The association between information processing speed and clinical features in people with multiple sclerosis and neuromyelitis optica: a comparative study.

Multiple Sclerosis (MS) and Neuromyelitis Optica Spectrum Disorder (NMOSD) are both autoimmune inflammatory disorders affecting the central nervous system. Cognitive decline is a common symptom in both disorders, particularly affecting information processing speed (IPS). The current study investigated the association between IPS and clinical parameters in people with MS (PwMS) and NMOSD (PwNMOSD). A total of 945 participants were enrolled in the study, including 617 PwMS, 128 PwNMOSD, and 200 healthy controls. IPS was evaluated using the Symbol Digit Modalities Test (SDMT). Clinical, serological, and radiological factors were retrospectively collected. General Linear Model (GLM) was used for data analysis. Based on GLM multivariate analysis adjusted for age, sex, and educational level, a significant association was observed between IPS and Expanded Disability Status Scale (EDSS), disease progression, disease duration, brain atrophy, and brain lesion load in PwMS. Similarly, significant association was found between IPS and EDSS, Aquaporin-4 (AQP-4) antibody positivity, brain atrophy, and number of cervical lesions in PwNMOSD. This study confirms the association between IPS and key risk factors such as EDSS, brain atrophy, and lesion load in PwMS. Additionally, it reveals a link between IPS and new factors, including AQP-4 antibody positivity and cervical lesions in PwNMOSD. Furthermore, disease progression emerged as a significant factor affecting IPS in PwMS.