Sensitivity and Specificity of Memory and Naming Tests for Identifying Left Temporal-Lobe Epilepsy

Naming assessment in bilinguals for epilepsy surgery-adaptation and standardization of Boston Naming Test in India

PURPOSE

Naming difficulty is associated with temporal lobe epilepsy and a decline in naming ability is reported following dominant temporal lobe resections. The Boston Naming Test (BNT) is the most frequently used test for assessing naming ability. Evaluating naming ability in bilingual/multilingual populations is a challenge when participants are restricted to responding in one language. The study aimed to adapt and standardize the BNT as a valid clinical tool for evaluating bilingual/multilingual people undergoing epilepsy surgery in urban India.

RESULTS

Culture-appropriate adaptations were done, and participants were allowed to respond in any language. Data from 197 participants showed a strong education effect. The adaptation showed strong internal consistency, reliability, construct validity, and high sensitivity to left temporal lobe epilepsy performance.

CONCLUSIONS

The adapted version that allowed for flexible use of more than one language is a useful clinical tool for evaluating bilingual people undergoing epilepsy surgery.

Reliable change on the selective reminding test in a series of left-hemisphere language dominant patients with right temporal lobe epilepsy

The Selective Reminding Test (SRT) is widely used in pre-surgical evaluations for people with epilepsy; however, important characteristics such as reliability and stability over time within an epilepsy-specific control cohort are unclear. In this study, we document test-retest reliabilities, practice effects, and Reliable Change Indices (RCI) for this test in a sample of right temporal lobe epilepsy patients who are left hemisphere dominant for language and underwent surgical resection on the right temporal lobe. A sample of 101 adults with a right temporal lobe seizure focus (mean age = 38.5) was administered the SRT pre- and post-right temporal lobe surgery. Test-retest reliabilities were modest (r = 0.44-0.59). Practice effects were minimal (0.25-2.04). Reliable Change Indices were calculated and ranged from 4 to 26 depending on the SRT index. The RCI's indicate that relatively moderate to large changes on the SRT are needed for a change score to be considered a significant change in an individual's performance. The RCIs can be used to detect a reliable change in patients undergoing left temporal lobe epilepsy surgery who are at significant risk for verbal memory decline.

Exploring the Semantic Structure of WMS-IV Verbal Paired Associates using the Hub-and-Spoke Model

OBJECTIVES

This study aimed to identify a well-fitting and theoretically justified item-level latent factor structure for the Wechsler Memory Scales (WMS)-IV verbal paired associates (VerbalPA) subtest to facilitate the ease and accuracy of score interpretations for patients with lateralized temporal lobe epilepsy (TLE).

METHODS

Archival data were used from 250 heterogeneous neurosciences patients who were administered the WMS-IV as part of a standard neuropsychological assessment. Three theoretically motivated models for the latent structure of VerbalPA were tested using confirmatory factor analysis. The first model, based on cognitive principles of semantic processing from hub-and-spoke theory, tested whether performance is related to specific semantic features of target words. The second, motivated by the Cattell-Horn-Carroll (CHC) model of cognitive abilities, investigated whether the associative properties of items influence performance. A third, Hybrid model tested whether performance is related to both semantic and associative properties of items. The best-fitting model was tested for diagnostic group effects contrasting the heterogeneous neuroscience patients with subsets of left and right TLE (n = 51, n = 26, respectively) patients.

RESULTS

The Hybrid model was found to have the best fit. Patients with left TLE scored significantly less well than the heterogeneous neurosciences sample on selected semantic factor scores, although the effect size was small.

CONCLUSIONS

Future editions of the WMS may consider implementing a semantic scoring structure for the VerbalPA to facilitate test score interpretation. Additionally, these results suggest that principles of hub-and-spoke theory may be integrated into CHC cognitive ability taxonomy.

Boston Naming Test: Lose the Noose

OBJECTIVE

Administering the noose item of the Boston Naming Test (BNT) has been questioned given the cultural, historical, and emotional salience of the noose in American culture. In response, some have modified the BNT by skipping/removing this item and giving the point as if the examinee responded correctly. It is unknown, however, whether modifying standardized administration and scoring in this manner affects clinical interpretation. In the present study, we examined the prevalence of noose item failure, whether demographic and clinical characteristics differed between those who responded correctly versus failed the item, and whether giving a point to those who failed affected clinical interpretation.

