Neuronavigation Combined with Electrophysiological Monitoring for Surgery of Lesions in Eloquent Brain Areas in 42 Cases: A Retrospective Comparison of the Neurological Outcome and the Quality of Resection with a Control Group with Similar Lesions

Abstract

The purpose of this study was to achieve a more radical resection of tumors in the area of the motor cortex via minimal craniotomy using a combination of neuronavigation and neurophysiological monitoring with direct electrical cortical stimulation and to compare retrospectively the clinical outcome and postoperative magnetic resonance imaging with a control group that was operated on in our service when the combination of these monitoring techniques was not available. A total of 42 patients with tumors in or near the central region underwent surgery with neuronavigation guidance and neurophysiological monitoring. The primary motor cortex was identified intraoperatively by the somatosensory evoked phase reversal method and direct cortical stimulation. The functional areas were transferred into the neuronavigation system. By stimulating the identified primary motor cortex and displaying the motor area in the operating microscope a permanent control of the motor function was possible during the whole operation. Using these techniques a more radical tumor resection - evaluated by postoperative MRI - was achieved in the study group (p = 0.04) and also a trend toward a better neurological outcome.

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

“…Moreover, cortical stimulation is a demanding, time consuming, and costly procedure and as such is often not possible during surgery. Therefore, because fMRI of motor and language tasks is feasible in patients with cerebral tumors (Mueller et al 1996), several groups have proposed the integration of functional data into the neuronavigation system in recent years (Krishnan et al 2004, Gralla et al 2003, Jannin et al 2002, Roessler et al 2005, Reithmeier et al 2003, Talos et al 2003, O'Shea et al 2006. And strong evidence that a more radical tumor resection may be achieved by using fMRI information during neurosurgery has been demonstrated by Krishnan et al 2004, Haberg et al 2004 Diffusion tensor imaging (DTI) has recently emerged as a potentially valuable tool for preoperative planning (Tummala et al 2004, Field et al 2004, Clark et al 2003, Wieshmann et al 2000, Moller-Hartmann et al 2002, Coenen et al 2003 and postoperative follow-up (Alexander et al 2003) of surgically treated brain tumors and vascular malformations.…”

Awake Mapping Optimizes the Extent of Resection for Low-Grade Gliomas in Eloquent Areas

“…11 However, it could be argued that preservation of functional sites might lead to a lesser degree of tumor removal. To the best of our knowledge, the extent of resection was never directly compared between "traditional" and awake procedures except in 2 previous reports: one by Reithmeier et al 12 and one by our team. 11 Even though both observed a better extent of resection with intraoperative mapping, the comparison was made with a control group and not in the same patients.…”

Awake surgery with continuous motor testing for resection of brain tumors in the primary motor area

“…Indeed, although elaborate electrophysiological monitoring led to a better neurological outcome in patients undergoing resection of brain tumors, 14% of patients experienced post-operative deterioration of motor function. 6 Although the use of fMRI and DTI could not prevent compromise of motor function, these modalities were useful in predicting the technical difficulty of awake surgery for brain tumors in the M1. For example, all patients designated as type A had suboptimal outcomes in terms of subtotal resection of the tumor or transient or permanent deterioration of motor function (Table 2; Figs.…”

“…[1][2][3] Investigators have attempted to improve outcomes in patients undergoing resection of M1 brain tumors by employing various pre-operative and intra-operative techniques, including pre-operative functional MRI (fMRI) and diffusion tensor imaging (DTI), and intra-operative electrophysiological monitoring of somatosensory evoked potential (SEP), cortical mapping, and neuronavigation. [4][5][6] However, functional reorganization of the M1 limits the utility of these techniques. 7,8 By contrast, studies have demonstrated that awake surgery with continuous motor testing can allow resection of M1 brain tumors while preserving motor function.…”