The neurosurgeon of the Ruber Internacional Hospital Jesús Martín-Fernández has designed a multimodal cognitive mapping model in three phases for awake brain surgery, which makes it possible to modify the surgical procedure according to the functional response of the brain during the operation and, in this way, safeguard not only language or mobility but also more complex cognitive functions.
"Our goal is no longer just for the patient to be able to speak or move a hand after surgery. We want to preserve what allows them to continue recognizing people, understanding the emotions of others, maintaining their relationships, and preserving their life project," explained Martín-Fernández, president of the World Society of Awake Brain Mapping.
In this "innovative" cognitive mapping approach, the patient carries out cognitive tasks during the intervention. As reported by the Ruber Internacional Hospital, Marcel, 32 years old, looked at a tablet with a series of faces and indicated the emotions they displayed while a brain tumor was being removed from the right precuneus, one of the most complex areas of the human brain.
His responses allowed Dr. Jesús Martín-Fernández to locate in real time the brain networks that are essential to preserve in order to maintain abilities such as social cognition, autobiographical memory, self-referential processing, or emotional recognition.
"The brain is functionally changing while we operate. It is not enough to make a map at the beginning of the intervention; we need to continuously update it. Our model turns mapping into a dynamic process that evolves as the brain evolves," the specialist pointed out.
A procedure in three phases and customized surgeries
As he specified, the protocol is structured in three stages: the localization of critical points of the brain networks through direct electrical stimulation; the continuous monitoring of different cognitive functions during resection with tasks tailored to each case; and the determination of the "connectome-stop points," that is, the deep functional limits that mark the moment when tumor resection must cease to prevent the disconnection of essential circuits.
Each surgery is planned in a personalized way, so that the patient performs certain tasks depending on the position of the tumor, the involved networks, and the capabilities that are key to their daily life, whether it be language, memory, attention, executive functions, or emotion recognition.
This approach allows for adapting intraoperative decisions to achieve the greatest possible resection of the tumor without compromising the functional profile of each person.
"Each brain is organized differently and each patient has different priorities. For some, it will be essential to preserve language; for others, to recognize the emotions of their loved ones or to maintain the necessary capabilities to continue practicing their profession. That is true personalized medicine applied to neurosurgery," highlighted Martín-Fernández.
In addition to Marcel's operation, that same day the team operated on a 60-year-old woman, who had been under follow-up for more than ten years for a tumor located in a critical area for language and whose resection had been delayed due to the high risk of leaving irreversible functional sequelae.
Thanks to the three-step multimodal cognitive mapping, it was possible to continuously monitor not only language but also other cognitive functions potentially affected by the location and connections of the tumor, which allowed for real-time adjustments to the surgery and maximized resection while maintaining the patient's functional profile.