Speech and language therapy approaches to managing primary progressive aphasia

Abstract

The term primary progressive aphasia (PPA) describes a group of neurodegenerative disorders with predominant speech and language dysfunction as their main feature. There are three main variants - the semantic variant, the nonfluent or agrammatic variant and the logopenic variant - each with specific linguistic deficits and different neuroanatomical involvement. There are currently no curative treatments or symptomatic pharmacological therapies. However, speech and language therapists have developed several impairment-based interventions and compensatory strategies for use in the clinic. Unfortunately, multiple barriers still need to be overcome to improve access to care for people with PPA, including increasing awareness among referring clinicians, improving training of speech and language therapists and developing evidence-based guidelines for therapeutic interventions. This review highlights this inequity and the reasons why neurologists should refer people with PPA to speech and language therapists.

Keywords: aphasia; frontotemporal dementia; primary progressive aphasia; speech therapy.

Figure 1

A clinical ‘road map’ for diagnosing the PPA subtypes – adapted from Marshall et al, 2018. ‘Atypical’ PPA here includes the unclassified or ‘not otherwise specified’ group of patients. lvPPA, logopenic variant; nfvPPA, nonfluent variant; svPPA, semantic variant.

Figure 2

Classical neuroimaging features of the PPA variants. Longitudinal imaging patterns at baseline and approximately 1 year and 2 years from baseline – top row shows coronal sections and bottom row shows axial sections (left hemisphere on right of picture for both): (A) asymmetrical anteroinferior temporal lobe atrophy in semantic variant PPA, (B) asymmetrical posteroinferior frontal and insular atrophy in nonfluent variant PPA, (C) asymmetrical posterior-superior temporal and inferior parietal atrophy in logopenic variant PPA, (D) widespread left hemispheric atrophy in PPA-not otherwise specified (in this case due to a progranulin mutation).

Figure 3

Clinicopathological correlations in primary progressive aphasia (adapted from Bergeron et al, 2018). Aβ is Alzheimer’s pathology; PiD is Pick’s disease, CBD is corticobasal degeneration, and PSP is progressive supranuclear palsy (all forms of tauopathy); TDP-A, TDP-B, TDP-C and TDP-U (unclassified) are all forms of TDP-43 proteinopathy. PPA-M/U here represents a mixed-unclassified variant, equivalent to the PPA-NOS group discussed in the text. lvPPA, logopenic variant; nfvPPA, nonfluent variant; NOS, not otherwise specified; svPPA, semantic variant.

Figure 4

Examples of interventions used for people with primary progressive aphasia. AAC, augmentative and alternative communication.