A factor analytic investigation of the Mercy Evaluation of Multiple Sclerosis

Standalone Performance Validity Tests May Be Differentially Related to Measures of Working Memory, Processing Speed, and Verbal Memory in Patients With Multiple Sclerosis

Cognitive functioning may account for minimal levels (i.e., 5%-14%) of variance of performance validity test (PVT) scores in clinical examinees. The present study extended this research twofold: (a) by determining the variance cognitive functioning explains within three distinct PVTs (b) in a sample of patients with multiple sclerosis (pwMS). Seventy-five pwMS (Mage = 48.50, 70.6% female, 80.9% White) completed the Victoria Symptom Validity Test (VSVT), Word Choice Test (WCT), Dot Counting Test (DCT), and three objective measures of working memory, processing speed, and verbal memory as part of clinical neuropsychological assessment. Regression analyses in credible groups (ns ranged from 54 to 63) indicated that cognitive functioning explained 24% to 38% of the variance in logarithmically transformed PVT variables. Variance from cognitive testing differed across PVTs: verbal memory significantly influenced both VSVT and WCT scores; working memory influenced VSVT and DCT scores; and processing speed influenced DCT scores. The WCT appeared least related to cognitive functioning of the included PVTs. Alternative plausible explanations, including the apparent domain/modality specificity hypothesis of PVTs versus the potential sensitivity of these PVTs to neurocognitive dysfunction in pwMS were discussed. Continued psychometric investigations into factors affecting performance validity, especially in multiple sclerosis, are warranted.

Language impairments in people with autoimmune neurological diseases: A scoping review

INTRODUCTION

Autoimmune neurological diseases (ANDs) are a specific type of autoimmune disease that affect cells within the central and peripheral nervous system. ANDs trigger various physical/neuropsychiatric symptoms. However, language impairments in people with ANDs are not well characterized. Here we aimed to determine the kinds of language impairment that most commonly emerge in 10 ANDs, the characteristics of the patients (demographic, neurological damage), and the assessment methods used.

METHODS

We followed the PRISMA Extension for Scoping Reviews (PRISMA-ScR). PubMed and Google Scholar were searched. We used a list of search terms containing 10 types of ANDs (e.g., multiple sclerosis, acute disseminated encephalomyelitis) in combination with the terms aphasia, dysphasia, fluency, language, listening, morphology, phonology, pragmatics, reading, semantics, speaking, syntax, writing. The reference lists and citations of the relevant papers were also investigated. The type of AND, patient characteristics, neurological damage and examination technique, language tests administered, and main findings were noted for each study meeting the inclusion criteria.

RESULTS

We found 171 studies meeting our inclusion criteria. These comprised group studies and case studies. Language impairments differed largely among types of ANDs. Neurological findings were mentioned in most of the papers, but specific language tests were rarely used.

CONCLUSIONS

Language symptoms in people with ANDs are commonly reported. These are often not full descriptions or only focus on specific time points in the course of the disease. Future research needs to assess specific language functions in people with ANDs and relate their language impairments to brain damage at different stages of disease evolution.

Examining the Clinical Utility of Selected Memory-Based Embedded Performance Validity Tests in Neuropsychological Assessment of Patients with Multiple Sclerosis

Within the neuropsychological assessment, clinicians are responsible for ensuring the validity of obtained cognitive data. As such, increased attention is being paid to performance validity in patients with multiple sclerosis (pwMS). Experts have proposed batteries of neuropsychological tests for use in this population, though none contain recommendations for standalone performance validity tests (PVTs). The California Verbal Learning Test, Second Edition (CVLT-II) and Brief Visuospatial Memory Test, Revised (BVMT-R)—both of which are included in the aforementioned recommended neuropsychological batteries—include previously validated embedded PVTs (which offer some advantages, including expedience and reduced costs), with no prior work exploring their utility in pwMS. The purpose of the present study was to determine the potential clinical utility of embedded PVTs to detect the signal of non-credibility as operationally defined by below criterion standalone PVT performance. One hundred thirty-three (133) patients (M age = 48.28; 76.7% women; 85.0% White) with MS were referred for neuropsychological assessment at a large, Midwestern academic medical center. Patients were placed into “credible” (n = 100) or “noncredible” (n = 33) groups based on a standalone PVT criterion. Classification statistics for four CVLT-II and BVMT-R PVTs of interest in isolation were poor (AUCs = 0.58–0.62). Several arithmetic and logistic regression-derived multivariate formulas were calculated, all of which similarly demonstrated poor discriminability (AUCs = 0.61–0.64). Although embedded PVTs may arguably maximize efficiency and minimize test burden in pwMS, common ones in the CVLT-II and BVMT-R may not be psychometrically appropriate, sufficiently sensitive, nor substitutable for standalone PVTs in this population. Clinical neuropsychologists who evaluate such patients are encouraged to include standalone PVTs in their assessment batteries to ensure that clinical care conclusions drawn from neuropsychological data are valid.

Nonmemory Composite Embedded Performance Validity Formulas in Patients with Multiple Sclerosis

OBJECTIVE

Research regarding performance validity tests (PVTs) in patients with multiple sclerosis (MS) is scant, with recommended batteries for neuropsychological evaluations in this population lacking suggestions to include PVTs. Moreover, limited work has examined embedded PVTs in this population. As previous investigations indicated that nonmemory-based embedded PVTs provide clinical utility in other populations, this study sought to determine if a logistic regression-derived PVT formula can be identified from selected nonmemory variables in a sample of patients with MS.

METHOD

A total of 184 patients (M age = 48.45; 76.6% female) with MS were referred for neuropsychological assessment at a large, Midwestern academic medical center. Patients were placed into "credible" (n = 146) or "noncredible" (n = 38) groups according to performance on standalone PVT. Missing data were imputed with HOTDECK.

RESULTS

Classification statistics for a variety of embedded PVTs were examined, with none appearing psychometrically appropriate in isolation (areas under the curve [AUCs] = .48-.64). Four exponentiated equations were created via logistic regression. Six, five, and three predictor equations yielded acceptable discriminability (AUC = .71-.74) with modest sensitivity (.34-.39) while maintaining good specificity (≥.90). The two predictor equation appeared unacceptable (AUC = .67).

CONCLUSIONS

Results suggest that multivariate combinations of embedded PVTs may provide some clinical utility while minimizing test burden in determining performance validity in patients with MS. Nonetheless, the authors recommend routine inclusion of several PVTs and utilization of comprehensive clinical judgment to maximize signal detection of noncredible performance and avoid incorrect conclusions. Clinical implications, limitations, and avenues for future research are discussed.