title: Hemodynamic and electrophysiological connectivity in the language system: simultaneous near-infrared spectroscopy and electrocorticography recordings during cortical stimulation.
abstract: We applied near-infrared spectroscopy (NIRS) and electrocorticography (ECoG) recordings during cortical stimulation to a temporal lobe epilepsy patient who underwent subdural electrode implantation. Using NIRS, changes in blood concentrations of oxyhemoglobin (HbO(2)) and deoxyhemoglobin (HbR) during cortical stimulation of the left language areas were measured in each hemisphere. NIRS revealed that 2 Hz stimulation with 5 mA produced no significant hemodynamic changes in either hemisphere. By contrast, 50 Hz stimulation elicited significant increases in both HbO(2) and HbR at the stimulation site. Furthermore, with 50 Hz stimulation of the left superior temporal gyrus, the increases in HbO(2) and HbR were observed not only at the stimulation site but also concurrently at the left inferior frontal gyrus. This suggests the existence of functional connectivity in the language system. The present study demonstrates that simultaneous NIRS and ECoG studies during cortical stimulation allow a novel analysis of cerebral connectivity.
authors.affiliation: Department of Neurosurgery, Brain Research Institute, Niigata University, Japan. yosuke@bri.niigata-u.ac.jp
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Sato
authors.forename: Makoto
authors.initials: M
authors.lastname: Oishi
authors.forename: Masafumi
authors.initials: M
authors.lastname: Fukuda
authors.forename: Yukihiko
authors.initials: Y
authors.lastname: Fujii
mesh_terms: D000293:Adolescent; D038481:Anterior Temporal Lobectomy; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000098:blood supply* / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology; D004558:Electric Stimulation; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000503:physiopathology* / Q000601:surgery*; D006439:Hemodynamics / Q000502:physiology*; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D021621:Imaging, Three-Dimensional; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology; D010108:Oxyhemoglobins / Q000378:metabolism; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011300:Preoperative Care; D012815:Signal Processing, Computer-Assisted; D019265:Spectroscopy, Near-Infrared; D013060:Speech / Q000502:physiology*
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin