Racial differences in adult-onset MRI-negative temporal lobe epilepsy.

OBJECTIVE: We recently detected a significant racial difference in our population with temporal lobe epilepsy (TLE) at the University of Alabama at Birmingham (UAB) seizure monitoring unit. We found that Black patients were more likely than their White counterparts to carry a TLE diagnosis. Using this same patient population, we focus on the patients with TLE to better describe the relationship between race and epidemiology in this population. METHODS: We analyzed the data from patients diagnosed with TLE admitted to the UAB seizure monitoring unit between January 2000 and December 2011. For patients with a video electroencephalography (EEG) confirmed diagnosis of TLE (n = 385), basic demographic information including race and magnetic resonance imaging (MRI) findings were collected. Descriptive statistics and multivariate logistic regression were used to explore the relationship between MRI findings, demographic data, and race. RESULTS: For Black patients with TLE, we found that they were more likely to be female (odds ratio [OR] = 1.91, 95% confidence interval [CI]: 1.14-3.19), have seizure onset in adulthood (OR = 2.39, 95% CI: 1.43-3.19), and have normal MRIs (OR = 1.69, 95% CI: 1.04-2.77) compared to White counterparts with TLE after adjusting for covariates. CONCLUSIONS: These data suggest that Black race (compared to White) is associated with higher expression of adult-onset MRI-negative TLE, an important subtype of epilepsy with unique implications for evaluation, treatment, and prognosis. If validated in other cohorts, the findings may explain the lower reported rates of epilepsy surgery utilization among Blacks. The racial differences in surgical utilization could be due to a greater prevalence of an epilepsy that is less amenable to surgical resection rather than to cultural differences or access to care.

Racial disparities in temporal lobe epilepsy.

OBJECTIVE: This study reports on epilepsy type period prevalence and black-white racial differences in a large patient population in the Southeastern United States. METHODS: For all patients visiting the University of Alabama at Birmingham's seizure monitoring unit between 2000 and 2011 (n = 3240), video EEG diagnosis was recorded along with basic demographic information. Descriptive statistics and multivariate logistic regression were used to identify factors associated with temporal lobe epilepsy (TLE) diagnosis. RESULTS: The racial distribution was 77.3% white, and 20.0% black (other races were only 2.3% of the population). Most patients had either TLE (n = 630) or PNES (n = 1150) compared to other focal (n = 424) or generalized epilepsies (n = 224). The diagnosis of TLE was significantly greater for blacks than whites (odds ratio [OR] = 1.87, 95% confidence interval [CI] 1.47-2.37). The period prevalence measures for the other conclusively diagnosed epilepsies were not significantly different. Women were disproportionately represented in the study population, and black women carried the most statistical weight for the TLE prevalence difference. INTERPRETATION: The nearly two-fold larger period prevalence of TLE among black patients is a striking finding that merits explanation. Although some selection bias exists due to a moderately lower than expected representation of blacks, socioeconomic status or access to care should not be assumed to be the only factors that might be responsible for the prevalence difference. Rather, all clues for distinct pathophysiological racial differences should be explored.

Association study of functional polymorphisms in serotonin transporter gene with temporal lobe epilepsy in Han Chinese population.

BACKGROUND AND PURPOSE: Serotoninergic dysfunction was reported to be involved in aetiology of temporal lobe epilepsy (TLE). Serotonin (5-HT) is actively cleared from synaptic cleft by serotonin transporter (5-HTT). We investigated the association between three common polymorphisms of 5-HTT gene, which may influence gene expression or function, and risk for TLE. METHODS: Three hundred and thirty-four patients with TLE and four hundred and eighty-seven non-epileptic control subjects from Han Chinese origin were enrolled for the present study. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method was used for genotyping. RESULTS: 10-repeat allele frequency of 17 bp variable number of tandem repeats in the second intron (5-HTTVNTR) was moderately higher in patients with TLE than in controls (9.1% vs. 6.1%, P=0.0187, OR=1.55, 95%CI=1.07-2.26). CONCLUSION: Our study suggested 10-repeat allele of 5-HTTVNTR may be associated with TLE susceptibility.

