Hemispherotomy for intractable epilepsy

Context: Hemispherotomy is a surgical procedure for hemispheric disconnection. It is a technically demanding surgery. Our experience is presented here. Aims: To validate and compare the two techniques for hemispherotomy performed in patients with intractable epilepsies. Settings and Design: A retrospective study 2001-March 2007: Nineteen cases of hemispherotomies from a total of 462 cases operated for intractable epilepsy. Materials and Methods: All the cases operated for intractable epilepsy underwent a complete epilepsy surgery workup. Age range 4-23 years (mean 5.2 years), 14 males. The seizure frequency ranged from 2-200 episodes per day; four were in status; three in epilepsia partialis continua. The pathologies included Rasmussen's, hemimegelencephaly (unilateral hemispheric enlargement with severe cortical and subcortical changes), hemispheric cortical dysplasia, post-stroke, post-traumatic encephalomalacia and encephalopathy of unknown etiology. The techniques of surgery included vertical parasaggital approach and peri-insular hemispherotomy. Neuronavigation was used in seven cases. Results: Class I outcome [Engel's] was seen in 18 cases and Class II in one assessed at 32-198 weeks of follow-up. The four patients in status epilepticus had Class I outcome. Four patients had an initial worsening of weakness which improved to preoperative level in five to eight weeks. Power actually improved in three other patients at 32-36 weeks of follow-up, but hand grip weakness persisted. In all the other patients, power continued to be as in preoperative state. Cognitive profile improved in all patients and 11 cases returned back to school. Conclusions: Both techniques were equally effective, the procedure itself is very effective when indicated. Four of our cases were quite sick and were undertaken for this procedure on a semi-emergency basis.