Purpose: Children with tuberous sclerosis complex (TSC) benefit from excisi
onal surgery if seizures can be localized to a single tuber. We evaluated t
he role of noninvasive studies to localize the epileptogenic tuber/region (
ET/R) and the outcome of focal resection.
Methods: We identified 21 children with TSC, ages 3 months to 15 years (mea
n 4.8 years). All had video-(electroencephalogram) EEG and magnetic resonan
ce imaging (MRI) scans, and 18 also had ictal single photon emission-comput
ed tomography (SPECT) studies. An ET/R was localized in 17 patients. Thirte
en patients underwent resection guided by intraoperative electrocorticograp
hy (n = 7) or subdural monitoring (n = 6).
Results: Interictal EEG revealed a principal spike focus (PSF) that corresp
onded 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 11 patients. Sixteen pati
ents demonstrated an ictal focus corresponding to the ET/R. Ictal SPECT rev
ealed focal hyperperfusion correlating with the ET/R in 10 patients. Althou
gh the MRIs in all children revealed multiple tubers, the ET/R corresponded
to a large discrete tuber in 8 patients and a calcified tuber in 13 patien
ts. 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 wer
e seizure-free, one had greater than 75% reduction in seizures, two were un
changed, 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 chil
dren with TSC and intractable epilepsy, The scalp EEG and MRI help define t
he ET/R and improve case selection when ictal SPECT is nonlocalizing.