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Background and Objectives:A new frontier in diagnostic radiology is the inclusion of machine-assisted support tools that facilitate the identification of subtle lesions often not visible to the human eye. Structural neuroimaging plays an essential role in the identification of lesions in patients with epilepsy, which often coincide with the seizure focus. Here we explore the potential for a convolutional neural network (CNN) to determine lateralization of seizure onset in patients with epilepsy using T1-weighted structural MRI scans as input.Methods:Using a dataset of 359 patients with temporal lobe epilepsy (TLE) from 7 surgical centers, we tested whether a CNN based on T1-weighted images could classify seizure laterality concordant with clinical team consensus. This CNN was compared to a randomized model (comparison to chance) and a hippocampal volume logistic regression (comparison to current clinically-available measures). Furthermore, we leveraged a CNN feature visualization technique to identify regions used to classify patients.Results:Across 100 runs, the CNN model was concordant with clinician lateralization on average 78% (SD= 5.1%) of runs with the best performing model achieving 89% concordance. The CNN outperformed the randomized model (average concordance of 51.7%) on 100% of runs with an average improvement of 26.2% and outperformed the hippocampal volume model (average concordance of 71.7%) on 85% of runs with an average improvement of 6.25%. Feature visualization maps revealed that in addition to the medial temporal lobe, regions in the lateral temporal lobe, cingulate, and precentral gyrus aided in classification.Discussion:These extra-temporal lobe features underscore the importance of whole-brain models to highlight areas worthy of clinician scrutiny during temporal lobe epilepsy lateralization. This proof-of-concept study illustrates that a CNN applied to structural MRI data can visually aid clinician-led localization of epileptogenic zone and identify extra-hippocampal regions that may require additional radiological attention.Classification of Evidence:This study provides Class II evidence that in patients with drug-resistant unilateral temporal lobe epilepsy, a convolutional neural network algorithm derived from T1-weighted MR images can correctly classify seizure laterality.

Background and ObjectivesNaming decline after left temporal lobe epilepsy (TLE) surgery is common and difficult to predict. Preoperative language fMRI may predict naming decline, but this application is still lacking evidence. We performed a large multicenter cohort study of the effectiveness of fMRI in predicting naming deficits after left TLE surgery.MethodsAt 10 US epilepsy centers, 81 patients with left TLE were prospectively recruited and given the Boston Naming Test (BNT) before and ≈7 months after anterior temporal lobectomy. An fMRI language laterality index (LI) was measured with an auditory semantic decision–tone decision task contrast. Correlations and a multiple regression model were built with a priori chosen predictors.ResultsNaming decline occurred in 56% of patients and correlated with fMRI LI (r= −0.41,p< 0.001), age at epilepsy onset (r =−0.30,p= 0.006), age at surgery (r= −0.23,p= 0.039), and years of education (r= 0.24,p= 0.032). Preoperative BNT score and duration of epilepsy were not correlated with naming decline. The regression model explained 31% of the variance, with fMRI contributing 14%, with a 96% sensitivity and 44% specificity for predicting meaningful naming decline. Cross-validation resulted in an average prediction error of 6 points.DiscussionAn fMRI-based regression model predicted naming outcome after left TLE surgery in a large, prospective multicenter sample, with fMRI as the strongest predictor. These results provide evidence supporting the use of preoperative language fMRI to predict language outcome in patients undergoing left TLE surgery.Classification of EvidenceThis study provides Class I evidence that fMRI language lateralization can help in predicting naming decline after left TLE surgery.

ObjectiveTo develop and externally validate models to predict the probability of postoperative verbal memory decline in adults after temporal lobe resection (TLR) for epilepsy using easily accessible preoperative clinical predictors.MethodsMultivariable models were developed to predict delayed verbal memory outcome on 3 commonly used measures: Rey Auditory Verbal Learning Test (RAVLT) and Logical Memory (LM) and Verbal Paired Associates (VPA) subtests from Wechsler Memory Scale–Third Edition. With the use of the Harrell step-down procedure for variable selection, models were developed in 359 adults who underwent TLR at the Cleveland Clinic and validated in 290 adults at 1 of 5 epilepsy surgery centers in the United States or Canada.ResultsTwenty-nine percent of the development cohort and 26% of the validation cohort demonstrated significant decline on at least 1 verbal memory measure. Initial models had good to excellent predictive accuracy (calibration [c] statistic range 0.77–0.80) in identifying patients with memory decline; however, models slightly underestimated decline in the validation cohort. Model coefficients were updated with data from both cohorts to improve stability. The model for RAVLT included surgery side, baseline memory score, and hippocampal resection. The models for LM and VPA included surgery side, baseline score, and education. Updated model performance was good to excellent (RAVLT c = 0.81, LM c = 0.76, VPA c = 0.78). Model calibration was very good, indicating no systematic overestimation or underestimation of risk.ConclusionsNomograms are provided in 2 easy-to-use formats to assist clinicians in estimating the probability of verbal memory decline in adults considering TLR for treatment of epilepsy.Classification of EvidenceThis study provides Class II evidence that multivariable prediction models accurately predict verbal memory decline after TLR for epilepsy in adults.

