Brain tumor surgery guided by navigated transcranial magnetic stimulation mapping for arithmetic calculation

Area of Science:

• Neuroscience
• Neurosurgery
• Cognitive Science

Background:

• The onco-functional balance is critical in neuro-oncology.
• Navigated transcranial magnetic stimulation (nTMS) is validated for motor and language mapping.
• Calculation and arithmetic processing mapping using nTMS remains unexplored.

Purpose of the Study:

• To present preliminary data on the use of nTMS for mapping calculation and arithmetic processing.
• To evaluate the feasibility and clinical outcomes of nTMS in preoperative planning for neurosurgical patients.

Main Methods:

• A monocentric prospective study was conducted using nTMS for preoperative planning of arithmetic processing.
• nTMS points guided direct cortical stimulation (DCS) in awake surgery cases.
• Navigated TMS-based tractography was employed for surgical planning, with statistical analysis of nTMS and DCS points.

Main Results:

• 61 nTMS calculation mapping procedures were performed with 92.8% of patients showing preserved or recovered arithmetic function at 3 months.
• Postoperative clinical results were comparable between awake and asleep surgery groups.
• nTMS identified key white matter tracts involved in calculation, including the arcuate fasciculus and frontal aslant tract.

Conclusions:

• nTMS is a feasible and advantageous tool for mapping cognitive functions, including calculation, to minimize neurological impairment.
• Postoperative outcomes were very good for patients undergoing surgery with nTMS-guided planning.
• Further research is warranted to validate these findings and explore other cognitive functions with nTMS.