Introduction: Evidence in support of hemispherectomy stems from a multitude of retrospective studies illustrating individual institutions’ experience. A systematic review of this topic is lacking in the literature.
Methods: A systematic review of hemispherectomy for the treatment of refractory epilepsy available up to October 2013 was performed using the following inclusion criteria: Reports of total of 10 or more patients of the pediatric age group (= 20 years) undergoing hemispherectomy; seizure outcome reported after a minimum follow-up of 1 year after the initial procedure; and description of the type of hemispherectomy. Only the most recent paper from institutions that published multiple papers with overlapping study periods was included. Two reviewers independently applied the inclusion criteria and extracted all the data.
Results: Twenty-nine studies with a total of 1,161 patients met the inclusion criteria. Seizure outcome was available for 1,102 patients and overall rate of seizure freedom at last follow up was 73.4%. Sixteen studies (55.2%) exclusively reported seizure outcomes of a single type of hemispherectomy. There was no statistically significant difference in seizure outcome and type of hemispherectomy (p = 0.737). Underlying etiology was reported for 85.4% of patients with documented seizure outcome and the overall distribution of acquired, developmental, and progressive etiologies was 30.5%, 40.7%, and 28.8%, respectively. Acquired and progressive etiologies where associated with significantly higher seizure free rates than developmental etiologies (p < 0.001). Twenty of the 29 (69%) studies reported complications. The overall rate of hydrocephalus requiring CSF diversion was 14%. Mortality within 30 days was 2.2% and not statistically different between types of hemispherectomy (p= 0.787).
Conclusions: Hemispherectomy is highly effective for treating refractory epilepsy in the pediatric age group, particularly for acquired and progressive etiologies. While the type of hemispherectomy does not have any influence on seizure outcome, hemispherotomy procedures are associated with a more favorable complication profile.
Patient Care: It will assist with identification of the optimal type of hemispherectomy for patients with intractable epilepsy.
Learning Objectives: By the conclusion of this session, participants should be able to:
1) Describe the role of hemispherectomy in the treamtne of refractory epilepsy
2) Discuss differences of different types of hemispherectomy
3) Identify the optimal type of hemispherectomy for various etiologies