Avraham Schweiger

Validity of a novel computerized cognitive battery for mild cognitive impairment.

BackgroundThe NeuroTrax Mindstreams computerized cognitive assessment system was designed for widespread clinical and research use in detecting mild cognitive impairment (MCI). However, the capability of Mindstreams tests to discriminate elderly with MCI from those who are cognitively healthy has yet to be evaluated. Moreover, the comparability between these tests and traditional neuropsychological tests in detecting MCI has not been examined.MethodsA 2-center study was designed to assess discriminant validity of tests in the Mindstreams Mild Impairment Battery. Participants were 30 individuals diagnosed with MCI, 29 with mild Alzheimers disease (AD), and 39 healthy elderly. Testing was with the Mindstreams battery and traditional neuropsychological tests. Receiver operating characteristic (ROC) analysis was used to examine the ability of Mindstreams and traditional measures to discriminate those with MCI from cognitively healthy elderly. Between-group comparisons were made (Mann-Whitney U test) between MCI and healthy elderly and between MCI and mild AD groups.ResultsMindstreams outcome parameters across multiple cognitive domains significantly discriminated among MCI and healthy elderly with considerable effect sizes (p < 0.05). Measures of memory, executive function, visual spatial skills, and verbal fluency discriminated best, and discriminability was at least comparable to that of traditional neuropsychological tests in these domains.ConclusionsMindstreams tests are effective in detecting MCI, providing a comprehensive profile of cognitive function. Further, the enhanced precision and ease of use of these computerized tests make the NeuroTrax system a valuable clinical tool in the identification of elderly at high risk for dementia.

Comparative neuropsychology of adult obsessive‐compulsive disorder and attention deficit/hyperactivity disorder: Implications for a novel executive overload model of OCD

Research implicates frontostriatal pathophysiology in both attention deficit/hyperactivity disorder (ADHD) and obsessive-compulsive disorder (OCD). Nevertheless, ADHD is characterized with frontostriatal hypoactivity and OCD with hyperactivity. Furthermore, both disorders seem to lie on opposite ends of a clinical impulsive-compulsive continuum. While never having directly been compared, and despite these differences, OCD and ADHD appear to share similar neuropsychological impairments especially in executive functions. This study aimed at comparing adults with OCD and adults with ADHD on neuropsychological measures and behavioural impulsivity and OC measures. Thirty OCD, 30 ADHD, and 30 matched healthy control (HC) participants were administered a comprehensive neuropsychological battery and completed several questionnaires. The groups were compared on all neuropsychological and clinical measures and correlations between neuropsychological and clinical symptoms were computed. The ADHD and OCD groups performed more poorly than HC on all neuropsychological domains and most domain subtests. The ADHD group reported significantly higher impulsivity than the OCD group. OCD patients did not differ from HC on behavioural impulsivity. A unique dissociation was found between impulsivity and response inhibition where both clinical groups showed similar response inhibition deficit, but differed significantly on impulsivity. Moreover, a negative association between OC symptoms and response inhibition and a bias in self-perception of impulsivity was found only in the OCD group. We propose an executive overload model of OCD that views neuropsychological impairments in OCD as an epiphenomenon, according to which continuous attempts to control automatic processes are associated with obsessive thoughts overflow that causes an overload on the executive system.

Computerized cognitive testing battery identifies mild cognitive impairment and mild dementia even in the presence of depressive symptoms

Cognitive and depressive symptoms co-occur, complicating detection of mild cognitive impairment (MCI) and early dementia. In this study, discriminant validity of a novel computerized cognitive battery for MCI detection was evaluated after covariation for depressive symptom severity. In addition to the computerized battery, participants at two sites received the 30-item self-administered Geriatric Depression Scale (GDS; n = 72); those at two other centers received the observer-administered Cornell Scale for Depression in Dementia (CSDD; n = 88). In both cohorts, a Global Cognitive Score and memory, executive function, visual spatial, and verbal index scores discriminated among cognitively healthy, MCI, and mild dementia groups after covariation for GDS or CSDD, respectively (p < 0.05). Thus, the computerized battery for detection of mild impairment is robust to comorbid depressive symptoms, supporting its clinical utility in identifying neurodegenerative disease even in elderly with depression.

Validity of the Mindstreams Computerized Cognitive Battery for Mild Cognitive Impairment

This article, published as an invited review in the special ISOA issue of the journal, was first published as an original article in BMC Geriatrics: Dwolatzky T, Whitehead V, Doniger GM, Simon ES, Schweiger A, Jaffe D, Chertkow H. Validity of a novel computerized cognitive battery for mild cognitive impairment. BMC Geriatrics, 3, 4–16, 2003. J Mol Neurosci (2008) 35:251 DOI 10.1007/s12031-007-9031-9

Neuropsychological Impairments and Their Association with Obsessive-Compulsive Symptom Severity in Obsessive-Compulsive Disorder

Neurobiological research in obsessive-compulsive disorder (OCD) consistently demonstrates an association between abnormal brain activity and symptom severity. Conversely, research addressing the corresponding neuropsychological impairments in OCD and their association with symptom severity has produced inconsistent results. This study reexamines neuropsychological performance and its association with symptom severity in 30 participants with OCD while controlling for confounding variables. We used a computerized neuropsychological battery that was expected to provide more objective and accurate information and minimize examinee-examiner interactions, which may affect performance by reducing anxiety. The OCD group revealed dysfunctions on all neuropsychological domains compared with controls. OCD severity correlated significantly with the composite performance, executive functions, and verbal domain indexes. These results did not change after controlling for depression severity. We suggest that controlling for potential confounding variables and using a computerized battery may have contributed to the association found between obsessive symptoms and neuropsychological impairments. Theoretical implications are discussed.

