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


METHODS
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. 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 < 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 < 0.0001). Electrographic evidence of seizures was seen in 29% of Group 1 compared with 10% of Group 2 patients (p > 0.05).


CONCLUSIONS
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.
Vitaz
Todd W
TW
Department of Neurological Surgery, University of Louisville School of Medicine, Louisville, Kentucky, USA. Tvitaz@NIKY.com
Marx
William
W
Victor
Jonathan D
JD
Gutin
Philip H
PH
D000230:Adenocarcinoma / Q000175:diagnosis / Q000556:secondary / Q000601:surgery; D000768:Anesthesia, General; D001931:Brain Mapping / Q000379:methods*; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000601:surgery*; D016292:Procedural Sedation; D003399:Craniotomy / Q000379:methods*; D005283:Fentanyl; D006801:Humans; D008874:Midazolam; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods; D009044:Motor Cortex / Q000473:pathology / Q000601:surgery*; D015742:Propofol; D012189:Retrospective Studies
D008874:Midazolam; D005283:Fentanyl; D015742:Propofol