EXTRAOPERATIVE CORTICAL STIMULATION MAPPING OF MOTOR FUNCTION IN INFANTS AND YOUNG CHILDREN
Abstract number :
2.456
Submission category :
Year :
2003
Submission ID :
3992
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Susan T. Arnold, Jeffrey G. Ojemann, Liu Lin Thio, Edwin Trevathan, T.S. Park, Michael Wong, John M. Zempel Dept of Neurology, Washington University School of Medicine, St Louis, MO; Dept of Neurosurgery, Washington University School of Medicine, St. Loui
Extraoperative cortical stimulation of motor function has been reported to require higher stimulation amperage in young children and to have a poor success rate with conventional technique. We report a series of 4 children under the age of 4 years with cortical dysplasias, who underwent successful extraoperative cortical stimulation mapping of motor cortex with conventional technique and with amperage thresholds below 10 mA.
Five children under the age of 4 years who underwent invasive monitoring for epilepsy surgery at the Washington University Pediatric Epilepsy Center at St Louis Children[apos]s Hospital were identified retrospectively. Extraoperative cortical stimulation mapping had been performed on the 4 children who had electrode grid placement over the motor cortex. (The fifth had an occipital grid). Their ages were 10 , 19, 28 and 39 months. Pairs of electrodes were stimulated using biphasic square pulses with a pulse duration of 1 msec, frequency 50 Hz, train duration of 2-5 sec and intensities increasing from 1 to 10 mA in 1-2 mA increments.
Upper extremity motor funtion was identified in all 4 children. In 2 cases, including the youngest patient, face and/or leg motor function were also identified and followed expected topographic organization. In most cases, motor responses were elicited at stimulus intensities of less than 5 mA. The procedure was well tolerated in all children. No significant complications occured although some afterdischarges and brief clinical seizures were induced, as would be expected in this population of children with cortical dysplasia. In all cases results of mapping were used to allow the surgical resection to successfully avoid motor cortex.
Extraoperative cortical stimulation mapping of motor function can be performed successfully in infants and children under the age of 4 years, and can improve surgical outcome by accurately delineating motor cortex and reducing the risk of a new post-operative motor deficit. In our population, stimulation thresholds were not significantly higher than those used in older children, and the procedure was well tolerated in all patients.