Word Memory Test Profiles in Two Cases with Surgical Removal of the Left Anterior Hippocampus and Parahippocampal Gyrus

Failing Performance Validity Cutoffs on the Boston Naming Test (BNT) Is Specific, but Insensitive to Non-Credible Responding

This study was designed to examine alternative validity cutoffs on the Boston Naming Test (BNT).Archival data were collected from 206 adults assessed in a medicolegal setting following a motor vehicle collision. Classification accuracy was evaluated against three criterion PVTs.The first cutoff to achieve minimum specificity (.87-.88) was T ≤ 35, at .33-.45 sensitivity. T ≤ 33 improved specificity (.92-.93) at .24-.34 sensitivity. BNT validity cutoffs correctly classified 67-85% of the sample. Failing the BNT was unrelated to self-reported emotional distress. Although constrained by its low sensitivity, the BNT remains a useful embedded PVT.

Evaluation of the classification accuracy of multiple performance validity tests in a mixed clinical sample

The Test of Memory Malingering (TOMM) and Word Memory Test (WMT) are among the most well-known performance validity tests (PVTs) and regarded as gold standard measures. Due to the many factors that impact PVT selection, it is imperative that clinicians make informed clinical decisions with respect to additional or alternative PVTs that demonstrate similar classification accuracy as these well-validated measures. The present archival study evaluated the agreement/classification accuracy of a large battery consisting of multiple other freestanding/embedded PVTs in a mixed clinical sample of 126 veterans. We examined failure rates for all standalone/embedded PVTs using established cut-scores and calculated pass/fail agreement rates and diagnostic odds ratios for various combinations of PVTs using the TOMM and WMT as criterion measures. TOMM and WMT demonstrated the best agreement, followed by Word Choice Test (WCT). The Rey Fifteen Item Test had an excessive number of false-negative errors and reduced classification accuracy. The Digit Span age-corrected scaled score (DS-ACSS) had highest agreement. Findings lend further support to the use of a combination of embedded and standalone PVTs in identifying suboptimal performance. Results provide data to enhance clinical decision making for neuropsychologists who implement combinations of PVTs in a larger clinical battery.

The license plate test performance in Canadian adolescents with learning disabilities: A preliminary study

Accurate identification of symptom exaggeration is essential when determining whether data obtained in pediatric evaluations are valid or interpretable. Performance validity measures identify performance patterns that are implausible if the test taker is investing full effort; however, it is unclear whether or not persons with preexisting cognitive difficulties such as Specific Learning Disabilities (SLD) might be falsely accused of poor test motivation due to actual but impaired reading, processing or memory skills. The purpose of this study was to evaluate the newly developed License Plate Test (LPT) performance in students with identified SLD providing good effort, to examine the influence of severe reading or learning problems on LPT performance. Participants were 29 students with SLDs aged 11-14 years (M = 12.1), who completed psycho-educational assessments as part of a transition program to secondary school. Results indicate that recognition memory measures on the LPT were insensitive to cognitive impairments in these children; all students achieved scores of 80% or higher on these tasks. Performance was more variable as test demands of the LPT increased, and the difference between performance on easy and hard subtests was related to greater difficulties with working memory. These results provide preliminary data regarding how children with SLD perform on the LPT, allowing for development of appropriate cut scores to maximize sensitivity and specificity of this test for use with child and adolescent populations.

Performance validity test failure in clinical populations-a systematic review

Performance validity tests (PVTs) are widely used in attempts to quantify effort and/or detect negative response bias during neuropsychological testing. However, it can be challenging to interpret the meaning of poor PVT performance in a clinical context. Compensation-seeking populations predominate in the PVT literature. We aimed to establish base rates of PVT failure in clinical populations without known external motivation to underperform. We searched MEDLINE, EMBASE and PsycINFO for studies reporting PVT failure rates in adults with defined clinical diagnoses, excluding studies of active or veteran military personnel, forensic populations or studies of participants known to be litigating or seeking disability benefits. Results were summarised by diagnostic group and implications discussed. Our review identified 69 studies, and 45 different PVTs or indices, in clinical populations with intellectual disability, degenerative brain disease, brain injury, psychiatric disorders, functional disorders and epilepsy. Various pass/fail cut-off scores were described. PVT failure was common in all clinical groups described, with failure rates for some groups and tests exceeding 25%. PVT failure is common across a range of clinical conditions, even in the absence of obvious incentive to underperform. Failure rates are no higher in functional disorders than in other clinical conditions. As PVT failure indicates invalidity of other attempted neuropsychological tests, the finding of frequent and unexpected failure in a range of clinical conditions raises important questions about the degree of objectivity afforded to neuropsychological tests in clinical practice and research.

