title: Assessment of metabolic brain damage and recovery following mild traumatic brain injury: a multicentre, proton magnetic resonance spectroscopic study in concussed patients.
abstract: Concussive head injury opens a temporary window of brain vulnerability due to the impairment of cellular energetic metabolism. As experimentally demonstrated, a second mild injury occurring during this period can lead to severe brain damage, a condition clinically described as the second impact syndrome. To corroborate the validity of proton magnetic resonance spectroscopy in monitoring cerebral metabolic changes following mild traumatic brain injury, apart from the magnetic field strength (1.5 or 3.0 T) and mode of acquisition, we undertook a multicentre prospective study in which a cohort of 40 athletes suffering from concussion and a group of 30 control healthy subjects were admitted. Athletes (aged 16-35 years) were recruited and examined at three different institutions between September 2007 and June 2009. They underwent assessment of brain metabolism at 3, 15, 22 and 30 days post-injury through proton magnetic resonance spectroscopy for the determination of N-acetylaspartate, creatine and choline-containing compounds. Values of these representative brain metabolites were compared with those observed in the group of non-injured controls. Comparison of spectroscopic data, obtained in controls using different field strength and/or mode of acquisition, did not show any difference in the brain metabolite ratios. Athletes with concussion exhibited the most significant alteration of metabolite ratios at Day 3 post-injury (N-acetylaspartate/creatine: -17.6%, N-acetylaspartate/choline: -21.4%; P < 0.001 with respect to controls). On average, metabolic disturbance gradually recovered, initially in a slow fashion and, following Day 15, more rapidly. At 30 days post-injury, all athletes showed complete recovery, having metabolite ratios returned to values detected in controls. Athletes self-declared symptom clearance between 3 and 15 days after concussion. Results indicate that N-acetylaspartate determination by proton magnetic resonance spectroscopy represents a non-invasive tool to accurately measure changes in cerebral energy metabolism occurring in mild traumatic brain injury. In particular, this metabolic evaluation may significantly improve, along with other clinical assessments, the management of athletes suffering from concussion. Further studies to verify the effects of a second concussive event occurring at different time points of the recovery curve of brain metabolism are needed.
authors.affiliation: Department of Neurosciences, University of Rome Tor Vergata, 00133 Rome, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Vagnozzi
authors.forename: Stefano
authors.initials: S
authors.lastname: Signoretti
authors.forename: Luciano
authors.initials: L
authors.lastname: Cristofori
authors.forename: Franco
authors.initials: F
authors.lastname: Alessandrini
authors.forename: Roberto
authors.initials: R
authors.lastname: Floris
authors.forename: Eugenio
authors.initials: E
authors.lastname: Isgrò
authors.forename: Antonio
authors.initials: A
authors.lastname: Ria
authors.forename: Simone
authors.initials: S
authors.lastname: Marziali
authors.forename: Simone
authors.initials: S
authors.lastname: Marziale
authors.forename: Giada
authors.initials: G
authors.lastname: Zoccatelli
authors.forename: Barbara
authors.initials: B
authors.lastname: Tavazzi
authors.forename: Franco
authors.initials: F
authors.lastname: Del Bolgia
authors.forename: Roberto
authors.initials: R
authors.lastname: Sorge
authors.forename: Steven P
authors.initials: SP
authors.lastname: Broglio
authors.forename: Tracy K
authors.initials: TK
authors.lastname: McIntosh
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lazzarino
mesh_terms: D000293:Adolescent; D000328:Adult; D001924:Brain Concussion / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D001928:Brain Diseases, Metabolic / Q000175:diagnosis* / Q000378:metabolism* / Q000503:physiopathology; D001930:Brain Injuries / Q000175:diagnosis / Q000378:metabolism* / Q000503:physiopathology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D011522:Protons; D020127:Recovery of Function / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult
chemical_list: D011522:Protons