Neural source estimation from a time-frequency component of somatic evoked high-frequency magnetic oscillations to posterior tibial nerve stimulation

• Published in: Clin Neurophysiol Vol. 110; no. 9; pp. 1585 - 1588
• Main Authors: Sakuma, Kenji, Sekihara, Kensuke, Hashimoto, Isao
• Format: Journal Article
• Language: English
• Published: Shannon Elsevier BV 01.09.1999; Elsevier Science
• Subjects: Adult; Biological and medical sciences; Brain Mapping; Electric Stimulation; Evoked Potentials, Somatosensory; Evoked Potentials, Somatosensory - physiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Magnetoencephalography; Male; Somesthesis and somesthetic pathways (proprioception, exteroception, nociception); interoception; electrolocation. Sensory receptors; Tibial Nerve; Tibial Nerve - physiology; Vertebrates: nervous system and sense organs; Human; Current source; Tibial nerve; Magnetoencephalography; Electrical stimulus; Central nervous system; Electrophysiology; Algorithm; Somatosensory cortex; Somesthetic pathway; Topography; Oscillation; Somatosensory evoked potential; Magnetic field; Brain (vertebrata)
• ISSN: 1388-2457
• DOI: 10.1016/s1388-2457(99)00120-0

High frequency oscillations (HFOs) evoked by posterior tibial nerve stimulation were recorded using magnetoencephalography (MEG). Time-frequency domain multiple signal classification (TF-MUSIC) algorithm was applied, and the usefulness of this method was demonstrated. Ten normal subjects were studied. To localize sources for the HFOs of those somatosensory evoked fields, we applied two kinds of methods: the single moving dipole (SMD) method and the TF-MUSIC method. The SMD method was applied after digitally band-pass filtering the somatosensory response with a bandwidth of 500-800 Hz. To estimate the locations of sources with the TF-MUSIC algorithm, we first set the target region on the spectrogram of the somatosensory responses. Then, the procedure described in Section 2.2 was applied with this target region. A clear, isolated region was detected in 6 out of 10 subjects using a time-frequency spectrogram. The averaged distance of the dipole sources between the HFOs and the underlying P37m using the TF-MUSIC algorithm was smaller than using the SMD method. The TF-MUSIC algorithm is suitable for extracting a target response whose spectrum changes significantly during the observation.