Effect of brain surgery on auditory and motor cortex activation: a preliminary functional magnetic resonance imaging study.
OBJECTIVE
The effect of glioma removal on blood oxygen level-dependent (BOLD) functional magnetic resonance imaging (fMRI) activation has not been widely documented. The aim of this preliminary study was to observe the effect of tumor resection on BOLD fMRI of the auditory and motor cortices.


METHODS
Seven patients with gliomas underwent preoperative and early postoperative BOLD fMRI, and five of them underwent additional late postoperative BOLD fMRI. The auditory and motor cortices were localized with activation studies. A hemispheric activation index was used to quantify the relative extent of BOLD activation.


RESULTS
The resection of a glioma with preoperative edema resulted in an increase from the preoperative to the early postoperative fMRI on auditory BOLD activation on the side of the tumor compared with the contralateral side. The same phenomenon was observed in one patient with motor BOLD activation. However, when no preoperative edema was present, a transient decrease in relative auditory BOLD activation was found.


CONCLUSIONS
The results of this study suggest that the resection of a glioma with preoperative edema affecting the auditory and/or motor cortex may cause a transient increase in the BOLD response ipsilateral to the tumor. It seems that when the tumor is resected, the pressure on the brain, specifically on the affected auditory and/or motor cortex, decreases and the functional cortex becomes more easily detectable in BOLD fMRI.
Kokkonen
Salla-Maarit
SM
Department of Diagnostic Radiology, Oulu University Hospital, Oulu, Finland. salla-maarit.kokkonen@ppshp.fi
Kiviniemi
Vesa
V
Mäkiranta
Minna
M
Yrjänä
Sanna
S
Koivukangas
John
J
Tervonen
Osmo
O
D000293:Adolescent; D000328:Adult; D000368:Aged; D001303:Auditory Cortex / Q000098:blood supply*; D001932:Brain Neoplasms / Q000473:pathology / Q000601:surgery*; D005260:Female; D005910:Glioma / Q000473:pathology / Q000601:surgery*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000098:blood supply*; D019635:Neurosurgical Procedures / Q000379:methods*; D010100:Oxygen / Q000097:blood; D012189:Retrospective Studies; D013997:Time Factors; D016896:Treatment Outcome
D010100:Oxygen