Thalamic Hypometabolism in MTBI: Insight from Data Driven Voxelwise Analysis of 3D 1H-MR Spectroscopy Imaging

Xiaodan YAN¹, Ivan Kirov¹, Oded Gonen¹

Traumatic brain injury (TBI) and related disabilities affect nearly 5.3 million people in the U.S, imposing a costly economic burden of about $56 billion. Diagnosis based on the Glassgow Coma Scale (GCS) indicates that 85% of TBI cases are mild (GCS:13-15). Mild-TBI (mTBI) pathology was previously believed to be microscopic and diffuse diseases. 1H MR spectroscopy imaging (MRSI) is a noninvasive technique for detecting microscopic and metabolic changes in the brain. In order to investigate whether there are focal metabolic changes associated with mTBI, a data-driven voxelwise analysis was adapted after MRSI data was co-registered to a standard space. This rigorous statistical approach avoids the bias and errors from manually outlining regions of interest (ROI-s).Significant group difference is found for NAA, Cr, Cho and mI in left thalamus (p < 0.01), and significant difference for Cho and NAA (p < 0.05) in right putamen, with mTBI patients showing decreased concentrations. Hypoactivity at thalamus, as well as decreased thickness of thalamus and putamen was also reported in previous studies. The hypometabolism in the present study together with hypoactivity in previous relevant studies, indicate dysfunction of thalamus and putamen may contribute to mTBI pathology.