title: Metabolic and cognitive response to human traumatic brain injury: a quantitative proton magnetic resonance study.
abstract: Proton magnetic resonance spectroscopy (1H-MRS) offers a unique insight into brain cellular metabolism following traumatic brain injury (TBI). The aim of the present study was to assess change in neurometabolite markers of brain injury during the recovery period following TBI. We studied 19 TBI patients at 1.5, 3, and 6 months postinjury and 28 controls. We used 1H-MRS to quantify N-acetylaspartate (NAA), creatine (Cre), choline (Cho), and myoinositol (mIns) in occipitoparietal gray matter (GM) and white matter (WM) remote from the primary injury focus. Neuropsychological testing quantified cognitive impairment and recovery. At 1.5 months, we found cognitive impairment (mean z score = -1.36 vs. 0.18,p < 0.01), lower NAA (GM: 12.42 mM vs. 13.03, p = 0.01; WM: 11.75 vs. 12.81, p < 0.01), and elevated Cho (GM: 1.51 vs. 1.25, p < 0.01; WM: 1.98 vs. 1.79, p < 0.01) in TBI patients compared with controls. GM NAA at 1.5 months predicted cognitive function at outcome (6 months postinjury; r = 0.63, p = 0.04). GM NAA continued to fall by 0.46 mM between 1.5 and 3 months (p = 0.02) indicating continuing neuronal loss, metabolic dysfunction, or both. Between 3 and 6 months, WM NAA increased by 0.55 mM (p = 0.06) suggesting metabolic recovery. Patients with poorer outcomes had elevated mean GM Cho at 3 months postinjury, suggesting active inflammation, as compared to patients with better outcomes (p = 0.002). 1H-MRS offers a noninvasive approach to assessing neuronal injury and inflammation following TBI, and may provide unique data for patient management and assessment of therapeutic efficacy.
authors.affiliation: Clinical & Magnetic Resonance Research Center, Department of Neurosciences, University of New Mexico, Albuquerque, USA. brooks@lizard.unm.edu
authors.forename: W M
authors.initials: WM
authors.lastname: Brooks
authors.forename: C A
authors.initials: CA
authors.lastname: Stidley
authors.forename: H
authors.initials: H
authors.lastname: Petropoulos
authors.forename: R E
authors.initials: RE
authors.lastname: Jung
authors.forename: D C
authors.initials: DC
authors.lastname: Weers
authors.forename: S D
authors.initials: SD
authors.lastname: Friedman
authors.forename: M A
authors.initials: MA
authors.lastname: Barlow
authors.forename: W L
authors.initials: WL
authors.lastname: Sibbitt
authors.forename: R A
authors.initials: RA
authors.lastname: Yeo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001224:Aspartic Acid / Q000031:analogs & derivatives* / Q000378:metabolism; D001930:Brain Injuries / Q000150:complications / Q000378:metabolism*; D002794:Choline / Q000378:metabolism*; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology / Q000378:metabolism; D003404:Creatinine / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007294:Inositol / Q000378:metabolism*; D016015:Logistic Models; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011522:Protons; D018709:Statistics, Nonparametric
chemical_list: D011522:Protons; D001224:Aspartic Acid; D007294:Inositol; C000179:N-acetylaspartate; D003404:Creatinine; D002794:Choline