ObjectiveTo develop and externally validate models to predict the probability of postoperative naming decline in adults following temporal lobe epilepsy surgery using easily accessible preoperative clinical predictors.MethodsIn this retrospective, prediction model development study, multivariable models were developed in a cohort of 719 patients who underwent temporal lobe epilepsy surgery at Cleveland Clinic and externally validated in a cohort of 138 patients who underwent temporal lobe surgery at one of 3 epilepsy surgery centers in the United States (Columbia University Medical Center, Emory University School of Medicine, University of Washington School of Medicine).ResultsThe development cohort was 54% female with an average age at surgery of 36 years (SD 12). Twenty-six percent of this cohort experienced clinically relevant postoperative naming decline. The model included 5 variables: side of surgery, age at epilepsy onset, age at surgery, sex, and education. When applied to the external validation cohort, the model performed very well, with excellent calibration and a c statistic (reflecting discriminatory ability) of 0.81. A second model predicting moderate to severe postoperative naming decline included 3 variables: side of surgery, age at epilepsy onset, and preoperative naming score. This model generated a c statistic of 0.84 in the external validation cohort and showed good calibration.ConclusionExternally validated nomograms are provided in 2 easy-to-use formats (paper version and online calculator) clinicians can use to estimate the probability of naming decline in patients considering epilepsy surgery for treatment of pharmacoresistant temporal lobe epilepsy.

Objective:To determine whether Epstein-Barr virus (EBV) or cytomegalovirus (CMV) seropositivity is associated with multiple sclerosis (MS) in blacks and Hispanics and to what extent measures of the hygiene hypothesis or breastfeeding could explain these findings. EBV and CMV have been associated with MS risk in whites, and the timing and frequency of both viruses vary by factors implicated in the hygiene hypothesis.Methods:Incident cases of MS or its precursor, clinically isolated syndrome (CIS), and matched controls (blacks, 111 cases/128 controls; Hispanics, 173/187; whites, 235/256) were recruited from the membership of Kaiser Permanente Southern California. Logistic regression models accounted for HLA-DRB1*1501 status, smoking, socioeconomic status, age, sex, genetic ancestry, and country of birth.Results:Epstein-Barr nuclear antigen-1 (EBNA-1) seropositivity was independently associated with an increased odds of MS/CIS in all 3 racial/ethnic groups (p < 0.001 for blacks and whites, p = 0.02 for Hispanics). In contrast, CMV seropositivity was associated with a lower risk of MS/CIS in Hispanics (p = 0.004) but not in blacks (p = 0.95) or whites (p = 0.96). Being born in a low/middle-income country was associated with a lower risk of MS in Hispanics (p = 0.02) but not after accounting for EBNA-1 seropositivity. Accounting for breastfeeding did not diminish the association between CMV and MS in Hispanics.Conclusions:The consistency of EBNA-1 seropositivity with MS across racial/ethnic groups and between studies points to a strong biological link between EBV infection and MS risk. The association between past CMV infection and MS risk supports the broader hygiene hypothesis, but the inconsistency of this association across racial/ethnic groups implies noncausal associations.

Objective:This retrospective, observational study examined the frequency and magnitude of change in naming ability as a function of side/site of epilepsy surgery and identified predictive factors to assist clinicians in identifying patients at low, moderate, or high risk of postoperative naming decline.Methods:A total of 875 adults with pharmacoresistant epilepsy (454 left/421 right; 763 temporal/87 frontal/25 posterior quadrant) met inclusion criteria and completed the Boston Naming Test before and after surgery. Clinically meaningful change in naming ability was assessed using reliable change indices for epilepsy. Demographic, cognitive, and seizure variables were examined to determine factors most predictive of naming decline and to develop a decision tree to assist with clinical decision-making.Results:Naming decline was rare in right-sided resections and did not exceed the level expected by chance (5% overall; 90% confidence interval [CI] ± 2%). Naming decline occurred in 41% (CI ± 5%) of patients after left temporal resection (TLR) compared to 10%–12% (CI ± 10%–19%) in other left-sided surgical groups. A sizable proportion of left TLR patients (17%; CI ± 4%) showed substantial declines in naming (>11 points). Decline following left TLR was related to later age at seizure onset, older age at surgery, and higher preoperative naming ability. These factors correctly predicted naming decline in 68% of patients and were associated with degree of decline following left TLR. A decision tree is provided to assist clinicians in identifying patients at low, moderate, or high risk for postoperative naming declines.Conclusions:In addition to discussions regarding risk for memory decline following left TLR, patients should be counseled about potential decline in word-finding ability.

