RT Journal Article SR Electronic T1 Neuroimaging of Rapidly Progressive Dementias, Part 1: Neurodegenerative Etiologies JF American Journal of Neuroradiology JO Am. J. Neuroradiol. FD American Society of Neuroradiology SP 418 OP 423 DO 10.3174/ajnr.A3454 VO 35 IS 3 A1 A.J. Degnan A1 L.M. Levy YR 2014 UL http://www.ajnr.org/content/35/3/418.abstract AB SUMMARY: Most dementias begin insidiously, developing slowly and generally occurring in the elderly age group. The so-called rapidly progressive dementias constitute a different, diverse collection of conditions, many of which are reversible or treatable. For this reason, prompt identification and assessment of acute and subacute forms of dementia are critical to effective treatment. Numerous other entities within this category of presenile rapid-onset dementias are untreatable such as the prion-related diseases. Neuroimaging aids in the diagnosis and evaluation of many of these rapidly progressive dementias, which include myriad conditions ranging from variations of more common neurodegenerative dementias, such as Alzheimer disease, dementia with Lewy bodies, and frontotemporal dementia; infectious-related dementias such as acquired immune deficiency syndrome dementia; autoimmune and malignancy-related conditions; to toxic and metabolic forms of encephalopathy. This first of a 2-part review will specifically address the ability of MR imaging and ancillary neuroimaging strategies to support the diagnostic evaluation of rapidly progressive dementias due to neurodegenerative causes. ADAlzheimer diseaseCBDcorticobasal degenerationDLBdementia with Lewy bodiesHDHuntington diseaseMSAmultiple-system atrophyPSPprogressive supranuclear palsy