title: Prospective longitudinal MRI study of brain volumes and diffusion changes during the first year after moderate to severe traumatic brain injury.
abstract: The objectives of this prospective study in 62 moderate-severe TBI patients were to investigate volume change in cortical gray matter (GM), hippocampus, lenticular nucleus, lobar white matter (WM), brainstem and ventricles using a within subject design and repeated MRI in the early phase (1-26 days) and 3 and 12 months postinjury and to assess changes in GM apparent diffusion coefficient (ADC) in normal appearing tissue in the cortex, hippocampus and brainstem. The impact of Glasgow Coma Scale (GCS) score at admission, duration of post-traumatic amnesia (PTA), and diffusion axonal injury (DAI) grade on brain volumes and ADC values over time was assessed. Lastly, we determined if MRI-derived brain volumes from the 3-month scans provided additional, significant predictive value to 12-month outcome classified with the Glasgow Outcome Scale-Extended after adjusting for GCS, PTA and age. Cortical GM loss was rapid, largely finished by 3 months, but the volume reduction was unrelated to GCS score, PTA, or presence of DAI. However, cortical GM volume at 3 months was a significant independent predictor of 12-month outcome. Volume loss in the hippocampus and lenticular nucleus was protracted and statistically significant first at 12 months. Slopes of volume reduction over time for the cortical and subcortical GGM were significantly different. Hippocampal volume loss was most pronounced and rapid in individuals with PTA > 2 weeks. The 3-month volumes of the hippocampus and lentiform nucleus were the best independent predictors of 12-month outcome after adjusting for GCS, PTA and age. In the brainstem, volume loss was significant at both 3 and 12 months. Brainstem volume reduction was associated with lower GCS score and the presence of DAI. Lobar WM volume was significantly decreased first after 12 months. Surprisingly DAI grade had no impact on lobar WM volume. Ventricular dilation developed predominantly during the first 3 months, and was strongly associated with volume changes in the brainstem and cortical GM, but not lobar WM volume. Higher ADC values were detected in the cortex in individuals with severe TBI, DAI and PTA > 2 weeks, from 3 months. There were no associations between ADC values and brain volumes, and ADC values did not predict outcome.
authors: Department of Circulation and Medical Imaging, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Medical Imaging, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway.
authors: Veronika
authors: V
authors: Brezova
authors: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Neurosurgery, St. Olav's Hospital, Trondheim, Norway.
authors: Kent Gøran
authors: KG
authors: Moen
authors: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Physical Medicine and Rehabilitation, St. Olav's Hospital, Trondheim, Norway.
authors: Toril
authors: T
authors: Skandsen
authors: Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway ; Department of Neurosurgery, St. Olav's Hospital, Trondheim, Norway.
authors: Anne
authors: A
authors: Vik
authors: Department of Radiology, University of California San Diego, San Diego, USA ; Department of Neurosciences, University of California San Diego, San Diego, USA.
authors: James B
authors: JB
authors: Brewer
authors: Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors: Oyvind
authors: O
authors: Salvesen
authors: Department of Medical Imaging, St. Olav's Hospital, Trondheim University Hospital, Trondheim, Norway ; Department of Neuroscience, Norwegian University of Science and Technology (NTNU), Trondheim, Norway.
authors: Asta K
authors: AK
authors: Håberg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001921:Brain / Q000473:pathology* / Q000503:physiopathology; D001930:Brain Injuries / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D015600:Glasgow Coma Scale; D006801:Humans; D015601:Injury Severity Score; D017846:Longitudinal Ligaments; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009929:Organ Size / Q000502:physiology; D011446:Prospective Studies; D055815:Young Adult
keywords: ADC; Diffuse axonal injury; Glasgow Coma Scale; Outcome; Post-traumatic amnesia