Abstracts

Rationale: Research strongly suggests that people with epilepsy experience higher rates of depression and anxiety, and the severity of these symptoms has proven to be a strong predictor of quality of life. Given the high rates of comorbid depression and anxiety, it is not surprising that individuals with epilepsy report higher levels of psychological distress than those without seizures. Moreover, individuals with epilepsy commonly report that stress exacerbates their seizures. Yet, few studies have investigated the effects of stress on seizure control. Methods: Analyses were performed retrospectively on neuropsychological data collected from 150 temporal lobe epilepsy (TLE) patients drawn from a sample of individuals who had undergone pre-surgical evaluation of medically intractable seizures. Seizure localization was confirmed based on the results of continuous video/EEG monitoring. An abbreviated version of the Minnesota Multiphasic Personality Inventory was used to determine perceived emotional stress, as measured by T-scores from Scales 2 (D) and 7 (Pt). An estimate of lifetime seizure load was calculated for each patient by multiplying epilepsy duration by an average number of seizures per year. Patients were divided into two groups based on a median Full Scale IQ split resulting in a high IQ (FSIQ ≥ 92) and a low IQ (FSIQ < 92) group. Results: Multiple regression analyses were used to model the effects of perceived emotional stress. Lifetime seizure load scores were positively skewed and were transformed using a log transformation. Analyses were carried out on transformed data. In the high IQ group, Scales 2 and 7 significantly predicted seizure load (p = .04). However, only Scale 2 was an individually significant predictor (β = .35, p = .03). A model with Scales 2 and 7 as predictors of seizure load was then tested in the low IQ group, and neither variable (Scale 2 (β = .05, p = .77) or Scale 7 (β = -.08, p = .66)) was individually significant. Conclusions: T-scores on Scale 2 of the MMPI appear to be significantly associated with an increase in seizure load only in those individuals with a higher IQ. Unexpectedly, T-scores on Scale 7 of the MMPI were not related to seizure load in either the high or low IQ group. This suggests that as one scores higher on Scale 7, becoming more anxious, tense, and agitated, they are not at greater risk for having an increase in seizures. Whereas, those individuals with high scores on Scale 2 who feel sad, dissatisfied with their life, and hopeless about overcoming their problems may experience an increase in seizures. Interestingly, it was found that only those individuals with a high IQ appear to experience an increase in lifetime seizure load due to an elevated Scale 2 T-score. The findings suggest that the individuals with greater intellectual resources are more affected by depressive symptoms, perhaps more aware of the negative impact they are having on their life, consequently resulting in higher levels of psychological distress.