A-200 “It’s on the Tip of My Tongue!” – Base Rates and Neuroanatomical Correlates of Confrontation Naming Deficits in Patients with Multiple Sclerosis

Abstract Objective: Word-finding difficulty is a commonly reported complaint in patients with multiple sclerosis (pwMS), though it is often under evaluated in clinical care. This study sought to identify base rates of confrontation naming impairments relative to other language tasks and examine its neuroanatomical correlates in pwMS. Method: Of 372 pwMS referred for neuropsychological assessment, 185 (MAge=48.8±11.23; MEd=14.5±2.4; 83% White; 73% women) met inclusion criteria for the final sample (i.e., estimated premorbid IQ ≥70, English-speaking, valid data on performance validity indices). Norm-based T scores for the following tests were of interest: Boston Naming Test (BNT); Controlled Oral Word Association Test (COWAT); and Animal Fluency (AF). A subset of 50 patients underwent recent quantitative MRI variables for whole brain fraction (WBF) and white matter lesion burden (T2LV). Results: PwMS showed greater impairment (≤1.5 SD) on the BNT (27.6%) as compared to AF (18.4%; p=.002), but not COWAT (24.3%; p=.304) based on binomial tests. Controlling for age and sex, significant partial correlations (ps<.05) were identified between BNT and both WBF (r=.32) and T2LV (r=-.30) and between AF and T2LV (r = -.30). COWAT did not correlate significantly with WBF (r=.08) or T2LV (r=-.09). Conclusions: Confrontation naming is relatively frequently impaired in pwMS, and correlates with both cerebral volume and lesion burden. Semantic fluency correlated only with lesion burden, and phonemic fluency did not correlate with neuroimaging. Future research should continue to investigate the clinical presentation and neuroanatomical underpinnings of language dysfunction, particularly naming/word-finding difficulties, in pwMS.