Beyond the Plateau: Repeated Treatment Opportunities Are Associated with Improved Naming in Chronic Post-Stroke Aphasia.

Background/Objectives: Speech-language treatment improves recovery in chronic post-stroke aphasia, but whether individuals continue to benefit from repeated treatment exposure remains unclear. We tested whether successive treatment episodes were associated with continued naming improvement and whether gains were reduced in later episodes relative to earlier episodes. Methods: We analyzed retrospective longitudinal data from 35 participants with post-stroke aphasia who completed at least two aphasia treatment studies. Philadelphia Naming Test scores were obtained before and after each treatment study. The primary analysis used a linear mixed-effects model with fixed effects for timepoint, treatment study, and their interaction, with random intercepts for participants and participant-specific treatment studies. Secondary analyses examined candidate predictors and compared within-treatment with between-treatment change while accounting for elapsed time. Results: Naming improved significantly from pre- to post-treatment across studies 1-3 (estimated mean gain = 5.56 points, 95% CI [3.44, 7.67], p < 0.001). The timepoint-by-treatment-study interaction was not significant (p = 0.384), providing no evidence that gains were attenuated across successive studies. Naming improved faster during treatment than between treatments (adjusted difference = 2.18 points per 30 days, p = 0.013). Conclusions: Repeated treatment opportunities were associated with continued naming improvement in chronic post-stroke aphasia, supporting a longitudinal view of aphasia rehabilitation.