The effects of intensity on a phonological treatment for anomia in post-stroke aphasia

Abstract

Introduction: The evidence regarding optimal treatment intensity is mixed, and differing definitions have further confounded existing findings. The primary objective of this study was to compare the efficacy of Phonological Components Analysis (PCA) treatment for anomia delivered at intense and non-intense schedules, using a well-controlled design. The number of teaching episodes and active ingredients of therapy are important considerations when defining intensity. We hypothesized that an active ingredient of PCA is the self-generation of phonological components during therapy sessions. Our secondary aim was to examine whether component generation predicted treatment outcome. Methods: Sixteen adults (M = 52.63 years old, SD = 11.40) with chronic post-stroke aphasia (M = 4.52 years post-onset, SD = 5.55) were randomly assigned to intensive (IT) or standard (ST) PCA treatment conditions. Cumulative treatment intensity in both conditions was equivalent: ST participants received PCA 1 hour/day, 3 days/week for 10 weeks, whereas IT participants received PCA 3 hours/day, 4 days/week for 2.5 weeks. The primary outcome was naming accuracy on a set of treated and (matched) untreated words, measured pre- and post-treatment, and at four- and eight-week follow-ups. Results: IT and ST conditions were similarly efficacious. However, secondary analyses suggest an advantage for the IT condition in naming of the treated words immediately post-treatment, but not at follow-ups. The self-generation of phonological components emerged as a significant positive predictor of naming accuracy for both the treated and untreated words. However, this relationship did not reach significance once baseline anomia severity was accounted for. Conclusions: Although replication in a larger sample is warranted, results suggest that PCA treatment is similarly efficacious when delivered at different intensities. Other factors related to the quality of treatment (i.e., active ingredients such as cue-generation) may play an important role in determining treatment efficacy and must also be considered when comparing treatment intensities.