Abstracts

Rationale: Depression and anxiety disorders are the most common psychiatric comorbidities in temporal lobe epilepsy, often associated with a decrease in the quality of life for these patients. Using high resolution MRI and volumetric techniques, hippocampal atrophy can be reliably identified and is the most prevalent underlying pathology in drug resistant temporal lobe epilepsy. In a previous study from our laboratory, we found a relationship between the presence of hippocampal atrophy and being symptomatic on the anxiety scale. This study aims to further quantify these changes by determining if the laterality of the hippocampal atrophy is associated with anxiety and depression in this population. Methods: This study included 54 consecutive patients (28 females) with a mean age of 35.8 ± 10.2 years. All patients suffered from treatment-resistant TLE and underwent volumetric measurement of bilateral hippocampal formations as part of their presurgical evaluation. T1 weighted MRI scans were acquired using a 3-D SPGR pulse sequence. Hippocampal volumes were derived by manually tracing consecutive coronal slices aligned perpendicular to the long axis of the hippocampus. Every patient completed the Minnesota Multiphasic Personality Inventory - Second Edition (MMPI-II). Patients were considered to be symptomatic in depression (scale 2) and anxiety (scale 7) scales if they had a T score of > 65. Correlations were carried out between normalized hippocampal volumes for patients with right, left as well as no hippocampal atrophy and depression and anxiety scores from the MMPI-II scales. Results: Among the 54 patients, 25 had hippocampal atrophy, 14 on the left and 11 on the right. Twenty six patients (48%) were symptomatic on the depression scale, 17 (31%) on the anxiety scale and 14 (26%) on both. There was a significant correlation between the amount of right hippocampal atrophy and the severity of anxiety scores in patients with left hippocampal atrophy (r = -0.63, p = 0.015). In addition, there was a statistical trend between the magnitude of right hippocampal atrophy and the severity in the depression scores (r = -0.51, p = 0.065). This relationship was not seen in patients with right hippocampal atrophy or those without hippocampal atrophy. Conclusions: These findings suggest that a smaller right hippocampus in patients with left hippocampal atrophy may be associated with anxiety and depression in temporal lobe epilepsy. This may help in the understanding and treatment of anxiety and depression in patients with temporal lobe epilepsy.