Predictors of decline in verbal fluency after frontal lobe epilepsy surgery.

Few studies have focused on language changes following frontal lobe epilepsy (FLE) surgery. The aim of the current study is to quantify the role of resection location and size in verbal fluency decline after FLE surgery and to examine its predictors. A retrospective chart review identified 36 adult patients who underwent FLE surgery. Verbal fluency was assessed using the Controlled Oral Word Association Test (COWAT). Nine (25%) of the patients had significant decline. Binary logistic regression incorporating side of resection and preoperative COWAT score significantly predicted decline and accounted for 25% of the variance. A trend was also noted for decliners to have higher postoperative seizure recurrence (p=0.067). There was no effect of size of resection. Patients undergoing FLE surgery are at risk of verbal fluency decline, especially if they have a high presurgical verbal fluency score, undergo a frontal lobe resection in the language dominant hemisphere, and have poor seizure outcome.

Role of cortisol in mood and memory in patients with intractable temporal lobe epilepsy.

OBJECTIVE: This study prospectively examined the relationships among late night salivary cortisol (NSC) levels and depressive symptoms, memory performance, and hippocampal volumes in patients with medically intractable temporal lobe epilepsy (TLE) and the potential mediating effects of cortisol in the relationships between these variables. METHODS: Participants included 24 adults with well-characterized medically refractory TLE (right = 11; left = 12; bitemporal = 1). All patients provided saliva samples and completed measures of mood, anxiety, and memory (objective and subjective). MRI-based volumetric analyses of the hippocampi were also conducted. RESULTS: As hypothesized, cortisol was found to be negatively related to several memory measures such that patients with higher cortisol levels demonstrated lower memory performance. However, unexpectedly, cortisol was not related to current symptoms of depression or anxiety, subjective memory ratings, or hippocampal volumes. Consistent with previous findings in the literature, a number of other relationships among the study variables were observed (objective memory and hippocampal volume; subjective memory and mood/anxiety). Results of mediator analyses suggested that cortisol does not mediate the relationship between depression and memory dysfunction or the relationship between depression and hippocampal atrophy. CONCLUSIONS: While cortisol may play a role in memory performance in patients with TLE, it does not fully explain the relationship between depression and mesial temporal dysfunction, likely reflecting the complex and multifactorial relationships among these variables. Results confirm the relationship between memory performance and structural brain integrity and provide further support for a role of depression in subjective memory complaints.