Purpose: To determine the incidence of psychiatric disorders before and after surgical treatment for partial epilepsy and to document the effectiveness of their treatment.
Methods: Fifty consecutive patients treated surgically for focal epilepsy (44 temporal and six frontal) were evaluated by established neuropsychiatric methods before surgery and over a mean period of 2 years after surgery. The patients with interictal dysphoric disorders, with or without psychotic episodes, were treated with tricyclic antidepressant medication alone or combined with serotonin selective reuptake inhibitors and, if necessary, with the addition of risperidone.
Results: Before surgery, 25 (57%) of the 44 patients with temporal lobe epilepsy had dysphoric disorders. After surgery, 17 (39%) of the 44 patients experienced either de novo psychiatric complications (six psychotic episodes, six dysphoric disorders, and two depressive episodes) or exacerbation of preoperative dysphoric disorder (three patients). Eight previously intact patients of the 19 (42%) developed dysphoric disorders after surgery that were significantly related to recurrence of seizures. All psychiatric complications occurred in the first 2 months after surgery, except for the six patients intact before surgery, who had a recurrence of seizures. A significant predictor of ultimate excellent psychiatric outcome was complete absence of seizures after surgery. All postoperative psychiatric complications remitted on treatment with psychotropic medication in the compliant patients.
Conclusions: An exceptional psychiatric morbidity is associated with the months after temporal lobectomy. Possible pathogenetic mechanisms are discussed. Antidepressant drugs are very effective in treating the psychiatric disorders of chronic epilepsy; their use in conjunction with the surgical treatment of epilepsy appears to be crucial for the overall positive outcome of a significant number of patients.