Overall Memory Impairment Identification with Mathematical Modeling of the CVLT-II Learning Curve in Multiple Sclerosis

• Main Authors: Igor I. Stepanov, Charles I. Abramson, Marietta Hoogs, Ralph H. B. Benedict
• Format: Article
• Language: English
• Published: Hindawi Limited 2012-01-01
• Series: Multiple Sclerosis International
• Online Access: http://dx.doi.org/10.1155/2012/312503

The CVLT-II provides standardized scores for each of the List A five learning trials, so that the clinician can compare the patient's raw trials 1–5 scores with standardized ones. However, frequently, a patient's raw scores fluctuate making a proper interpretation difficult. The CVLT-II does not offer any other methods for classifying a patient's learning and memory status on the background of the learning curve. The main objective of this research is to illustrate that discriminant analysis provides an accurate assessment of the learning curve, if suitable predictor variables are selected. Normal controls were ninety-eight healthy volunteers (78 females and 20 males). A group of MS patients included 365 patients (266 females and 99 males) with clinically defined multiple sclerosis. We show that the best predictor variables are coefficients 𝐵3 and 𝐵4 of our mathematical model 𝐵3∗exp(−𝐵2∗(𝑋−1))+𝐵4∗(1−exp(−𝐵2∗(𝑋−1))) because discriminant functions, calculated separately for 𝐵3 and 𝐵4, allow nearly 100% correct classification. These predictors allow identification of separate impairment of readiness to learn or ability to learn, or both.