SUMMARYPurpose: Verbal memory decline is a frequent complication of left anterior temporal lobectomy (L-ATL). The goal of this study was to determine whether preoperative language mapping using functional magnetic resonance imaging (fMRI) is useful for predicting which patients are likely to experience verbal memory decline after L-ATL. Methods: Sixty L-ATL patients underwent preoperative language mapping with fMRI, preoperative intracarotid amobarbital (Wada) testing for language and memory lateralization, and pre-and postoperative neuropsychological testing. Demographic, historical, neuropsychological, and imaging variables were examined for their ability to predict pre-to postoperative memory change. Results: Verbal memory decline occurred in over 30% of patients. Good preoperative performance, late age at onset of epilepsy, left dominance on fMRI, and left dominance on the Wada test were each predictive of memory decline. Preoperative performance and age at onset together accounted for roughly 50% of the variance in memory outcome (p < 0.001), and fMRI explained an additional 10% of this variance (p ≤ 0.003). Neither Wada memory asymmetry nor Wada language asymmetry added additional predictive power beyond these noninvasive measures. Discussion: Preoperative fMRI is useful for identifying patients at high risk for verbal memory decline prior to L-ATL surgery. Lateralization of language is correlated with lateralization of verbal memory, whereas Wada memory testing is either insufficiently reliable or insufficiently material-specific to accurately localize verbal memory processes.

Summary Purpose To more definitively characterize Wada/fMRI language dominance discordance rates with the largest sample of epilepsy patients to date, and to examine demographic, clinical, and methodological predictors of discordance. Methods 229 epilepsy patients underwent both a standardized Wada test and a semantic-decision fMRI language protocol in a prospective research study. Language laterality indices were computed for each test using automated and double-blind methods, and Wada/fMRI discordance rates were calculated using objective criteria for discordance. Regression analyses were used to explore a range of variables that might predict discordance, including subject variables, Wada quality indices, and fMRI quality indices. Key findings Discordant results were observed in 14% of patients. Discordance was highest among those categorized by either test as having bilateral language. In a multivariate model, the only factor that predicted discordance was the degree of atypical language dominance on fMRI. Significance FMRI language lateralization is generally concordant with Wada testing. The degree of rightward shift of language dominance on fMRI testing is strongly correlated with Wada/fMRI discordance, suggesting that fMRI may be more sensitive than Wada to right hemisphere language processing, though the clinical significance of this increased sensitivity is unknown. The relative accuracy of fMRI vs. Wada testing for predicting post-surgical language outcome in discordant cases remains a topic for future research.

Summary Purpose:  Language lateralization measured by preoperative functional magnetic resonance imaging (fMRI) was shown recently to be predictive of verbal memory outcome in patients undergoing left anterior temporal lobe (L‐ATL) resection. The aim of this study was to determine whether language lateralization or functional lateralization in the hippocampus is a better predictor of outcome in this setting. Methods:  Thirty L‐ATL patients underwent preoperative language fMRI, preoperative hippocampal fMRI using a scene encoding task, and pre‐ and postoperative neuropsychological testing. A group of 37 right ATL (R‐ATL) surgery patients was included for comparison. Results:  Verbal memory decline occurred in roughly half of the L‐ATL patients. Preoperative language lateralization was correlated with postoperative verbal memory change. Hippocampal activation asymmetry was strongly related to side of seizure focus and to Wada memory asymmetry but was unrelated to verbal memory outcome. Discussion:  Preoperative hippocampal activation asymmetry elicited by a scene encoding task is not predictive of verbal memory outcome. Risk of verbal memory decline is likely to be related to lateralization of material‐specific verbal memory networks, which are more closely correlated with language lateralization than with overall asymmetry of episodic memory processes.

