Preoperative fMRI, Tractography and Continuous Task during Awake Surgery for Maintenance of Motor Function Following Surgical Resection of Metastatic Tumor Spread to the Primary Motor Area

Abstract

The goal of the present study was to determine the efficacy of preoperative fMRI, tractography, and intraoperative continuous task during awake surgery in preserving postoperative motor function in patients undergoing resection of metastatic brain tumors in or near the primary motor area. Three patients with metastatic brain tumors in the primary motor area elected to undergo surgical treatment. Preoperative fMRI and tractography were performed, and various primary motor areas (e. g., hand, arm, face and leg) were identified and confirmed by cortical mapping or by the outcome of awake surgery. Cortical mapping and continuous appropriate task were performed during awake surgery. Preoperative fMRI and tractography correctly identified the primary motor area. In contrast, cortical mapping identified the gyrus of the primary motor area but was unable to identify specific primary motor areas, such as those for the hand or arm, which were compressed by the tumor. Tumor resection was terminated when any deterioration in continuous task performance was observed during awake surgery. Paresis was transient and resolved within one week in all cases. The combination of preoperative fMRI, tractography and continuous task during awake surgery helped to maintain motor function following surgical management of metastatic brain tumors of the primary motor cortex.

Selection of intraoperative tasks for awake mapping based on relationships between tumor location and functional networks

“…This is the reason why awake surgery is recommended for treatment of both superficial and deep tumors in the vicinity of pyramidal and thalamocortical path-ways, with the aim of testing movement very accurately (complex movement, fine movement, movement arrest, somatosensory feedback, and so forth), and not only to avoid hemiplegia. 20,37,39,57,130,133,155 Optic radiations are part of the posterior thalamic projection system and run to the primary visual cortexsuperiorly within the parietal lobe, coursing posteriorly, and inferiorly coursing anteriorly around the temporal horn of the lateral ventricle before turning posteriorly (the Meyer loop). Optic radiations maintain a retinotopic organization along their route, allowing for the application of an intraoperative modified naming task with 2 pictures presented in opposite quadrants in a computer screen (see above).…”

“…20,37,39,57,130,133,155 In the same vein, a complete hemianopia may have a serious negative impact on a patient's quality of life, affecting activities of daily living, especially because in most developed countries individuals with this condition are not allowed to drive. Mapping the visual pathways is possible using awake EBM procedures for tumors involving the temporooccipital junction, by eliciting both visual positive responses (for example, phosphenes or hallucinations as metamorphopsias) and negative disturbances such as visual field deficits or blurred vision: thus, avoidance of hemianopia should be more regularly addressed.…”

Non-rigid alignment of pre-operative MRI, fMRI, and DT-MRI with intra-operative MRI for enhanced visualization and navigation in image-guided neurosurgery

“…DTI provides information about the normal course, displacement, or interruption of white matter tracts in and around a tumor, as well as detecting the widening of fiber bundles due to edema or tumor infiltration (Beppu et al, 2003;Clark et al, 2003;Hendler et al, 2003;Lu et al, 2003;Price et al, 2003;Tummala et al, 2003;Wieshmann et al, 1999;Yamada et al, 2003). Consequently, efforts have been made in recent years to integrate DTI data with neurosurgical navigation systems , Coenen et al 2003, Talos et al 2003, Berman et al 2004, Shinoura et al 2005, Nimsky et al 2006. Such a study on the role of diffusion tensor imaging of the corticospinal tract (CST) before and after mass resection, and the correlations with clinical motor findings, was recently published by Laundre et al 2005. Interventional MRI (iMRI) has proven to be an effective tool for improving the completeness of low grade glioma resection (Claus et al 2005, Bradley 2002, Schneider et al 2001, Schneider et al 2005, Knauth et al 1999, Wirtz et al 2000.…”

Precentral Knob Corresponds to the Primary Motor and Premotor Area

“…Continuous adequate task judging from the preoperative fMRI, and intraoperative cortical mapping was performed during the removal of tumor near the eloquent motor area responsible for the movement of hand, arm, leg, eye and speech. Removal of tumor was assisted by a neuronavigation system, which showed the location of the area activated in fMRI 17 . Gross total resection was attempted in all cases.…”

“…Mapping and awake tumor resection was performed as described previously 17 . Briefly, patients were positioned in the supine position and given rigid head fixation (Sugita headrest; Mizuho Medical Co., Tokyo, Japan) after administration of a local anesthetic agent (1% xylocaine and 0.75% anapain) at the pin sites and regional field block sites.…”