S. Belliard and ?. , Declare no competing interests Vincent de La Sayette ? Declare no competing interests Francis Eustache ? Declare no competing interests

D. Alsop, M. Casement, C. De-bazelaire, T. Fong, and D. Press, Hippocampal hyperperfusion in Alzheimer's disease, NeuroImage, vol.42, issue.4, pp.1267-1274, 2008.
DOI : 10.1016/j.neuroimage.2008.06.006

E. Arenaza-urquijo, B. Landeau, L. Joie, R. Mevel, K. Mézenge et al., Relationships between years of education and gray matter volume, metabolism and functional connectivity in healthy elders, NeuroImage, vol.83, pp.450-457, 2013.
DOI : 10.1016/j.neuroimage.2013.06.053
URL : https://hal.archives-ouvertes.fr/inserm-00844867

Z. Arvanitakis, A. Capuano, S. Leurgans, D. Bennett, and J. Schneider, Relation of cerebral vessel disease to Alzheimer's disease dementia and cognitive function in elderly people: a cross-sectional study, The Lancet Neurology, vol.15, issue.9, pp.934-943, 2016.
DOI : 10.1016/S1474-4422(16)30029-1

J. Ashburner, A fast diffeomorphic image registration algorithm, NeuroImage, vol.38, issue.1, pp.95-113, 2007.
DOI : 10.1016/j.neuroimage.2007.07.007

A. Bejanin, B. Desgranges, L. Joie, R. Landeau, B. Perrotin et al., Distinct white matter injury associated with medial temporal lobe atrophy in Alzheimer's versus semantic dementia, Human Brain Mapping, vol.36, issue.4, pp.1791-1800, 2017.
DOI : 10.1523/JNEUROSCI.1975-15.2016

H. Braak and E. Braak, Neuropathological stageing of Alzheimer-related changes, Acta Neuropathologica, vol.80, issue.4, pp.239-259, 1991.
DOI : 10.1007/978-3-642-70644-8_2

R. Buckner, J. Sepulcre, T. Talukdar, F. Krienen, H. Liu et al., Cortical Hubs Revealed by Intrinsic Functional Connectivity: Mapping, Assessment of Stability, and Relation to Alzheimer's Disease, Journal of Neuroscience, vol.29, issue.6, pp.1860-1873, 2009.
DOI : 10.1523/JNEUROSCI.5062-08.2009

A. Caroli, M. Lorenzi, C. Geroldi, F. Nobili, B. Paghera et al., Metabolic Compensation and Depression in Alzheimer???s Disease, Dementia and Geriatric Cognitive Disorders, vol.29, issue.1, pp.37-45, 2010.
DOI : 10.1159/000257761

D. Chan, N. Fox, R. Scahill, W. Crum, J. Whitwell et al., Patterns of temporal lobe atrophy in semantic dementia and Alzheimer's disease, Annals of Neurology, vol.38, issue.4, pp.433-442, 2001.
DOI : 10.1212/WNL.42.1.183

G. Chételat, B. Desgranges, B. Landeau, F. Mézenge, J. Poline et al., Direct voxel-based comparison between grey matter hypometabolism and atrophy in Alzheimer's disease, Brain, vol.131, issue.1, pp.60-71, 2008.
DOI : 10.1093/brain/awm288

I. Choo, D. Lee, J. Oh, J. Lee, D. Lee et al., Posterior cingulate cortex atrophy and regional cingulum disruption in mild cognitive impairment and Alzheimer's disease, Neurobiology of Aging, vol.31, issue.5, pp.772-779, 2010.
DOI : 10.1016/j.neurobiolaging.2008.06.015

R. Davies, G. Halliday, J. Xuereb, J. Kril, and J. Hodges, The neural basis of semantic memory: Evidence from semantic dementia, Neurobiology of Aging, vol.30, issue.12, pp.2043-2052, 2009.
DOI : 10.1016/j.neurobiolaging.2008.02.005

