A Scoping Review of Neuropsychological and Neuroimaging Advances in Primary Progressive Apraxia of Speech (PPAOS)
Keywords:
PPAOS, Primary Progressive Apraxia of Speech, Neuropsychology, Neuroimaging, Neurodegeneration, SpeechAbstract
Background: Primary progressive apraxia of speech (PPAOS) is a neurodegenerative disorder characterized by isolated speech production difficulties. Neuropsychological and neuroimaging investigations have contributed significantly to our understanding of this condition. This review aims to map recent advances in neuropsychological and neuroimaging research on PPAOS, highlighting their contributions to diagnosis and clinical characterization. Materials and methods: This scoping review explored studies from four databases: MEDLINE, Web of Science, Google Scholar, and Scopus. A summary of clinical neuropsychological and neuroimaging characteristics has been depicted for the selected studies. Results: A total of twenty-four studies highlighted the necessity of assessing cognitive-linguistic and motor speech functions in PPAOS. Neuropsychological findings have refined the diagnostic criteria for PPAOS, differentiating it from other aphasic variants. Neuroimaging studies have identified progressive atrophy in brain regions crucial for speech motor planning and execution, providing valuable insights into the neural correlates of PPAOS. Conclusion: Advances in neuropsychology and neuroimaging have significantly enhanced our comprehension of PPAOS. These findings hold promise for improved diagnosis, differential diagnosis, and the development of targeted interventions. Future research should focus on longitudinal studies to elucidate disease progression and explore potential speech biomarkers for earlier screening clinically, cross-culturally and cross-linguistically
References
Josephs KA, Whitwell JL. Progressive apraxia of speech and primary progressive aphasias. Movement Disorders in Dementias. 2014:213-30.
Duffy JR, Utianski RL, Josephs KA. Primary progressive apraxia of speech: From recognition to diagnosis and care. Aphasiology. 2021 Apr 3;35(4):560-91.
Botha H, Duffy JR, Whitwell JL, Strand EA, Machulda MM, Schwarz CG, Reid RI, Spychalla AJ, Senjem ML, Jones DT, Lowe V. Classification and clinicoradiologic features of primary progressive aphasia (PPA) and apraxia of speech. Cortex. 2015 Aug 1;69:220-36.
Josephs KA, Duffy JR, Strand EA, Machulda MM, Senjem ML, Master AV, Lowe VJ, Jack Jr CR, Whitwell JL. Characterizing a neurodegenerative syndrome: primary progressive apraxia of speech. Brain. 2012 May 1;135(5):1522-36.
Utianski RL, Duffy JR, Clark HM, Strand EA, Boland SM, Machulda MM, Whitwell JL, Josephs KA. Clinical progression in four cases of primary progressive apraxia of speech. American Journal of Speech-Language Pathology. 2018 Nov 21;27(4):1303-18.
Tetzloff KA, Duffy JR, Clark HM, Josephs KA, Whitwell JL, Utianski RL. Characterizing Speech Errors Across Primary Progressive Apraxia of Speech Subtypes. Journal of Speech, Language, and Hearing Research. 2024 Mar 11;67(3):811-20.
Kwon M, Shim WH, Jo Y, Park S, Lim JS, Lee JH. Pure prosodic type of primary progressive apraxia of speech mimicking nonfluent aphasia and later progressing to corticobasal syndrome. Alzheimer Disease & Associated Disorders. 2022 Oct 1;36(4):365-7.
Duffy, J. R., & Josephs, K. A. The diagnosis and understanding of apraxia of speech: Why including neurodegenerative etiologies may be important. Journal of Speech, Language, and Hearing Research. 2012 : 55(5), S1518–S1522.
Josephs KA, Duffy JR, Martin PR, Stephens YC, Singh NA, Clark HM, Botha H, Lowe VJ, Whitwell JL, Utianski RL. Acoustic analysis and neuroimaging correlates of diadochokinetic rates in mild-moderate primary progressive apraxia of speech. Brain and language. 2023 May 1;240:105254.
