Executive function and memory in patients with relapsing-remitting multiple sclerosis

Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system very heterogeneous in its characteristics. In contrast to the well known sensitive/motor deficits, the cognitive dysfunction has only been analyzed in the last few decades. Attention, executive function, and memory were assessed in 28 patients with recurrent-remittent MS (RRMS) (duration, median 7 years; EDSS median 2) by means of a specific neuropsychological battery. Depression (BDI), anxiety (STAI) and fatigue (FSS) were also assessed. Twenty-five of these patients were selected for statistical study because they presented deficits in some cognitive areas. Twenty-four percent of the patients displayed memory deficits and 80% showed attention and executive function deficits related to prefrontal lobe function. No global memory difficulties were found, except for immediate visual memory of complex elements (immediate recall of the Rey figure), although the visual reproduction I subtest of the WMSR was unaffected. In RRMS patients with a relatively short duration and low level of incapacity, cognitive impairments mainly affected prefrontal functions. The difficulties in immediate visual memory of complex elements could also be explained by a failure in these areas, due to the alteration of the organization and strategic use of the material to be encoded.