Risk Reduction in Dominant Temporal Lobe Epilepsy Surgery Combining fMRI/DTI Maps, Neuronavigation and Intraoperative 1.5-Tesla MRI

Abstract

Background: In dominant temporal lobe epilepsy surgery, speech, memory and visual systems are at risk. Objective: Functional magnetic resonance imaging (fMRI) and diffusion tensor imaging combined with intraoperative neuronavigation and MRI were investigated retrospectively regarding risk reductions for favorable neurological and seizure outcome. Methods: Functional imaging risk maps were generated for 14 patients suffering from dominant temporal lobe epilepsy [7 with hippocampal sclerosis (HS), 7 with various lesions] and used for neuronavigation-guided tailored resection. Postoperative neurological and seizure outcome and complications were evaluated. Results: None of the patients had postoperative speech dysfunction despite 2.3/3.6-cm mean hippocampal/neocortical resection. Verbal memory decline was found in 2 of the 14 (14.3%) patients, correlating with surgical lesions in fMRI memory-activated functional areas in the dominant posterior parahippocampal gyrus. Verbal memory scores did not statistically differ between the HS and the lesional group, neither pre- nor postoperatively. A contralateral visual field defect occurred in 1 patient (7.1%). An Engel class I seizure outcome was found in 12 patients (85.7%), and 11 were completely seizure free (78.6%) at a mean follow-up of 19.5 months. Conclusion: This retrospectively investigated protocol led to an excellent neurological and seizure outcome and a low complication rate in dominant temporal lobe epilepsy surgery.

Age of epilepsy onset as modulating factor for naming deficit after epilepsy surgery: a voxel-based lesion-symptom mapping study

“… 32 Individual factors such as like organization of language on a regional level, including activation in the dominant FG during picture naming, prognosis postsurgical speech dysfunction and naming decline. 8 , 33 Direct cortical stimulation in the middle FG was used to delineate an area in which isolated picture naming was impaired, while sentence repetition and motor function remained intact. 7 A functional MRI study depicted a significantly higher activation of the left frontal region besides activation of ITG in patients with early epilepsy onset during a visual language task as evidence of intra-hemispheric reorganization.…”

Resection of dominant fusiform gyrus is associated with decline of naming function when temporal lobe epilepsy manifests after the age of five: A voxel-based lesion-symptom mapping study

“…The BTLA does not appear to harbor exclusively picture naming functions but rather be partially compensable leading to an extent of picture naming decline of 10 to 20% but no complete anomia after resection. Because of the dynamic of neuropsychological changes following surgery, results of long-term postoperative neuropsychological assessment are more relevant, yet early postoperative deficits with the risk of partial persistence can be of relevance for the individual patient and should thus be noted ( Baxendale et al, 2019 , Wilson et al, 2015 , Rössler et al, 2015 , Trimmel et al, 2019 ).…”

The role of blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-fMRI) combined with diffusion tensor imaging (DTI) in surgery for tumors involving motor pathways

“…Although conventional MRI can show the boundaries of tumors, surgeons cannot always distinguish the anatomical relationship among the CST, M1, and tumors. In two previous studies, during the operation, the CST was inevitably damaged, which caused motor function damage [4,5]. The combination of BOLD-fMRI with DTI in the treatment of intracranial tumors has been studied previously.…”