R. Davies, J. Hodges, J. Kril, K. Patterson, G. Halliday et al., The pathological basis of semantic dementia, Brain, vol.128, issue.9, pp.1984-1995, 2005.
DOI : 10.1016/0304-3940(92)90569-S

B. Desgranges, V. Matuszewski, P. Piolino, G. Chételat, F. Mézenge et al., Anatomical and functional alterations in semantic dementia: A voxel-based MRI and PET study, Neurobiology of Aging, vol.28, issue.12, pp.1904-1913, 2007.
DOI : 10.1016/j.neurobiolaging.2006.08.006
URL : https://hal.archives-ouvertes.fr/inserm-00277856

A. Drzezga, T. Grimmer, G. Henriksen, I. Stangier, R. Perneczky et al., Imaging of amyloid plaques and cerebral glucose metabolism in semantic dementia and Alzheimer???s disease, NeuroImage, vol.39, issue.2, pp.619-633, 2008.
DOI : 10.1016/j.neuroimage.2007.09.020

C. Duval, A. Bejanin, P. Piolino, M. Laisney, V. De-la-sayette et al., Theory of mind impairments in patients with semantic dementia, Brain, vol.29, issue.1, pp.228-241, 2012.
DOI : 10.1159/000255141
URL : https://hal.archives-ouvertes.fr/inserm-00642036

C. Duval, B. Desgranges, V. De-la-sayette, S. Belliard, F. Eustache et al., What happens to personal identity when semantic knowledge degrades? A study of the self and autobiographical memory in semantic dementia, Neuropsychologia, vol.50, issue.2, pp.254-265, 2012.
DOI : 10.1016/j.neuropsychologia.2011.11.019

A. Ernst and J. Frisén, Adult Neurogenesis in Humans- Common and Unique Traits in Mammals, PLOS Biology, vol.59, issue.1
DOI : 10.1371/journal.pbio.1002045.g004
URL : https://doi.org/10.1371/journal.pbio.1002045

C. Galton, K. Patterson, K. Graham, M. Lambon-ralph, G. Williams et al., Differing patterns of temporal atrophy in Alzheimer's disease and semantic dementia, Neurology, vol.57, issue.2, pp.216-225, 2001.
DOI : 10.1212/WNL.57.2.216

M. Gorno-tempini, A. Hillis, S. Weintraub, A. Kertesz, M. Mendez et al., Classification of primary progressive aphasia and its variants, Neurology, vol.76, issue.11, pp.1006-1014, 2011.
DOI : 10.1212/WNL.0b013e31821103e6
URL : http://europepmc.org/articles/pmc3059138?pdf=render

M. Grothe and S. Teipel, Spatial patterns of atrophy, hypometabolism, and amyloid deposition in Alzheimer's disease correspond to dissociable functional brain networks, Human Brain Mapping, vol.34, issue.1, pp.35-53, 2016.
DOI : 10.1093/brain/awq075

J. Hodges, J. Mitchell, K. Dawson, M. Spillantini, J. Xuereb et al., Semantic dementia: demography, familial factors and survival in a consecutive series of 100 cases, Brain, vol.24, issue.3, pp.300-306, 2010.
DOI : 10.1006/brln.1997.1840

L. Ittner and J. Götz, Amyloid-?? and tau ??? a toxic pas de deux in Alzheimer's disease, Nature Reviews Neuroscience, vol.37, issue.2, pp.65-72, 2011.
DOI : 10.1016/j.nbd.2009.09.004

B. James, R. Wilson, P. Boyle, J. Trojanowski, D. Bennett et al., TDP-43 stage, mixed pathologies, and clinical Alzheimer???s-type dementia, Brain, vol.11, issue.11, 2016.
DOI : 10.1002/brb3.66
URL : https://academic.oup.com/brain/article-pdf/139/11/2983/7511113/aww224.pdf

A. Kapasi, C. Decarli, and J. Schneider, Impact of multiple pathologies on the threshold for clinically overt dementia, Acta Neuropathologica, vol.60, issue.494???503, pp.171-186, 2017.
DOI : 10.1111/j.1532-5415.2011.03839.x

