title: A voxel-based analysis of FDG-PET in traumatic brain injury: regional metabolism and relationship between the thalamus and cortical areas.
abstract: The objective was to study the correlations and the differences in glucose metabolism between the thalamus and cortical structures in a sample of severe traumatic brain injury (TBI) patients with different neurological outcomes. We studied 49 patients who had suffered a severe TBI and 10 healthy control subjects using 18F-fluorodeoxyglucose positron emission tomography (18F-FDG-PET). The patients were divided into three groups: a vegetative or minimally-conscious state (MCS&VS) group (n=17), which included patients who were in a vegetative or a minimally conscious state; an In-post-traumatic amnesia (In-PTA) group (n=12), which included patients in PTA; and an Out-PTA group (n=20), which included patients who had recovered from PTA. SPM5 software was used to determine the metabolic differences between the groups. FDG-PET images were normalized and four regions of interest were generated around the thalamus, precuneus, and the frontal and temporal lobes. The groups were parameterized using Student's t-test. Principal component analysis was used to obtain an intensity-estimated-value per subject to correlate the function between the structures. Differences in glucose metabolism in all structures were related to the neurological outcome, and the most severe patients showed the most severe hypometabolism. We also found a significant correlation between the cortico-thalamo-cortical metabolism in all groups. Voxel-based analysis suggests a functional correlation between these four areas, and decreased metabolism was associated with less favorable outcomes. Higher levels of activation of the cortico-cortical connections appear to be related to better neurological condition. Differences in the thalamo-cortical correlations between patients and controls may be related to traumatic dysfunction due to focal or diffuse lesions.
authors.affiliation: Grupo de Informática Biomédica, Instituto de Aplicaciones de las Tecnologías de la Información y de las Comunicaciones Avanzadas (ITACA), Universidad Politécnica de Valencia, Valencia, Spain.
authors.forename: Javier
authors.initials: J
authors.lastname: García-Panach
authors.forename: Nuria
authors.initials: N
authors.lastname: Lull
authors.forename: Juan José
authors.initials: JJ
authors.lastname: Lull
authors.forename: Joan
authors.initials: J
authors.lastname: Ferri
authors.forename: Carlos
authors.initials: C
authors.lastname: Martínez
authors.forename: Pablo
authors.initials: P
authors.lastname: Sopena
authors.forename: Montserrat
authors.initials: M
authors.lastname: Robles
authors.forename: Javier
authors.initials: J
authors.lastname: Chirivella
authors.forename: Enrique
authors.initials: E
authors.lastname: Noé
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000647:Amnesia / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism; D001930:Brain Injuries / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000378:metabolism; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000000981:diagnostic imaging* / Q000378:metabolism; D018458:Persistent Vegetative State / Q000000981:diagnostic imaging / Q000209:etiology / Q000378:metabolism; D011877:Radionuclide Imaging; D013788:Thalamus / Q000000981:diagnostic imaging* / Q000378:metabolism