Surgical Outcome in Extratemporal Epilepsies Based on Multimodal Pre-Surgical Evaluation and Sequential Intraoperative Electrocorticography

Abstract

Objective: to present the postsurgical outcome of extratemporal epilepsy (ExTLE) patients submitted to preoperative multimodal evaluation and intraoperative sequential electrocorticography (ECoG). Subjects and methods: thirty-four pharmaco-resistant patients with lesional and non-lesional ExTLE underwent comprehensive pre-surgical evaluation including multimodal neuroimaging such as ictal and interictal perfusion single photon emission computed tomography (SPECT) scans, subtraction of ictal and interictal SPECT co-registered with magnetic resonance imaging (SISCOM) and electroencephalography (EEG) source imaging (ESI) of ictal epileptic activity. Surgical procedures were tailored by sequential intraoperative ECoG, and absolute spike frequency (ASF) was calculated in the pre- and post-resection ECoG. Postoperative clinical outcome assessment for each patient was carried out one year after surgery using Engel scores. Results: frontal and occipital resection were the most common surgical techniques applied. In addition, surgical resection encroaching upon eloquent cortex was accomplished in 41% of the ExTLE patients. Pre-surgical magnetic resonance imaging (MRI) did not indicate a distinct lesion in 47% of the cases. In the latter number of subjects, SISCOM and ESI of ictal epileptic activity made it possible to estimate the epileptogenic zone. After one- year follow up, 55.8% of the patients was categorized as Engel class I–II. In this study, there was no difference in the clinical outcome between lesional and non lesional ExTLE patients. About 43.7% of patients without lesion were also seizure- free, p = 0.15 (Fischer exact test). Patients with satisfactory seizure outcome showed lower absolute spike frequency in the pre-resection intraoperative ECoG than those with unsatisfactory seizure outcome, (Mann– Whitney U test, p = 0.005). Conclusions: this study has shown that multimodal pre-surgical evaluation based, particularly, on data from SISCOM and ESI alongside sequential intraoperative ECoG, allow seizure control to be achieved in patients with pharmacoresistant ExTLE epilepsy.

Relation of Brain Perfusion Patterns to Sudden Unexpected Death Risk Stratification: A Study in Drug Resistant Focal Epilepsy

“…Furthermore, no differences in the number and PI of the hyperperfused and hypoperfused subcortical and cortical structures between the evaluated epilepsy types were found. As can be seen in Table 2, there was a tendency towards a greater number of the hypoperfused subcortical structures (8)(9)(10)(11)(12) and hyperperfused cortical structures (10)(11)(12)(13).…”

“…Numerous advances in structural and functional neuroimaging and computational neuroscience suggest that neural dysfunction in focal epilepsy is not restricted to the epileptogenic zone (EZ) but can affect widespread networks throughout the brain. These findings may lead to improved strategies for outcome prediction in epilepsy and EZ localization [ 7 , 8 , 9 , 10 ].…”

“…Although the relationship between SPECT and surgical outcome has not been established [ 20 ], multimodal imaging using SPECT coregistered to MRI are useful to improve EZ localization. The concordance of these techniques with other tests such as EEG, MRI, and semiology are predictive for good seizure outcome after epilepsy surgery [ 9 , 21 , 22 ]. In addition, we have reported that brain perfusion patterns in patients with DRFE show hyperperfusion in brain structures related to the EZ [ 23 ].…”

Epileptic Seizures Detection Using Deep Learning Techniques: A Review

“…The structural neuroimaging modalities provide physicians with substantial information about the brain structure of individuals with epileptic seizures [ 4 , 5 , 6 , 7 , 8 , 9 ]. The most important functional neuroimaging techniques are EEG [ 5 ], magnetoencephalography (MEG) [ 6 ], positron emission tomography (PET) [ 7 ], single-photon emission computed tomography (SPECT) [ 7 , 10 ], functional MRI (fMRI) [ 4 , 11 ], electrocorticography (ECoG) [ 12 ], and functional near-infrared spectroscopy (fNIRS) [ 13 ]. In contrast, structural MRI (sMRI) and diffusion tensor imaging (DTI) are among the most significant structural neuroimaging techniques [ 4 , 14 ].…”

Cirugía de la Epilepsia en Pediatría. Experiencia en el Centro Internacional de Restauración Neurológica

“…Este trabajo constituye el primer reporte de cirugía de la epilepsia en edad pediátrica, avalado por la experiencia de nuestra institución en el manejo de la cirugía de la epilepsia en adultos. 11,12,13 A diferencia de los reportes revisados, en el trabajo incluimos la variable porciento de variación de la frecuencia de crisis como una forma de abordar la evaluación post quirúrgica a corto plazo, teniendo en cuenta la heterogeneidad de los reportes en relación a la temática.…”