Objectives: The objective of this cohort study was to compare neuropsychological outcomes following left temporal lobe resection (TLR) in patients with epilepsy who had or had not undergone prior invasive monitoring. Methods: Data were obtained from an institutional review board–approved, neuropsychology registry for patients who underwent epilepsy surgery at Cleveland Clinic between 1997 and 2013. A total of 176 patients (45 with and 131 without invasive EEG) met inclusion criteria. Primary outcome measures were verbal memory and language scores. Other cognitive outcomes were also examined. Outcomes were assessed using difference in scores from before to after surgery and by presence/absence of clinically meaningful decline using reliable change indices (RCIs). Effect of invasive EEG on cognitive outcomes was estimated using weighting and propensity score adjustment to account for differences in baseline characteristics. Linear and logistic regression models compared surgical groups on all cognitive outcomes. Results: Patients with invasive monitoring showed greater declines in confrontation naming; however, when RCIs were used to assess clinically meaningful change, there was no significant treatment effect on naming performance. No difference in verbal memory was observed, regardless of how the outcome was measured. In secondary outcomes, patients with invasive monitoring showed greater declines in working memory, which were no longer apparent using RCIs to define change. There were no outcome differences on other cognitive measures. Conclusions: Results suggest that invasive EEG monitoring conducted prior to left TLR is not associated with greater cognitive morbidity than left TLR alone. This information is important when counseling patients regarding cognitive risks associated with this elective surgery.

Objective: Misleading manifestations of common epilepsy syndromes might account for some epilepsy surgery failures, thus we sought to characterize patients with difficult to diagnose (atypical) mesial temporal lobe epilepsy (mTLE). Methods: We retrospectively reviewed our surgical database over 12 years to identify patients who underwent a standard anterior temporal lobectomy after undergoing intracranial EEG (ICEEG) evaluation with a combination of depth and subdural electrodes. We carefully studied electroclinical manifestations, neuroimaging data, neuropsychological findings, and indications for ICEEG. Results: Of 835 patients who underwent anterior temporal lobectomy, 55 were investigated with ICEEG. Ten of these had atypical mTLE features and were not considered to have mTLE preoperatively. All of them had Engel class I outcome for 3 to 7 years (median 3.85). Five reported uncommon auras, and 3 had no auras. Scalp-EEG and nuclear imaging studies failed to provide adequate localization. None had MRI evidence of hippocampal sclerosis. However, ICEEG demonstrated exclusive mesial temporal seizure onset in all patients. Clues suggesting the possibility of mTLE were typical auras when present, anterior temporal epileptiform discharges or ictal patterns, small hippocampi, asymmetrical or ipsilateral temporal hypometabolism on PET, anterior temporal hyperperfusion on ictal SPECT, and asymmetry of memory scores. Histopathology revealed hippocampal sclerosis in 6 patients and gliosis in 2. Conclusions: Atypical electroclinical presentation may be deceptive in some patients with mTLE. We emphasize the importance of searching for typical mTLE features to guide ICEEG study of mesial temporal structures in such patients, who may otherwise mistakenly undergo extramesial temporal resections or be denied surgery.

