Localized in vivo H-MRS of traumatic brain injury

¹H-MRS examinations were carried out on 14 patients, recovering from traumatic brain injury (TBI), who were in a stabilized clinical status and showed a good clinical outcome. Magnetic resonance spectra were recorded in subcortical (SC) and mid-brain (MB) areas where no detectable lesions appeared under magnetic resonance imaging. These two brain areas were selected because they are crucial sites of damage due to the physiopathologic mechanisms of TBI. A significant increase in inositol and choline peaks was found in MB compared to a control group of healthy individuals, whereas lower N-acetyl-aspartate peaks in the same area were detected. Reduced levels in the latter metabolite were also evident in the SC area. A significant correlation emerged between the inositol concentration in MB and the Glasgow Coma Scale Score measured just after the trauma. No correlation was found between the Glasgow Outcome Scale (GOS) at the time of the ¹H-MRS examination and the peaks of all the metabolites. Our study demonstrated that ¹H-MRS is a sensitive tool to evidentiate brain metabolic damage after TBI even in areas with lesions that are not detectable with current imaging techniques. The present research also shows an association between the alteration in one of the brain metabolites and the clinical parameters of TBI severity, but does not provide a clinical index of the patient's recovery. Further longitudinal studies on more conspicuous groups of patients with TBI could help to clarify whether metabolite modifications revealed by ¹H-MRS could be predictive of clinical outcome.