V. Kljajevic, M. Grothe, M. Ewers, and S. Teipel, Distinct pattern of hypometabolism and atrophy in preclinical and predementia Alzheimer's disease, Neurobiology of Aging, vol.35, issue.9, pp.1973-1981, 2014.
DOI : 10.1016/j.neurobiolaging.2014.04.006

L. Joie, R. Landeau, B. Perrotin, A. Bejanin, A. Egret et al., Intrinsic connectivity identifies the hippocampus as a main crossroad between Alzheimer's and semantic dementiatargeted networks, Neuron, vol.81, pp.1417-1428, 2014.

L. Joie, R. Perrotin, A. Barré, L. Hommet, C. Mézenge et al., Region-Specific Hierarchy between Atrophy, Hypometabolism, and ??-Amyloid (A??) Load in Alzheimer's Disease Dementia, Journal of Neuroscience, vol.32, issue.46, pp.16265-16273, 2012.
DOI : 10.1523/JNEUROSCI.2170-12.2012

L. Joie, R. Perrotin, A. , D. L. Sayette, V. Egret et al., Hippocampal subfield volumetry in mild cognitive impairment, Alzheimer's disease and semantic dementia, NeuroImage: Clinical, vol.3, pp.155-162, 2013.
DOI : 10.1016/j.nicl.2013.08.007

G. Mckhann, D. Drachman, M. Folstein, R. Katzman, D. Price et al., Clinical diagnosis of Alzheimer's disease: Report of the NINCDS-ADRDA Work Group* under the auspices of Department of Health and Human Services Task Force on Alzheimer's Disease, Neurology, vol.34, issue.7, pp.939-944, 1984.
DOI : 10.1212/WNL.34.7.939

G. Mckhann, D. Knopman, H. Chertkow, B. Hyman, C. Jack et al., The diagnosis of dementia due to Alzheimer???s disease: Recommendations from the National Institute on Aging-Alzheimer???s Association workgroups on diagnostic guidelines for Alzheimer's disease, Alzheimer's & Dementia, vol.7, issue.3, pp.263-269, 2011.
DOI : 10.1016/j.jalz.2011.03.005

M. Mesulam, S. Weintraub, E. Rogalski, C. Wieneke, C. Geula et al., Asymmetry and heterogeneity of Alzheimer???s and frontotemporal pathology in primary progressive aphasia, Brain, vol.26, issue.4, pp.1176-1192, 2014.
DOI : 10.1212/WNL.0000000000000261

K. Moodley, L. Minati, A. Barnes, J. Dickson, P. Ell et al., Simultaneous PET/MRI in frontotemporal dementia, European Journal of Nuclear Medicine and Molecular Imaging, vol.6, issue.3, pp.468-469, 2013.
DOI : 10.1371/journal.pone.0018111

S. Nag, L. Yu, A. Capuano, R. Wilson, S. Leurgans et al., Hippocampal sclerosis and TDP-43 pathology in aging and Alzheimer disease, Annals of Neurology, vol.2, issue.6, pp.942-952, 2015.
DOI : 10.1002/brb3.66
URL : http://europepmc.org/articles/pmc4447563?pdf=render

P. Nestor, T. Fryer, and J. Hodges, Declarative memory impairments in Alzheimer's disease and semantic dementia, NeuroImage, vol.30, issue.3, pp.1010-1020, 2006.
DOI : 10.1016/j.neuroimage.2005.10.008

J. Rohrer, T. Lashley, J. Schott, J. Warren, S. Mead et al., Clinical and neuroanatomical signatures of tissue pathology in frontotemporal lobar degeneration, Brain, vol.133, issue.5, pp.2565-2581, 2011.
DOI : 10.1093/brain/awq075

J. Schneider, Z. Arvanitakis, S. Leurgans, and D. Bennett, The neuropathology of probable Alzheimer disease and mild cognitive impairment, Annals of Neurology, vol.71, issue.4, pp.200-208, 2009.
DOI : 10.1093/gerona/60.4.471

