Intraoperative brain mapping

What it is

Intraoperative brain mapping is a technique used during surgery to identify critical functional areas of the brain — such as those controlling movement, language, or sensation — by stimulating the brain and observing the effects. This guides the surgeon to remove tumor while protecting those essential areas.

Understanding Intraoperative brain mapping

During surgery, the surgeon can apply a small electrical current to areas of the brain (or nearby pathways) and observe what happens: stimulating a motor area may cause a muscle to move, while stimulating a language area may temporarily interrupt speech. By mapping these responses, the team identifies which areas are functionally critical and must be preserved, and which can be safely removed. This is often done during an awake craniotomy (for language and other functions requiring the patient's participation) but can also be done under anesthesia for some functions (such as motor mapping with monitoring). Brain mapping provides direct, real-time, patient-specific information about function — more precise than imaging alone — enabling the surgeon to maximize safe tumor removal. It is a key tool for operating near eloquent areas. Understanding intraoperative brain mapping clarifies how identifying critical areas during surgery protects function.

Why it matters

Understanding intraoperative brain mapping helps patients and families see how the surgical team identifies critical areas during surgery — directly testing functions to remove tumor safely while protecting abilities like movement and language.