Cognition evaluation in patients with Multiple Sclerosis with virtual reality and the volume of thalamus

Introduction: Multiple Sclerosis (MS), a chronic, inflammatory, and demyelinating disease affecting the central nervous system, may also lead to cognitive impairments that often remain overshadowed by more prominent clinical symptoms. It has been shown that cognitive dysfunctions may develop insidiously from the early stages of the disease. A typical cognitive profile in MS is characterized by frequent impairments in information processing speed, learning and memory, visuospatial and executive functions, while language and general intelligence tend to be relatively preserved. This study aimed to assess cognitive functions in patients with early-stage Relapsing-Remitting MS (RRMS) using a virtual reality (VR)-based evaluation method and to examine the relationship between cognitive performance and thalamic volume. Materials and Methods: This cross-sectional study included 32 RRMS patients diagnosed according to the 2017 McDonald criteria and 34 age- and sex-matched healthy controls. Participants underwent a VR-based cognitive test battery, and three separate z-scored composite scores were calculated to represent attention, information processing speed, and working memory. Additionally, classical neuropsychological tests were administered, including the Turkish version of the Montreal Cognitive Assessment (MoCA-TR), the Multiple Sclerosis Functional Composite (MSFC), the Symbol Digit Modalities Test (SDMT), and the Paced Auditory Serial Addition Test (PASAT). Thalamic volumes were measured using brain magnetic resonance imaging (MRI). Data were analyzed using SPSS 27.0, with group comparisons and correlation analyses performed. Results: Scores for attention, information processing speed, and total cognitive scores obtained from the VR test battery were significantly lower in the patient group compared to controls (all p<0.001). The total VR cognitive score showed moderate- to-strong positive correlations with MoCA-TR, MSFC, SDMT, and PASAT (r=0.488–0.575, p<0.01). Additionally, significant positive correlations were observed between total VR cognitive scores and thalamic volume, as well as between the working memory subscore and thalamic volume (r=0.444 and r=0.46, respectively). Conclusion: The findings indicate that VR-based cognitive assessments yield results consistent with classical cognitive evaluation tools and may be associated with thalamic volume. These features suggest that VR-based approaches hold potential as complementary tools for evaluating cognitive function in early-stage MS. However, further studies are needed to explore their applicability across different cognitive domains and task designs. Keywords: Multipl Sclerosis, Cognition, Virtual Reality, Thalamic Volume, Cognitive Assessment