Cognitive phenotypes in patients with relapsing-remitting multiple sclerosis with different disease duration, applying the international classification of cognitive disorders in MS (IC-CoDiMS)

Abstract

Objective: Cognitive impairment is experienced by 40–70% of multiple sclerosis patients, with information processing speed and memory most affected. Until now, cognitive results classified patients as impaired and not impaired. With this dichotomous approach, it is difficult to identify, in a heterogeneous group of patients with cognitive impairment, which cognitive domain(s) are most altered. This study aims to identify cognitive phenotypes in a clinical cohort of adult patients with Relapsing-Remitting Multiple Sclerosis (RRMS) using the International Classification of Cognitive Disorders in MS (IC-CoDiMS) and to characterize their clinical features. Methods: Three hundred patients with RRMS underwent neuropsychological assessment with the Brief Repeatable Battery of Neuropsychological Tests (BRBN-T) and the Brief International Cognitive Multiple Sclerosis (BICAMS). Results: In our cohort, the mean age was 41.38 [11.48 SD] years, and 205 [68.3%] were women. At the −1 SD threshold, 49% were cognitively intact, 25% had uni-domain impairment, 17% had bi-domain impairment, and 9% had multi-domain impairment. Processing speed was the most frequent single-domain impairment, followed by memory and verbal fluency. At the −1.5 SD threshold, 74.7% were cognitively intact, 17% had uni-domain impairment, 6% had bi-domain impairment, had bi-domain impairment, and 3.0% had multi-domain impairment. Memory was the most frequent single-domain impairment, followed by processing speed and verbal fluency. Conclusions: This study corroborates the importance of determining cognitive phenotypes through taxonomy (IC-CoDiMS). In addition, it contributes to improving the classification of cognitive phenotypes in patients with RRMS to enhance the development of more effective treatments and cognitive interventions.

Keywords:

• Cognitive phenotype
• multiple sclerosis
• neuropsychological assessment
• brief international cognitive assessment multiple sclerosis
• brief repeatable battery neuropsychological test

Acknowledgements

We want to thank all the people with MS followed as out-patients at the MS Clinic Department of Neurology by Centro Hospitalar Universitário S. João, Oporto (CHUSJ) for participating in this research. Also, we thank all the neurologists in the consultation: Joana Guimarães, Pedro Abreu, Teresa Mendonça, Mafalda Seabra, and Ricardo Reis.

Authors’ contributions

Claudia Sousa: contributed to study concept and design, drafting and revising the manuscript, and acquiring and interpreting data. Teresa Jacques: drafting and revising the manuscript in acquiring and interpreting data and statistical analysis. Marcia França: drafting and revising the manuscript and in the acquisition and interpretation of data Patricia Campos: drafting and revising the manuscript and in the acquisition and interpretation of data Maria José Sá: contributed to study concept and design, drafting and revising the manuscript, in the analysis and interpretation of data and study supervision Rui Alves: contributed to study concept and design, drafting and revising the manuscript, in the analysis and interpretation of data and study supervision. All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research received no specific grant from funding agencies in the public, commercial, or not-for-profit sectors. The second author is supported by a doctoral grant from the Portuguese Foundation for Science and Technology (Grant 2020.05024.BD)