Predictivity Of Executive Functions In Episodic Memory In Multiple Sclerosis (P4.168)

OBJECTIVE: To determinate the influence of the other cognitive functions on episodic memory disorder in different Multiple Sclerosis (MS) subtypes. BACKGROUND: Cognitive impairment in MS is one of the main factors of disability and poor quality of life. Several cognitive functions could be damaged, such as information processing speed, attention or executive functioning; but alteration of memory is one of the most observed and recorded complained cognitive deficits in MS. However, a memory deficit could reflect the presence of another cognitive deficit and vice versa. DESIGN/METHODS: 275 patients (145 RRMS; 107 SPMS; 23 PPMS) were assessed by an extensive neuropsychological battery (BCcogSEP (Dujardin et al., 2004), a french adaptation of the BRB-N, Rao et al. 1991) including eight tests assessing seven cognitive functions. A step wise multivariate regression analysis has been applied; to first determinate which cognitive function was the most predictive of the episodic memory deficit present in MS and then, whether it was the same according to the phenotype. RESULTS: 62% patients (69 RRMS; 76 SPMS; 14 PPMS) were identified as cognitively impaired by the multidimensional neuropsychological battery (getting 4 or more pathological scores). All phenotypes considered, the episodic memory performance (mean retrieval and learning index) was the most predicted by working memory and information processing speed (PASAT; p , Symbol Digit Modalities Test; p ), inhibition ability; Go/No Go Task; p ) and verbal initiation (verbal fluency; p ). This pattern of regression was found in each phenotype. CONCLUSIONS: Processes involved in an episodic memory task (encoding, stocking, retrieval) require an implication of executive functions, as well as a timed test requires an information processing speed. In our study, information processing speed and executive functions appeared to be the ones predicting the most the episodic memory performance. This study confirms the major contribution of executive functions in memory disorders, and thus the non-specific aspect of memory complaint in MS. Study Supported by: Disclosure: Dr. Barthelemy has nothing to disclose. Dr. Lenne has nothing to disclose. Dr. Leuse has nothing to disclose. Dr. Kwiatkowski has nothing to disclose. Dr. Hautecoeur has nothing to disclose.