Racial disparities in the surgical management of intractable temporal lobe epilepsy in the United States: a population-based analysis.

OBJECTIVE: To determine whether, over a long time span, race and/or other predictive factors for patients with intractable temporal lobe epilepsy (TLE) who receive anterior temporal lobectomy (ATL) exist on a national level. DESIGN: Retrospective cohort study. PATIENTS: Adult patients with TLE admitted for ATL (International Classification of Diseases, Ninth Revision, Clinical Modification, 345.41, 345.51; primary procedure code, 01.53). INTERVENTIONS: A population-based analysis was performed using the Nationwide Inpatient Sample from 1988 through 2003. Variables besides race that were examined included patient age, sex, and insurance status. RESULTS: Of the 5779 adults admitted with TLE from 1988 through 2003, 562 (9.7%) received ATL. Multivariate analyses revealed that African American race (odds ratio [OR], 0.56; 95% confidence interval [CI], 0.38-0.84; P = .005) and increased age (OR, 0.98; 95% CI, 0.97-0.99; P < .001 per 1-year increase in age) independently predicted decreased likelihood of receiving ATL for TLE, while private insurance increased the odds of ATL receipt (OR, 1.85; 95% CI, 1.39-2.46; P < .001). These findings remained stable over time. CONCLUSIONS: Fewer than 10% of the TLE patient population receives ATL. Younger age and private insurance are independent predictors of receiving ATL, and African American race independently predicts decreased likelihood of receiving ATL. Despite recent attempts to bridge racial health disparities, the gap between African American and other races in optimal TLE management has remained relatively unchanged on a nationwide level.

Detecting differential memory performance among Spanish-speaking patients with temporal lobe epilepsy.

There is relatively little research pertaining to neuropsychological assessment of Spanish-speaking individuals with intractable temporal lobe epilepsy (TLE). The current study examined verbal and visual memory performances in 38 primarily Spanish-speaking patients with TLE (Right = 15, Left = 23) of similar epilepsy duration to determine if lateralizing differences can be found using verbal and nonverbal memory tests. On a test specifically designed to assess auditory learning and memory among Spanish-speaking individuals, the Spanish Verbal Learning Test (SVLT), patients with left TLE performed significantly worse than patients with right TLE. In contrast, no significant differences in story or visual memory were seen using common memory tests translated into Spanish. Similar to what has been found in English speakers, these results show that verbal memory differences can be seen between left and right sided TLE patients who are Spanish-speaking to aid in providing lateralizing information; however, these differences may be best detected using tests developed for and standardized on Spanish-speaking patients.

Race/ethnicity, sex, and socioeconomic status as predictors of outcome after surgery for temporal lobe epilepsy.

BACKGROUND: Several risk factors have been attributed to seizure recurrence after surgery. It is unknown whether race/ethnicity plays a role in outcome. OBJECTIVE: To evaluate whether race/ethnicity plays a role in seizure recurrence after surgery. DESIGN: Cohort study. SETTING: We evaluated data obtained from the epilepsy centers at the University of Alabama at Birmingham and New York University, New York, NY. PATIENTS: All patients included had a diagnosis of mesial temporal sclerosis and underwent temporal lobectomy. MAIN OUTCOME MEASURES: Occurrence of seizure after surgery was registered 1 year after surgery. We used multiple logistic regression analysis to model the presence of seizure recurrence after surgery and generated odds ratios (ORs) for seizure recurrence after surgery for African American and Hispanic patients relative to white patients. An unadjusted model incorporated only race/ethnicity as the independent variable, and an adjusted model included socioeconomic status, age, duration of epilepsy, education, history of febrile seizures, sex, handedness, lateralization of epileptogenic focus, and number of antiepileptics as the independent variables. RESULTS: Two hundred fifty-two patients underwent surgical treatment with pathological confirmation of mesial temporal sclerosis. No differences were found between racial/ethnic groups in terms of seizure recurrence in any models. For African American patients, the ORs were 0.9 (95% confidence interval [CI], 0.4-2.1) for the unadjusted model and 0.8 (95% CI, 0.3-2.0) for the adjusted model; for Hispanic patients, the ORs were 1.6 (95% CI, 0.8-3.2) for the unadjusted model and 1.1 (95% CI, 0.5-2.6) for the adjusted model, relative to white patients. CONCLUSION: Our data suggest that although sex appears to play a role in the outcomes of surgery for temporal lobe epilepsy, race and socioeconomic status do not.

