of Speech-Language Pathology, 27(1S), 336–349.
Funding
The data collection for this research was supported in part by National Institute on Deafness and Other Communication Disorders Grants R01 DC011317, awarded to Argye E. Hillis, and R03 DC013403, awarded to Maya L. Henry. We are also grateful for access to data made available through National Institute on Deafness and Other Communication Disorders Grant K24 DC015544 and National Institute of Neurological Disorders and Stroke Grant R01 NS050915, both awarded to Maria Luisa Gorno-Tempini, and National Institute on Aging Grant P01 AG019724, awarded to Bruce Miller, at the University of California, San Francisco.