Medically treated patients suffering from
tuberous sclerosis complex (
TSC) have less than 30% chance of achieving a sustained remission. Both the international
TSC consensus conference in 2012, and the panel of European experts in 2012 and 2018 have concluded that surgery should be considered for medically refractory
TSC patients. However, surgery remains currently underutilized in
TSC. Case series, meta-analyses and guidelines all agree that a 50 to 60% chance of long-term seizure freedom can be achieved after surgery in
TSC patients and a presurgical work-up should be done as early as possible after failure of two appropriate AEDs. The presence of
infantile spasms, the second most common seizure type in
TSC, had initially been a barrier to surgical planning but is now no longer considered a
contraindication for surgery in
TSC patients.
TSC patients undergoing presurgical evaluation range from those with few tubers and good anatomo-electro-clinical correlations to patients with a significant "tuber burden" in whom the limits of the epileptogenic zone is much more difficult to define. Direct surgery is often possible in patients with a good electro-clinical and MRI correlation. For more complex cases, invasive monitoring is often mandatory and bilateral investigations can be necessary. Multiple non-invasive tools have been shown to be helpful in determining the placement of these invasive
electrodes and in planning the resection scheme. Additionally, at an individual level, multimodality imaging can assist in identifying the epileptogenic zone. Increased availability of investigations that can be performed without sedation in young and/or cognitively impaired children such as MEG and HR EEG would most probably be of great benefit in the
TSC population. Of those selected for invasive EEG, rates of seizure freedom following surgery are close to cases where invasive monitoring is not required, strengthening the important and efficient role of intracranial investigations in
drug-resistant
TSC associated
epilepsy.