Selective Stimulus Intensity during Hotspot Search Ensures Faster and More Accurate Preoperative Motor Mapping with...

Area of Science:

• Neurosurgery
• Neurophysiology
• Medical Technology

Background:

• Navigated transcranial magnetic stimulation (nTMS) is an innovative neurosurgical technique.
• Accurate execution of nTMS motor mapping is crucial but often variable.
• Stimulation intensity (SI) selection significantly impacts map activation and reliability.

Purpose of the Study:

• To evaluate the impact of a selective SI selection method on nTMS motor mapping accuracy and efficiency.
• To compare a proposed method of SI selection with a random method.
• To reduce inaccurate responses and time expenditure in nTMS motor mapping.

Main Methods:

• Retrospective analysis of nTMS motor mappings from March 2020 to July 2022.
• Comparison of two groups: random SI selection (Group A, 16 patients) and selective SI selection (Group B, 15 patients).
• Collected parameters included MEPs, TPs, FPs, and mapping time.

Main Results:

• Statistically significant reductions in total stimuli, procedural time, and false positives (FPs) were observed with the selective SI method.
• Significant increases in true positives (TPs), ratio of TPs to total stimuli, and ratio of TPs to valid MEPs were noted.
• Consistent trends of increased TPs and decreased FPs were found across subgroups.

Conclusions:

• Precise SI selection in nTMS motor mapping yields reliable cortical maps efficiently.
• This method enhances the functional eloquence of mapped cortical points.
• The approach improves mapping intuitiveness, particularly for centers with less neurophysiology expertise.