Abstracts

Multiple subpial transection (MST) has been considered a treatment option since 1989 for refractory partial seizures involving eloquent cortex, but there is very little published experience in children. We assessed our experience with MST in a childhood population with developmentally-based seizures
From a total of 324 surgeries between 1992 and 2002 we identified 13 children aged 1.9 to 17.7 years (mean=8.1 years) who underwent MST for intractable seizures related to a developmental substrate confirmed by neuroimaging or histopathogy. Preoperative MR imaging revealed tuberous sclerosis (n=1), and developmental tumor (n=2). Seizure outcome was assessed according to Engel[rsquo]s classification. Post surgical deficits were recorded as mild or severe based on parental interview and physical examination.
Four children underwent MST alone Of these, seizures in 3 patients were unchanged; the fourth experienced a 50% reduction of seizures and became seizure free 11 months later following a change of medication. Nine children had MSTs combined with resection. Seizures in 5 children were unchanged 2 had 50% reduction and 2 had 90% reduction. None were seizure free. MSTs were performed over language cortex only in 2 children, over sensorimotor cortex in 9, and over both regions in 2. None had new language deficits. Motor status was unchanged in 8 children, mild transient paresis occurred in 1 and permanent severe hemiparesis in 1. MRI scan in the hemiparetic patient revealed encephalomalacia in the MST region. Histopathology showed cortical dysplasia in 10 (gr I=7, gr II=2, gr III=1),DNET in 1; no specimen was available in 2. Four children needed a second resective procedure and are now seizure free
Multiple subpial transection is a palliative intervention for medically resistant partial seizures caused by developmental lesions presenting in early childhood. The poor seizure control and higher rates of functional sequelae may be related to the underlying disorganized cytoarchitectural substrate