Subdural grid arrays are used when seizure activity cannot be located by scalp recordings and when functional cortical mapping is required before surgery. Subdural cortical surface electrodes can be placed with low morbidity and can precisely identify seizure foci and eloquent areas of the brain.
For grid insertion, a large field is planned in order to permit adequate exposure of the cortical surface for the electrodes, as well as for the subsequent resection. A craniotomy is then performed in which a bone flap is removed from the skull, to access the brain. |
