Objective: To determine clinical and diagnostic variables that predict the development of mania after temporal lobectomy for treatment of refractory epilepsy.
Methods: From a large surgical database, 16 patients with new-onset mania after temporal lobectomy were identified. Mania patients were frequency matched for age, gender, and laterality of surgery to 16 temporal lobectomy patients with no postoperative mood disorder. These groups were compared on pre- and postoperative clinical and diagnostic data with each other and with 30 patients with depression after temporal lobectomy. Posthoc analyses compared mania and depression groups with the general surgical database matched for gender and laterality of surgery.
Results: Preoperative evaluations in postoperative mania patients, in particular EEG, were more likely to yield findings of brain dysfunction localizing to the hemisphere contralateral to temporal lobectomy. Right temporal lobectomy was more common in the postoperative mania group. Duration of manic episodes was usually transient, and all but one case remitted within 1 year after onset. In comparison with the control group, mania and depression groups had a higher likelihood for preoperative generalized tonic-clonic seizures and lack of seizure freedom following surgery.
Conclusions: A limitation of this study was the relatively small number of patients. Despite this, clinical features that distinguish patients at risk for postoperative mania from those with depression and those with no psychiatric illness include bihemispheric abnormalities, in particular bitemporal EEG activity, and right temporal lobectomy.