Reports on seizure outcomes following surgery for lesional epilepsy consistently cite extent of resection as a significant predictor of outcome. Unfortunately, gross-total resection is not technically feasible in all cases of medically refractory tumor-associated epilepsy. Here, the authors present the case of a 4-year-old girl whose epilepsy was medically controlled after 1-stage electrocorticography-guided subtotal resection (STR) of a large diffuse protoplasmic astrocytoma. They also review the modern literature on epilepsy associated with brain tumors. Outcomes are compared with those following surgical treatment of focal cortical dysplasia and vascular lesions. Gross-total lesional resection shows significant superiority across pathologies and anatomical regions. Despite a considerable number of STRs yielding seizure freedom, other favorable treatment factors have not been defined. Although gross-total lesional resection, if possible, is clearly superior, tailored surgery may still offer patients a significant opportunity for a good outcome. Treatment factors yielding successful seizure control following STR remain to be fully elucidated.
William C. Gump, Karen L. Skjei and Shefali N. Karkare
Karen L. Skjei, Ephraim W. Church, Brian N. Harding, Mariarita Santi, Katherine D. Holland-Bouley, Robert R. Clancy, Brenda E. Porter, Gregory G. Heuer and Eric D. Marsh
Mutations in the sodium channel alpha 1 subunit gene (SCN1A) have been associated with a wide range of epilepsy phenotypes including Dravet syndrome. There currently exist few histopathological and surgical outcome reports in patients with this disease. In this case series, the authors describe the clinical features, surgical pathology, and outcomes in 6 patients with SCN1A mutations and refractory epilepsy who underwent focal cortical resection prior to uncovering the genetic basis of their epilepsy.
Medical records of SCN1A mutation-positive children with treatment-resistant epilepsy who had undergone resective epilepsy surgery were reviewed retrospectively. Surgical pathology specimens were reviewed.
All 6 patients identified carried diagnoses of intractable epilepsy with mixed seizure types. Age at surgery ranged from 18 months to 20 years. Seizures were refractory to surgery in every case. Surgical histopathology showed evidence of subtle cortical dysplasia in 4 of 6 patients, with more neurons in the molecular layer of the cortex and white matter.
Cortical resection is unlikely to be beneficial in these children due to the genetic defect and the unexpected neuropathological finding of mild diffuse malformations of cortical development. Together, these findings suggest a diffuse pathophysiological mechanism of the patients’ epilepsy which will not respond to focal resective surgery.