Garcia-Guaqueta DP, Botha H, Utianski RL, Duffy JR, Clark HM, Goodrich AW, Pham NT, Machulda MM, Baker M, Rademakers R, Whitwell JL. Progression to corticobasal syndrome: a longitudinal study of patients with nonfluent primary progressive aphasia and primary progressive apraxia of speech. Journal of Neurology. 2024 Apr 7:1-2.
Whitwell JL, Duffy JR, Strand EA, Xia R, Mandrekar J, Machulda MM, Senjem ML, Lowe VJ, Jack Jr CR, Josephs KA. Distinct regional anatomic and functional correlates of neurodegenerative apraxia of speech and aphasia: an MRI and FDG-PET study. Brain and language. 2013 Jun 1;125(3):245-52. 5
Sintini I, Duffy JR, Clark HM, Utianski RL, Botha H, Machulda MM, Senjem ML, Strand EA, Schwarz CG, Lowe VJ, Jack CR. Functional connectivity to the premotor cortex maps onto longitudinal brain neurodegeneration in progressive apraxia of speech. Neurobiology of aging. 2022 Dec 1;120:105-16.
Tetzloff KA, Duffy JR, Strand EA, Machulda MM, Boland SM, Utianski RL, Botha H, Senjem ML, Schwarz CG, Josephs KA, Whitwell JL. Clinical and imaging progression over 10 years in a patient with primary progressive apraxia of speech and autopsy-confirmed corticobasal degeneration. Neurocase. 2018 Mar 4;24(2):111-20.
Seckin ZI, Whitwell JL, Utianski RL, Botha H, Ali F, Duffy JR, Clark HM, Machulda MM, Jordan LG, Min HK, Lowe VJ. Ioflupane 123I (DAT scan) SPECT identifies dopamine receptor dysfunction early in the disease course in progressive apraxia of speech. Journal of neurology. 2020 Sep;267:2603-11.
Arksey H, O'Malley L. Scoping studies: towards a methodological framework. International journal of social research methodology. 2005 Feb 1;8(1):19-32. https://doi.org/10.1080/1364557032000119616
Botha H, Duffy JR, Strand EA, Machulda MM, Whitwell JL, Josephs KA. Nonverbal oral apraxia in primary progressive aphasia and apraxia of speech. Neurology. 2014 May 13;82(19):1729-35.
Josephs KA, Duffy JR, Fossett TR, Strand EA, Claassen DO, Whitwell JL, Peller PJ. Fluorodeoxyglucose F18 positron emission tomography in progressive apraxia of speech and primary progressive aphasia variants. Archives of neurology. 2010 May 1;67(5):596-605.
Botha H, Duffy JR, Whitwell JL, Strand EA, Machulda MM, Spychalla AJ, Tosakulwong N, Senjem ML, Knopman DS, Petersen RC, Jack Jr CR. Non-right handed primary progressive apraxia of speech. Journal of the neurological sciences. 2018 Jul 15;390:246-54.
Botha H, Utianski RL, Whitwell JL, Duffy JR, Clark HM, Strand EA, Machulda MM, Tosakulwong N, Knopman DS, Petersen RC, Jack Jr CR. Disrupted functional connectivity in primary progressive apraxia of speech. NeuroImage: Clinical. 2018 Jan 1;18:617-29.
Josephs KA, Duffy JR, Strand EA, Machulda MM, Senjem ML, Gunter JL, Schwarz CG, Reid RI, Spychalla AJ, Lowe VJ, Jack Jr CR. The evolution of primary progressive apraxia of speech. Brain. 2014 Oct 1;137(10):2783-95.
Utianski, R. L., Whitwell, J. L., Schwarz, C. G., Duffy, J. R., Botha, H., Clark, H. M., Machulda, M. M., Senjem, M. L., Knopman, D. S., Petersen, R. C., Jack, C. R., Jr, Lowe, V. J., & Josephs, K. A. Tau uptake in agrammatic primary progressive aphasia with and without apraxia of speech. European journal of neurology. 2018 25(11), 1352–1357.
