title: Pathophysiology of the behavioral variant of frontotemporal lobar degeneration: A study combining MRI and FDG-PET.
abstract: Gray matter (GM) lobar atrophy and glucose hypometabolism are well-described hallmarks of frontotemporal lobar degeneration (FTLD), but the relationships between them are still poorly understood. In this study, we aimed to show the patterns of GM atrophy and hypometabolism in a sample of 15 patients with the behavioral variant of FTLD (bv-FTD), compared to 15 healthy controls, then to provide a direct comparison between GM atrophy and hypometabolism, using a voxel-based method specially designed to statistically compare the two imaging modalities. The participants underwent structural magnetic resonance imaging and18F-fluorodeoxyglucose (FDG) positron emission tomography examinations. First, between-group comparisons of GM volume and metabolism were performed. Then, in the patient group, correlations between regional alterations and direct between-modality voxelwise comparison were performed. Finally, we examined individual patterns of brain abnormalities for each imaging modality and each patient. The observed patterns of GM atrophy and hypometabolism were consistent with previous studies. We found significant voxelwise correlations between changes in GM and FDG uptake, mainly in the frontal cortex, corresponding to the typical profile of alterations in bv-FTD. The direct comparison revealed regional variability in the relationship between hypometabolism and atrophy. This analysis revealed greater atrophy than hypometabolism in the right putamen and amygdala, and left insula and superior temporal gyrus, whereas hypometabolism was more severe than GM atrophy in the left caudate nucleus and anterior cingulate cortex. Finally, GM atrophy affected the right amygdala/hippocampus and left insula in 95 % of the patients. These findings provide evidence for regional variations in the hierarchy of hypometabolism and GM atrophy and the relationships between them, and enhance our understanding of the pathophysiology of bv-FTD.
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, U1077, Caen, France.
authors: M-S
authors: MS
authors: Buhour
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, U1077, Caen, France.
authors: F
authors: F
authors: Doidy
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, U1077, Caen, France.
authors: M
authors: M
authors: Laisney
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, U1077, Caen, France.
authors: A L
authors: AL
authors: Pitel
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, Service de Neurologie, Caen, France.
authors: V
authors: V
authors: de La Sayette
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, Service de Neurologie, Caen, France.
authors: F
authors: F
authors: Viader
authors: Inserm, U1077, Caen, France.|Université de Caen Normandie, UMR-S1077, Caen, France.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France.|Centre Hospitalier Universitaire de Caen, U1077, Caen, France.
authors: F
authors: F
authors: Eustache
authors: Inserm, U1077, Caen, France. beatrice.desgranges@unicaen.fr.|Université de Caen Normandie, UMR-S1077, Caen, France. beatrice.desgranges@unicaen.fr.|Ecole Pratique des Hautes Etudes, UMR-S1077, Caen, France. beatrice.desgranges@unicaen.fr.|Centre Hospitalier Universitaire de Caen, U1077, Caen, France. beatrice.desgranges@unicaen.fr.
authors: B
authors: B
authors: Desgranges
mesh_terms: D000368:Aged; D001284:Atrophy; D000076103:Biological Variation, Individual; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D019788:Fluorodeoxyglucose F18; D057174:Frontotemporal Lobar Degeneration / Q000000981:diagnostic imaging / Q000503:physiopathology*; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D064847:Multimodal Imaging; D009929:Organ Size; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: Individual analysis; Structural MRI, FDG-PET; Voxel-based morphometry; bv-FTD