We compared the California Learning Verbal Test II (CVLT II) and the Open Trial-Selective Reminding Test (OT-SRT) in assessing learning in persons with Multiple Sclerosis. One-hundred and twelve participants with multiple sclerosis performed the OT-SRT and the CVLT II on two different days. All participants completed additional cognitive tests assessing information processing speed (IPS), working memory (WM), and executive functions (EF). By definition, all participants were identified as having impaired learning on the OT-SRT (i.e., z score <-1.0); however, only 38 participants (33.9%) were identified as having impaired learning on the CVLT II (i.e., a z score <-1 total correct responses trials 1-5). The sample was thus divided into two groups, those who failed both tests (Fail-2) and those who failed only one (Fail-1). The Fail-2 group showed poorer performance on EF, WM and IPS in comparison with the Fail-1 group. On the CVLT II, the Fail-1 group showed a significantly greater improvement between trials 1 and 5, as compared with the Fail-2 group. However, the two groups performed similarly on the OT-SRT. Correlation analysis showed that EF is positively correlated with CVLT II learning slope but not with OT-SRT learning slope. The CVLT II and the OT-SRT are not equivalent tests: while the CVLT II appears to be sensitive to overall cognitive dysfunction, the OT-SRT is more sensitive to focal learning and memory impairments.
Keywords: Cognitive assessment; learning; multiple sclerosis.