A prospective study of anxiety with respect to seizure outcome after epilepsy surgery

Purpose: To evaluate if degree of anxiety proneness is affected by seizure outcome after epilepsy surgery. Methods: Five scales related to anxiety, which are part of the Karolinska Scales of Personality (KSP), were administered pre-operatively and 2–8 years post-operatively to 31 female and 26 male patients. High scores indicate a high degree of anxiety. Seizure outcome was either Engel I or Engel II-IV. Results: Mean age of the patients was 39 years (S.D. 10). Forty-seven patients had temporal surgery and 10 patients had extra-temporal surgery. The outcome in 34 patients was classified as Engel I and in 23 patients as Engel II-IV. There were statistically significant decreases (paired t test) in t scores for the Somatic Anxiety scale (expected mean 50, from 55.4 to 50.2, P=0.001) and the Psychic Anxiety scale (expected mean 50, from 56.2 to 51.6, P=0.006) in patients in Engel I. No other significant differences were observed. After taking baseline imbalances into account (ANCOVA), there were no statistically significant differences in the change in degree of anxiety proneness between patients in the two outcome groups. Conclusion: Patients undergoing successful epilepsy surgery experienced small decreases in somatic anxiety and psychic anxiety. Since there were important pre-operative imbalances between the two outcome groups, these differences could not be attributed to the effect of seizure freedom after epilepsy surgery.