Refractory seizures: Prediction of outcome of surgical intervention based on results from PET-CT, PET-MRI and electroencephaolography

Abstract

Purpose The purpose of this article is to evaluate the effectiveness of fluorodeoxyglucose (FDG) positron emission tomography (PET)-computed tomography (CT) and PET-magnetic resonance imaging (MRI) with scalp and intracranial electroencephalogram (EEG) in predicting surgical outcomes in patients with refractory seizures. Methods Patients who underwent PET-CT and MRI fusion, scalp and intracranial EEG, and subsequent surgical intervention were retrospectively included. PET-CT were fused with MRI and interpreted by an experienced blinded reader. An area of hypometabolism on PET was identified as the location of the epileptic focus. The site of seizure focus was correlated with scalp and intracranial EEG findings. Surgical outcomes were evaluated. Thirty-six patients were included; all had presurgical PET-CT, scalp EEG, and PET-MRI fusion, and 28 of these patients had intracranial EEGs. Results PET-CT showed concordance of epileptic foci with scalp EEG in 7/36 patients (19%) and with intracranial EEG in 9/28 patients (32%). PET-MRI was concordant with scalp EEG in 6/36 patients (17%) and with intracranial EEG in 8/28 patients (29%). All patients with concordance of epileptic foci between PET-CT and PET-MRI and scalp EEG had improvement or resolution of seizures postintervention, and 89% of patients had concordance between intracranial EEG and PET studies. However, 45% of patients with discordant PET-CT and scalp EEG, 37% with discordance PET-CT and intracranial EEG, 43% with discordant PET-MRI and scalp EEG, and 35% of patients with discordant PET-MRI and intracranial EEG did not improve postsurgically. Conclusion Concordance of epileptic foci localization between PET imaging and EEG yields favorable postoperative outcome in nearly all patients, whereas discordance has an equal probability of favorable vs unfavorable outcomes.

Application of combined multimodal neuroimaging and video-electroencephalography in intractable epilepsy patients for improved post-surgical outcome prediction

“…This finding further confirmed that multimodal imaging, as an independent complementary method that supplements the clinical information, has a significant value in pre-surgical evaluation and the prediction of post-surgical prognosis. The present results were partially consistent with those of Johnson et al 30 Two patients in the concordant group of the present study had poor outcomes because the resection range was smaller than the pre-surgical lesion range, and brain tissue gliosis was found around the operative area (Fig 4). Two patients in the discordant group (unilateral image abnormality with bilateral v-EEG abnormalities) had favourable outcomes, which might be related to the rapid diffusion of abnormal discharges.…”

Utility of hybrid PET/MRI in stereoelectroencephalography guided radiofrequency thermocoagulation in MRI negative epilepsy patients

“…Hybrid PET/MRI In clinical practice, PET could serve as a complementary presurgical examination to EEG for SOZ identification. Johnson et al (2020) revealed that concordance of SOZ localization between PET and EEG was associated with favorable surgical outcomes in almost all patients while discordance had equal chance of favorable or unfavorable outcomes. According to Desarnaud et al (2018) the localization rate of SOZs was 83% after integration of electroclinical data and PET/MRI in patients with pathologically proven focal cortical dysplasia type 2 (FCD2), significantly higher than that of PET or EEG alone.…”

Seizure control does not predict hippocampal subfield volume change in children with focal drug-resistant epilepsy

“…4,9 However, in adults with temporal lobe epilepsy, volume reduction in the hippocampus has been shown to correlate with the duration of epilepsy. [10][11][12] Most studies that have assessed hippocampal volumes in children with epilepsy have evaluated total or regional hippocampal volume; that is, hippocampal head, body and tail, and have been cross-sectional in design. [4][5][6]8,11,13,14 Hence, it is uncertain if hippocampal volumes decline over time with ongoing seizures.…”