Epilepsy Surgery in Children with Tuberous Sclerosis Complex: Presurgical Evaluation and Outcome

Abstract

Summary:Purpose: Children with tuberous sclerosis complex (TSC) benefit from excisional surgery if seizures can be localized to a single tuber. We evaluated the role of noninvasive studies to localize the epileptogenic tuberhegion (ET/R) and the outcome of focal resection.Methods: We identified 21 children with TSC, ages 3 months to 15 years (mean 4.8 years). All had video-(electroencephalogram) EEG and magnetic resonance imaging (MRI) scans, and 18 also had ictal single photon emission-computed tomography (SPECT) studies. An ET/R was localized in 17 patients. Thirteen patients underwent resection guided by intraoperative electrocorticography (n = 7) or subdural monitoring (n = 6).Results: Interictal EEG revealed a principal spike focus (PSF) that corresponded to the ET/R in 14 children. In seven, PSFs occurred in rhythmic runs. PSFs were not observed remote from the ET/R. Focal polymorphic slowing and attenuation occurred in the region of the PSF in 1 I patients. Sixteen patients demonstrated an ictal focus corresponding to the ET/R. Ictal SPECT revealed focal hyperperfusion correlating with the ET/R in 10 patients. Although the MRIs in all children revealed multiple tubers, the E T R corresponded to a large discrete tuber in 8 patients and a calcified tuber in 13 patients. Patchy calcified tubers were also seen elsewhere in six patients. At a mean follow-up of 26 months, 9 of the 13 children who underwent surgery were seizure-free, one had greater than 75% reduction in seizures, two were unchanged, and one was lost to follow-up. New seizures developed in one child from a contralateral tuber.Conclusions: Surgical resection of an ET/R alleviates seizures in most children with TSC and intractable epilepsy. The scalp EEG and MRI help define the ET/R and improve case selection when ictal SPECT is nonlocalizing.

Pulsed Arterial Spin-Labeled MR Imaging Evaluation of Tuberous Sclerosis

“…18,33 However, the hyperperfused lesions were identified during the ictal acquisition. The patients in our series did not have clinically apparent seizures during or preceding perfusion imaging.…”

Epilepsy Related to Developmental Tumors and Malformations of Cortical Development

“…Increasing evidence supports the importance of the perituberal cortex in TSC (for reviews see [165,218] and [219]). Accordingly, although epilepsy surgery targeting tubers may result in seizure freedom, [216,220] some patients continue to have seizures after tuber resection and, in fact, cases of TSC patients becoming seizure-free after resection of nontuberal cortex have been reported [221] (for a review see [165]). …”

Epilepsy surgery in tuberous sclerosis: a review

“…However, a number of studies have established a role for ictal SPECT in the localization of epileptogenic regions in patients with tuberous sclerosis complex. Koh et al 21 found areas of hyperperfusion on ictal SPECT in 10 of 18 patients that corresponded to the region of seizure onset defined by scalp EEG. Another group used subtraction ictal SPECT coregistered to MRI in the evaluation of 6 patients with TSC.…”