Hemispherectomy techniques for intractable epilepsy in childhood

Objective: To present the surgical and clinical results of the therapy of 96 hemispherical intractable epilepsies in children and juveniles, who were operated on in Bethel Epilepsy Centre, Bielefeld, between 1990 and 2006, undergoing either hemispherectomy or hemispherotomy.

Method: We analysed retrospectively these 96 cases. The age at the operation ranged from 4 months to about 17 years (30% aged 3–14 years, 33% 1–3 years and 29% infants). The indication for hemispherectomy/hemispherotomy was set in cases with congenital etiologies (hemimegalencephaly, cortical dysplasia and Sturge-Weber cases) as well as in cases with acquired lesions (Rasmussen encephalitis, porencephaly after MCA-infarct and other encephaloclastic lesions). By the functional hemispherectomy, the big central region tissue resection was followed from the temporal lobectomy, amygdalohippocampectomy, callosotomy and undercutting disconnection of frontal and occipital lobes. By the hemispherotomy, we achieved through smaller craniotomies, shorter operating times and less blood loss. The disconnection of the hemisphere was achieved from inside the lateral ventricle. The epilepsy outcome is evaluated according to the Engels classification, with mean follow up of 6 years and 4 months.

Results: 28 patients underwent functional hemispherectomy and 68 patients peri-insular hemispherotomy. The advantages of hemispherotomy are obvious in the porencephalic and the atrophic lesions. The epilepsy outcome is 71% seizure free or almost seizure free additionally 17% of cases benefited from the operation (Engels III). The rates of incomplete disconnection have been reduced by the hemispherotomy. 7% of cases needed a shunt implantation. The mortality was 2,1%.

Conclusion: The peri-insular hemispherotomy can be safely applied in all etiologies of hemispheric intractable epilepsy and comparable to functional hemispherectomy, has better surgical and clinical results. The early operation is beneficial for the development of the children, taking full advantage of the brain plasticity in this stage.