Clinical Scorecard: Awake Tumor Resection Utilizing Direct Electrical Stimulation Mapping and Real-Time Cognitive Assessment: Our Approach

At a Glance

Key Highlights

• Awake surgery with DES is the gold standard for DLGG, improving onco-functional outcomes with <2% permanent deficits and ~94% return-to-work rates.
• Preoperative cognitive and language assessments tailor intraoperative tasks to patient-specific profiles and tumor topography.
• Intraoperative cortical mapping is performed with calibrated stimulation intensities, real-time cognitive testing, and functional site tagging to maximize tumor resection while preserving function.

Guideline-Based Recommendations

Diagnosis

• Perform comprehensive preoperative cognitive and language assessments by specialized speech therapists or neuropsychologists to establish baseline and select intraoperative tasks.

Management

• Use an asleep–awake–asleep protocol with lateral decubitus positioning contralateral to tumor and head secured in a three-pin clamp.
• Avoid preoperative sedatives and optimize antiseizure medication to reduce intraoperative risk.
• Induce general anesthesia with laryngeal mask airway to preserve vocal cord integrity.
• Perform cortical mapping after awakening using DES starting at 1 mA, increasing by 0.5 mA increments up to 5 mA, calibrating at ventral premotor cortex.
• Limit coagulation to pial surface and preserve vessels supplying eloquent cortex.

Monitoring & Follow-up

• Conduct continuous real-time cognitive and language testing by blinded neuropsychologists or speech therapists during stimulation.
• Monitor for seizures and have cold sterile saline ready for immediate cortical application.

Risks

• Risk of intraoperative seizures mitigated by stimulation intensity limits and antiseizure medication optimization.
• Potential brain swelling managed by discontinuing anesthesia before dural opening.
• Avoid pressure points during positioning to maintain patient cooperation.

Patient & Prescribing Data

Patients undergoing awake craniotomy for supratentorial brain tumors, primarily diffuse low-grade gliomas

Tailored cognitive tasks and real-time functional mapping enable maximal safe tumor resection with high preservation of cognitive and motor functions, supporting long-term survival and quality of life.

Clinical Best Practices

• Preoperative cognitive and language baseline assessment to personalize intraoperative testing.
• Avoid sedatives preoperatively and optimize antiseizure drugs to minimize intraoperative complications.
• Use lateral decubitus positioning with free contralateral upper limb to facilitate monitoring.
• Employ laryngeal mask airway instead of endotracheal tube to protect vocal cords.
• Calibrate DES stimulation intensity at ventral premotor cortex to induce speech arrest without motor side effects.
• Blinded neuropsychological evaluation during stimulation to reduce bias.
• Tag functional cortical sites intraoperatively to guide resection boundaries.
• Limit coagulation to pial surface and preserve vascular supply to eloquent cortex.

References

• Development of DES for epilepsy and brain tumor resection
• Onco-functional outcomes and survival data
• Anatomo-functional considerations and compensation capacity
• Patient-centered cognitive task tailoring
• Use of laryngeal mask to avoid vocal cord damage