title: Evoked-cerebral blood oxygenation changes in false-negative activations in BOLD contrast functional MRI of patients with brain tumors.
abstract: Blood oxygenation level dependent contrast functional MRI (BOLD-fMRI) has been used to define the functional cortices of the brain in preoperative planning for tumor removal. However, some studies have demonstrated false-negative activations in such patients. We compared the evoked-cerebral blood oxygenation (CBO) changes measured by near-infrared spectroscopy (NIRS) and activation mapping of BOLD-fMRI in 12 patients with brain tumors who had no paresis of the upper extremities. On the nonlesion side, NIRS demonstrated a decrease in deoxyhemoglobin (Deoxy-Hb) with increases in oxyhemoglobin (Oxy-Hb) and total hemoglobin (Total-Hb) during a contralateral hand grasping task in the primary sensorimotor cortex (PSMC) of all patients. On the lesion side, NIRS revealed a decrease in Deoxy-Hb in five patients (Deoxy-decrease group), and an increase in Deoxy-Hb in seven patients (Deoxy-increase group); the Oxy-Hb and Total-Hb were increased during activation in both groups, indicating the occurrence of rCBF increases in response to neuronal activation. BOLD-fMRI demonstrated clear activation areas in the PSMC on the nonlesion side of all patients and on the lesion side of the Deoxy-decrease group. However, in the Deoxy-increase group, BOLD-fMRI revealed only a small activation area or no activation on the lesion side. Intraoperative brain mapping identified the PSMC on the lesion side that was not demonstrated by BOLD-fMRI. The false-negative activations might have been caused by the atypical evoked-CBO changes (i.e. increases in Deoxy-Hb) and the software employed to calculate the activation maps, which does not regard an increase of Deoxy-Hb (i.e., a decrease in BOLD-fMRI signal) as neuronal activation.
authors.affiliation: Department of Neurosurgery, Nihon University School of Medicine, Tokyo, Japan.
authors.forename: Norio
authors.initials: N
authors.lastname: Fujiwara
authors.forename: Kaoru
authors.initials: K
authors.lastname: Sakatani
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Katayama
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Murata
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Hoshino
authors.forename: Chikashi
authors.initials: C
authors.lastname: Fukaya
authors.forename: Takamitsu
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D000328:Adult; D000368:Aged; D001931:Brain Mapping; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D002540:Cerebral Cortex / Q000503:physiopathology* / Q000601:surgery; D004292:Dominance, Cerebral / Q000502:physiology*; D004558:Electric Stimulation; D004569:Electroencephalography; D005188:False Negative Reactions; D005260:Female; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D007089:Image Enhancement; D007090:Image Interpretation, Computer-Assisted; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009044:Motor Cortex / Q000503:physiopathology / Q000601:surgery; D010100:Oxygen / Q000097:blood*; D010108:Oxyhemoglobins / Q000378:metabolism; D011712:Pyramidal Tracts / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology; D012984:Software; D013003:Somatosensory Cortex / Q000503:physiopathology / Q000601:surgery; D019265:Spectroscopy, Near-Infrared
chemical_list: D006454:Hemoglobins; D010108:Oxyhemoglobins; C100003:deoxyhemoglobin; D010100:Oxygen