B - 10 Performance Validity Test Failure Base Rates among Presurgical Epilepsy Referrals

Abstract Objective Patients with epilepsy undergoing presurgical workup are generally considered a population without clear incentive to perform invalidly during neuropsychological evaluation. This study investigated the base rates of performance validity test (PVT) failure among a sample of presurgical epilepsy patients. Participants and. Methods Data were collected from 68 consecutive patients with epilepsy undergoing outpatient neuropsychological evaluation for surgical candidacy. The sample included 33 males/35 females, had a mean age of 36.29 (SD = 12.07), mean education of 12.51 (SD = 2.23), and was racially and ethnically diverse. All patients were administered a number of freestanding (Test of Memory Malingering [TOMM], Dot Counting Test [DCT], Coin-in-Hand [CIH]) and embedded (Rey Auditory Verbal Learning Test-Forced Choice [RAVLT-FC], Wechsler Memory Scale–3rd Edition Digit Span Reliable Digit Span [WMS-III DS RDS]) PVTs within a comprehensive neuropsychological assessment battery. Results Overall, 9% of the sample failed ≥2 PVTs, suggesting invalidity. An additional 22% failed 1 PVT. However, a large portion of the sample (69%) passed all freestanding and embedded PVTs. Among the freestanding PVTs, the failure rates were TOMM: 4%, DCT: 21%, and CIH: 3%. Failure rates on embedded PVTs were RAVLT-FC: 15% and WMS-III DS RDS: 3%. Conclusions Although there is not an expected incentive for suboptimal neuropsychological performance among presurgical epilepsy patients, results show a critical need for objective validity assessment to guard against inaccurate surgical prognostication from invalid test data for patients undergoing high-stakes presurgical evaluations. Given the high invalidity rate on some individual PVTs, further research is necessary to cross-validate established PVT cut-scores in epilepsy-specific populations.