Epilepsia
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Depression is a common comorbidity of epilepsy, and its timely identification in persons with epilepsy is essential. The use of screening tools to detect depression is common in epilepsy, but some scales in current use have not been validated using a gold standard in this population. The present study aims to validate three commonly used depression-screening scales and assess new cut points for scoring in those with epilepsy. ⋯ The PHQ-9 at a cut point of 9 and the HADS at a cut point of 7 had the best overall balance of sensitivity and specificity. However, for screening purposes the PHQ-9 algorithm method is ideal (optimizing specificity), whereas for case finding the HADS at a cut point of 6 performed best (optimizing sensitivity). Appropriate scale cut points should be chosen based on the study's goals and available resources. Disease-specific scale cut points are recommended for future studies assessing depression in persons with epilepsy.
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Autosomal dominant lateral temporal epilepsy (ADLTE) is a focal epileptic syndrome characterized by auditory or aphasic auras. Mutations in the LGI1 gene account for <50% of ADLTE families. To identify copy number variants (CNVs) related to ADLTE, we examined a collection of ADLTE families without LGI1 mutations. ⋯ Our results provide clues on genes for susceptibility to ADLTE, particularly in those families where the inheritance pattern is less compatible with autosomal dominance. Some of these genes also confer risk for other epilepsy syndromes.
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Multiple tubers in patients with tuberous sclerosis complex (TSC) often are responsible for drug-resistant epilepsy. The complexity of the epileptic network formed by multiple tubers complicates localization of the epileptogenic zone that is needed to design a surgical treatment strategy. High frequency oscillations (HFOs) on intracranial video-electroencephalography (IVEEG) may be a valuable surrogate marker for the localization of the epileptogenic zone. The purpose of this study was to test the hypothesis that high occurrence rate (OR) of interictal HFOs can guide the localization of the epileptogenic zone. ⋯ The multiple extensive zones with high-OR HFOs suggest a complex and widespread epileptic network in patients with TSC. In a subset of TSC patients with drug-resistant epilepsy, resection of cortex with both interictal high-OR FRs and ripples on IVEEG correlated with a good seizure outcome.
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In temporal lobe epilepsy (TLE), the epileptogenic focus is focal and unilateral in the majority of patients. A key characteristic of focal TLE is the presence of subclinical epileptiform activity in both the ictal and contralateral "healthy" hemisphere. Such interictal activity is clinically important, as it may reflect the spread of pathology, potentially leading to secondary epileptogenesis. The role played by white matter pathways in this process is unknown. ⋯ Our results indicate that, among the tracts investigated, only the tapetum was associated with contralateral epileptiform activity, implicating this structure in seizures and possible secondary epileptogenesis. We describe two mechanisms that might explain this association (the interruption of inhibitory signals or the toxic effect of carrying epileptiform signals toward the healthy hemisphere), but also acknowledge other rival factors that may be at work. We also report that patients with TLE with bilateral spikes had increased lateral bitemporal lobe connectivity. Our current results can be seen as bringing together important functional and structural data to elucidate the basis of contralateral interictal activity in focal, unilateral epilepsy. A PowerPoint slide summarizing this article is available for download in the Supporting Information section here.
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The interpretation of critical care electroencephalography (EEG) studies is challenging because of the presence of many periodic and rhythmic patterns of uncertain clinical significance. Defining the clinical significance of these patterns requires standardized terminology with high interrater agreement (IRA). We sought to evaluate IRA for the final, published American Clinical Neurophysiology Society (ACNS)-approved version of the critical care EEG terminology (2012 version). Our evaluation included terms not assessed previously and incorporated raters with a broad range of EEG reading experience. ⋯ IRA for most terms in the ACNS critical care EEG terminology is high. These terms are suitable for multicenter research on the clinical significance of critical care EEG patterns. A PowerPoint slide summarizing this article is available for download in the Supporting Information section http://dx.doi.org/10.1111/epi.12653/supinfo.