Presurgical identification of the primary sensorimotor cortex by functional magnetic resonance imaging

Abstract

The ability of functional magnetic resonance (MR) imaging to detect a selective sensorimotor cortex activation in healthy subjects and the feasibility of motor activation in patients with lesions around the central sulcus were investigated. Twenty-five healthy volunteers performed 100 motor activation trials, using a variety of motor tasks, which were monitored by several image analysis methods. The functional images were obtained using a 1.5-tesla standard MR imaging system magnet with blood oxygenation level-dependent contrast. Four patients were assessed using functional MR imaging and invasive cortical mapping. Rolandic cortex activation was observed in 98% of the trials performed on healthy subjects in which no head motion occurred. Nevertheless, the cortical response was not selective in a task-rest analysis due to concurrent activation of neighboring regions. Across-task comparison analyses were useful in cancelling nonrelevant activity in most cases (86%). In the patient group, the region identified as the sensorimotor cortex by invasive means corresponded accurately to the area that was activated in functional MR imaging. Present data support the feasibility of detecting selective activation of the rolandic cortex, even in the clinical setting, leading the authors to suggest the usefulness of this widely available technique in surgical planning.

Rater-dependent accuracy in predicting the spatial location of functional centers on anatomical MR images

“…Functional Magnetic Resonance Imaging (fMRI) is being used as a means to localize eloquent cortex in patients with brain tumors and other lesions [1][2][3][4][5][6][7][8][9][10][11][12][13]. The results of this study strengthen the rationale for using fMRI as an additional modality for planning neurosurgical procedures.…”

“…Functional MRI is being used increasingly for applications such as surgical planning [1][2][3][4][5][6][7][8][9][10][11][12][13]. Typically, susceptibility-weighted echo-planar imaging (EPI) is used to rapidly acquire a time series of whole-brain images while the patient performs specific tasks designed to activate relevant cortical areas.…”

Relationship between the coronal suture and the central lobe: how important is it and how can we use it in surgical planning?

“…so, although these measurements give the neurosurgeon an idea about the localization of the central sulcus, the use of other tools becomes necessary in the surgical planning. For such cases the use of functional magnetic resonance (fMrI) and/or electrophysiological studies [10][11][12][13][14] or awake craniotomy are recommended 15 . It is very important to remember that the central lobe must be manipulated carefully, avoiding excessive and unnecessary traction of the structures according to the principles of yasargil 16 .…”

Incorporating Functional MR Imaging into Diffusion Tensor Tractography in the Preoperative Assessment of the Corticospinal Tract in Patients with Brain Tumors

“…20,22 With fMRI, the PMAs are accurately identified, [3][4][5] and this information allows reliable region-of-interest placement in the hand and foot PMAs within the precentral gyrus. The possibility of distinguishing the hand and foot fibers within the CST is not only relevant in the preoperative assessment of patients with brain tumors but could also be extended to other clinical situations, for example, for planning functional neurosurgery in patients with Parkinson disease and related disorders.…”

“…[1][2][3] The site of activation on BOLD-fMRI has been proved to correlate well with the site at which intraoperative cortical stimulation identifies the PMA. [3][4][5] Therefore, fMRI information is used increasingly by neurosurgeons to plan their surgical procedures to maximize resection of tumor tissue while preserving eloquent brain areas. 6,7 However, neither fMRI nor anatomic MR images provide information on the (invisible) course of the important subcortical and deep white matter tracts, such as the corticospinal tract (CST).…”