Metabolic and Structural Alterations in the Motor System Following Spinal Cord Injury: An In-Vivo ¹H-MR Spectroscopy...

Area of Science:

• Neuroscience
• Radiology
• Biomarkers

Background:

• Spinal cord injury (SCI) disrupts neural pathways critical for motor control.
• Understanding the metabolic and structural consequences of SCI is crucial for developing effective treatments.

Purpose of the Study:

• To investigate metabolite concentration differences in the primary motor cortex (M1) and lumbar cord enlargement (LCE) between SCI patients and healthy controls (HC).
• To correlate metabolic and structural changes with clinical impairment in chronic SCI.

Main Methods:

• Proton magnetic resonance spectroscopy (¹H-MRS) was used to quantify metabolites in M1 and LCE.
• Structural MRI (T₁- and T₂*-weighted) assessed tissue atrophy.
• Associations between metabolic, structural changes, and clinical impairment were analyzed.

Main Results:

• Significant white matter and gray matter atrophy was observed in the LCE of SCI patients compared to HCs.
• Reduced total N-acetylaspartate to total creatine ratio (tNAA/tCr) was found in the M1 and LCE of SCI patients.
• These metabolic changes correlated with observed atrophy and neurodegeneration.

Conclusions:

• Reduced tNAA/tCr in atrophied M1 and LCE suggests widespread neuronal damage, including cell atrophy and loss, following SCI.
• Findings provide in vivo evidence for retrograde and trans-synaptic neurodegeneration in SCI.
• Metabolic and structural biomarkers show potential for monitoring neurodegeneration and guiding regenerative strategies in SCI.