Intraoperative identification of the central sulcus: a practical method

Area of Science:

• Neurosurgery
• Neurophysiology

Background:

• Intraoperative identification of the central sulcus is crucial for neurosurgical procedures in the peri-rolandic area.
• Accurate localization prevents damage to motor pathways, reducing postoperative neurological deficits.

Purpose of the Study:

• To introduce and evaluate a practical method for intraoperative central sulcus identification using cortical evoked potentials (EP).
• To assess the efficacy of this technique in patients with peri-rolandic lesions, particularly tumors.

Main Methods:

• Stimulation of median, trigeminal, and tibial nerves to achieve wide coverage of the rolandic fissure.
• Monitoring for phase-reversal of cortical evoked potentials (EP) across the central sulcus.
• Investigated 18 adult patients with peri-rolandic lesions.

Main Results:

• Successfully identified the central sulcus in 13 out of 18 patients using the phase-reversal phenomenon.
• Cortical EP were not detected in 3 patients with significant hemiplegia/aphasia.
• In 2 cases, EP were obtained but without phase-reversal.
• Enabled aggressive tumor removal without severe motor dysfunction in most cases.

Conclusions:

• The proposed method using multi-nerve stimulation and EP phase-reversal is effective for intraoperative central sulcus identification.
• This technique facilitates safe and aggressive resection of peri-rolandic tumors, preserving motor function.