Epilepsy research
-
Comparative Study
White matter abnormalities in patients with temporal lobe epilepsy and amygdala enlargement: Comparison with hippocampal sclerosis and healthy subjects.
Cases of temporal lobe epilepsy (TLE) with ipsilateral amygdala enlargement (AE) have increasingly been reported. However, the white matter (WM) abnormalities of TLE patients with AE remain poorly investigated. Here we explored macrostructural and microstructural WM abnormalities in TLE patients with AE compared to normal controls and TLE patients with hippocampal sclerosis (HS). ⋯ Our findings regarding the WM of TLE patients with AE may reflect characteristic pathophysiology such as the anatomical and functional connection between the amygdala and medial prefrontal cortex, and our results may thus provide insights into TLE with AE.
-
Hippocampal sclerosis (HS) is a common pathology in MTLE, patients may show different surgical outcomes and clinical features. The 2013 ILAE classification subdivides HS into 3 types (HS type 1: severe neuronal loss and gliosis predominantly in CA1 and CA4 regions; - HS type 2: CA1 predominant; HS type 3: CA4 predominant) and includes "gliosis only, as no-HS". The association of clinical and electrophysiological findings with different HS types has not been reported previously in detail. ⋯ The patients with HS types 2 and 3 have more frequent SGTCS or status epilepticus as well as increased family history of epilepsy. These findings can be helpful in understanding the epileptogenicity-prognoses of HS.
-
Fast ripples (FR, 250-500Hz) are proposed biomarkers of the epileptogenic zone on the basis of several retrospective reports linking postoperative seizure freedom to their complete resection. There are no clinical trials or prospective reports validating the use of FR as characterized by electrocorticography (ECoG), to guide the scope of epilepsy surgery, and to inform prognosis thereafter. We set out to prospectively evaluate the utility of FR resection to predict postoperative epilepsy outcomes, and examine the feasibility of "live" intraoperative FR ascertainment. ⋯ In a prospective fashion, including "live" review, FR were detected in 80% of pediatric ECoG studies, and incomplete resection of FR cortex predicted postoperative seizures. These findings extend the notion that interictal FR are surrogate markers of the epileptogenic zone, and that their intraoperative localization could be used to inform prognosis and guide surgical resections in children.
-
Comparative Study
Accuracy of MEG in localizing irritative zone and seizure onset zone: Quantitative comparison between MEG and intracranial EEG.
We conducted the study to examine accuracy of the magnetoencephalography (MEG) spike source localization in presurgical evaluation of patients with medically refractory focal epilepsy. ⋯ MEG spike sources, especially clustered ones, from interictal recording could localize the irritative zone of ICEEG with a high accuracy. However, MEG spike sources have relatively poor correlation with seizure onset zone and lower sensitivity in identifying all irritative zones of ICEEG. This limitation should be considered in the interpretation of MEG results.
-
In some cases of single focus epilepsy, conventional video electroencephalography (EEG) cannot reveal the epileptogenic focus even when intracranial electrodes are used. Here, we tested whether analyzing high frequency oscillations (HFOs) can be used to determine the ictal onset zone in suspected bitemporal epilepsy and improve seizure outcome. ⋯ Bilateral placement of subdural strip and depth electrodes for seizure monitoring in patients with suspected bitemporal epilepsy is both safe and effective. Monitoring high frequency oscillations can help determine the laterality of the onset zone when localization using conventional EEG or brain MRI fails.