Summary Objective To describe the phenomenology of monitored Sudden Unexpected Death in Epilepsy (SUDEP) occurring in the inter-ictal period where death occurs without a seizure preceding it. Methods We report a case series of monitored definite and probable SUDEP where no electroclinical evidence of underlying seizures was found preceding death. Results Three patients (2 definite and 1 probable) suffered SUDEP. They had a typical high SUDEP-risk profile with longstanding intractable epilepsy and frequent generalized tonic-clonic seizures (GTCS). All patients had varying patterns of respiratory and bradyarrhythmic cardiac dysfunction with profound EEG suppression. In two patients, patterns of cardio-respiratory failure were similar to those seen in some patients in the Mortality in Epilepsy Monitoring Units Study (MORTEMUS). Significance Sudden Unexpected Deaths in Epilepsy (SUDEP) almost always occur postictally, after GTCS and less commonly after a partial seizure. Monitored SUDEP or near-SUDEP cases without a seizure have not yet been reported in literature. When non-monitored SUDEP occurs in an ambulatory setting without an overt seizure, the absence of EEG information prevents the exclusion of a subtle seizure. These cases confirm the existence of non-seizure SUDEP; such deaths may not be prevented by seizure detection based devices. SUDEP risk in epilepsy patients may constitute a spectrum of susceptibility wherein some are relatively immune, death occurs in others with frequent GTCS with one ultimately proving fatal, while in others still, death may occur even in the absence of a seizure. We emphasize the heterogeneity of SUDEP phenomena.

Highlights Cognitive impairment is a major comorbidity of temporal lobe epilepsy (TLE). Three discrete cognitive phenotypes of TLE are identified here. The phenotypes are linked to network, clinical, and socioeconomic characteristics. This taxonomy advances clinical and theoretical understanding of the cognitive complications of TLE.

Objective: To define left temporal lobe regions where surgical resection produces a persistent postoperative decline in naming visual objects. Methods: Pre-and postoperative brain magnetic resonance imaging data and picture naming (Boston Naming Test) scores were obtained prospectively from 59 people with drug-resistant left temporal lobe epilepsy. All patients had left hemisphere language dominance at baseline and underwent surgical resection or ablation in the left temporal lobe. Postoperative naming assessment occurred approximately 7 months after surgery. Surgical lesions were mapped to a standard template, and the 1940 | BINDER Et al. How to cite this article: Binder JR, Tong J-Q, Pillay SB, et al; fMRI in Anterior Temporal Epilepsy Surgery (FATES) study. Temporal lobe regions essential for preserved picture naming after left temporal epilepsy surgery.

Summary Purpose Subdural electrodes are implanted for recording intracranial EEG (iEEG) in cases of medically refractory epilepsy as a means to locate cortical regions of seizure onset amenable to surgical resection. Without the aid of imaging-derived 3D electrode models for surgical planning, surgeons have relied on electrodes remaining stationary from the time between placement and follow-up resection. This study quantifies electrode shift with respect to the cortical surface occurring between electrode placement and subsequent reopening. Methods CT and structural MRI data were gathered following electrode placement on 10 patients undergoing surgical epilepsy treatment. MRI data were used to create patient specific post-grid 3D reconstructions of cortex, while CT data were co-registered to the MRI and thresholded to reveal electrodes only. At the time of resective surgery, the craniotomy was reopened and electrode positions were determined using intraoperative navigational equipment. Changes in position were then calculated between CT coordinates and intraoperative electrode coordinates. Results Five out of ten patients showed statistically significant overall magnitude differences in electrode positions (mean: 7.2 mm), while 4 exhibited significant decompression based shift (mean: 4.7 mm), and 3 showed significant shear displacement along the surface of the brain (mean: 7.1 mm). Discussion Shift in electrode position with respect to the cortical surface has never been precisely measured. We show that in 50% of our cases statistically significant shift occurred. These observations demonstrate the potential utility of complimenting electrode position measures at the reopening of the craniotomy with 3D electrode and brain surface models derived from post-implantation CT and MR imaging for better definition of surgical boundaries.

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