Racial disparities in the use of surgical treatment for intractable temporal lobe epilepsy.

OBJECTIVE: To compare the use of surgical treatment for epilepsy among different ethnic and racial groups with surgically remediable temporal lobe epilepsy (TLE). METHODS: The authors used multiple logistic regression analysis to model the use of anterior temporal lobectomy in a cross-sectional study of video-EEG monitoring discharge data among residents of Alabama and surrounding states discharged from the University of Alabama at Birmingham Hospital between July 1998 and January 2003 with a primary diagnosis of TLE. RESULTS: Of 432 patients diagnosed with TLE, 130 had evidence of mesial temporal sclerosis on MRI studies. Seventy patients underwent surgery; African Americans were less likely than non-Hispanic whites to undergo surgical treatment (odds ratio, 0.3; 95% CI, 0.2 to 0.8). After potential demographic (age, education, and sex), socioeconomic, medical insurance coverage, and clinical confounders (bitemporal seizure onset) were controlled, African Americans had a 60% less chance to receive surgery than non-Hispanic whites. CONCLUSIONS: There are disparities in the use of surgical treatment for temporal lobe epilepsy. Race appears to be an influential factor related to such disparities.

Mutation analysis of the leucine-rich, glioma inactivated 1 gene (LGI1) in Japanese febrile seizure patients.

Mutations in the leucine-rich, glioma inactivated 1 gene (LGI1) were recently identified in some families with autosomal dominant lateral temporal epilepsy (ADLTE). To investigate whether the LGI1 gene is a susceptibility gene for febrile seizures (FS), we performed a systematic search for mutations in 94 unrelated Japanese patients with FS. We detected two intronic polymorphisms (IVS2 + 19 A/G and IVS6 - 18 T/C). No non-synonymous mutation was detected. We genotyped these polymorphisms and performed a case-control study and transmission disequilibrium testing (TDT) of 62 FS families (n = 230) and 105 control subjects. None of the polymorphisms was significantly associated with FS. Our results indicate that genomic variations in the LGI1 gene are not likely to be substantially involved in the etiology of FS in the Japanese population.

Lateralizing value of the Wada memory test in non-Western patients with temporal lobe epilepsy.

The Wada memory test measures a psychological construct (i.e. memory), which is widely acknowledged to be under the influence of a vast array of moderating variables including culture. Thus, the lateralizing value of the Wada memory test for epileptogenic foci may potentially differ for Western versus non-Western patients with temporal lobe epilepsy (TLE). In the present study, the lateralizing value of the Wada memory test was investigated in 17 Korean patients with medically intractable TLE who were post-operatively seizure-free. The Wada memory stimuli were composed of eight drawings of common objects, animals, and fruits. A clinical criterion of at least 2 points difference between left and right injections correctly classified 14 patients (82%) into left and right TLE groups, with only one patient (6%) falsely classified. This diagnostic accuracy is at least as high as that reported for Western TLE patients. These results indicate that whatever culture-specific factors Korean TLE patients may bring to the Wada memory test, they do not significantly reduce the lateralizing value of the test.

Malaysian children with: "benign epilepsy of childhood with centrotemporal spikes".

Benign epilepsy of childhood with centrotemporal spikes (BECT) was studied in Malaysian children, and was observed in Chinese, Malay and Indian children in the ratio 10:6:5. There were 12 boys and 9 girls. Fit frequency varied from almost daily to a single fit. The age of onset ranged from 2-13 years and BECT was not noted in any child over 13 years old. There was a strong circadian rhythm and fits occurred mainly in sleep. Generalised seizures were more common than partial seizures. During the 3-year study from April 1989 to April 1992, 21 children with BECT were identified from the EEG records done at the University Hospital and it was found that this genetic epilepsy which is autosomal dominant with age dependent penetrance occurs in approximately 4.8% of our epileptic children. In addition there were 3 children in whom petit mal co-existed with a BECT EEG trait.