Multiple subpial transections in the treatment of pediatric epilepsy
Jeffrey P Blount1, Wayne Langburt, Hiroshi Otsubo
1Division of Neurosurgery and Neurology, The Hospital for Sick Children, The University of Toronto, Ontario, Canada.
Object:
The technique involved in multiple subpial transections (MSTs) allows the surgeon treating patients with epilepsy the capability to make disconnective lesions in epileptogenic regions of eloquent cortex. Although there have been increasing numbers of reports in adults of the efficacy and relative safety of this technique, there are relatively few such reports in children. The authors present their experience in 30 children who underwent MSTs during the surgical management of the seizure disorder.
Methods:
Thirty consecutive children who underwent MSTs with or without cortical excision form the basis of this retrospective review. An analysis of neurological adverse effects following MSTs and seizure outcome was performed. Between 1996 and 2000, MSTs were performed either as stand-alone therapy (four patients) or in conjunction with planned cortical excisions (26 patients). Twenty-three children underwent invasive monitoring after placement of subdural grid electrodes, and in seven intraoperative electrocorticography alone was performed. The mean follow-up period for the group was 3.5 years (minimum 30 months in all cases). All 20 patients in whom MSTs were performed in the primary motor cortex experienced transient hemiparesis (mild in 12 and moderate in eight) lasting up to 6 weeks; however, no patient suffered a permanent motor deficit in the long-term follow-up period. In 26 patients who underwent cortical resections followed by MSTs, 12 (46%) were seizure free (Engel Class I) following surgery. Eleven patients (42%) (Engel Classes II and III) continued to suffer seizures but improvement in seizure control was adequate following surgery. In the 23 patients in whom subdural grids were placed to capture the ictal onset zone by invasive video-electroencephalography, MSTs comprised a mean of 37% of the surgically treated area under the grid.
Conclusions:
The results of this series demonstrate that MSTs can be performed with acceptable morbidity in children undergoing epilepsy surgery. The precise role of MSTs in controlling seizure frequency and outcome, especially when combined with planned cortical resections, awaits further study.
Insights
Multiple subpial transections (MSTs) are a safe epilepsy surgery technique for children. This study found MSTs acceptable for managing pediatric seizure disorders, with transient hemiparesis as the main adverse effect.
Area of Science:
- Neurosurgery
- Pediatric Epilepsy Surgery
- Epileptology
Background:
- Multiple subpial transections (MSTs) create disconnective lesions in eloquent cortex for epilepsy surgery.
- While established in adults, MSTs in pediatric epilepsy surgery are less reported.
- This study evaluates MSTs in a pediatric cohort for seizure disorder management.
Purpose of the Study:
- To assess the efficacy and safety of multiple subpial transections (MSTs) in children undergoing epilepsy surgery.
- To analyze neurological adverse effects and seizure outcomes following MSTs in pediatric patients.
- To determine the role of MSTs, particularly when combined with cortical resections.
Main Methods:
- Retrospective review of 30 consecutive children undergoing MSTs between 1996-2000, with or without cortical excision.
- Analysis included neurological adverse effects and seizure outcome (Engel Class I-III).
- Invasive monitoring (subdural grids or electrocorticography) was used in 23 and 7 patients, respectively.
Main Results:
- Transient hemiparesis occurred in all 20 patients with MSTs in the primary motor cortex, resolving within 6 weeks without permanent deficit.
- In patients with cortical resections and MSTs, 46% were seizure-free (Engel Class I) and 42% had adequate seizure control (Engel Classes II/III).
- MSTs constituted a mean of 37% of the surgically treated area under the grid in 23 patients.
Conclusions:
- Multiple subpial transections (MSTs) demonstrate acceptable morbidity in pediatric epilepsy surgery.
- MSTs can be a viable option for managing pediatric seizure disorders.
- Further research is needed to define the precise role of MSTs in seizure control, especially with concurrent cortical resections.
