PURPOSE: Narration within a story grammar framework requires speakers to organize characters and events logically. Despite abundant research characterizing narrative deficits following a traumatic brain injury (TBI), the evolution of narrative story grammar over the first 2 years post-TBI has rarely been explored. This study analyzed story grammar in complex narratives of adults with and without severe TBI to (a) examine between-group differences and (b) investigate longitudinal changes over the first 2 years post-TBI. METHOD: Story grammar analyses of Cinderella narratives from 57 participants with TBI and 57 participants with no brain injury yielded measures of productivity (total number of episodes, total number of story grammar elements), elaboration (total number of elaborated-complete episodes, mean number of episodic elements per episode), and completeness (total number of incomplete episodes). Mann-Whitney U tests compared measures across groups; generalized estimating equation (GEE) models identified predictors of change, including recovery time (3, 6, 9, 12, and 24 months post-TBI) and demographic/injury-related characteristics. RESULTS: Between-group differences were statistically significant for all productivity and elaboration measures at 3, 6, and 9 months post-TBI; one productivity measure and one elaboration measure at 12 months; and none of the measures at 24 months. GEE models showed significant improvements in all productivity and elaboration measures over the first 24 months post-TBI, with educational attainment and duration of posttraumatic amnesia affecting recovery. Incomplete episodes only showed between-group differences at 12 months and did not capture recovery. CONCLUSION: Productivity and elaboration are key story grammar variables that (a) differentiate complex narration in individuals with and without severe TBI and (b) capture narrative improvements over the first 2 years post-TBI. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.25148999.
