A Longitudinal Study of Cognitive Function in a Tunisian Cohort of Multiple Sclerosis

• Published in: Multiple sclerosis and related disorders Vol. 80; p. 105187
• Main Authors: Sellami, Sirine, Farhat, Nouha, Moalla, Khadija, Daoued, Sawsan, Bouattour, Nadia, Sakka, Salma, Dammak, Mariem, Mhiri, Chokri
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-12-2023
• ISSN: 2211-0348
• DOI: 10.1016/j.msard.2023.105187

Cognitive impairment is a common and disabling feature of multiple sclerosis (MS). Numerous cross-sectional studies report cognitive impairment in MS but longitudinal studies with sufficiently long term follow up are scarce.
Patients diagnosed with definite MS according to the 2017 McDonald criteria and followed up in the department of Neurology of Habib Bourguiba Hospital were recruited and submitted to cognitive assessment using 7 tests. The patients underwent a longitudinal investigation comparing neuropsychological test performance at study entry and over a 5-year follow up (between 2018 and 2023).
MS patients in the study included 24 females (80%) and 6 males (20%). As compared to controls, people with MS experienced significant worse performance in all cognitive assessment measures. During the 5-year follow up, significant declines were observed on measures of information processing speed and attention (p=0,004), and learning memory and visuospatial functions (p<0,001). There was no evidence of more dramatic decline occurring in episodic memory, executive functions and in particular in verbal fluency. Information processing tests were found to be strong predictors of long term cognitive decline. In addition, high score on the Expanded Disability Status Scale (EDSS) was associated with decline in information process speed. Results also showed that patients with secondary progressive MS (SPMS) deteriorated significantly more than the other with relapsing-remitting MS (RRMS) groups, particularly in attention, episodic and learning memory.
Cognitive impairment progresses throughout the course of MS. Information processing speed is the domain most sensitive to the impact of MS on cognitive functioning over time. A longer prospective follow-up is needed to build definitive conclusions.