Frontal Eye Field in the Precentral Sulcus: A Direct Electrical Cortical Stimulation Study With Stereo-EEG...

Area of Science:

• Neuroscience
• Epileptology
• Neurosurgery

Background:

• Understanding eye movements (EMs) induced by brain stimulation is crucial for mapping cortical functions.
• The precentral sulcus (PrCS) is implicated in motor control, but its role in generating EMs requires further elucidation.
• Investigating the influence of the epileptogenic zone on stimulation-induced EMs can refine surgical targeting.

Purpose of the Study:

• To map stimulation-induced eye movements (EMs) from different regions of the precentral sulcus (PrCS).
• To determine if the location of the seizure onset zone (SOZ) affects the occurrence and characteristics of EMs.
• To identify factors correlating with positive EMs during direct electrical stimulation.

Main Methods:

• Analysis of high-frequency direct electrical stimulation mapping data from SEEG explorations in epilepsy patients.
• Statistical analysis of patient demographics, EMs effects, seizure characteristics, and stimulation parameters.
• Multivariate regression to identify predictors of positive EMs.

Main Results:

• Out of 778 contacts in 77 patients, 18 (23.4%) showed induced EMs in the PrCS.
• The superior PrCS (SP) yielded more positive EMs than the inferior PrCS (IP) (60.3% vs. 39.7%, p=0.017).
• Positive EMs were significantly correlated with the SOZ being located within the PrCS (p=0.004), independent of other factors.

Conclusions:

• Eye deviation is the predominant EMs response to PrCS stimulation.
• The SP is a more sensitive area for eliciting EMs compared to the IP.
• The likelihood of inducing EMs is associated with the PrCS being part of the SOZ.