Thalamic Atrophy in Active and Inactive Secondary Progressive Multiple Sclerosis Patients: A Comparative Study Publisher

Summary: Does thalamus shrinkage signal active multiple sclerosis? A 38-person study found greater thalamic atrophy in active SPMS, linked to cognitive outcomes. #MultipleSclerosis #MRI

Bahrami S ; Ramezani N ; Panah M Y ; Vaheb S ; Mirmosayyeb O ; Davanian F ; Golparvar S ; Adibi I ; Shaygannejad V
Source: Caspian Journal of Internal Medicine Published:2026

Abstract

Background: Thalamic atrophy may be an indicator of neurodegeneration in people with secondary progressive multiple sclerosis (pwSPMS). The atrophy usually begins asymmetrically, and the thalamic asymmetry index (TAI) can be used to estimate the severity of neurodegeneration. SPMS is commonly divided into two groups of active and inactive. No study has compared TAI between SPMS groups and examine its relationships with cognitive and motor measures in pwSPMS. This study aimed to compare the TAI between active and inactive pwSPMS and to examine its relationship with key clinical, cognitive, and motor variables. Methods: In this cross-sectional study, 38 pwSPMS (15 active and 23 inactive) were enrolled from February to November 2024. MRI-based volumetric measurements were used to determine thalamic volumes and calculate the TAI. Cognitive and motor tests, including the SDMT, PASAT, and 9HPT were also administered alongside clinical examinations. Results: Active SPMS patients had significantly lower NTV compared to inactive patients (Cohen’s d =-1.58, p < 0.001). No significant difference in TAI was observed between groups. NTV correlated with cognitive scores in both active (r = 0.74, P = 0.002) and inactive (r = 0.65, p < 0.001) groups and with disability in the inactive group (r =-0.5, P= 0.014). Active SPMS patients showed worse cognitive and motor performance. Conclusion: Thalamic atrophy is more severe in active SPMS and is associated with worse cognitive and motor outcomes. While thalamic asymmetry did not differentiate between subgroups, it may serve as a marker for functional status in SPMS. © The Author(s).