Sensitivity of Green's Word Memory Test genuine memory impairment profile to temporal pathology: a study in patients with temporal lobe epilepsy

Abstract

Performance validity tests (PVTs) such as Green's Word Memory Test (WMT) are designed to have face validity as memory tests while individuals with neurologically based memory deficits can score adequately provided there is sufficient task engagement. Some patients with severe memory loss have performed poorly on the WMT, raising questions about false positive errors. This study compared performances of 43 patients with left, right, or bilateral temporal lobe epilepsy on the WMT to a test known to be sensitive to temporal lobe pathology, the Rey Auditory Verbal Learning Test (RAVLT). The right TLE group outperformed the left on the WMT free recall (FR) scores and RAVLT short-delay and long-delay trials (Trials 6 and 7) (p < .05); no other between-group differences occurred (p ≥ .10). Ten participants (20.4%) performed below the cut-off score on at least one WMT effort subtest, but eight (80%) exhibited the genuine memory impairment profile (GMIP). Logistic regression found no WMT subtest contributed to predicting side of seizure with RAVLT scores in the model. Data suggest WMT primary effort subtests are generally insensitive to known temporal lobe pathology, and using the GMIP is valuable to identify individuals with severe memory loss who score below criterion on WMT primary effort subtests.

Keywords: Epilepsy; Malingering.; Performance validity test; Sensitivity; Word Memory Test.