Less invasive disconnection surgery using advanced image guidance for wide spread cortical malformations

Purpose: Cortical dysplasia (CD) is the important pathogenesis in the pediatric intractable epilepsy. The surgical treatment is extremely effective if the epileptogenic zone is adequately detected and resected. The extent of CD is, however, usually obscure even with careful MR imaging. In widespread or multilober CD, localization of epileptogenic zone is more difficult because of multifocal and synchronous electrophysiological abnormalities. In those cases, the eloquent cerebral tissue is involved frequently inside the CD tissue in mosaic pattern, and it should be preserved intact in the surgical intervention. For better seizure control and less invasive surgery, we have introduced subcortical disconnection with techniques including intraoperative ECoG, and advanced image-guidance.

Method: Thirty-nine CD patients with intractable epilepsy were operated. Numbers of involved cerebral lobes were; one in 6 cases, two in 9 cases, three in 6 cases and hemispheric in 18 cases. Among them, 15 cases were diagnosed as symptomatic West syndrome.

Results: The surgical procedures were; focus resection in 12 cases, multilober disconnection in 12 cases and functional hemispherotomy in 15 cases, respectively. Engel Class I (no disabling seizure after the surgery) was attained in 33 cases and rare seizures in 3 cases. No serious permanent complication was experienced. Considerable amelioration in development was observed in 28 patients.

Conclusion: Less invasive disconnection surgery using advanced image guidance was successful for wide spread cortical malformations The intervention at earlier age would be recommended for better seizure control and psychomotor development.