[HEMISPHEROTOMY FOR TREATMENT OF REFRACTORY EPILEPSY IN CHILDREN].

INTRODUCTION: Hemispherotomies are an extreme treatment for epilepsy. As opposed to focal resections, in hemispherotomies the entire hemisphere is disconnected from the remaining nervous system, including functional regions and fibers. Despite this, hemispherotomy is recommended for certain indications, with good epilepsy and functional outcomes. AIMS: To summarize the experience of hemispherotomy performed at a tertiary national center. METHODS: A retrospective study was conducted including all patients operated on between 2001 and 2014. Patients were 10 months to 18 years old at the time of surgery, and all underwent hemispherotomy for treatment of refractory epilepsy. RESULTS: A total of 14 children were included in the study. The main etiology for epilepsy included Rasmussen encephalitis (5), hemispheral cortical dysplasia (3), and ischemic stroke (2). Six children had previous surgeries. All children underwent peri-insular hemispherotomy. One child lives abroad and was lost to follow-up. Of the remaining 13: 9 are seizure-free since surgery, 3 have rare seizures and 1 has frequent seizures (however, less than preoperatively). The average number of antiepileptic drugs was reduced by about 50%. All children had neurological deficits similar to their preoperative status, or had gradual improvement in motor and cognitive/linguistic skills. There was one complication - an infection that had no neurological impact, but necessitated surgical wound revision. CONCLUSIONS: Hemispherotomy changes the natural history of refractory hemispheric epilepsy. The epilepsy and functional outcomes are good. DISCUSSION: Hemispherotomy surgery is part of the treatment options for children with refractory hemispheric epilepsy. Despite the hemispheric disconnection, functional outcome is encouraging. The degree of functional outcome depends on preoperative neurological injury, thus it is important not to delay surgery if indicated.

Epilepsy surgery in children compared to adults.

AIM: The purpose of this study was to compare the frequency of various surgical techniques and surgical outcome between pediatric and adult populations that underwent epilepsy surgery by the same team. METHODS: All patients who underwent epilepsy surgery at the Tel Aviv Medical Center between 1997 and 2006 and had been followed up for >2 years were eligible for this study. The majority (90%) of all epilepsy surgeries carried out in Israel were performed in this institution and by a single neurosurgeon. Only patients that underwent video-EEG monitoring as part of the presurgical evaluation were included in the study. RESULTS: A total of 186 patients (131 adults and 55 children) underwent epilepsy surgery in our institute during the study period, and follow-up was available for 177 patients (95%). While the adults underwent significantly more temporal lobe resections (51 vs. 20%, p < 0.0001), the children had significantly more extra-temporal non-lesional resections (18 vs. 1%, p < 0.0001) and hemispherectomies (5 vs. 1%, p = 0.002). Over one half (54%) of all the patients had a postoperative reduction in seizures of >90%, and 72% had a reduction of >50%, with no group difference in surgical success. Among the lesionectomies, the outcome was better for tumors, especially those in the temporal lobe. Only 1% of the patients had a long-term neurological deficit. CONCLUSIONS: Children comprised 30% of the epilepsy surgical cases during the study period. Children underwent more non-lesional resections and hemispherectomies, while adults underwent more temporal lobe resections. There was no age-related difference in surgical outcome.

The prognostic significance of interictal epileptiform activity in postoperative EEGs of patients with mesial temporal lobe epilepsy.

It has not been established whether electroencephalography (EEG) is a contributing factor in predicting the outcome of surgery for epilepsy. We conducted a prospective study on 26 patients (M/F 14/12, age: 33 +/- 7.5 years, range 19-48) with mesial temporal lobe epilepsy (MTLE) who were followed for 2 years after surgery and who underwent routine EEG recordings 5.6 +/- 3 months (range 3-12) postoperatively. Interictal epileptiform activity (IEA) on the EEG was compared in 17 seizure-free patients to 9 patients with recurrent seizures. The two groups were similar in gender, age, febrile convulsions, trauma, family history, seizure frequency prior to surgery, epilepsy duration and number of antiepileptic drugs. Following surgery, 17 study patients (65%) became seizure free; 9 (35%) had seizure recurrence. Post-operative EEG recordings showed IEA in 8/26 study patients (31%), 3 of whom were from the seizure-free group (3/17, 18%); 5 had seizure recurrence (5/9, 56%) (p=0.078). IEAs in postoperative EEGs were less frequently demonstrated in patients who were seizure free, but the presence of postoperative IEAs does not preclude successful surgical outcome.

Effects of topiramate on memory performance on the intracarotid amobarbital (Wada) test.

We evaluated the effects of topiramate (TPM) on memory function in the intracarotid amobarbital (Wada) test in nine patients with mesial temporal lobe epilepsy (MTLE) whose antiepileptic drugs (AEDs) included TPM and compared their scores with those of 16 patients with MTLE on AEDs not including TPM. Sodium amobarbital was injected first into the hemisphere ipsilateral to the seizure focus and then into a contralateral site, and the patients were tested for naming and memorization. There was no statistical difference in percentage memory scores between the two patient groups following the contralateral injection. After the ipsilateral injection, however, TPM patients had significantly lower percentage memory scores compared with non-TPM patients (P < 0.02). We conclude that a possible adverse effect of TPM on memory performance should be considered when evaluating the Wada test memory scores of patients on TPM therapy.