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Background and purpose: Accurate localization of the epileptic focus is essential for surgical treatment of patients with drug‐resistant epilepsy. Electric source imaging (ESI) is increasingly used in pre‐surgical evaluation. However, most previous studies have analysed interictal (II) discharges. Prospective studies comparing the feasibility and accuracy of II and ictal (IC) ESI are lacking. Methods: We prospectively analysed long‐term video‐electroencephalography recordings (LTM) of patients admitted for pre‐surgical evaluation. We performed ESI of II and IC signals using two methods, i.e. equivalent current dipole (ECD) and a distributed source model (DSM). LTM recordings employed the standard 25‐electrode array (including inferior temporal electrodes). An age‐matched template head model was used for source analysis. Results were compared with intracranial recordings, conventional neuroimaging methods [magnetic resonance imaging (MRI), positron emission tomography (PET), single‐photon emission computed tomography (SPECT)] and outcome at 1 year after surgery. Results: A total of 87 consecutive patients were analysed. ECD gave a significantly higher proportion of patients with localized focal abnormalities (94%) compared with MRI (70%), PET (66%) and SPECT (64%). Agreement between the ESI methods and intracranial recording was moderate to substantial (k = 0.56–0.79). A total of 54 patients were operated (47 patients more than 1 year ago) and 62% of them became seizure‐free. The localization accuracy of II‐ESI was 51% for DSM and 57% for ECD, and that for IC‐ESI was 51% for DSM and 62% for ECD. The differences between the ESI methods were not significant. Differences in localization accuracy between ESI and MRI (55%), PET (33%) and SPECT (40%) were not significant. Conclusions: The II‐ESI and IC‐ESI of LTM data have high feasibility and their localization accuracy is similar to that of conventional neuroimaging methods. [ABSTRACT FROM AUTHOR]

Background and purpose Strokes caused by lesions to certain brain areas are associated with poor outcome, which is important both prognostically and to understand the neural basis for recovery. However, lesion anatomy associations with outcome may occur because of effects on baseline severity rather than because of effects on recovery per se. Here, all common stroke locations were surveyed to determine the strongest lesion anatomy associations separately for baseline functional severity and proportional recovery. Since most recovery occurs early, the focus here is on functional changes over the first week. Method Global functional scores (National Institutes of Health Stroke Scale) at baseline and proportional recovery over 1 week were derived from the records of 550 ischaemic stroke patients and related to magnetic resonance imaging lesion location using voxel-lesion mapping. The effects of lesions extending over more than one location were also considered. Cross-validation estimated the percentage of recovery rate variance ( r2) accountable by lesion location information. Results High baseline severity was associated with lesions to the left capsule, striatum and thalamocortical white matter, whereas high recovery rate was associated with lesions to more superficial left fronto-temporal areas. Low recovery rates were associated with lesions to bilateral parietal, right insula, medial frontal, capsule and brainstem. Inclusion of these regions into a multivariate model of proportional recovery rate increased r2 from 8% to 45%. Conclusion The strongest stroke lesion location associations with 1-week recovery were identified, and it was shown that anatomical information accounts for a sizeable proportion of early recovery variability. [ABSTRACT FROM AUTHOR]