METHOD

Participants included a mixed clinical sample of 762 adults, ages 18-88 years, seen for neuropsychological evaluation at one of five sites within the USA.

RESULTS

Those who failed the item (13.78%) were more likely to be female, non-White, and have primary diagnoses of major neurocognitive disorder, epilepsy, or neurodevelopmental disorder. Noose item failure was associated with lower BNT total score, fewer years of education and lower intellectual functioning, expressive vocabulary, and single word reading. Giving a point to those who failed the item resulted in descriptor category change for 17.1%, primarily for patients with poor overall BNT performance.

CONCLUSIONS

Only a small percentage of patients fail the noose item, but adding a point for these has an impact on score interpretation. Factors associated with poorer overall performance on the BNT, rather than specific difficulty with the noose item, likely account for the findings.

Teleneuropsychology in the time of COVID-19: The experience of The Australian Epilepsy Project

PURPOSE

Traditional neuropsychological testing carries elevated COVID-19 risk for both examinee and examiner. Here we describe how the pilot study of the Australian Epilepsy Project (AEP) has transitioned to tele-neuropsychology (teleNP), enabling continued safe operations during the pandemic.

METHODS

The AEP includes adults (age 18-60) with a first unprovoked seizure, new diagnosis of epilepsy or drug resistant focal epilepsy. Shortly after launching the study, COVID-related restrictions necessitated adaptation to teleNP, including delivery of verbal tasks via videoconference; visual stimulus delivery via document camera; use of web-hosted, computerised assessment; substitution of oral versions for written tests; online delivery of questionnaires; and discontinuation of telehealth incompatible tasks.

RESULTS

To date, we have completed 24 teleNP assessments: 18 remotely (participant in own home) and six on-site (participant using equipment at research facility). Five face-to-face assessments were conducted prior to the transition to teleNP. Eight of 408 tests administered via teleNP (1.9 %) have been invalidated, for a variety of reasons (technical, procedural, environmental). Data confirm typical patterns of epilepsy-related deficits (p < .05) affecting processing speed, executive function, language and memory. Questionnaire responses indicate elevated rates of patients at high risk of mood (34 %) and anxiety disorder (38 %).

CONCLUSION

Research teleNP assessments reveal a typical pattern of impairments in epilepsy. A range of issues must be considered when introducing teleNP, such as technical and administrative set up, test selection and delivery, and cohort suitability. TeleNP enables large-scale neuropsychological research during periods of social distancing (and beyond), and offers an opportunity to expand the reach and breadth of neuropsychological services.

Cortical gray-white matter blurring and declarative memory impairment in MRI-negative temporal lobe epilepsy

Magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) may be a distinct syndrome from TLE with mesial temporal sclerosis (TLE-MTS). Imaging and neuropsychological features of TLE-MTS are well-known; yet, these features are only beginning to be described in MRI-negative TLE. This study examined whether a quantitative measure of cortical gray and white matter blurring (GWB) was elevated in the temporal lobes ipsilateral to the seizure onset zone of individuals with MRI-negative TLE relative to TLE-MTS and healthy controls (HCs) and whether GWB elevations were associated with neuropsychological comorbidity. Gray-white matter blurring from 34 cortical regions and hippocampal volumes were quantified and compared across 28 people with MRI-negative TLE, 15 people with TLE-MTS, and 51 HCs. Declarative memory was assessed with standard neuropsychological tests and the intracarotid amobarbital procedure (IAP). In the group with MRI-negative TLE (left and right onsets combined), hippocampal volumes were within normal range but GWB was elevated, relative to HCs, across several mesial and lateral temporal lobe regions ipsilateral to the seizure onset zone. Gray-white matter blurring did not differ between the groups with TLE-MTS and HC or between the groups with TLE-MTS and MRI-negative TLE. The group with MRI-negative TLE could not be distinguished from the group with TLE-MTS on any of the standard neuropsychological tests; however, ipsilateral hippocampal volumes and IAP memory scores were lower in the group with TLE-MTS than in the group with MRI-negative TLE. The group with left MRI-negative TLE had lower general cognitive abilities and verbal fluency relative to the HC group, which adds to the characterization of neuropsychological comorbidities in left MRI-negative TLE. In addition, ipsilateral IAP memory performance was reduced relative to contralateral memory performance in MRI-negative TLE, indicating some degree of ipsilateral memory dysfunction. There was no relationship between hippocampal volume and IAP memory scores in MRI-negative TLE; however, decreased ipsilateral IAP memory scores were correlated with elevated GWB in the ipsilateral superior temporal sulcus of people with left MRI-negative TLE. In sum, GWB elevations in the ipsilateral temporal lobe of people with MRI-negative TLE suggest that GWB may serve as a marker for reduced structural integrity in regions in or near the seizure onset zone. Although mesial temporal abnormalities might be the major driver of memory dysfunction in TLE-MTS, a loss of structural integrity in lateral temporal lobe regions may contribute to IAP memory dysfunction in MRI-negative TLE.