Unwanted intrusive and worrisome thoughts in adults with Attention Deficit\Hyperactivity Disorder

Attention Deficit/Hyperactivity Disorder (ADHD) is associated with deficient motor and cognitive inhibitory mechanisms. The aim of this article is to examine two symptoms associated with cognitive disinhibition, namely: intrusive unwanted thoughts, worrisome thoughts and their suppression. Thirty-seven college students diagnosed with ADHD and 23 healthy college students were compared on the Distressing Thoughts Questionnaire and on the Anxious Thoughts Inventory. Results show that in comparison to the control group, participants with ADHD experienced significantly higher ratings on all intrusive thoughts scales, and three worrisome thoughts scales. Our results suggest that worrisome intrusive thoughts are an important phenotypical expression of adults with ADHD. A neurobiological explanation for this phenomenon is suggested, and clinical implications are discussed.

Neuropsychological investigations in obsessive-compulsive disorder: A systematic review of methodological challenges

The inconsistent nature of the neuropsychology literature pertaining to obsessive-compulsive disorder (OCD) has long been recognized. However, individual studies, systematic reviews, and recent meta-analytic reviews were unsuccessful in establishing a consensus regarding a disorder-specific neuropsychological profile. In an attempt to identify methodological factors that may contribute to the inconsistency that is characteristic of this body of research, a systematic review of methodological factors in studies comparing OCD patients and non-psychiatric controls on neuropsychological tests was conducted. This review covered 115 studies that included nearly 3500 patients. Results revealed a range of methodological weaknesses. Some of these weaknesses have been previously noted in the broader neuropsychological literature, while some are more specific to psychiatric disorders, and to OCD. These methodological shortcomings have the potential to hinder the identification of a specific neuropsychological profile associated with OCD as well as to obscure the association between neurocognitive dysfunctions and contemporary neurobiological models. Rectifying these weaknesses may facilitate replicability, and promote our ability to extract cogent, meaningful, and more unified inferences regarding the neuropsychology of OCD. To that end, we present a set of methodological recommendations to facilitate future neuropsychology research in psychiatric disorders in general, and in OCD in particular.

Adjustment of Cognitive Scores with a Co-Normed Estimate of Premorbid Intelligence: Implementation Using Mindstreams Computerized Testing

Neuropsychological assessment is critically dependent upon comparison to a standard normative database. While generally appropriate for individuals of near-average intelligence, high-intelligence individuals may be erroneously scored as unimpaired and low-intelligence individuals as impaired on cognitive measures. The current paper describes an approach for minimizing such misclassifications that is standardized and practical for clinical use. A computerized test of nonverbal reasoning co-normed with cognitive measures is used for automatic adjustment of normalized cognitive scores. This premorbid estimate showed good construct validity, and adjustment raised cognitive scores for low-intelligence individuals, and lowered cognitive scores for high-intelligence individuals similarly across demographic (age, education, computer experience) and clinical (cognitively healthy, mild cognitive impairment, dementia) subgroups. Adjustment was typically up to three normalized units for scores on the premorbid estimate of ±1 SD and 6 normalized units for scores of ±2 SD. The present approach shows promise as a practical solution for assessment of high- and low-intelligence individuals.

Detecting Response Bias on the MindStreams Battery

The most effective tests for detection of negative response bias (NRB) are based on the forced choice paradigm, but patients coached prior to their administration may easily discern their purpose. Algorithms for NRB detection based upon parameters from standard neuropsychological tests may be more difficult for patients to discern and thus more effective in detecting NRB. The current study aimed to uncover abnormal performance patterns associated with NRB on the MindStreams computerized battery. Simulators, cognitively healthy controls, and genuinely cognitively impaired patients participated in the study. A repeated measures analysis was applied to delineate anomalous patterns on Verbal Memory, Non-Verbal Memory, Staged Information Processing Speed, and Stroop tests. The variables derived from this analysis were entered into a multivariate discriminant function analysis (DFA). The DFA model, based on accuracy, reaction time (RT) and accuracy/RT measures, differentiated efficiently between simulators and the two control groups. Various cut-offs were provided based on this model. It is concluded that computerized cognitive testing may be valuable for malingering assessment using detection strategies based on performance patterns.

Empirically derived algorithm for performance validity assessment embedded in a widely used neuropsychological battery: Validation among TBI patients in litigation.

Introduction: Validity of neuropsychological assessment depends, inter alia, on the cooperation of the examinee, requiring separate assessment. Stand-alone tests devised for detecting negative response bias (NRB) are exposed to potential threats to their validity. In this study, an algorithm was developed for assessing NRB within a standardized, computerized neuropsychological battery (NeuroTrax), making it difficult to detect and circumvent. Method: Data were collected from the archived medical records of 75 outpatients with mild to moderate head injury, all in litigation. Participants were classified as low or high likelihood for NRB, using a known test for effort assessment (Test of Memory Malingering). Results: Variables judged to be prone for exaggeration and showing large differences between the groups were entered into a logistic regression analysis. The resulting formula exhibited high specificity (98.0%) and sensitivity (87.5%), classifying correctly 94% of the cases. Conclusion: It is suggested that the algorithm developed empirically using scores on the NeuroTrax computerized battery can be a useful tool for assessing effort. This algorithm should resist threats to its validity and can be automatically computed while assessing a range of cognitive skills.