Intraoperative electrocorticography in epilepsy surgery: useful or not?

Area of Science:

• Neurosurgery
• Epileptology
• Neurophysiology

Background:

• Intraoperative electrocorticography (ECoG) is a long-standing technique in epilepsy surgery.
• Its precise indications and limitations in clinical practice remain subjects of ongoing investigation.

Purpose of the Study:

• To elucidate the specific roles and boundaries of ECoG in managing medically refractory partial epilepsies.
• To evaluate ECoG's effectiveness in guiding surgical resection and assessing its completeness.

Main Methods:

• ECoG application in various epilepsy surgeries, including temporal lobectomies and resections for brain malformations.
• Correlation of intraoperative ECoG findings with postoperative seizure recurrence and neurological outcomes.

Main Results:

• ECoG is vital for tailored temporal lobectomies and resections of cortical dysplasias.
• ECoG offers limited value in standard medial temporal lobe epilepsy resections with MRI-defined mesial temporal sclerosis.
• Residual hippocampal spikes on ECoG predict seizure recurrence, while its use can help spare functionally critical hippocampus.

Conclusions:

• ECoG is indispensable for resecting highly epileptogenic lesions like cortical dysplasias and guiding tailored resections.
• ECoG's role is nuanced, being essential in some epilepsy surgeries but not others, influencing surgical strategy and patient outcomes.
• Intraoperative ECoG can aid in preserving hippocampal function, potentially mitigating memory deficits.