Neuropsychological outcome after frontal surgery for pediatric-onset epilepsy with focal cortical dysplasia in adolescent and young adult.

OBJECTIVE: We investigated neuropsychological outcome in patients with pharmacoresistant pediatric-onset epilepsy caused by focal cortical dysplasia (FCD), who underwent frontal lobe resection during adolescence and young adulthood. METHODS: Twenty-seven patients were studied, comprising 15 patients who underwent language-dominant side resection (LDR) and 12 patients who had languagenondominant side resection (n-LDR). We evaluated intelligence (language function, arithmetic ability, working memory, processing speed, visuo-spatial reasoning), executive function, and memory in these patients before and two years after resection surgery. We analyzed the relationship between neuropsychological outcome and resected regions (side of language dominance and location). RESULTS: Although 75% of the patients showed improvement or no change in individual neuropsychological tests after surgical intervention, 25% showed decline. The cognitive tests that showed improvement or decline varied between LDR and n-LDR. In patients who had LDR, decline was observed in Vocabulary and Phonemic Fluency (both 5/15 patients), especially after resection of ventrolateral frontal cortex, and improvement was observed in WCST-Category (7/14 patients), Block Design (6/15 patients), Digit Symbol (4/15 patients), and Delayed Recall (3/9 patients). In patients who underwent n-LDR, improvement was observed in Vocabulary (3/12 patients), but decline was observed in Block Design (2/9 patients), and WCST-Category (2/9 patients) after resection of dorsolateral frontal cortex; and Arithmetic (3/10 patients) declined after resection of dorsolateral frontal cortex or ventrolateral frontal cortex. General Memory (3/8 patients), Visual Memory (3/8 patients), Delayed Recall (3/8 patients), Verbal Memory (2/9 patients), and Digit Symbol (3/12 patients) also declined after n-LDR. CONCLUSION: Postoperative changes in cognitive function varied depending on the location and side of the resection. For precise presurgical prediction of neuropsychological outcome after surgery, further prospective studies are needed to accumulate data of cognitive changes in relation to the resection site.

Neuropsychological outcomes after frontal lobectomy to treat intractable epilepsy.

OBJECTIVE: Frontal lobectomy is often used as a surgical treatment for frontal lobe epilepsy, especially when a large epileptogenic zone in the frontal lobe is inferred from preoperative evaluation. The frontal lobe is important for cognitive functions such as executive functions and verbal fluency, but the neuropsychological outcome after a frontal or prefrontal lobectomy that includes both the dorsolateral prefrontal cortex and ventral prefrontal cortex has not been studied thoroughly. In the present study, we evaluated neuropsychological outcomes after patients with frontal lobe epilepsy received a frontal or prefrontal lobectomy. METHODS: We retrospectively reviewed the data of patients with frontal lobe epilepsy who underwent a frontal or prefrontal lobectomy that includes both the dorsolateral prefrontal cortex and ventral prefrontal cortex at 16 years or older from October 2004 to December 2014, with a minimum postoperative follow-up of 24 months. We analyzed and compared neuropsychological outcomes, including executive functions, verbal fluency, intelligence, and memory, before and after the operation. RESULTS: Eighteen patients were 16 years or older and underwent pre- and postoperative (2 years after the operation) neuropsychological evaluations. Patients showed significant deterioration only on the Benton Visual Retention Test. Performance on tests of frontal lobe functions, such as executive function and verbal fluency, showed no significant deterioration. CONCLUSIONS: Overall cognitive performance, including functions widely thought to depend on the frontal lobe, is stable after a frontal or prefrontal lobectomy to treat frontal lobe epilepsy.