Abstracts

Rationale: Psychogenic nonepileptic seizures (PNES) are a relatively common and debilitating problem in neurology and the etiology remains poorly understood. Though relatively little is known about the causes of PNES, it has been shown that these patients often have abnormal psychological profiles. In this pilot study, we sought to determine the impact of depression, anxiety, and patterns of health locus of control (LOC) on these patients. The study was designed to evaluate levels of depression and anxiety, patterns of health LOC, and the interrelationship of these findings. Methods: Patients diagnosed with psychogenic nonepileptic seizures (PNES) at the University of Maryland Epilepsy Center were included in the study. 16 patients completed the Beck Depression Inventory-II (BDI-II®), Beck Anxiety Inventory (BAI®), and Multidimensional Health Locus of Control (MHLC) Form C between April 16th, 2007 and May 15, 2008. Scores were calculated for the BDI-II® and BAI® and analysis was performed based on severity of dysfunction (minimal, mild, moderate, or severe). Scores were also calculated for the subsets of the MHLC Form C (internal, chance, and external) and were compared to normative data and correlated to levels of depression and anxiety. Results: The BAI and BDI were completed by 16 patients. Anxiety was found to be minimal in 37.5%, mild in 25%, moderate in 25%, and severe in 12.5% of patients. Depression was found to be minimal in 62.5%, mild in 12.5%, moderate in 6.25%, and severe in 18.75% of patients (Shown in Graph 1). The MHLC was completed by 16 patients. The mean scores for internal locus of control (LOC) was 18.69, chance LOC 12.56, and external LOC 21.75. Comparison to normative data is shown in Graph 2 and demonstrates a pattern of relatively higher external LOC. A comparison of the MHLC with the BDI-II® and BAI® found a significant correlation between higher chance LOC and higher levels of depression (correlation coefficient = 0.71) and anxiety (correlation coefficient = 0.50). No significant correlations were found between internal or external LOC with anxiety and depression. Conclusions: This pilot study demonstrates that patients with psychogenic nonepileptic seizures (PNES) have significant rates of depression and anxiety, as well as a more external locus of control (LOC). The pattern of external LOC suggests that PNES patients in general do not feel that they have control over their condition. Higher chance LOC was also correlated with higher levels of depression and anxiety. This suggests that patients who believe that neither they nor their doctors have control over their symptoms are more likely to experience mood disorders. These findings support the need for identification of psychiatric comorbidity in PNES patients. Additional study is needed to confirm these results in a larger patient population and to further elucidate the role of these findings in the development of targeted treatment strategies.