Depression in Intractable Partial Epilepsy Varies by Laterality of Focus and Surgery

Abstract

Summary:Purpose: Depression sometimes occurs after surgical treatment for medically intractable partial epilepsy. The risk of pre-and postsurgical depression may vary by laterality of seizure focus. We reviewed the pre-and postsurgical psychological assessments and clinical courses of patients to identify those at highest risk for postsurgical mood disorders.Methods: Depression status was assessed in a consecutive series of epilepsy patients before and 1 year after epilepsy surgery with the use of Scale 2 of the MMPI-2 and a clinical depression index (CDI) scoring the occurrence of depressive symptoms, psychiatric referral, or attempted/completed suicide. Outcome at 1 year was modeled by regression techniques as functions of preoperative mood measurements, side of epilepsy surgery, and preoperative verbal intelligence.Results: The CDI and Scale 2 MMPI-2 correlated significantly (r ‫ס‬ 0.341; p Յ 0.01). Left (n ‫ס‬ 54 subjects) and right (n ‫ס‬ 53) surgery groups did not differ by sex, seizure outcome, age, education, age at first seizure, duration of epilepsy, or intellect. Higher presurgical depressive morbidity (p ‫ס‬ 0.0037) and right-sided surgery (p ‫ס‬ 0.0003) predicted higher postoperative CDI. Higher preoperative Scale 2 scores, indicating worse depressive traits, predicted worse postoperative Scale 2 scores (p < 0.0001). Although side of surgery did not predict Scale 2 scores, Scale 2 scores of patients with preoperative right-sided foci tended to have worse postsurgical Scale 2 scores (p ‫ס‬ 0.08). Findings for the temporal lobectomy subgroup (n ‫ס‬ 90) were similar to those of the overall sample.Conclusions: Patients undergoing right hemispheric epilepsy surgery, especially those with high presurgical depressionrelated morbidity, may be particularly susceptible to clinical depression. Our findings support other studies that show an interhemispheric modulation of depressive traits and symptoms.

Surgical Effects of Focus Resection for Patients With Intractable Epilepsy

“…15) The present and previous findings have implicated TLE and presurgical psychiatric history as important risk factors for postoperative psychiatric problems. 1,5,9,14) In contrast to the present results, some earlier studies identified poor seizure outcome and surgical side as strong predictive factors. 1,2,15) The findings of the types of postoperative disorders have also varied: earlier papers more commonly report milder psychiatric issues 9) and transient mood disorders such emotional lability and depression, 5) whereas we predominately observed conditions requiring treatment with antipsychotic drugs.…”

“…[1][2][3][4][5][6]9,11,[13][14][15]17,19) These problems have recently become a focus of interest, as intractable epilepsy is recognized as a chronic encephalopathy in which one seizure induces other seizures. 7) Therefore, we need to analyze the overall effects on the quality of life to demonstrate the benefits of surgery.…”

Risk factors for postoperative depression in 150 subjects treated for drug-resistant focal epilepsy

“…Quigg et al (2003) found that right-sided epilepsy patients with pre-surgical depression may be particularly susceptible to post-surgical depression, but Wrench et al (2004) have not confirmed a relationship between depression and temporal lobe epilepsy. Thirty-one subjects became depressed after 6 months, only two after 12 months from surgery.…”

Kindling epileptogenesis in immature rats leads to persistent depressive behavior

“…In contrast to post-status epilepticus epilepsy, kindling is not accompanied by hippocampal sclerosis and spontaneous seizures. Eliminating spontaneous seizures as a variable permits this model to accommodate an important clinical feature of epilepsyassociated depression observed by Attarian et al [34] and Quigg et al [35]. Those authors found that the prevalence depression was independent of the degree of seizure control.…”