M. Schroeter and J. Neumann, Combined Imaging Markers Dissociate Alzheimer's Disease and Frontotemporal Lobar Degeneration ??? An ALE Meta-Analysis, Frontiers in Aging Neuroscience, vol.3, p.10, 2011.
DOI : 10.3389/fnagi.2011.00010
URL : http://journal.frontiersin.org/article/10.3389/fnagi.2011.00010/pdf

W. Seeley, R. Crawford, J. Zhou, B. Miller, and M. Greicius, Neurodegenerative Diseases Target Large-Scale Human Brain Networks, Neuron, vol.62, issue.1, pp.42-52, 2009.
DOI : 10.1016/j.neuron.2009.03.024

D. Shattuck, M. Mirza, V. Adisetiyo, C. Hojatkashani, G. Salamon et al., Construction of a 3D probabilistic atlas of human cortical structures, NeuroImage, vol.39, issue.3, pp.1064-1080, 2008.
DOI : 10.1016/j.neuroimage.2007.09.031

E. Spinelli, M. Mandelli, Z. Miller, M. Santos-santos, S. Wilson et al., Typical and atypical pathology in primary progressive aphasia variants, Annals of Neurology, vol.53, issue.pt 11, pp.430-443, 2017.
DOI : 10.3233/JAD-151063

T. Spires-jones and B. Hyman, The Intersection of Amyloid Beta and Tau at Synapses in Alzheimer???s Disease, Neuron, vol.82, issue.4, pp.756-771, 2014.
DOI : 10.1016/j.neuron.2014.05.004

R. Tan, J. Kril, Y. Yang, N. Tom, J. Hodges et al., Assessment of amyloid ?? in pathologically confirmed frontotemporal dementia syndromes, Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring, vol.9, pp.10-20, 2017.
DOI : 10.1016/j.dadm.2017.05.005

S. Teipel, A. Drzezga, M. Grothe, H. Barthel, G. Chételat et al., Multimodal imaging in Alzheimer's disease: validity and usefulness for early detection, The Lancet Neurology, vol.14, issue.10, 2015.
DOI : 10.1016/S1474-4422(15)00093-9

S. Teipel and M. Grothe, Alzheimer´s Disease Neuroimaging Initiative. Does posterior cingulate hypometabolism result from disconnection or local pathology across preclinical and clinical stages of Alzheimer's disease?, Eur. J. Nucl. Med. Mol. Imaging, 2015.

D. Thal, U. Rüb, M. Orantes, and H. Braak, Phases of A??-deposition in the human brain and its relevance for the development of AD, Neurology, vol.58, issue.12, pp.1791-1800, 2002.
DOI : 10.1212/WNL.58.12.1791

N. Villain, B. Desgranges, F. Viader, V. De-la-sayette, F. Mézenge et al., Relationships between Hippocampal Atrophy, White Matter Disruption, and Gray Matter Hypometabolism in Alzheimer's Disease, Journal of Neuroscience, vol.28, issue.24, pp.6174-6181, 2008.
DOI : 10.1523/JNEUROSCI.1392-08.2008
URL : http://www.jneurosci.org/content/jneuro/28/24/6174.full.pdf

N. Villain, M. Fouquet, J. Baron, F. Mézenge, B. Landeau et al., Sequential relationships between grey matter and white matter atrophy and brain metabolic abnormalities in early Alzheimer's disease, Brain, vol.169, issue.4, pp.3301-3314, 2010.
DOI : 10.1007/s00221-005-0187-7
URL : https://academic.oup.com/brain/article-pdf/133/11/3301/16695091/awq203.pdf

R. Viviani, A Digital Atlas of Middle to Large Brain Vessels and Their Relation to Cortical and Subcortical Structures, Frontiers in Neuroanatomy, vol.5, 2016.
DOI : 10.1002/(sici)1097-0193(1997)5:4218::AID-HBM23.3.CO;2-h