Neuropsychological functioning in dysgenesis of the corpus callosum with colpocephaly.

Dysgenesis of the corpus callosum is a rare developmental abnormality in brain structure that is associated with changes in physical appearance, as well as behavioral and cognitive consequences. A relatively commonly co-occurring structural abnormality with callosal dysgenesis is colpocephaly, characterized by enlargement of the posterior lateral ventricles and reductions in posterior brain volume. Although some case studies of individuals with this combination of structural malformations exist, they do not often report results of neuropsychological evaluation. Furthermore, those that do contain neuropsychological data may be of limited generalizability due to unique patient characteristics. The current manuscript overcomes these limitations by presenting the case of a 55-year-old male with callosal dysgenesis and colpocephaly identified in adulthood. The paper includes a full profile of his performance on a comprehensive neuropsychological test battery with discussion of differential diagnosis and treatment planning. Findings indicated low average intellectual abilities with deficits in processing speed, executive functions, and social cognition, consistent with expectations based on callosal dysgenesis. One surprising finding was that despite the significant posterior involvement of colpocephaly, visuospatial skills were a relative strength. The manuscript provides a clear characterization of callosal dysgenesis with colpocephaly to facilitate future clinical comparisons and set the stage for future research on this rare neuromorphological presentation.

The utility of the Wisconsin card sorting test, 64-card version to detect noncredible attention-deficit/hyperactivity disorder.

Clinicians who evaluate patients with concerns related to attention-deficit/hyperactivity disorder (ADHD) are encouraged to include validity indicators throughout clinical assessment procedures. To date, no known previous literature has examined the Wisconsin Card Sorting Test (WCST) specifically to address noncredible ADHD, and none has attempted to identify an embedded PVT within the 64-card version. The present study sought to address these gaps in the literature with a simulation study. Sixty-seven undergraduate participants (M age = 19.30) were grouped as credible (combining healthy controls and individuals with ADHD) or noncredible (combining coached and uncoached participants simulating ADHD-related impairment) and administered a battery of neuropsychological tests. Results revealed the noncredible group performed significantly worse on several WCST-64 variables, including failure to maintain set, number of trials to first category, and total categories. Raw scores from these variables were entered as predictors as one set in a logistic regression (LR) with group membership as the outcome variable. An exponentiated equation (EE) derived from LR results yielded acceptable discriminability (area under receiver operating characteristic curve = .73) with modest sensitivity (.38) while maintaining ideal specificity (.91), generally commensurate with a standalone forced-choice memory PVT and better than an embedded attention-based PVT. These findings suggested the WCST-64 may be sensitive to noncredible performance in the context of ADHD and reiterates the importance of considering tests of various cognitive abilities in the evaluation of performance validity. Implications of these findings, limitations of the present study, and directions for future inquiry, including cross-validation in clinical samples, were discussed.