title: Effect of local anesthesia on trigeminal somatosensory-evoked magnetic fields.
abstract: For objective neurophysiological evaluation of the function of the trigeminal system, magnetoencephalography- based TSEF (trigeminal somatosensory-evoked field) assessment would be valuable in providing spatial and temporal profiles of cortical responses. However, this necessitates knowledge of how TSEF varies with trigeminal nerve dysfunctions. We introduced a conduction block of the trigeminal nerve using local anesthesia (lidocaine) to temporally mimic nerve dysfunctions, and monitored TSEF changes. Following an electrical stimulation of the lower lip, a magnetic response with peak latency of approximately 20 ms was identified in all participants. Dipole for the peak was estimated on the post-central gyrus in the participant's own magnetic resonance image. After normalization to Montreal Neurological Institute (MNI) space and inter-participant data integration, the summary equivalent current dipole localization among participants remained in the post-central gyrus, suggesting validity of the use of MNI space. Partial anesthesia of the lower lip led to a loss of the waveform characteristics of TSEF for electrical stimulation to the trigeminal nerve. We verified that the 20-ms latency cortical response of TSEF components localized at the primary sensory cortex can serve as a robust neurofunctional marker of experimental trigeminal nerve dysfunction.
authors.affiliation: Department of Craniofacial Growth and Developmental Dentistry, Kanagawa Dental College, 82 Inaoka-cho, Yokosuka, Kanagawa 238-8580, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Otsuka
authors.forename: H
authors.initials: H
authors.lastname: Dan
authors.forename: I
authors.initials: I
authors.lastname: Dan
authors.forename: M
authors.initials: M
authors.lastname: Sase
authors.forename: T
authors.initials: T
authors.lastname: Sano
authors.forename: D
authors.initials: D
authors.lastname: Tsuzuki
authors.forename: A
authors.initials: A
authors.lastname: Fujita
authors.forename: K
authors.initials: K
authors.lastname: Sasaguri
authors.forename: N
authors.initials: N
authors.lastname: Okada
authors.forename: M
authors.initials: M
authors.lastname: Kusama
authors.forename: Y
authors.initials: Y
authors.lastname: Jinbu
authors.forename: E
authors.initials: E
authors.lastname: Watanabe
mesh_terms: D000328:Adult; D000766:Anesthesia, Dental / Q000379:methods; D000772:Anesthesia, Local / Q000379:methods; D000779:Anesthetics, Local / Q000494:pharmacology; D001931:Brain Mapping / Q000379:methods*; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000494:pharmacology; D008046:Lip / Q000294:innervation; D015225:Magnetoencephalography; D008297:Male; D008340:Mandibular Nerve / Q000187:drug effects / Q000502:physiology*; D009407:Nerve Block; D011930:Reaction Time / Q000187:drug effects; D012016:Reference Values; D013003:Somatosensory Cortex / Q000502:physiology*
chemical_list: D000779:Anesthetics, Local; D008012:Lidocaine