Abstracts

Rationale:
To explore temporal lobe epilepsy (TLE) disease duration (DD) with cognitive performances across multiple domains in a unique, primarily immigrant, Spanish-speaking cohort living in the US.
Method:
Retrospective analysis of neuropsychological exams of Spanish-speaking people with intractable TLE was done to explore the relationship of DD of TLE with cognitive functioning. The Neuropsychological Screening Battery for Hispanics (Ponton, 1996) was part of a comprehensive presurgical evaluation. Intellect, attention, processing speed, language, visuospatial, visual memory, verbal learning and memory, executive functioning and fine motor dexterity were measured. Subtest raw scores were converted to z-scores using education-based normative data (Ponton, 2001). Pearson's correlations were used to explore the relationship of DD on cognitive performance. The cohort was divided into three DD groups; 1 - 20 years (G1, n = 8), 21 - 30 years (G2, n = 10), and 31+ years (G3, n = 8) allow ANOVA analyses to explore the impact on cognition across different DD subgroups.
Results:
Spanish-speaking participants (n=26), mostly female (54%), had a mean age of 36-years and a mean reported level of education of 8-years. Mean DD was 26.7-years.  Pearson’s correlations yielded significant, negative correlations. Longer DD was associated with poorer neuropsychological performances across select cognitive domains. Specific domains and respective subtests included: Intelligence, (Raven’s Progressive Matrices - a nonverbal test of intelligence; r (24) = -0.54, p < 0.01); Processing Speed (Color Trails 1, r (24) = -0.48, p = 0.01); Executive Functioning (Colors Trails 2, r (24) = -0.44, p = 0.02); Visuospatial (Rey Complex Figure Test [RCFT] Copy, r (24) = -0.47, p = 0.01 and Block Design, r (24) = -0.39, p = 0.04); Verbal Learning and Memory (WHO-AVLT Trial 5 - verbal learning, r (24) = -0.39, p = 0.05 and Trial 7 - short-delay verbal memory, r (24) = -0.38, p = 0.05).   ANOVA results were significant on the Raven’s, F (2, 23) = 8.4, p = 0.001), with G1 (M = 0.26, SD = 0.60) scores significantly higher than both G2 (M = -1.02, SD = 0.95) and G3 (M = -1.00, SD = 0.47). WHO-AVLT Trial 5, was significant, F, (2, 23) = 4.39, p = 0.002), with G1 (M = 0.17, SD = 0.51) scores significantly higher than G3 (M = -1.06, SD = 0.87), and trending higher than G2 (M = -0.82, SD = 1.10). WHO-AVLT Trial 7 was significant, F (2, 23) = 4.35, p = 0.02), with G1 (M = -0.06, SD = 1.43) higher than G2 (M = -1.59, SD = 1.08) and G3 (M = -1.56, SD = 1.12). ANOVA results for remaining subtests revealed similar, trending results (i.e., p < 0.1) on select measures of delayed memory, language, attention, processing speed, visuospatial and motor dexterity.
Conclusion:
Longer DD of TLE negatively impacts performance in multiple cognitive domains in a unique, Spanish-speaking, primarily immigrant cohort living in the US. This relationship has not been well studied in this population. Results were consistent with previous research that was largely done with English-speaking cohorts of the majority population. Significant and trending patterns suggested that DD of < 20 years was associated with statistically better performance than groups with DDs > 21 years. Declines of intelligence, verbal learning and short-term memory recall reduced to clinically impaired levels. Processing speed, executive functioning and visuospatial scores also declined with longer DD; however, these domains were relatively spared, or clinically intact (i.e., > 9th percentile). This study was limited by a small sample. Larger, prospective studies are encouraged to rule out a critical DD of TLE that negatively impacts neuropsychological functioning after 20-years and to characterize functional limitations associated with DD in this population.
Funding:
:None.