title: Imaging of somatotopic representation of sensory cortex with intrinsic optical signals as guides for brain tumor surgery.
abstract: OBJECTIVE
  Intrinsic optical signals in response to somatosensory stimuli were intraoperatively recorded during brain tumor surgery. In the present study, the authors report on the use of this technique as an intraoperative guide for the safe resection of tumors adjacent to or within the sensorimotor cortex.
  
  
  METHODS
  In 14 patients with tumors adjacent to or within the sensorimotor cortex, intrinsic optical signals in response to somatosensory stimuli were recorded by illuminating the brain surface with Xe white light and imaging the reflected light passing through a bandpass filter (605 nm). Results were compared with intraoperative recordings of sensory evoked potentials in all 14 patients and with noninvasive mapping modalities such as magnetoencephalography and positron emission tomography in selected patients. In all but two patients, the somatosensory optical signals were recorded on the primary sensory cortex. Optical signals elicited by stimulation of the first and fifth digits and the three branches of the trigeminal nerve were recorded at different locations on the sensory strip. This somatotopic information was useful in determining the resection border in patients with glioma located in the sensorimotor cortex.
  
  
  CONCLUSIONS
  Optical imaging of intrinsic signals is a useful technique with superior spatial resolution for delineating the somatotopic representation of human primary sensory cortex. Furthermore, it can be used as an intraoperative monitoring tool to improve the safety and accuracy of resections of brain tumors adjacent to or within the sensorimotor cortex.
authors.affiliation: Department of Neurosurgery and Physiology, Tokyo Medical and Dental University, Tokyo Metropolitan Institute of Gerontology, Tokyo, Japan. nariai.nsrg@tmd.ac.jp
authors.forename: Tadashi
authors.initials: T
authors.lastname: Nariai
authors.forename: Katsushige
authors.initials: K
authors.lastname: Sato
authors.forename: Kimiyoshi
authors.initials: K
authors.lastname: Hirakawa
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Ohta
authors.forename: Yoji
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kiichi
authors.initials: K
authors.lastname: Ishiwata
authors.forename: Kenji
authors.initials: K
authors.lastname: Ishii
authors.forename: Kohtaro
authors.initials: K
authors.lastname: Kamino
authors.forename: Kikuo
authors.initials: K
authors.lastname: Ohno
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000601:surgery*; D005260:Female; D005910:Glioma / Q000601:surgery*; D006801:Humans; D007432:Intraoperative Period; D015225:Magnetoencephalography; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods; D055095:Optics and Photonics; D049268:Positron-Emission Tomography; D013003:Somatosensory Cortex / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery*