Brief ReportsCapgras Syndrome in the Young Schizophrenia or Alzheimer Disease?Ng, Kok Pin MRCP*; Wong, Benjamin BSc*; Xie, Wanying FRCR†; Kandiah, Nagaendran FRCP*,‡Author Information *Department of Neurology, National Neuroscience Institute †Department of Nuclear Medicine and Molecular Imaging, Singapore General Hospital ‡Duke-NUS, Singapore, Singapore K.P.N.: study design, compose figure and manuscript draft. B.W.: data acquisition and manuscript draft. W.X.: image processing and manuscript draft. N.K.: study concept and design, study supervision and critical revision of the manuscript. The authors declare no conflicts of interest. Reprints: Nagaendran Kandiah, FRCP, Department of Neurology, National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore (e-mail: firstname.lastname@example.org). Alzheimer Disease & Associated Disorders: January–March 2020 - Volume 34 - Issue 1 - p 94-96 doi: 10.1097/WAD.0000000000000360 Buy Metrics Abstract This is a case report of an atypical presentation of early onset Alzheimer disease (EOAD) in a young patient with Capgras syndrome and cognitive impairment. The concurrent onset of psychiatric and cognitive symptoms prompted a detailed evaluation for a neurodegenerative disease. A 50-year-old male lawyer presented with low mood, apathy, delusions, and auditory hallucinations over 18 months. He considered his wife as an imposter and would require her text message to confirm her identity. He became more forgetful and had to give up his law practice. His neuropsychological assessment was impaired in all domains. Genetic testing revealed homozygosity for APOEe4 alleles. His magnetic resonance imaging showed predominant parietal and medial temporal atrophy, [18F]Fluorodeoxyglucose positron emission tomography showed frontal, parietal and posterior temporal hypometabolism and [18F]Flutemetamol positron emission tomography was positive for amyloid deposition, leading to the diagnosis of EOAD. This case highlights EOAD as a differential diagnosis in young patients who present with Capgras syndrome. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.