Clinical correlations of proton magnetic resonance spectroscopy findings in acute phase after mild traumatic brain injury

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Introduction: Standard brain magnetic resonance imaging (MRI) is typically normal in most patients after mild traumatic brain injury (MTBI). Proton magnetic resonance spectroscopy (¹H-MRS) is more sensitive to detect subtle post-traumatic changes. The aim of the study was to evaluate the clinical correlations of these changes in the acute phase (within 3 days) after MTBI.

Methods: Twenty-one patients with MTBI and 22 controls were studied. Both groups underwent neuropsychological testing and single-voxel ¹H-MRS examination of both frontal lobes and upper brainstem.

Results: Significant decrease in NAA was found in both frontal lobes and in NAA/Cre ratio in the right frontal lobe (p < 0.05). Correlation analysis showed a correlation of NAA in the left frontal lobe with Backward Digit Span (p = 0.022) and Stroop test A (p = 0.0034) and a weak correlation with TMT B time (p = 0.046). The NAA/Cre in the right frontal lobe correlated with Stroop test A (p = 0.007) and with the total score of Digit Span (p = 0.016). Lower NAA was found in the upper brainstem (p = 0.0157) in the sub-group of patients with post-traumatic unconsciousness.

Conclusions: This study found a correlation of ¹H-MRS metabolite changes with cognitive decline and presence or absence of loss of consciousness in the acute phase after MTBI.

• Magnetic resonance spectroscopy
• mild traumatic brain injury
• neuropsychological testing