Preoperative Magnetoencephalographic Sensory Cortex Mapping

Abstract

The use of functional neuroimaging holds the promise of improving neurosurgical outcomes by providing preoperative localization of critical brain functions. The brain representation of somatosensory function can be effectively localized using magnetoencephalography (MEG) in both normal subjects and in patients with tumors, vascular malformation, and epilepsy. This study investigates the pattern of somatosensory localization in 45 patients. Thirty-two of these patients underwent subsequent resective surgery for brain pathologies. Electrical stimulation of the median nerve was conducted, and the most prominent somatosensory peak in the resultant averaged data was localized using the single equivalent current dipole technique. Results showed that this peak localized either to the central or postcentral sulcus of the somatosensory cortex. We found that neither age nor the presence of brain pathologies had significant effect on the recognition of the somatosensory cortex. Patients who underwent surgery after presurgical planning using MEG suffered no new somatosensory deficits, indicating the valuable role of pre-surgical mapping using MEG in the surgical planning.

High Frequency Neuromagnetic Signals: A New Biomarker for Localizing Epileptic Areas Running Title: High-Frequency Neuromagnetic Signals in Epilepsy

“…Ideally, non-invasive MEG will replace invasive ECoG [18][19][20][21], but proof of its reliability is still lacking [22]. Recent success in localizing high-frequency brain signals (HFBS, 70-2,500 Hz) using MEG opens a new window for reliably localizing ictogenic zones [16,[23][24][25][26][27].…”

High Frequency Neuromagnetic Signals: A New Biomarker for Localizing Epileptic Areas Running Title: High-Frequency Neuromagnetic Signals in Epilepsy

“…Ideally, non-invasive MEG will replace invasive ECoG [18][19][20][21], but proof of its reliability is still lacking [22]. Recent success in localizing high-frequency brain signals (HFBS, 70-2,500 Hz) using MEG opens a new window for reliably localizing ictogenic zones [16,[23][24][25][26][27].…”

Transformer-Based High-Frequency Oscillation Signal Detection on Magnetoencephalography From Epileptic Patients

“…A favorable surgical outcome depends on many factors, one of which is the accurate identification of epileptogenic zones (Rosenow and Lüders, 2001). Magnetoencephalography (MEG) is a non-invasive technology for pre-operative workup prior to epilepsy surgery (Xiang et al, 2009), which help clinicians localize epileptogenic zones (Rampp et al, 2010;Niranjan et al, 2013). Recently, several studies showed that high-frequency oscillations (HFOs), which can be observed within 80-500 Hz of MEG data, are putative biomarkers to locate the epileptogenic tissue.…”