Objective:This retrospective cohort study characterized cognitive and motor outcomes in a large sample of adults who underwent frontal lobe resections for treatment of pharmacoresistant epilepsy.Methods:Ninety patients who underwent unilateral frontal lobe resection for epilepsy (42 language-dominant hemisphere/48 nondominant hemisphere) between 1989 and 2014 completed comprehensive preoperative and postoperative neuropsychological evaluations that included measures of verbal and nonverbal intellectual functioning, attention/working memory, processing speed, language, executive functioning, verbal and visual memory, and motor functioning. Objective methods were used to assess meaningful change across a wide range of abilities and to identify factors associated with neuropsychological decline following frontal lobectomy. Detailed postoperative neuroimaging analysis was conducted to characterize region, extent, and volume of resection.Results:Forty-eight percent of patients did not demonstrate meaningful postoperative declines in cognition and an additional 42% demonstrated decline in 1 or 2 cognitive domains. When cognitive decline was observed, it usually occurred on measures of intelligence, visuomotor processing speed, or executive functioning. Side and site of resection were unrelated to cognitive outcome, but played a role in decline of contralateral manual dexterity following supplementary motor area resection. Higher preoperative ability, older age at surgery, absence of a malformation of cortical development on MRI, and poor seizure outcome were related to cognitive decline on some measures, but had poor sensitivity in identifying at-risk patients.Conclusions:The vast majority of patients who undergo frontal lobectomy for treatment of pharmacoresistant epilepsy demonstrate good cognitive and motor outcomes.

Objective: To examine the association between past pregnancy, offspring number, and first clinical demyelination risk. Methods: Cases (n = 282) were aged 18–59 years with a first clinical diagnosis of CNS demyelination (first clinical demyelinating event [FCD]) and resident within 1 of 4 Australian centers (from latitudes 27° south to 43° south) from 2003 to 2006. Controls (n = 542) were matched to cases on age, sex, and study region, without first clinical diagnosis of CNS demyelination. Results: Higher offspring number was associated with FCD risk among women ( p p = 0.71); difference in effect; p = 0.001. Among women, higher parity was associated with reduced risk of FCD (adjusted odds ratio 0.51 [95% confidence interval 0.36, 0.72] per birth) with a similar magnitude of effect observed among classic first demyelinating events (adjusted odds ratio 0.47 [95% confidence interval 0.29, 0.74]). The apparent beneficial effect of higher parity was also evident among parous women only ( p Conclusions: These findings are consistent with a cumulative beneficial effect of pregnancy. Temporal changes toward an older maternal age of parturition and reduced offspring number may partly underlie the increasing female excess among MS cases over time.

The course of multiple sclerosis (MS) is highly variable, manifest by a wide range in age at onset, either relapsing or progressive course from onset, and major differences in attack severity and recovery.1 Not surprisingly, the rate and age at which severe and permanent disabilities are attained are also highly variable. Most of these descriptors of outcome are generally considered independently of one another, as are the clinical and radiologic features of disease; however, certain features cluster and may define unique subtypes of CNS demyelinating disease. For example, neuromyelitis optica spectrum disorders (NMOSD), which had been traditionally considered as a type of MS, are characterized by older age at onset, relative selectivity for certain parts of the nervous system, and lack of association with a progressive course despite being associated with severe attacks.2 Until it was recognized that these characteristics define a unique subtype of disease, NMOSD was included in studies of prototypic MS, thereby distorting the perceived clinical course of MS. Furthermore, because NMOSD is associated with black ancestry, spurious conclusions were made about an association of black ancestry with severe attacks and adverse outcomes of MS. Quantitative differences in MS course also associate with race/ethnicity in individuals with MS, even when patients with NMOSD are excluded. African Americans have a worse prognosis than whites3; whites have a worse prognosis than Japanese.4

Objectives: To assess risk of a first clinical diagnosis of CNS demyelination (FCD) in relation to measures of Epstein-Barr virus (EBV) infection within the context of other known risk factors. Methods: This was a multicenter incident case-control study. FCD cases (n = 282) aged 18–59 years and controls (n = 558, matched on age, sex, and region) were recruited from 4 Australian centers between November 1, 2003, and December 31, 2006. A nested study (n = 215 cases, n = 216 controls) included measurement of whole blood quantitative EBV DNA load and serum EBV-specific antibodies. Conditional logistic regression was used to analyze case-control differences. Results: There were no significant case-control differences in the proportion with detectable EBV DNA (55.8% vs 50.5%, respectively, p = 0.28), or in quantitative EBV DNA load ( p = 0.33). Consistent with previous work, higher anti-EBV–specific immunoglobulin G (IgG) titers and a history of infectious mononucleosis were associated with increased FCD risk and there was an additive interaction with HLA-DRB1*1501 status. We found additional interactions between high anti-EBNA IgG titer and SNPs in HLA-A (adjusted odds ratios [AOR] = 19.84 [95% confidence interval (CI) 5.95 to 66.21] for both factors compared to neither) and CTLA-4 genes (AOR = 0.31 [95% CI 0.13 to 0.76] for neither factor compared to both). EBV DNA load was lower at higher serum 25-hydroxyvitamin D concentrations in controls ( r = −0.17, p = 0.01). An adverse effect of higher EBV DNA load on FCD risk was increased with higher 25-hydroxyvitamin D concentration ( p [interaction] = 0.02). Conclusion: Past infection with EBV, but not current EBV DNA load in whole blood, is significantly associated with increased FCD risk. These associations appear to be modified by immune-related gene variants.

