Intraoperative Topographic Mappings of the Central Sulcus by Somatosensory Evoked Potential Phase Reversals on Subdural Electrodes.
- Author:
Dae Won SEO
1
;
Seung Bong HONG
;
Do Hyun NAM
;
Jung IL LEE
;
Jong Soo KIM
;
Seung Chul HONG
;
Kwan PARK
;
Ik Soo JUNG
Author Information
1. Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Korea. dwseo@smc.samsung.co.kr
- Publication Type:Original Article
- Keywords:
Evoked potentials;
Somatosensory;
Brain mapping;
Neurosurgery;
Epilepsy
- MeSH:
Arteriovenous Malformations;
Brain Mapping;
Electrodes*;
Epilepsy;
Evoked Potentials;
Evoked Potentials, Somatosensory*;
Hemangioma;
Hemangioma, Cavernous;
Humans;
Median Nerve;
Motor Cortex;
Neurosurgery;
Pathology;
Rabeprazole
- From:Journal of the Korean Neurological Association
2001;19(6):624-628
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Topographic mappings of somatosensory evoked potentials (SEP) on subdural electrodes help identify the motor cortex quickly during chronic subdural recordings or during the operation. We tried to assess the ease and reliability of the routine use of SEP for identification of the sensorimotor cortex depending on pathology and location of the lesion. METHODS: We reviewed 75 SEP studies of 63 patients who needed functional mappings of the sensorimotor area. The phase reversal (PR) of SEP around the 20 msec latency in response to contralateral median nerve stimulations by subdural electrodes was used to identify the position of the central sulcus. The patients included 20 with nonlesional epilepsy, 30 with tumor, 12 with arteriovenous malformation (AVM), and 1 with cavernous angioma. RESULTS: SEP-PRs were successfully recorded in 67 SEP among 75 studies (89.3%). SEP-PRs were recorded in 37 of 43 patients with lesions (86.0%), and in all patients without lesions (100.0%). In regards to pathology, the absence of SEP-PR was noted in 3 out of 12 patients with AVM (25.0%), 3 out of 30 patients with tumor (10.0%), and 0 out of 1 patient with cav-ernous angioma (0.0%). The SEP-PRs were obtained the least frequently for the location of lesions when the lesions involved both the frontal and parietal areas. CONCLUSIONS: Intraoperatively, the SEP-PR can be easily obtained and the median nerve SEP is an useful test for confirming the identification of the central sulcus. SEP-PR can be detected more frequently in patients without lesions rather than in those with lesions, especially patients with AVM or whose lesions are over the frontoparietal areas.
