Wada-test, functional magnetic resonance imaging and direct electrical stimulation – brain mapping methods
|K. Minkin, M. Penkov, R. Tanova, A. Bussarsky, V. Hadjidekov, L. Penev, D. Iakimovski, E. Naidenov, N. Stoyanchev, V. Bussarsky|
Modern neurosurgery requires accurate preoperative and intraoperative localization of brain pathologies but also of brain functions. The presence of individual variations in healthy subjects and the shift of brain functions in brain diseases provoke the introduction of various methods for brain mapping. The aim of this paper was to analyze the most widespread methods for brain mapping: Wada-test, functional magnetic resonance imaging (fMRI) and intraoperative direct electrical stimulation (DES). This study included 4 patients with preoperative brain mapping using Wada-test and fMRI. Intraoperative mapping with DES during awake craniotomy was performed in one case. The histopathological diagnosis was low-grade glioma in 2 cases, cortical dysplasia (1 patient) and arteriovenous malformation (1 patient). The brain mapping permits total lesion resection in three of four patients. There was no new postoperative deficit despite surgery near or within functional brain areas. Brain plasticity provoking shift of eloquent areas from their usual locations was observed in two cases. The brain mapping methods allow surgery in eloquent brain areas recognized in the past as “forbidden areas”. Eachmethod has advantages and disadvantages. The precise location of brain functions and pathologies frequently requires combination of different brain mapping methods.
Key words: WADA-TEST. FUNCTIONAL MAGNETIC RESONANCE IMAGING. DIRECT ELECTRICAL STIMULATION. BRAIN PLASTICITY