OBJECTIVE: To study the effects of moderate to severe traumatic brain injury (TBI) on the functional neuroanatomy supporting memory retrieval. METHODS: Subjects were six patients who had sustained a moderate to severe TBI about four years before scanning and had since made a good recovery. Eleven healthy young adults matched to the patients for age and education served as controls. An established H(2)(15)0 positron emission tomography paradigm was used to elicit brain activations in response to memory retrieval. TBI patients' patterns of brain activation were compared statistically with those of control subjects. Both group and individual case data were analysed. RESULTS: Both TBI patients and controls engaged frontal, temporal, and parietal regions known to be involved in memory retrieval, yet the TBI patients showed relative increases in frontal, anterior cingulate, and occipital activity. The hemispheric asymmetry characteristic of controls was attenuated in patients with TBI. Reduced activation was noted in the right dorsomedial thalamus. Although local aspects of this pattern were affected by the presence of focal lesions and performance differences, the overall pattern was reliable across patients and comparable to functional neuroimaging results reported for normal aging, Alzheimer's disease, and other patients with TBI. CONCLUSIONS: The TBI patients performed memory tasks using altered functional neuroanatomical networks. These changes are probably the result of diffuse axonal injury and may reflect either cortical disinhibition attributable to disconnection or compensation for inefficient mnemonic processes.
OBJECTIVE: To study the effects of moderate to severe traumatic brain injury (TBI) on the functional neuroanatomy supporting memory retrieval. METHODS: Subjects were six patients who had sustained a moderate to severe TBI about four years before scanning and had since made a good recovery. Eleven healthy young adults matched to the patients for age and education served as controls. An established H(2)(15)0 positron emission tomography paradigm was used to elicit brain activations in response to memory retrieval. TBIpatients' patterns of brain activation were compared statistically with those of control subjects. Both group and individual case data were analysed. RESULTS: Both TBIpatients and controls engaged frontal, temporal, and parietal regions known to be involved in memory retrieval, yet the TBIpatients showed relative increases in frontal, anterior cingulate, and occipital activity. The hemispheric asymmetry characteristic of controls was attenuated in patients with TBI. Reduced activation was noted in the right dorsomedial thalamus. Although local aspects of this pattern were affected by the presence of focal lesions and performance differences, the overall pattern was reliable across patients and comparable to functional neuroimaging results reported for normal aging, Alzheimer's disease, and other patients with TBI. CONCLUSIONS: The TBIpatients performed memory tasks using altered functional neuroanatomical networks. These changes are probably the result of diffuse axonal injury and may reflect either cortical disinhibition attributable to disconnection or compensation for inefficient mnemonic processes.
Authors: T W McAllister; A J Saykin; L A Flashman; M B Sparling; S C Johnson; S J Guerin; A C Mamourian; J B Weaver; N Yanofsky Journal: Neurology Date: 1999-10-12 Impact factor: 9.910
Authors: S Duke Han; Wes S Houston; Amy J Jak; Lisa T Eyler; Bonnie J Nagel; Adam S Fleisher; Gregory G Brown; Jody Corey-Bloom; David P Salmon; Leon J Thal; Mark W Bondi Journal: Neurobiol Aging Date: 2006-01-24 Impact factor: 4.673
Authors: Theresa Currier Thomas; Sarah B Ogle; Benjamin M Rumney; Hazel G May; P David Adelson; Jonathan Lifshitz Journal: Behav Brain Res Date: 2016-12-29 Impact factor: 3.332
Authors: Franck Amyot; David B Arciniegas; Michael P Brazaitis; Kenneth C Curley; Ramon Diaz-Arrastia; Amir Gandjbakhche; Peter Herscovitch; Sidney R Hinds; Geoffrey T Manley; Anthony Pacifico; Alexander Razumovsky; Jason Riley; Wanda Salzer; Robert Shih; James G Smirniotopoulos; Derek Stocker Journal: J Neurotrauma Date: 2015-09-30 Impact factor: 5.269