Evaluating Processing Speed in Multiple Sclerosis: A Comparison of Two Rapid Serial Processing Measures

Abstract

Processing speed deficits in patients with multiple sclerosis (MS) are usually assessed with tests requiring rapid serial processing. Two such tests were compared here, the Paced Auditory Serial Addition Test (PASAT) and a computerized version of the Stroop test. The purpose of this study was to examine the concurrent validity of processing speed measures derived from the Stroop test and to relate these measures to disability ratings in a sample of 75 patients with relapsing-remitting MS. Patients evidenced slower processing speed than controls on both tests. Processing speed scores on the Stroop test were more closely related to patients’ disability status. These results demonstrate the usefulness of rapid serial processing tests in assessing what is increasingly recognized as the primary cognitive deficit in MS. A less-distressing approach than the item-paced performance required by the PASAT appears to be fully adequate for evaluating this deficit.

Keywords:

• Cognition
• Information processing speed
• Attention
• Stroop test
• Disability

Acknowledgments

The data reported in this article were collected in conjunction with a project funded by a grant from EMD Serono-Pfizer. The results were presented in part at the 23rd annual congress of the European Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS) in Prague, Czech Republic (October 12, 2007). The data for this project were collected in compliance with the authors’ institutions and in accordance with the guidelines of the Helsinki Declaration.