Abstracts

Rationale: Children with drug-resistant epilepsy (DRE; poor seizure control despite medical treatment on >=2 antiepileptic drugs), experience higher rates of anxiety and depression compared to those with well controlled seizures and their typically developing peers. Surgery improves seizure control and benefits may extend to emotional functioning. Yet, few studies have examined emotional functioning following surgery in children with DRE. Those that have lacked an adequate control group or relied on parental report. However, children are reliable informants of internalising difficulties and report greater severity and different symptoms compared to their parents. This study examined changes in self-reported emotional functioning after surgery (compared to medical treatment) in children with DRE.  Methods: This prospective, longitudinal, multi-centre study recruited 128 children with DRE aged 8 to 18 years (M=13.09, SD=2.66; 58% male) evaluated for surgical candidacy; 48 went on to have surgery, and 80 continued medical treatment only. Child-validated self-report measures of anxiety and depression were administered at baseline, 6- and 12-months follow-up. Standardized z-scores were calculated with lower scores indicative of fewer symptoms.  Results: Baseline characteristics were comparable between groups (surgical vs. medical, p.050). At 6- and 12-months follow-up, seizure freedom was higher in the surgical (64 & 77%, respectively), compared to the medical (11 & 24%, respectively) group, p<.001. Linear mixed modelling (controlling for age) found a significant main effect of time, F(1, 120.65)=7.10, p=.009, and seizure status, F(1, 212.38)=4.27, p=.040, but not group, F(1, 128.90)=0.78, p=.377, for depression; scores decreased over the 12-month period for the entire sample and fewer symptoms were reported among seizure free patients (M=0.13, 95%CI [-0.06, 0.31], SE=0.10), relative to those with ongoing seizures (M=0.34, 95%CI [0.22, 0.46], SE=0.06). A significant main effect of time, F(1, 131.87)=4.79, p=.030, but not group, F(1, 140.23)=0.55, p=.459, or seizure status, F(1, 166.29)=0.46, p=.500, was found for anxiety; scores decreased over time for the entire sample. No significant interactions were found, p.050.  Conclusions: All patients reported a reduction in depression and anxiety over the first 12-months. Seizure freedom at follow-up was associated with fewer depressive, but not anxiety, symptoms overall. Despite more patients achieving seizure freedom with surgical treatment, surgery itself was not associated with better outcome. Changes in anxiety and depression may require a longer time to emerge post-surgery. However, being seizure-free is associated with fewer depressive symptoms, irrespective of treatment.  Funding: This study was funded by a grant from the Canadian Institute of Health Research. Dr. Phillips is supported by a postdoctoral fellowship from the SickKids Foundation.