Utianski RL, Duffy JR, Clark HM, Strand EA, Botha H, Schwarz CG, Machulda MM, Senjem ML, Spychalla AJ, Jack Jr CR, Petersen RC. Prosodic and phonetic subtypes of primary progressive apraxia of speech. Brain and language. 2018 Sep 1;184:54-65.
Tetzloff KA, Utianski RL, Duffy JR, Clark HM, Strand EA, Josephs KA, Whitwell JL. Quantitative analysis of agrammatism in agrammatic primary progressive aphasia and dominant apraxia of speech. Journal of Speech, Language, and Hearing Research. 2018 Sep 19;61(9):2337-46.
Spengler D, Baerga DR, Pattany P, Gomes-Osman J, Adams D, Luca C. Localization of primary progressive apraxia of speech using functional MRI–a case study (P4. 196). Neurology. 2017 Apr 18;88(16_supplement):P4-196.
Utianski RL, Martin PR, Hanley H, Duffy JR, Botha H, Clark HM, Whitwell JL, Josephs KA. A longitudinal evaluation of speech rate in primary progressive apraxia of speech. Journal of Speech, Language, and Hearing Research. 2021 Feb 17;64(2):392-404.
Utianski RL, Martin PR, Botha H, Schwarz CG, Duffy JR, Petersen RC, Knopman DS, Clark HM, Butts AM, Machulda MM, Jack Jr CR. Longitudinal flortaucipir ([18F] AV-1451) PET imaging in primary progressive apraxia of speech. Cortex. 2020 Mar 1;124:33-43.
Ash S, Nevler N, Irwin DJ, Shellikeri S, Rascovsky K, Shaw L, Lee EB, Trojanowski JQ, Grossman M. Apraxia of Speech in the Spontaneous Speech of Nonfluent/Agrammatic Primary Progressive Aphasia. Journal of Alzheimer's Disease Reports. 2023 Jan 1;7(1):589-604.
Robinson CG, Duffy JR, Clark HA, Utianski RL, Machulda MM, Botha H, Singh NA, Pham NT, Ertekin‐Taner N, Dickson DW, Lowe VJ. Clinicopathological associations of hemispheric dominance in primary progressive apraxia of speech. European journal of neurology. 2023 May;30(5):1209-19.
Meade G, Pham NT, Schwarz CG, Clark HM, Duffy JR, Senjem ML, Lowe V, Botha H, Whitwell JL, Josephs KA, Utianski RL. The yes–no reversal phenomenon in patients with primary progressive apraxia of speech. Cortex. 2024 Aug 1;177:28-36.
Meade G, Whitwell JL, Dickson DW, Duffy JR, Clark HM, Ahlskog JE, Machulda MM, Josephs KA, Utianski RL. Primary Progressive Apraxia of Speech Caused by TDP-43: A Case Report. Neurology: Genetics. 2024 Mar 19;10(2):e200134.
Uyama N, Yokochi F, Bandoh M, Mizutani T. Primary progressive apraxia of speech (AOS) in a patient with Pick's disease with Pick bodies: a neuropsychological and anatomical study and review of literature. Neurocase. 2013 Feb 1;19(1):14-21.
Dial H, Pugalenthi LS, Gnanateja GN, Li JJ, Henry ML. Application of machine learning and temporal response function modeling of EEG data for differential diagnosis in primary progressive aphasia. Scientific Reports. 2025 Aug 12;15(1):29539.
Taiebine M, Keegan LC. Telepractice for bilingual and multilingual people with aphasia: a scoping review. Aphasiology. 2024 Jul 4:1-23.
Taiebine M, Aidi S, Benabdeljlil M, Faris ME. Neurolinguistic analysis of a case of crossed apraxia of speech in Arabic. International Journal of Brain and Cognitive Sciences. 2017;6(2):21-5.
Tricco AC, Lillie E, Zarin W, O'Brien KK, Colquhoun H, Levac D, Moher D, Peters MD, Horsley T, Weeks L, Hempel S. PRISMA extension for scoping reviews (PRISMA-ScR): checklist and explanation. Annals of internal medicine. 2018 Oct 2;169(7):467-73.
Downloads
Published
License
Copyright (c) 2025 East African Journal of Neurological Sciences
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
