Ayman Shahein

University of Calgary · Department of Clinical Neurosciences

This study was designed to expand on a recent meta-analysis that identified ≤42 as the optimal cutoff on the Word Choice Test (WCT). We examined the base rate of failure and the classification accuracy of various WCT cutoffs in four independent clinical samples (N = 252) against various psychometrically defined criterion groups. WCT ≤ 47 achieved a...

Objective: This study was designed to compare different versions of the letter fluency test (FAS/CFL), evaluate the effect of repeat administration and the classification accuracy of traditional and novel cutoffs as performance validity tests (PVTs). Method: Archival data were collected from a mixed clinical sample (n = 64) of patients physician-re...

Background: Delirium is a common neurologic manifestation of coronavirus disease 2019 (COVID–19) in older adults who present to the emergency department (ED). Objective: To investigate clinical characteristics associated with delirium as a presenting symptom of COVID–19 in older adults and develop a logistic regression to predict the likelihood of...

Objective : Replicate previous research on Logical Memory Recognition (LMRecog) and perform a critical item analysis. Method : Performance validity was psychometrically operationalized in a mixed clinical sample of 213 adults. Classification of the LMRecog and nine critical items (CR-9) was computed. Results : LMRecog ≤20 produced a good combinat...

Objective This study was designed to investigate clinical characteristics associated with mortality and predictors of survival in older adults hospitalized with COVID-19 with a focus on neurological comorbidities and presenting neurological manifestations.Methods We compared clinical characteristics in an age- and gender-matched sample of 75 deceas...

Background: Balloon guide catheters are increasingly used to improve clot retrieval by temporarily stopping proximal blood flow during endovascular thrombectomy. Purpose: Our aim was to provide a summary of the literature comparing the procedural and clinical outcomes of endovascular thrombectomy with or without balloon guide catheters, dependin...

Objective: This study was designed to examine the classification accuracy of verbal fluency (VF) measures as performance validity tests (PVT). Method: Student volunteers were assigned to the control (n = 57) or experimental malingering (n = 24) condition. An archival sample of 77 patients with TBI served as a clinical comparison. Results: Among stu...

Introduction Randomized trials of direct aspiration (ADAPT) vs retrievable stent (RS) did not show a difference in 90-day outcomes. We searched existing literature for differences in reperfusion times and success between the two techniques. Methods We performed a systematic review to identify relevant articles in electronic databases and referen...

Introduction: Randomized trials of direct aspiration (ADAPT) vs retrievable stent (RS) did not show a difference in 90-day outcomes. We searched existing literature for differences in reperfusion times and success between the two techniques. Methods: We performed a systematic review to identify relevant articles in electronic databases and referenc...

Cognitive reserve could mask the deleterious effects of neurodegenerative disorders in older adults with high premorbid functioning, resulting in false negatives on cognitive screening tests. Failing to detect early signs of cognitive decline may result in missing a critical period of intervention with disease modifying drugs or making informed dec...

Lenient scoring of spatial orientation errors (SOE) on the Mini-Mental State Exam (MMSE) is common practice, even though it deviates from standard protocol and may compromise its diagnostic power. This study was designed to empirically evaluate the effect of lenient scoring on the MMSE’s classification accuracy. Participants were 113 community dwel...

A link between noncredible responding and low scores on the Grooved Pegboard Test (GPB) is well documented in the clinical literature. However, no specific validity cutoffs have emerged in previous research. This study was designed to examine the classification accuracy of various demographically adjusted cutoffs on the GPB against established meas...

Introduction: The Recognition Memory Test (RMT) and Word Choice Test (WCT) are structurally similar, but psychometrically different. Previous research demonstrated that adding a time-to-completion cutoff improved the classification accuracy of the RMT. However, the contribution of WCT time-cutoffs to improve the detection of invalid responding has...