Using electrocorticography for presurgical language mapping in epilepsy patients.

Area of Science:

• Neuroscience
• Neurosurgery
• Epileptology

Background:

• Preoperative functional cortical mapping is crucial for epilepsy surgery.
• Electrical cortical stimulation (ECS) and electrocorticography (ECoG) are methods used for this mapping.
• The left posterior inferior frontal gyrus (LPIFG) is an area of interest for language function.

Purpose of the Study:

• To compare the efficacy of ECS and ECoG in mapping language and sensorimotor functions.
• To evaluate the utility of ECoG for detailed preoperative functional cortical mapping in epilepsy patients.

Main Methods:

• Five epilepsy patients with subdural electrodes underwent ECS and ECoG recordings during language production tasks.
• Data analysis focused on event-related cortical high gamma activities identified by ECoG.
• Activation patterns were correlated with auditory, visual, and sensorimotor functions.

Main Results:

• ECS on the LPIFG did not elicit language production symptoms in the studied patients.
• ECoG identified several cortical sites with high gamma activity linked to specific functions.
• ECoG-identified sensorimotor sites showed high agreement with ECS findings, with ECoG revealing additional crucial sites in the LPIFG.

Conclusions:

• There is consistency between ECS and ECoG findings in functional cortical mapping.
• ECoG is a valuable tool for detailed preoperative functional cortical mapping in epilepsy surgery.
• ECoG can identify important functional sites, including those in the LPIFG, not detected by ECS.