Objectives: To examine whether past and recent sun exposure and vitamin D status (serum 25-hydroxyvitamin D [25(OH)D] levels) are associated with risk of first demyelinating events (FDEs) and to evaluate the contribution of these factors to the latitudinal gradient in FDE incidence in Australia. Methods: This was a multicenter incident case-control study. Cases (n = 216) were aged 18–59 years with a FDE and resident within one of 4 Australian centers (from latitudes 27°S to 43°S), from November 1, 2003, to December 31, 2006. Controls (n = 395) were matched to cases on age, sex, and study region, without CNS demyelination. Exposures measured included self-reported sun exposure by life stage, objective measures of skin phenotype and actinic damage, and vitamin D status. Results: Higher levels of past, recent, and accumulated leisure-time sun exposure were each associated with reduced risk of FDE, e.g., accumulated leisure-time sun exposure (age 6 years to current), adjusted odds ratio (AOR) = 0.70 (95% confidence interval [CI] 0.53–0.94) for each ultraviolet (UV) dose increment of 1,000 kJ/m 2 (range 508–6,397 kJ/m 2 ). Higher actinic skin damage (AOR = 0.39 [95% CI 0.17–0.92], highest grade vs the lowest) and higher serum vitamin D status (AOR = 0.93 [95% CI 0.86–1.00] per 10 nmol/L increase in 25(OH)D) were independently associated with decreased FDE risk. Differences in leisure-time sun exposure, serum 25(OH)D level, and skin type additively accounted for a 32.4% increase in FDE incidence from the low to high latitude regions. Conclusions: Sun exposure and vitamin D status may have independent roles in the risk of CNS demyelination. Both will need to be evaluated in clinical trials for multiple sclerosis prevention.

The etiology of multiple sclerosis (MS) is complex, involving genetic and environmental risk factors and their interactions. Furthermore, evidence suggests that the timing of exposure to environmental factors may be important. The exploration of risk associated with exposures distant in time, e.g., in childhood, or even before birth, presents particular difficulties. For example, month of birth has been considered a proxy for early-life vitamin D status. Thus, the finding that people with MS are more likely to have been born in spring and less likely to have been born in autumn in both southern and northern hemispheres (reviewed in reference 1) has been interpreted as possibly indicating that early-life vitamin D deficiency increases the risk of MS in adulthood. Determining any change in risk associated with other in utero exposures has been more challenging because of a lack of suitable validated proxies and a need to rely on self-reported events that occurred many years previously, during the pregnancy of the patient's mother. For example, in the Nurses' Health Studies, late initiation of prenatal care, diabetes during pregnancy, and maternal prepregnancy overweight/obesity were associated with modest increases in MS risk, although in most instances, the number of affected persons was small.2

Evidence of past infection with Epstein-Barr virus (EBV) and smoking are well-known risk factors for multiple sclerosis (MS). These 2 exposures together also are risk factors for several cancers, including nasopharyngeal carcinoma (NPC)[1][1],[2][2] and Hodgkin lymphoma (HL).[3][3],[4][4] For these

Objective: To investigate the relationship between the apolipoprotein (ApoE) e4 allele and memory performance (verbal and nonverbal) in patients with medically intractable temporal lobe epilepsy (TLE) who underwent temporal lobectomy. Methods: Presurgical and postsurgical memory performance was examined in 87 adult patients with TLE (e4 = 22; non-e4 = 65) to determine whether the expression of ApoE-e4 may be associated with memory performance in this population and to examine how this relationship may be affected by duration of epilepsy. Results: There was a significant interaction between ApoE-e4 status and duration of epilepsy such that e4 carriers with a long duration of epilepsy demonstrated the poorest memory performance on both verbal and nonverbal measures. This relationship was observed both before and after temporal lobectomy, with little change in test performance over time. Conclusions: The ApoE-e4 allele interacts with longstanding seizures to affect memory performance, both verbal and nonverbal, in patients with medically intractable temporal lobe epilepsy.

Fractures, particularly hip fractures, are a major public health issue, being associated with high morbidity and mortality.[1][1] Less than half of all hip fracture patients will ever fully recover ability to perform basic activities of daily living.[1][1] A number of the risk factors for falls and