Abstracts

RATIONALE: In adult epilepsy, the study of memory functions and correlates with biological variables has proven fruitful in helping to predict losses following surgery. Memory measurement is less well developed in pediatric epilepsy, and the relationship of memory tests to biological variables is poorly documented with inconsistent findings. In the current study, we evaluated a widely used memory measure in pediatrics, the Wide Range Assessment of Memory and Learning (WRAML) to address the following questions. Are verbal memory scores significantly lower than nonverbal memory scores in left temporal lobe epilepsy patients (1) prior to surgery or (2) following surgery; (3) is there a decrement in verbal memory following temporal lobectomy; and (4) does premorbid functioning predict post surgical memory scores?
METHODS: We retrospectively examined the charts of 8 children/adolescents with left temporal lobe epilepsy who had undergone TL for seizure remediation. Each subject had undergone neuropsychological assessment prior to surgery and six months following resection (mean = 200 days; SD = 32 days). Average age at surgery was 11.4 years (SD = 1.0 years). Average age of seizure onset was 8.8 years (SD = 0.7). The mean Wechsler VIQ = 90.8 (SD = 20.0) and PIQ = 95.8 (SD = 21.2). WRAML subtests included: Story Memory, Design Memory, Verbal Learning, and Visual Learning. Using the Wilcoxon signed-ranks test, we compared verbal vs. nonverbal memory scores (i.e. Story vs. Design Memory and Verbal vs. Visual Learning) as well as pre- vs. post-surgical scores.
RESULTS: Pre-surgically, verbal vs. nonverbal memory scores were not significantly different. Post-surgical Verbal Learning scores were significantly lower than presurgical scores on the same variable (p [lt] 0.01), but post-surgical versus pre-surgical comparisons for other variables were not significant. The correlation coefficient between pre-surgical Verbal Learning scores and amount of change between pre-surgical and post-surgical scores was .90.
CONCLUSIONS: Results suggest that children/adolescents, like adults, undergoing tailored left TL may experience decrements in their verbal learning abilities. List learning, not story memory, was affected. The higher the subject[ssquote]s premorbid functioning, the more likely that subject was to show decrements. Results will be discussed with respect to EEG findings, extent of resection, and pathology. The small sample size of the current investigation is a limitation, and caution should be taken when generalizing these findings.