The use of the MSVT in children and adolescents with epilepsy

Pediatric neuropsychologists are increasingly recognizing the importance of performance validity testing during evaluations. The use of such measures to detect insufficient effort is of particular importance in pediatric epilepsy evaluations, where test results are often used to guide surgical decisions and failure to detect poor task engagement can result in postsurgical cognitive decline. The present investigation assesses the utility of the Medical Symptom Validity Test (MSVT) in 104 clinically referred children and adolescents with epilepsy. Though the overall failure rate was 15.4% of the total group, children with 2nd grade or higher reading skills (a requirement of the task) passed at a very high rate (96.6%). Of the three failures, two were unequivocally deemed true positives, while the third failed due to extreme somnolence during testing. Notably, for those with ≥2nd grade reading levels, MSVT validity indices were unrelated to patient age, intellectual functioning, or age of epilepsy onset, while modest relations were seen with specific memory measures, number of epilepsy medications, and seizure frequency. Despite these associations, however, this did not result in more failures in this population of children and adolescents with substantial neurologic involvement, as pass rates exceeded 92% for those with intellectual disability, high seizure frequency, high medication burden, and even prior surgical resection of critical memory structures.

Performance validity test failure predicts suppression of neuropsychological test results in developmentally disabled children

There is increasing awareness of the need to use Performance Validity Tests (PVTs) when assessing cognitive abilities in children. Since 1996, there has been an ongoing clinical study of the use of three PVTs with a consecutive series of 1,285 developmentally disabled children. In this study, we report on the results of these PVTs in children of many diagnostic categories. Failure rates on all three tests were very low. The mean scores on the effort measures in those passing the PVTs were extremely high. Failure on each PVT was found to be associated with a significant and widespread suppression of scores across a neuropsychological battery. Failure on even one PVT significantly suppresses ability test scores.

A Comparative Study of Feature Selection Methods for the Discriminative Analysis of Temporal Lobe Epilepsy

It is crucial to differentiate patients with temporal lobe epilepsy (TLE) from the healthy population and determine abnormal brain regions in TLE. The cortical features and changes can reveal the unique anatomical patterns of brain regions from structural magnetic resonance (MR) images. In this study, structural MR images from 41 patients with left TLE, 34 patients with right TLE, and 58 normal controls (NC) were acquired, and four kinds of cortical measures, namely cortical thickness, cortical surface area, gray matter volume (GMV), and mean curvature, were explored for discriminative analysis. Three feature selection methods including the independent sample t-test filtering, the sparse-constrained dimensionality reduction model (SCDRM), and the support vector machine-recursive feature elimination (SVM-RFE) were investigated to extract dominant features among the compared groups for classification using the support vector machine (SVM) classifier. The results showed that the SVM-RFE achieved the highest performance (most classifications with more than 84% accuracy), followed by the SCDRM, and the t-test. Especially, the surface area and GMV exhibited prominent discriminative ability, and the performance of the SVM was improved significantly when the four cortical measures were combined. Additionally, the dominant regions with higher classification weights were mainly located in the temporal and the frontal lobe, including the entorhinal cortex, rostral middle frontal, parahippocampal cortex, superior frontal, insula, and cuneus. This study concluded that the cortical features provided effective information for the recognition of abnormal anatomical patterns and the proposed methods had the potential to improve the clinical diagnosis of TLE.

Neuropsychological outcomes following stereotactic laser amygdalohippocampectomy

OBJECTIVE

The objective was to analyze neuropsychological testing data from 15 patients before and after stereotactic laser ablation surgery for temporal lobe epilepsy and to describe the seizure outcomes after stereotactic laser ablation surgery.

METHODS

A retrospective review of 15 patients who underwent stereotactic laser ablation and who also underwent neuropsychological testing before and after surgery was performed. Verbal and visual memory was assessed in all 15 patients using California Verbal Learning Test and Wechsler Memory Scale IV. Naming was assessed in 9 of 15 patients using the Boston Naming Test. Statistical analysis was performed to determine clinically significant changes using previously validated reliable change indices and proprietary Advanced Clinical Solutions software. Seizure outcome data were evaluated using Engel classification.

