Thalamic Nuclei Atrophy in Type 1 Diabetes Mellitus Across Disease Duration

ABSTRACT Background Thalamic volume loss is one of the most consistent neuroimaging findings in type 1 diabetes mellitus (T1DM). However, the thalamus comprises multiple nuclei with distinct functions, and whether specific nuclei show differential vulnerability remains unclear. Purpose To investigate the characteristics of intra‐thalamic nuclear atrophy in T1DM and evaluate its association with disease duration. Field Strength/Sequence 3.0 T/T1‐weighted magnetization‐prepared‐rapid‐acquisition‐of‐gradient‐echo (MPRAGE). Study Type Prospective. Population Forty‐two subjects with T1DM (18–68 years, 17 males/25 females) and 39 healthy controls (18–69 years, 16 males/23 females). Assessment Multi‐atlas‐based segmentation was used to quantify volumes of 20 thalamic nuclei. Additionally, volumes of anatomical and functional subregions were derived based on topographic and functional nuclear classifications. Statistical Tests Group differences were assessed using general linear models. Associations between thalamic volume loss and disease duration were evaluated via partial correlations and exponential regression models to estimate duration‐related atrophy rates. p value < 0.05 was considered significant. Results Participants with T1DM showed significant bilateral reductions in total thalamic volume (left: 7.6%, Cohen's d = 0.91; right: 8.0%, Cohen's d = 0.95). The most pronounced atrophy was observed in the anterior, medial, and lateral thalamic subregions, with volume reductions of 15.8%, 8.6%, and 7.3%, respectively, particularly in cognition‐ and motor‐related nuclei (9.4% and 9.2%, respectively). Longer disease duration was significantly associated with smaller thalamic volumes in the bilateral whole thalamus ( r left = −0.48 and r right = −0.46), as well as in the Pul ( r left = −0.64 and r right = −0.57), VLp ( r left = −0.39 and r right = −0.38), and MD‐Pf nuclei ( r left = −0.55 and r right = −0.37), and in the left LGN ( r = −0.43). Estimated disease‐duration–related annualized atrophy rates exceeded age‐related rates in several left‐sided nuclei, including the MD‐Pf (−0.67%), Pul (−0.69%), and LGN (−0.75%). Data Conclusion T1DM is associated with spatially heterogeneous atrophy of thalamic nuclei, with preferential involvement of the anterior, medial, and lateral subregions. Disease duration seems to accelerate neurodegenerative changes. Evidence Level 2. Technical Efficacy Stage 2.