title: Early-onset dementias: Specific etiologies and contribution of MRI.
abstract: Early-onset dementias are defined by onset of first symptoms before the age of 65. They have specific diagnostic features which differ from those of elderly patients in terms of their many causes and atypical clinical presentations. MRI is an essential procedure for identifying the underlying cause of the dementia (degenerative, vascular, infectious, inflammatory, metabolic or toxic). Clinical clues and MRI signs are described, and their defining features are related to the young age of the patients concerned. Diagnostic algorithms are proposed from signs which can be seen on the different MRI sequences (T1-weighted volume acquisition, T2-weighted FLAIR sequences, T2-weighted gradient-echo, diffusion-weighted imaging). Once obvious causes have been excluded, MRI can point towards the rarer causes of dementia which are characteristic in young people (particularly metabolic and autoimmune) and which require specific management and genetic counseling.
authors.affiliation: Department of general radiology/diagnostic and interventional neuroradiology, Bretonneau Hospital, Tours University Hospitals, boulevard Tonnellé, 37044 Tours cedex, France. Electronic address: celine.quach@etu.univ-tours.fr.
authors.forename: C
authors.initials: C
authors.lastname: Quach
authors.affiliation: Department of Internal Geriatric Medicine and CMRR (French Memory Research and Resource Centre), Bretonneau Hospital, Tours University Hospitals, 37044 Tours cedex, France.
authors.forename: C
authors.initials: C
authors.lastname: Hommet
authors.affiliation: Department of Internal Geriatric Medicine and CMRR (French Memory Research and Resource Centre), Bretonneau Hospital, Tours University Hospitals, 37044 Tours cedex, France.
authors.forename: K
authors.initials: K
authors.lastname: Mondon
authors.affiliation: Department of general radiology/diagnostic and interventional neuroradiology, Bretonneau Hospital, Tours University Hospitals, boulevard Tonnellé, 37044 Tours cedex, France.
authors.forename: M A
authors.initials: MA
authors.lastname: Lauvin
authors.affiliation: Department of general radiology/diagnostic and interventional neuroradiology, Bretonneau Hospital, Tours University Hospitals, boulevard Tonnellé, 37044 Tours cedex, France.
authors.forename: X
authors.initials: X
authors.lastname: Cazals
authors.affiliation: Department of general radiology/diagnostic and interventional neuroradiology, Bretonneau Hospital, Tours University Hospitals, boulevard Tonnellé, 37044 Tours cedex, France.
authors.forename: J P
authors.initials: JP
authors.lastname: Cottier
mesh_terms: D017668:Age of Onset; D000465:Algorithms; D002494:Central Nervous System Infections / Q000150:complications; D003704:Dementia / Q000175:diagnosis* / Q000209:etiology*; D015140:Dementia, Vascular / Q000150:complications; D006801:Humans; D008279:Magnetic Resonance Imaging; D008659:Metabolic Diseases / Q000150:complications; D019636:Neurodegenerative Diseases / Q000150:complications
keywords: Dementia; Early-onset dementia; MRI