RESULTS

Postsurgery neuropsychological evaluation demonstrated that all 15 patients experienced at least 1 clinically significant decline in either verbal or visual memory. Ten patients in this series, including five with dominant-hemisphere surgery, demonstrated decline in delayed memory for narrative information (Logical Memory II). By contrast, the Boston Naming Test demonstrated more favorable results after surgery. Two of nine patients demonstrated a clinically significant increase in naming ability, and only one of nine patients demonstrated a clinically significant decline in naming ability. With at least 6months of follow-up after surgery, 33% reported seizure freedom.

CONCLUSION

Stereotactic laser ablation can result in clinically significant and meaningful decline in verbal and visual memory when comparing patients to their own presurgical baseline. Naming ability, conversely, is much less likely to be impacted by stereotactic laser ablation and may improve after the procedure.

Word Memory Test Predicts Recovery in Claimants With Work-Related Head Injury

OBJECTIVE

To investigate the predictive validity of the Word Memory Test (WMT), a verbal memory neuropsychological test developed as a performance validity measure to assess memory, effort, and performance consistency.

DESIGN

Cohort study with 1-year follow-up.

SETTING

Workers' compensation rehabilitation facility.

PARTICIPANTS

Participants included workers' compensation claimants with work-related head injury (N=188; mean age, 44y; 161 men [85.6%]).

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Outcome measures for determining predictive validity included days to suspension of wage replacement benefits during the 1-year follow-up and work status at discharge in claimants undergoing rehabilitation. Analysis included multivariable Cox and logistic regression.

RESULTS

Better WMT performance was significantly but weakly correlated with younger age (r=-.30), documented brain abnormality (r=.28), and loss of consciousness at the time of injury (r=.25). Claimants with documented brain abnormalities on diagnostic imaging scans performed better (∼9%) on the WMT than those without brain abnormalities. The WMT predicted days receiving benefits (adjusted hazard ratio, 1.13; 95% confidence interval, 1.04-1.24) and work status outcome at program discharge (adjusted odds ratio, 1.62; 95% confidence interval, 1.13-2.34).

CONCLUSIONS

Our results provide evidence for the predictive validity of the WMT in workers' compensation claimants. Younger claimants and those with more severe brain injuries performed better on the WMT. It may be that financial incentives or other factors related to the compensation claim affected the performance.

Utility of Green's Word Memory Test Free Recall Subtest as a Measure of Verbal Memory: Initial Evidence from a Temporal Lobe Epilepsy Clinical Sample

This study investigated the Word Memory Test (WMT) Free Recall (FR) subtest as a conventional memory measure. Nineteen participants with pharmacoresistant left temporal lobe epilepsy (LTLE) and 16 with right temporal lobe epilepsy (RTLE) completed the WMT, Rey Auditory Verbal Learning Test (RAVLT), and Wechsler Memory Scale-Fourth Edition Logical Memory (LM) subtest during presurgical evaluation. LTLE participants performed significantly worse on FR subtest (p < .05, [Formula: see text]) and RAVLT Trial 7 (p < .01, [Formula: see text]), but not on LM subtest. Age was a significant covariate for FR (p < .01, [Formula: see text]). Logistic regression revealed FR plus age and RAVLT age-adjusted T-scores both yielded 77.1% classification accuracy and respective diagnostic odds ratios of 11.36 and 11.84. Receiver operating characteristic curves to classify seizure laterality found that RAVLT and FR were significant (area under the curve [AUC] = 0.82 and 0.74), whereas LM was nonsignificant (AUC = 0.67). Cut scores and positive/negative predictive values were established for improved clinical classification.

Effort, symptom validity testing, performance validity testing and traumatic brain injury

BACKGROUND

To understand the neurocognitive effects of brain injury, valid neuropsychological test findings are paramount.

REVIEW

This review examines the research on what has been referred to a symptom validity testing (SVT). Above a designated cut-score signifies a 'passing' SVT performance which is likely the best indicator of valid neuropsychological test findings. Likewise, substantially below cut-point performance that nears chance or is at chance signifies invalid test performance. Significantly below chance is the sine qua non neuropsychological indicator for malingering. However, the interpretative problems with SVT performance below the cut-point yet far above chance are substantial, as pointed out in this review. This intermediate, border-zone performance on SVT measures is where substantial interpretative challenges exist. Case studies are used to highlight the many areas where additional research is needed. Historical perspectives are reviewed along with the neurobiology of effort. Reasons why performance validity testing (PVT) may be better than the SVT term are reviewed.

CONCLUSIONS

Advances in neuroimaging techniques may be key in better understanding the meaning of border zone SVT failure. The review demonstrates the problems with rigidity in interpretation with established cut-scores. A better understanding of how certain types of neurological, neuropsychiatric and/or even test conditions may affect SVT performance is needed.