title: Capturing Pain in the Cortex during General Anesthesia: Near Infrared Spectroscopy Measures in Patients Undergoing Catheter Ablation of Arrhythmias.
abstract: The predictability of pain makes surgery an ideal model for the study of pain and the development of strategies for analgesia and reduction of perioperative pain. As functional near-infrared spectroscopy reproduces the known functional magnetic resonance imaging activations in response to a painful stimulus, we evaluated the feasibility of functional near-infrared spectroscopy to measure cortical responses to noxious stimulation during general anesthesia. A multichannel continuous wave near-infrared imager was used to measure somatosensory and frontal cortical activation in patients undergoing catheter ablation of arrhythmias under general anesthesia. Anesthetic technique was standardized and intraoperative NIRS signals recorded continuously with markers placed in the data set for the timing and duration of each cardiac ablation event. Frontal cortical signals only were suitable for analysis in five of eight patients studied (mean age 14 ± 1 years, weight 66.7 ± 17.6 kg, 2 males). Thirty ablative lesions were recorded for the five patients. Radiofrequency or cryoablation was temporally associated with a hemodynamic response function in the frontal cortex characterized by a significant decrease in oxyhemoglobin concentration (paired t-test, p<0.05) with the nadir occurring in the period 4 to 6 seconds after application of the ablative lesion. Cortical signals produced by catheter ablation of arrhythmias in patients under general anesthesia mirrored those seen with noxious stimulation in awake, healthy volunteers, during sedation for colonoscopy, and functional Magnetic Resonance Imaging activations in response to pain. This study demonstrates the feasibility and potential utility of functional near-infrared spectroscopy as an objective measure of cortical activation under general anesthesia.
authors.affiliation: Center for Pain and the Brain, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Barry D
authors.initials: BD
authors.lastname: Kussman
authors.affiliation: Center for Pain and the Brain, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Aasted
authors.affiliation: Department of Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Meryem A
authors.initials: MA
authors.lastname: Yücel
authors.affiliation: Center for Pain and the Brain, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Steele
authors.affiliation: Department of Cardiology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Mark E
authors.initials: ME
authors.lastname: Alexander
authors.affiliation: Department of Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: David A
authors.initials: DA
authors.lastname: Boas
authors.affiliation: Center for Pain and the Brain, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: David
authors.initials: D
authors.lastname: Borsook
authors.affiliation: Center for Pain and the Brain, Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Anesthesiology, Perioperative and Pain Medicine, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.|Department of Radiology, Martinos Center for Biomedical Imaging, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Lino
authors.initials: L
authors.lastname: Becerra
mesh_terms: D000293:Adolescent; D000768:Anesthesia, General / Q000379:methods; D001145:Arrhythmias, Cardiac / Q000601:surgery*; D017115:Catheter Ablation / Q000379:methods; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002648:Child; D005260:Female; D059907:Functional Neuroimaging / Q000379:methods; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D010146:Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology; D019265:Spectroscopy, Near-Infrared