Comparison of conscious sedation and general anesthesia for motor mapping and resection of tumors located near motor cortex

Abstract

<jats:sec> <jats:title>Object</jats:title> <jats:p>The surgical treatment of tumors located near eloquent cortex carries a high risk of inducing worsening neurological deficits. Intraoperative electrocorticography techniques have been developed to help identify these areas at the time of surgery in an effort to minimize such risks. The optimal anesthetic technique for conducting these procedures, however, has never been determined.</jats:p></jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>The authors conducted a retrospective study to compare patients who underwent intraoperative motor mapping between September 2000 and May 2002. Demographic and neurophysiological monitoring data were collected from the hospital records. Patients were divided into two groups based on the anesthetic technique used for surgery: in Group 1 general anesthesia was used, and in Group 2 conscious sedation.</jats:p> <jats:p>Group 1 comprised 24 patients (mean age 47 years) with 16 right- and eight left-sided lesions. Group 2 consisted of 21 patients (mean age 46 years) with 18 right- and three left-sided lesions. Pathological diagnoses were similar between the two groups. Motor stimulation was elicited in 12 patients (50%) in Group 1 and in 21 patients (100%) in Group 2 (p &lt; 0.001). In addition, the mean stimulation amplitude required was significantly higher (13 mA) in patients in whom conscious sedation was used as opposed to general anesthesia (5 mA, p &lt; 0.0001). Electrographic evidence of seizures was seen in 29% of Group 1 cmpared with 10% of Group 2 patients (p &gt; 0.05).</jats:p></jats:sec> <jats:sec> <jats:title>Conclusions</jats:title> <jats:p>The use of conscious sedation as an anesthetic technique for motor mapping not only improves the chances of achieving successful stimulation and identification of motor cortex in relationship to the lesion, but it also allows for repetitive monitoring of the patient's motor function during resection of the lesion.</jats:p></jats:sec>

Cerebral motor cortical mapping: Awake procedure is preferable to general anaesthesia

“…A higher rate of electrographic evidence of seizure in the GA group was also reported in another series. However, their mean stimulation amplitude in the awake group was higher than in the GA group 5 . In the present report, the percentage of existing preoperative seizures was similar between the two groups (GA group: 62.5%, awake group: 55%).…”

“…It is often determined by the practice and experience of the team. There have been conflicting results reported in the literature 5,6 . A recent report showed that the GA group had a better outcome in terms of postoperative neurological deficits and extent of resection 6 .…”

“…There have been conflicting results reported in the literature. 5,6 A recent report showed that the GA group had a better outcome in terms of postoperative neurological deficits and extent of resection. 6 However, another series held a similar conclusion to the present report.…”

Cortical stimulation of language fields under local anesthesia: optimizing removal of brain lesions adjacent to speech areas

“…Given intraoperative cortical stimulation can identify eloquent areas, many authors routinely adopt this technique to guide brain lesion resections and to maintain integrity of the functional pathways 8 . vitaz et al 9 compared the use of local anesthesia with general anesthesia in patients submitted to resection of lesions adjacent to eloquent cortex and reported a higher success rate of stimulation in awake patients (100% versus 50%) who required a significantly lower stimulation current (5 mA versus 13 mA, p<0.0001). A recent randomized prospective study compared general anesthesia with awake surgery and found that better tumor cytoreduction and neurological improvement was seen in the former, demonstrating that this topic remains controversial 10 .…”

Combination of Functional Magnetic Resonance Imaging-guided Neuronavigation and Intraoperative Cortical Brain Mapping Improves Targeting of Motor Cortex Stimulation in Neuropathic Pain

“…Although a longitudinal electrode may improve the probability to cover the appropriate target on the motor strip, a perpendicular orientation offers a more selective stimulation and increases the number of bipolar electrical combinations that enable an analgesic effect (34)(35)(36)(37)(38). Conscious sedation as an anesthesia technique could improve the accuracy of iCM (10,58,65). Other technical alternatives may be developed, such as covering a larger zone of the functional cortex by two Resume electrodes (or a grid) or integrating transcranial magnetic coil stimulation in the navigation device (18).…”