Selective Decline in Information Processing in Subgroups of Multiple Sclerosis: An 8-Year Longitudinal Study

Abstract

Multiple sclerosis (MS) is an inflammatory and degenerative disease of the central nervous system (CNS) that causes white matter and cortical lesions over many years. The CNS is selectively affected by the disease with a great variety of symptoms between patients. In this study, we describe the impact on various aspects of cognition over an 8-year follow-up period in 31 consecutive MS patients subgrouped as relapsing remitting (RR) MS, secondary progressive (SP) MS, and primary progressive (PP) MS. Results showed a differential pattern of cognitive decline already at baseline in speed of information processing. During the follow-up, a pronounced decline occurred in speed of information processing, finger-motor speed, copying geometrical designs, episodic memory, and visuospatial short-term memory. A striking difference was observed between a marked decline in visual reaction time, whereas no significant change was seen in auditory reaction time. In contrast, there was no time-related decline in verbal abilities. However, an initial marked cognitive impairment predicted further cognitive decline over the 8-year follow-up. Information-processing tests were found to be an especially strong predictor of long-term cognitive decline. In addition, high EDSS score at follow-up was associated with decline in information processes. Results also showed that SP-MS patients deteriorated significantly more than the other two groups, particularly in visual compared to auditory information processing. To conclude, cognitive decline appeared particularly in SP-MS patients and in visual information processing.

Memory decline evolves independently of disease activity in MS

“…A degree of controversy exists on the correlation between cognitive impairment and the degree of physical disability measured with the EDSS scale [5,[27][28][29][30]. We found that SDMT decline was associated with the progression of physical disability.…”

Impaired information processing speed and attention allocation in multiple sclerosis patients versus controls: A high-density EEG study

“…It is important to identify CI as early as possible and to monitor CI frequently. CI may have predictive utility for disease progression (26) and it has been shown that neuropsychological rehabilitation can improve attention, information processing and executive functions in MS patients with low disability levels (27). The PASAT is subject to practice effects(7) and can be affected by educational level, anxiety and motor delay of speech; many patients dislike performing the PASAT, a consideration especially important in the context of clinical trials in which repeated testing might increase the dropout rate (28).…”

Effect of Cognitive Demand on Functional Mobility in Ambulatory Individuals with Multiple Sclerosis

“…[3][4][5] Although many domains of cognition may be affected, one of the most affected in people with MS is the ability to rapidly process information. [6][7][8][9] This ability has been linked to working memory, another cognitive construct that is also frequently affected in MS. [10][11][12] Much of the research on working memory in people with MS has compared the ability to perform rapidly or accurately under a high working memory load. [10][11][12] The prevailing hypothesis is that people with MS have deficits in processing speed and working memory, both of which negatively affect performance as task difficulty increases.…”