title: Metabolic levels in the corpus callosum and their structural and behavioral correlates after moderate to severe pediatric TBI.
abstract: Diffuse axonal injury (DAI) secondary to traumatic brain injury (TBI) contributes to long-term functional morbidity. The corpus callosum (CC) is particularly vulnerable to this type of injury. Magnetic resonance spectroscopy (MRS) was used to characterize the metabolic status of two CC regions of interest (ROIs) (anterior and posterior), and their structural (diffusion tensor imaging; DTI) and neurobehavioral (neurocognitive functioning, bimanual coordination, and interhemispheric transfer time [IHTT]) correlates. Two groups of moderate/severe TBI patients (ages 12-18 years) were studied: post-acute (5 months post-injury; n = 10), and chronic (14.7 months post-injury; n = 8), in addition to 10 age-matched healthy controls. Creatine (energy metabolism) did not differ between groups across both ROIs and time points. In the TBI group, choline (membrane degeneration/inflammation) was elevated for both ROIs at the post-acute but not chronic period. N-acetyl aspartate (NAA) (neuronal/axonal integrity) was reduced initially for both ROIs, with partial normalization at the chronic time point. Posterior, not anterior, NAA was positively correlated with DTI fractional anisotropy (FA) (r = 0.88), and most domains of neurocognition (r range 0.22-0.65), and negatively correlated with IHTT (r = -0.89). Inverse corerlations were noted between creatine and posterior FA (r = -0.76), neurocognition (r range -0.22 to -0.71), and IHTT (r = 0.76). Multimodal studies at distinct time points in specific brain structures are necessary to delineate the course of the degenerative and reparative processes following TBI, which allows for preliminary hypotheses about the nature and course of the neural mechanisms of subsequent functional morbidity. This will help guide the future development of targeted therapeutic agents.
authors.affiliation: Semel Institute for Neuroscience and Human Behavior Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California-Los Angeles, 760 Westwood Plaza, Room C8-746, Los Angeles, CA 90095, USA. tbabikian@mednet.ucla.edu
authors.forename: Talin
authors.initials: T
authors.lastname: Babikian
authors.forename: Sarah Deboard
authors.initials: SD
authors.lastname: Marion
authors.forename: Sarah
authors.initials: S
authors.lastname: Copeland
authors.forename: Jeffry R
authors.initials: JR
authors.lastname: Alger
authors.forename: Joseph
authors.initials: J
authors.lastname: O'Neill
authors.forename: Fabienne
authors.initials: F
authors.lastname: Cazalis
authors.forename: Richard
authors.initials: R
authors.lastname: Mink
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Giza
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Vu
authors.forename: Suzanne M
authors.initials: SM
authors.lastname: Hilleary
authors.forename: Claudia L
authors.initials: CL
authors.lastname: Kernan
authors.forename: Nina
authors.initials: N
authors.lastname: Newman
authors.forename: Robert F
authors.initials: RF
authors.lastname: Asarnow
mesh_terms: D000293:Adolescent; D000367:Age Factors; D000375:Aging / Q000502:physiology; D016880:Anisotropy; D001224:Aspartic Acid / Q000031:analogs & derivatives / Q000378:metabolism; D001369:Axons / Q000378:metabolism / Q000473:pathology; D015415:Biomarkers / Q000032:analysis / Q000378:metabolism; D001930:Brain Injuries / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D002648:Child; D002794:Choline / Q000378:metabolism; D003072:Cognition Disorders / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D003337:Corpus Callosum / Q000254:growth & development / Q000378:metabolism* / Q000473:pathology*; D020833:Diffuse Axonal Injury / Q000378:metabolism* / Q000473:pathology* / Q000503:physiopathology; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D014855:Wallerian Degeneration / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D001224:Aspartic Acid; C000179:N-acetylaspartate; D002794:Choline