Effects of zonisamide on cognitive functions in patients with refractory focal epilepsy

Objective: to evaluate the influence of zonisamide (ZNS) as add-on therapy on cognitive functions in patients with Refractory Focal Epilepsy. Methods: subjects were affected by Focal Epilepsy refractory to at least two previous antiepileptic drugs. After three months baseline period at stable therapy, ZNS were titrated, as adjunctive therapy, up to 300 mg/day in 8 weeks. All patients underwent a neuropsychological battery test at two points: prior to titration and 24 weeks after reaching 300 mg/day dosage of ZNS. Results: we report the preliminary results of the first 10 patients enrolled (4 M; mean age 48+10 yrs; mean educational 7.9+3.7 yrs); ZNS was added to 1 AED in 7 patients and to > 1 AED in 3. After ZNS therapy we observed in neuropsychological tests a significant (p = 0,015) worsening of performance in FLUS (Baseline: 31 + 6,23; T1:26,2 + 3,76). Conclusions: this pilot study shows a good tolerability of ZNS on cognitive performance with no significant changes apart from phonemic and semantic fluency.