title: Neuropsychological, Metabolic, and GABAA Receptor Studies in Subjects with Repetitive Traumatic Brain Injury.
abstract: Repetitive traumatic brain injury (rTBI) occurs as a result of mild and accumulative brain damage. A prototype of rTBI is chronic traumatic encephalopathy (CTE), which is a degenerative disease that occurs in patients with histories of multiple concussions or head injuries. Boxers have been the most commonly studied patient group because they may experience thousands of subconcussive hits over the course of a career. This study examined the consequences of rTBI with structural brain imaging and biomolecular imaging and investigated whether the neuropsychological features of rTBI were related to the findings of the imaging studies. Five retired professional boxers (mean age, 46.8 ± 3.19 years) and four age-matched controls (mean age, 48.5 ± 3.32 years) were studied. Cognitive-motor related functional impairment was assessed, and all subjects underwent neuropsychological evaluation and behavioral tasks, as well as structural brain imaging and functional-molecular imaging. In neuropsychological tests, boxers showed deficits in delayed retrieval of visuospatial memory and motor coordination, which had a meaningful relationship with biomolecular imaging results indicative of neuronal injury. Morphometric abnormalities were not found in professional boxers by structural magnetic resonance imaging (MRI). Glucose metabolism was impaired in frontal areas associated with cognitive dysfunction, similar to findings in Alzheimer's disease. Low binding potential (BP) of (18)F-flumazenil (FMZ) was found in the angular gyrus and temporal cortical regions, revealing neuronal deficits. These results suggested that cognitive impairment and motor dysfunction reflect chronic damage to neurons in professional boxers with rTBI.
authors.affiliation: 1 Department of Neuroscience, Seoul National University College of Medicine , Seoul, Republic of Korea.|2 Department of Nuclear Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.
authors.forename: Seong Ae
authors.initials: SA
authors.lastname: Bang
authors.affiliation: 2 Department of Nuclear Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.
authors.forename: Yoo Sung
authors.initials: YS
authors.lastname: Song
authors.affiliation: 2 Department of Nuclear Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.
authors.forename: Byung Seok
authors.initials: BS
authors.lastname: Moon
authors.affiliation: 2 Department of Nuclear Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.|4 Center for Nanomolecular Imaging and Innovative Drug Development, Advanced Institutes of Convergence Technology , Suwon, Republic of Korea.
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Lee
authors.affiliation: 2 Department of Nuclear Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.
authors.forename: Ho-Young
authors.initials: HY
authors.lastname: Lee
authors.affiliation: 5 Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.
authors.forename: Jong-Min
authors.initials: JM
authors.lastname: Kim
authors.affiliation: 1 Department of Neuroscience, Seoul National University College of Medicine , Seoul, Republic of Korea.|2 Department of Nuclear Medicine, Seoul National University Bundang Hospital , Seongnam, Republic of Korea.|3 Department of Transdisciplinary Studies, Graduate School of Convergence Science and Technology, Seoul National University , Seoul, Republic of Korea.|4 Center for Nanomolecular Imaging and Innovative Drug Development, Advanced Institutes of Convergence Technology , Suwon, Republic of Korea.
authors.forename: Sang Eun
authors.initials: SE
authors.lastname: Kim
mesh_terms: D000328:Adult; D001265:Athletic Injuries / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D001914:Boxing; D000070642:Brain Injuries, Traumatic / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D060825:Cognitive Dysfunction / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D005442:Flumazenil / Q000378:metabolism; D005462:Fluorine Radioisotopes / Q000378:metabolism; D018757:GABA Modulators / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011597:Psychomotor Performance / Q000502:physiology*; D011963:Receptors, GABA-A / Q000378:metabolism*
chemical_list: D005462:Fluorine Radioisotopes; D018757:GABA Modulators; D011963:Receptors, GABA-A; D005442:Flumazenil; C000615276:Fluorine-18
keywords: GABAA receptor; brain metabolism; neuropsychological evaluation; repetitive traumatic brain injury