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Classification and clinicoradiologic features of primary progressive aphasia (PPA) and apraxia of speech
Botha H, Duffy JR, Whitwell JL, Strand EA, Machulda MM, Schwarz CG, Reid RI, Spychalla AJ et al.. Cortex; a journal devoted to the study of the nervous system and behavior, 2015-05-27
Topic: Risk, prevention and care in population studies
The consensus criteria for the diagnosis and classification of primary progressive aphasia (PPA) have served as an important tool in studying this group of disorders. However, a large proportion of patients remain unclassifiable whilst others simultaneously meet criteria for multiple subtypes. We prospectively evaluated a large cohort of patients with degenerative aphasia and/or apraxia of speech using multidisciplinary clinical assessments and multimodal imaging. Blinded diagnoses were made using operational definitions with important differences compared to the consensus criteria. Of the 130 included patients, 40 were diagnosed with progressive apraxia of speech (PAOS), 12 with progressive agrammatic aphasia, 9 with semantic dementia, 52 with logopenic progressive aphasia, and 4 with progressive fluent aphasia, while 13 were unclassified. The PAOS and progressive fluent aphasia groups were least impaired. Performance on repetition and sentence comprehension was especially poor in the logopenic group. The semantic and progressive fluent aphasia groups had prominent anomia, but only semantic subjects had loss of word meaning and object knowledge. Distinct patterns of grey matter loss and white matter changes were found in all groups compared to controls. PAOS subjects had bilateral frontal grey matter loss, including the premotor and supplementary motor areas, and bilateral frontal white matter involvement. The agrammatic group had more widespread, predominantly left sided grey matter loss and white matter abnormalities. Semantic subjects had bitemporal grey matter loss and white matter changes, including the uncinate and inferior occipitofrontal fasciculi, whereas progressive fluent subjects only had left sided temporal involvement. Logopenic subjects had diffuse and bilateral grey matter loss and diffusion tensor abnormalities, maximal in the posterior temporal region. A diagnosis of logopenic aphasia was strongly associated with being amyloid positive (46/52 positive). Our findings support consideration of an alternative way of identifying and categorizing subtypes of degenerative speech and language disorders.
Key findings
- Blinded diagnoses were made using operational definitions with important differences compared to the consensus criteria.
- Distinct patterns of grey matter loss and white matter changes were found in all groups compared to controls.
- A diagnosis of logopenic aphasia was strongly associated with being amyloid positive (46/52 positive).
- Our findings support consideration of an alternative way of identifying and categorizing subtypes of degenerative speech and language disorders.
Why it matters
This study classified 130 patients with degenerative speech and language disorders into subtypes and found distinct patterns of brain loss, with logopenic aphasia strongly associated with being amyloid positive. It is about classifying these disorders, not about treating, curing, or preventing Alzheimer's disease.
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Study details
- Evidence strengthModerate
How this study scored 47/100
Published in a peer-reviewed journal. Scored zero for study design, sample size, effect reported, studied in people and randomised / blinded because the record does not state it.
| Component | Points | Why |
|---|---|---|
| Journal tier | 7 / 10 | Tier 3 — peer-reviewed journal (Cortex; a journal devoted to the study of the nervous system and behavior) |
| Journal's citation record | 2 / 4 | Cortex: journal h-index 202 (OpenAlex, 2026-10-29) |
| Study design | 0 / 12 | No study design recorded — scores zero, not guessed (not stated in the record — scored 0) |
| Strength of evidence | 3 / 5 | Rated “moderate” in our summary |
| Peer-review validation | 10 / 10 | Peer-reviewed. Published as an article in a named peer-reviewed journal. |
| How recent | 1 / 5 | 2015 — within 20 year(s) of the newest study here |
| Sample size | 0 / 4 | Participant count not stated — scores zero (not stated in the record — scored 0) |
| Effect reported | 0 / 3 | No effect size reported — scores zero (not stated in the record — scored 0) |
| Studied in people | 0 / 3 | Not stated whether this was studied in people — scores zero (not stated in the record — scored 0) |
| Randomised / blinded | 0 / 2 | No randomisation or blinding stated — scores zero (not stated in the record — scored 0) |
| Times cited | 5 / 7 | Cited 173 times (OpenAlex, 2026-10-10) |
| Citations per year | 3 / 5 | 13.3 citations a year over 13 year(s) since 2015 |
| Impact for its field and year | 4 / 6 | Cited 8.2× the average for papers of its field and year (OpenAlex FWCI) |
| Cited by studies here | 2 / 6 | Cited by 3 other studies in this library |
| Still being cited | 2 / 4 | Cited 37 times in 2024–2026 (2026 still in progress; OpenAlex) |
| Senior author's track record | 4 / 4 | Last-listed author Keith A. Josephs: h-index 119 (OpenAlex, whole career) |
| Institution's track record | 2 / 3 | Mayo Clinic: institution h-index 1,606 (OpenAlex) |
| Multi-centre collaboration | 0 / 3 | OpenAlex lists 1 institution(s) in 1 country — scores zero (affiliation lists can be incomplete) |
| Indexed in PubMed | 2 / 2 | Indexed in PubMed (PMID 26103600) |
| Free to read | 0 / 2 | Behind a paywall — scores zero |
| Total | 47 / 100 | — |
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Read the original
- DOI: 10.1016/j.cortex.2015.05.013
- PubMed: 26103600
- Original source →
- Free full text: PubMed Central →
Full text: free to read — OpenAlex lists this copy as free to read: the link above (checked 6 Feb 1020).
Cite this study APA, Vancouver, BibTeX · download .bib or .ris
Built from the record alzhub holds for this paper, not looked up. Volume, issue and page numbers are not held in the record. The record's author list ends in “et al.”, so not every author is named. Check the citation against the original before you use it.
APA 7th
Botha, H., Duffy, JR., Whitwell, J. L., Strand, E. A., Machulda, M. M., Schwarz, C. G., et al. (2015). Classification and clinicoradiologic features of primary progressive aphasia (PPA) and apraxia of speech. Cortex; a journal devoted to the study of the nervous system and behavior. https://doi.org/10.1016/j.cortex.2015.05.013
Vancouver
Botha H, Duffy JR, Whitwell JL, Strand EA, Machulda MM, Schwarz CG, et al. Classification and clinicoradiologic features of primary progressive aphasia (PPA) and apraxia of speech. Cortex; a journal devoted to the study of the nervous system and behavior. 2015. doi:10.1016/j.cortex.2015.05.013. PMID: 26103600.
BibTeX
@article{botha2015-26103600,
author = {Botha, H. and Duffy, JR. and Whitwell, J. L. and Strand, E. A. and Machulda, M. M. and Schwarz, C. G. and Reid, R. I. and Spychalla, A. J. and others},
title = {{Classification and clinicoradiologic features of primary progressive aphasia (PPA) and apraxia of speech}},
journal = {Cortex; a journal devoted to the study of the nervous system and behavior},
year = {2015},
doi = {10.1016/j.cortex.2015.05.013},
pmid = {26103600},
url = {https://doi.org/10.1016/j.cortex.2015.05.013}
}
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