Abnormal Long-Term Episodic Memory Profiles in Multiple Sclerosis?Saenz Amaya1,2, Bakchine Serge1,2,3, Stepanov Igor4, Omigie Diana2,5,6,7, and Ehrlé Nathalie1,2,3*
- Corresponding Author:
- Nathalie Ehrlé
Hôpital Maison-Blanche (Service de neurologie) 45
rue Cognacq-Jay 51092 Reims Cedex France
Tel: (00 33) 3 26 78 39 64
Fax: (00 33) 326784319
E-mail: [email protected]
Received date: April 09, 2014; Accepted date: May 22, 2014; Published date: May 26, 2014
Citation: Amaya S, Serge B, Igor S, Diana O, and Nathalie E (2014) Abnormal Long-Term Episodic Memory Profiles in Multiple Sclerosis?. J Mult Scler 1:105. doi:10.4172/2376-0389.1000105
Copyright: © 2014 Ehrlé N, 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.
Objective: Various verbal episodic memory impairments have been demonstrated in multiple sclerosis (MS),
including encoding, retrieval and storage processes. Our clinical experiment suggests that a subset of MS patients
may show another pattern with a distinctive evolution of performances after a 20 minutes delay (short-delay versus
long-delay free recall).
Methods: The current study assessed performances on the California Verbal Learning Test (CVLT) in MS with a
special focus on evolution after delay to identify a subgroup of patients who may show a significant spontaneous
improvement of long-delay free recall in comparison with short-delay free recall. Data from 52 MS patients were
compared with those from 32 controls. Group analyses were conducted on classical scores. Individual MS
performances were also analyzed, according to confidence intervals calculated using control data.
Results: From individual analysis, memory comorbidities were frequently observed in a MS patient (17% of MS
patients had only one impaired score, 17% had two or three scores, 27% had four or five scores and 38% had six or
more). Regarding the evolution after delay, three profiles were highlighted: two classical (stable and worsening, i.e.
storage deficit) and a third showing a significant degree of improvement. The improvement was significantly
correlated with processing speed, primacy effect and sensitivity to retroactive interference only in this third MS
subgroup. This benefit from delay was not related to the effect of semantic clustering.
Conclusion: The current study suggests that a subgroup of MS patients might present a previously unreported
abnormal long-term memory profile, in which an impaired short-term performance contrasts with a significant
spontaneous improvement with delay. Previous studies have demonstrated the relevance of spaced learning in MS
rehabilitation. If our results are corroborated in a larger sample, the CVLT may help to select patients that are likely
to benefit from this temporal memory care.