RESUMO
Purpose: We investigated the distribution of spikes and HFOs recorded during intraoperative electrocorticography (ioECoG) and tried to elaborate a predictive model for postsurgical outcomes of patients with lateral neocortical temporal lobe epilepsy (TLE) whose mesiotemporal structures are left in situ. Methods: We selected patients with temporal lateral neocortical epilepsy focus who underwent ioECoG-tailored resections without amygdalo-hippocampectomies. We visually marked spikes, ripples (80-250 Hz), and fast ripples (FRs; 250-500 Hz) on neocortical and mesiotemporal channels before and after resections. We looked for differences in event rates and resection ratios between good (Engel 1A) and poor outcome groups and performed logistic regression analysis to identify outcome predictors. Results: Fourteen out of 24 included patients had a good outcome. The poor-outcome patients showed higher rates of ripples on neocortical channels distant from the resection in pre- and post-ioECoG than people with good outcomes (p pre = 0.04, p post = 0.05). Post-ioECoG FRs were found only in poor-outcome patients (N = 3). A prediction model based on regression analysis showed low rates of mesiotemporal post-ioECoG ripples (OR mesio = 0.13, p mesio = 0.04) and older age at epilepsy onset (OR = 1.76, p = 0.04) to be predictors of good seizure outcome. Conclusion: HFOs in ioECoG may help to inform the neurosurgeon of the hippocampus-sparing resection success chance in patients with lateral neocortical TLE.
RESUMO
BACKGROUND AND OBJECTIVES: Multiple factors have been found to contribute to the high risk of epilepsy in infants with tuberous sclerosis complex (TSC), including evolution of EEG abnormalities, TSC gene variant, and MRI characteristics. The aim of this prospective multicenter study was to identify early MRI biomarkers of epilepsy in infants with TSC aged <6 months and before seizure onset, and associate these MRI biomarkers with neurodevelopmental outcomes at 2 years of age. The study was part of the EPISTOP project. METHODS: We evaluated brain MRIs performed in infants younger than 6 months with TSC. We used harmonized MRI protocols across centers and children were monitored closely with neuropsychological evaluation and serial video EEG. MRI characteristics, defined as tubers, radial migration lines, white matter abnormalities, cysts, calcifications, subependymal nodules (SEN), and subependymal giant cell astrocytoma (SEGA), were visually evaluated and lesions were detected semiautomatically. Lesion to brain volume ratios were calculated and associated with epilepsy and neurodevelopmental outcomes at 2 years. RESULTS: Lesions were assessed on MRIs from 77 infants with TSC; 62 MRIs were sufficient for volume analysis. The presence of tubers and higher tuber-brain ratios were associated with the development of clinical seizures, independently of TSC gene variation and preventive treatment. Furthermore, higher tuber-brain ratios were associated with lower cognitive and motor development quotients at 2 years, independently of TSC gene variation and presence of epilepsy. DISCUSSION: In infants with TSC, there is a significant association between characteristic TSC lesions detected on early brain MRI and development of clinical seizures, as well as neurodevelopmental outcomes in the first 2 years of life. According to our results, early brain MRI findings may guide clinical care for young children with TSC. CLASSIFICATION OF EVIDENCE: This study provides Class I evidence that in infants with TSC, there is a significant association between characteristic TSC lesions on early brain MRI and the development of clinical seizures and neurodevelopmental outcomes in the first 2 years of life.