title: Effect of Age on Working Memory Performance and Cerebral Activation after Mild Traumatic Brain Injury: A Functional MR Imaging Study.
abstract: OBJECTIVE
  To evaluate the age effect on working memory (WM) performance and functional activation after mild traumatic brain injury (MTBI).
  
  
  METHODS
  This study was approved by the local research ethics committee. All participants provided written informed consent. N-back WM cerebral activation was assessed with functional magnetic resonance (MR) imaging in 13 younger (mean age, 26.2 years ± 2.9; range, 21-30 years) and 13 older (mean age, 57.8 years ± 6.6; range, 51-68 years) patients with MTBI and 26 age- and sex-matched control subjects. Two functional MR images were obtained within 1 month after injury and 6 weeks after the initial study. Group comparison and regression analysis were performed among postconcussion symptoms, neuropsychologic tests, and WM activity in both groups.
  
  
  RESULTS
  In younger patients, initial hyperactivation was seen in the right precuneus and right inferior parietal gyrus (P = .047 and P = .025, respectively) in two-back greater than one-back conditions compared with younger control subjects, whereas in older patients, hypoactivation was seen in the right precuneus and right inferior frontal gyrus (P = .013 and P =.019, respectively) compared with older control subjects. Increased WM activity was associated with increased postconcussion symptoms in the right precuneus (r = 0.57; P = .026) and right inferior frontal gyrus (r = 0.60; P = .019) and poor WM performance in the right precuneus (r = -0.55; P = .027) in younger patients at initial studies but not in older patients. At follow-up examinations, partial recovery of activation pattern and decreased postconcussion symptoms (P = .04) were observed in younger patients but not in older patients.
  
  
  CONCLUSIONS
  The different manifestations of postconcussion symptoms at functional MR imaging between younger and older patients confirmed the important role of age in the activation, modulation, and allocation of WM processing resources after MTBI. These findings also supported that younger patients have better neural plasticity and clinical recovery than do older patients.
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: David Yen-Ting
authors.initials: DY
authors.lastname: Chen
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Hui-Ling
authors.initials: HL
authors.lastname: Hsu
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Ying-Sheng
authors.initials: YS
authors.lastname: Kuo
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Changwei Wesley
authors.initials: CW
authors.lastname: Wu
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Wen-Ta
authors.initials: WT
authors.lastname: Chiu
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Feng-Xian
authors.initials: FX
authors.lastname: Yan
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Wei-Shuan
authors.initials: WS
authors.lastname: Wang
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Chi-Jen
authors.initials: CJ
authors.lastname: Chen
authors.affiliation: From the Department of Radiology (D.Y.T.C., H.L.H., Y.S.K., F.X.Y., W.S.W., C.J.C., Y.C.T.), Brain and Consciousness Research Center (D.Y.T.C., C.W.W., Y.C.T.), and Graduate Institute of Injury Prevention and Control (W.T.C.), Taipei Medical University-Shuang-Ho Hospital, 291 Jhong-Jheng Road, 235 Jhonghe District, New Taipei City, Taiwan, ROC; Department of Biomedical Sciences and Engineering, National Central University, Taoyuan, Taiwan (C.W.W.); and Department of Radiology, Chia-Yi Hospital, Ministry of Health and Welfare, Chiayi City, Taiwan (C.J.C.).
authors.forename: Ying-Chi
authors.initials: YC
authors.lastname: Tseng
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D001930:Brain Injuries / Q000503:physiopathology*; D017352:Echo-Planar Imaging; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D008875:Middle Aged; D011446:Prospective Studies