title: Evaluation of lip sensory disturbance using somatosensory evoked magnetic fields.
abstract: OBJECTIVE
  To evaluate lip sensory dysfunction in patients with inferior alveolar nerve injury by lip-stimulated somatosensory evoked fields (SEFs).
  
  
  METHODS
  SEFs were recorded following electrical lip stimulation in 6 patients with unilateral lip sensory disturbance and 10 healthy volunteers. Lip stimulation was applied non-invasively to each side of the lip with the same intensity using pin electrodes.
  
  
  RESULTS
  All healthy volunteers showed the earliest response clearly and consistently at around 25ms (P25m) and at least one of the following components, P45m, P60m, or P80m, over the contralateral hemisphere. The ranges of the peak latencies were 23-33, 42-50, 56-67, and 72-98ms for right-side stimulation and 23-34, 46-49, 52-68, and 71-90ms for left-side stimulation. Affected-side stimulation did not evoke P25m component in any patients, but invoked traceable responses in 5 patients whose latencies were 57, 89, 65, 53, and 54ms. Unaffected-side stimulation induced P25m in 2 patients at 27 and 25ms, but not in the other 4 patients.
  
  
  CONCLUSIONS
  The P25m component of lip SEFs can be an effective parameter to indicate lip sensory abnormality.
  
  
  CONCLUSIONS
  Lip sensory dysfunction can be objectively evaluated using magnetoencephalography.
authors.affiliation: Human Brain Research Center, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan; Department of Oral Physiology, Graduate School of Dental Medicine, Hokkaido University, Kita-ku, Sapporo 060-8586, Japan. Electronic address: maezawa@den.hokudai.ac.jp.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Maezawa
authors.affiliation: Human Brain Research Center, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Matsuhashi
authors.affiliation: Department of Oral and Maxillofacial Surgery, National Hospital Organization, Kyoto Medical Center, Fushimi-ku, Kyoto 612-8555, Japan.
authors.forename: Kazuya
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Human Brain Research Center, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Mima
authors.affiliation: Human Brain Research Center, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan; Department of Systems Neuroscience, School of Medicine, Sapporo Medical University, Chuo-ku, Sapporo 060-8556, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Nagamine
authors.affiliation: Human Brain Research Center, Graduate School of Medicine, Kyoto University, Sakyo-ku, Kyoto 606-8507, Japan.
authors.forename: Hidenao
authors.initials: H
authors.lastname: Fukuyama
mesh_terms: D000328:Adult; D004558:Electric Stimulation; D005073:Evoked Potentials, Somatosensory / Q000502:physiology*; D005260:Female; D006801:Humans; D008046:Lip / Q000294:innervation* / Q000503:physiopathology; D060526:Magnetic Fields; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D012678:Sensation Disorders / Q000175:diagnosis* / Q000503:physiopathology
keywords: Inferior alveolar nerve; MEG; Magnetoencephalography; Nerve injury; Sensory deficit; Somatosensory evoked fields