Dementia-Related Neuropsychological Testing Considerations in Non-Hispanic White and Latino/Hispanic Populations

Hispanic individuals are at greater risk for health disparities, less than optimal health care, and are diagnosed at later stages of cognitive impairment than white non-Hispanics. Acculturation and different attitudes toward test-taking may result in decrements in performance, especially on unfamiliar measures that emphasize speed and accuracy. Non-Hispanic individuals often outperform Hispanic individuals on cognitive and neuropsychological measures in community and clinical populations. Current neuropsychological testing may not provide accurate data related to monolingual and bilingual individuals of Hispanic descent. Testing instruments were identified by searching academic databases using combinations of relevant search terms. Neuropsychological instruments were included if they were designed to detect cognitive impairment, had an administration time of less than 45 minutes, and were available in English. Validity studies were required to employ gold standard comparison diagnostic criteria. Twenty-nine instruments were evaluated in dementia staging, global cognition, memory, memory and visual abilities, working memory and attention, verbal learning and memory, recall, language, premorbid intelligence, literacy/cognitive reserve, visuospatial, attention, problem-solving, problem solving and perception, functional assessment, and mood/daily functioning domains. Spanish-language neuropsychological instruments need to be made widely available and existing instruments to be normed in Spanish to best serve and assess diverse populations. Psychometric data were reported for neuropsychological instruments, which may be administered to Hispanic older adults presenting for evaluation related to dementia-spectrum disorders. This is one of the few reviews to provide an overview of the sensitivity and specificity of available Spanish translated neuropsychological instruments.

Machine learning as a new paradigm for characterizing localization and lateralization of neuropsychological test data in temporal lobe epilepsy

In this study, we employed a kernel support vector machine to predict epilepsy localization and lateralization for patients with a diagnosis of epilepsy (n = 228). We assessed the accuracy to which indices of verbal memory, visual memory, verbal fluency, and naming would localize and lateralize seizure focus in comparison to standard electroencephalogram (EEG). Classification accuracy was defined as models that produced the least cross-validated error (CVϵ). In addition, we assessed whether the inclusion of norm-based standard scores, demographics, and emotional functioning data would reduce CVϵ. Finally, we obtained class probabilities (i.e., the probability of a particular classification for each case) and produced receiver operating characteristic (ROC) curves for the primary analyses. We obtained the least error assessing localization data with the Gaussian radial basis kernel function (RBF; support vectors = 157, CVϵ = 0.22). There was no overlap between the localization and lateralization models, such that the poorest localization model (the hyperbolic tangent kernel function; support vectors = 91, CVϵ = 0.36) outperformed the strongest lateralization model (RBF; support vectors = 201, CVϵ = 0.39). Contrary to our hypothesis, the addition of norm, demographics, and emotional functioning data did not improve the accuracy of the models. Receiver operating characteristic curves suggested clinical utility in classifying epilepsy lateralization and localization using neuropsychological indicators, albeit with better discrimination for localizing determinations. This study adds to the existing literature by employing an analytic technique with inherent advantages in generalizability when compared to traditional single-sample, not cross-validated models. In the future, class probabilities extracted from these and similar analyses could supplement neuropsychological practice by offering a quantitative guide to clinical judgements.