Deficits in Processing Speed and Decision Making in Relapsing-Remitting Multiple Sclerosis: The Digit Clock Drawing Test(dCDT)David J. Libon1*, Dana L. Penney2, Randal Davis3, David S. Tabby4, Joel Eppig1, Christine Nieves1, Aaron Bloch1, Jacqueline B. Donohue1, Laura Brennan1, Katherine L. Rife1, Graham Wicas1, Melissa Lamar5, Catherine C. Price6, Rhoda Au7, Rod Swenson8 and Kelly Davis Garrett9, on behalf of the Clock Sketch Consortium
- Corresponding Author:
- David J. Libon, Ph.D
Department of Neurology, Drexel University College of Medicine
245 North 15th Street, Philadelphia, PA, 19102, USA
E-mail: [email protected]
Received date: April 11, 2014; Accepted date: August 27, 2014; Published date: September 01, 2014
Citation: Libon DJ, Penney DL, Davis R, Tabby DS, Eppig J et al. (2014) Deficits in Processing Speed and Decision Making in Relapsing-Remitting Multiple Sclerosis: The Digit Clock Drawing Test (dCDT). J Mult Scler 1:113. doi:10.4172/2376-0389.1000113
Copyright: © 2014 Libon DJ, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
The current research assessed how digital clock drawing test (dCDT) parameters compliment and convey additional information in conjunction with traditional clock drawing scoring methods in patients with multiple sclerosis (MS). MS and normal control (NC) clock drawing performance was initially scored using a 10-point scale where NC test performance classified MS patients into impaired versus non-impaired clock drawing groups. dCDT variables included intra-component latencies or the time elapsed between clock drawing components (i.e., time between last element drawn followed by the first clock hand); inter-digit latency (i.e., average time between drawing numbers; and quartile drawing time (i.e., total drawing time divided into four equal segments. Subsequent analyses assessed dCDT parameters and other neuropsychological tests related to deficits in processing speed and other neurocognitive functions. In the command condition impaired MS patients produced slower selected intracomponents and slower 3rd and 4th quartile latencies (p<0.032) compared to other groups. In the copy condition impaired MS patients also displayed slower selected intra-components and slower latencies in all four quartiles compared to NCs (p<0.003), but slower latencies only for the 3rd and 4th quartiles compared to non-impaired MS patients (p<0.016). Regression analyses associated slower combined intra-component latencies with reduced processing speed (Symbol Copy, WAIS-R-NI), category (‘animal’) fluency, and CVLT recognition discriminability, and the propensity to endorse selected CVLT list B recognition foils. The dCDT compliments traditional clock scoring methods, captures behavior previously unobtainable, and is related to processing speed and dysexecutive impairment known to be present in MS.