Retraining speech production and fluency in non-fluent/agrammatic primary progressive aphasia

• Published in: Brain (London, England : 1878) England : 1878), 2018-06, Vol.141 (6), p.1799-1814
• Main Authors: Henry, Maya L, Hubbard, H Isabel, Grasso, Stephanie M, Mandelli, Maria Luisa, Wilson, Stephen M, Sathishkumar, Mithra T, Fridriksson, Julius, Daigle, Wylin, Boxer, Adam L, Miller, Bruce L, Gorno-Tempini, Maria Luisa
• Format: Article
• Language: English
• Subjects: Editor's Choice; Original
• ISSN: 0006-8950; 1460-2156
• DOI: 10.1093/brain/awy101

There are few proven treatments for primary progressive aphasia and little is known regarding neural mechanisms that support recovery. Henry et al. report findings from the first study documenting successful and lasting remediation of speech and grammar in the non-fluent/agrammatic variant, showing that spared neural regions contribute to successful outcomes. Abstract The non-fluent/agrammatic variant of primary progressive aphasia (nfvPPA) presents with a gradual decline in grammar and motor speech resulting from selective degeneration of speech-language regions in the brain. There has been considerable progress in identifying treatment approaches to remediate language deficits in other primary progressive aphasia variants; however, interventions for the core deficits in nfvPPA have yet to be systematically investigated. Further, the neural mechanisms that support behavioural restitution in the context of neurodegeneration are not well understood. We examined the immediate and long-term benefits of video implemented script training for aphasia (VISTA) in 10 individuals with nfvPPA. The treatment approach involved repeated rehearsal of individualized scripts via structured treatment with a clinician as well as intensive home practice with an audiovisual model using 'speech entrainment'. We evaluated accuracy of script production as well as overall intelligibility and grammaticality for trained and untrained scripts. These measures and standardized test scores were collected at post-treatment and 3-, 6-, and 12-month follow-up visits. Treatment resulted in significant improvement in production of correct, intelligible scripted words for trained topics, a reduction in grammatical errors for trained topics, and an overall increase in intelligibility for trained as well as untrained topics at post-treatment. Follow-up testing revealed maintenance of gains for trained scripts up to 1 year post-treatment on the primary outcome measure. Performance on untrained scripts and standardized tests remained relatively stable during the follow-up period, indicating that treatment helped to stabilize speech and language despite disease progression. To identify neural predictors of responsiveness to intervention, we examined treatment effect sizes relative to grey matter volumes in regions of interest derived from a previously identified speech production network. Regions of significant atrophy within this network included bilateral inferior frontal cortices and supplement