There is little data in the literature examining postoperative psychiatric outcome from extratemporal lesions in children. Rates of mental health problems appear lower than for children undergoing temporal lobectomy [6], but are still significant. In a study of psychiatric outcome at least a year following surgery (range 12 months to 12 years) in 71 children undergoing extratemporal resection (predominantly frontal resections), one or more psychiatric diagnoses was present in 31/71 (44 %) children preoperatively and 32/71 (45 %) postoperatively [17]. Mental health problems improved postoperatively in eight (11 %) children, of these, five (7 %) completely resolved; in 6/71 (9 %) children with no preoperative diagnosis, a DSM-IV diagnoses evolved postoperatively. The nature of the psychiatric diagnoses is summarized in Table 8.2. There was no association between any change in psychopathology (positive or negative) and seizure outcome, or indeed any other factors such as pathology, location of surgery, etc. As with surgery in the temporal lobe, the removal of the epileptic focus producing epileptic discharges could result in marked improvement in behavior, particularly in the frontal lobe cases. Equally removal of frontal lobe tissue could cause disinhibition and other problems leading to behavioral disturbance [18].

A smaller study of 34 patients undergoing extratemporal resection found high rates of behavior problems in the children that underwent neuropsychology testing (18/34) pre- and postoperatively (1 year postop) using the CBCL to assess behavioral problems [19]. Overall, these children were found to score highly in the domain of attentional problems reported by parents and greater than normal in domains of somatic complaints, social problems, and anxiety/depression. Postoperatively, there were no measureable improvements in these areas, despite overall seizure freedom of 68 % of patients though parents did report some improvements.

Children undergoing hemispherectomy seem to have better behavioral outcomes postoperatively than those undergoing temporal lobectomy. Historically, hemispherectomy was reported to lead to remarkable behavioral improvements with a report by Wilson [20] describing 50 patients of whom 80 % had behavioral problems of whom following surgery, 94 % had a normalization of behavior. In the more recent literature, Pulsifer et al. [21] reported a series of 71 patients with hemispherectomy, 53 of whom underwent follow-up at a mean of 5.4 years postoperatively. The CBCL was used to assess behavioral problems and the overall score was not consistent with clinical problems. However, on the subscales of clinical problems with attention and thought problems, the scores were consistent with a clinically significant problem, but these scales improved significantly after surgery. In another large series of pediatric hemispherectomy [5], with a median follow-up 3.4 years, behavior difficulties were present in 12 children (36 %). The most common problem was difficulty with concentration (75 %), followed by fluctuating mood with or without socially intrusive behavior (66 %). Ninety-two percent of children had improvement in behavior post hemispherectomy who had been found to have preoperative behavioral problems. Five children were reported to have behavioral problems postoperatively having not experienced them preoperatively. The emergence of behavioral problems was neither related to seizure outcome nor to the cognitive abilities of the child.

The mechanisms leading to behavioral problems in children undergoing hemispherectomy, as with other epilepsy surgery candidates, are likely to be multifactorial. The role of epileptic discharges may be important in hemispherectomy candidates, as frequent, widespread epileptic discharges are common. Hemispherectomy prevents the spread of epileptic discharges to the unaffected hemisphere and may be one reason why behavioral problems may improve postoperatively in some children (Case 2).

In palliative surgery for epilepsy, it is also important to consider wider outcomes than just seizure control. Corpus callosotomy is performed as a palliative procedure with the aim of stopping, or at least reducing “drop” seizures which are associated with injury. It would not be expected that this type of surgery would lead to seizure freedom as children who have “drop” seizures typically have other seizure types. No brain tissue is removed during surgery, so the concept of removing abnormal brain tissue and the epileptic focus thereby improving behavioral problems does not apply. However, corpus callosotomy can prevent the spread of epileptic discharges from one hemisphere to another, so the concept of limiting the extent of electrical disturbance and evaluating whether this leads to an improvement in functioning has been considered. Yonekawa et al. [22] investigated 15 children undergoing corpus callosotomy with EEG and used the CBCL to assess their behavior. They were followed after just under a year (mean 0.8 years). The attention problem scale and total CBCL score significantly improved in children who had an improvement postoperatively in their EEG. Other studies [23–26] have also demonstrated improvements in behaviors (particularly attention, hyperactivity, and aggressive behaviors) post callosotomy with mean periods of follow-up ranging from 19 to 40 months after surgery.