Specificity of performance validity tests in patients with confirmed epilepsy

Area of Science:

• Neuropsychology
• Epilepsy Research
• Psychometrics

Background:

• Performance validity tests (PVTs) are crucial in neuropsychological evaluations.
• Concerns exist regarding PVT use in epilepsy due to potential performance fluctuations.
• This study investigates PVT specificity in a confirmed epilepsy cohort.

Purpose of the Study:

• To assess the specificity of the Warrington Recognition Memory Test (WRMT)-Words and the Test of Memory Malingering (TOMM) at established cutoffs in epilepsy patients.
• To determine if these PVTs maintain diagnostic accuracy in this population.

Main Methods:

• Eighty-two epilepsy patients underwent neuropsychological evaluation including WRMT-Words and TOMM.
• Frequency tables were used to calculate specificity rates for each PVT.
• Analysis focused on established and suggested cutoffs for accuracy and time scores.

Main Results:

• WRMT-Words Accuracy Score cutoff (≤42) showed 90.2% specificity; Total Time cutoff (≥207s) showed 95.1% specificity.
• TOMM Trial 1 (<40) had 93.9% specificity; Trial 2 (<45) and Retention Trial (<45) showed 98.6% and 100.0% specificity, respectively.
• Specificity remained acceptable across various epilepsy characteristics.

Conclusions:

• The WRMT-Words and TOMM demonstrate acceptable specificity in a select epilepsy population.
• PVTs can be valuable tools in neuropsychological assessments for epilepsy patients.
• Factors like interictal discharges may influence performance and warrant further investigation.