A-282 Verbal Fluencies are Differentially Associated with Processing Speed in Temporal Lobe Epilepsy

Abstract

Abstract Objective: The current study sought to better understand the impact of processing speed on pre-surgical assessment of verbal fluencies in temporal lobe epilepsy (TLE) by examining whether processing speed is differentially related to category and letter fluencies across patients with left and right unilateral TLE. Method: The retrospective data sample included 36 adults aged 17-60 (56% female) with cryptogenic TLE and both video EEG evidence for unilateral seizure focus (right TLE n =16; left TLE n=20) and confirmed left hemisphere language dominance, who had undergone pre-surgical neuropsychological evaluation including assessment of category fluency (Animal Naming), letter fluency (FAS), and processing speed (Coding). Primary partial correlation analyses controlled for age and years of education. Results: After controlling for demographic variables in each of the following analyses, there was a statistically significant relationship between Coding and Animal Naming (r=.47, p<.01) but not FAS in the full sample of TLE patients. Similarly in the left TLE group, there was a statistically significant relationship between Coding and Animal Naming (r=.47, p<.05) but not FAS. In the right TLE group, neither Animal Naming nor FAS were statistically significantly related to Coding. Conclusion: Results suggest that processing speed may have a greater influence on measurement of category as opposed to letter fluency in individuals with left TLE but not right TLE. While further research in larger samples is indicated, a better understanding of these relationships is important in assessing the lateralizing/localizing value of semantic and phonemic fluencies in pre-surgical neurocognitive profiles of patients with unilateral TLE with impaired processing speed.