title: Rapidly Progressive Dementia: Prevalence and Causes in a Neurologic Unit of a Tertiary Hospital in Brazil.
abstract: BACKGROUND
  Rapidly progressive dementia (RPD) is usually associated with Creutzfeldt-Jakob disease, a fatal condition. Current advances in the understanding of immune-mediated diseases allow the diagnosis of previously unrecognized treatable RPDs.
  
  
  OBJECTIVE
  The objective of the study was to describe the prevalence and causes of RPD in a neurology service, identifying potentially reversible causes.
  
  
  METHODS
  We carried out a cross-sectional evaluation of all patients admitted to the neurology unit of a tertiary hospital in Brazil between March 2012 and February 2015. We included patients who had progressed to moderate or severe dementia within a few months or up to 2 years at the time of hospitalization, and used multivariable logistic regression analysis to identify factors associated with a favorable outcome.
  
  
  RESULTS
  We identified 61 RPD (3.7%) cases among 1648 inpatients. Mean RPD patients' age was 48 years, and median time to progression was 6.4 months. Immune-mediated diseases represented the most commonly observed disease group in this series (45.9% of cases). Creutzfeldt-Jakob disease (11.5%) and nonprion neurodegenerative diseases (8.2%) were less common in this series. Outcome was favorable in 36/61 (59.0%) RPD cases and in 28/31 (89.3%) of immune-mediated cases. Favorable outcome was associated with shorter time from symptom onset to diagnosis and abnormal cerebrospinal fluid findings.
  
  
  CONCLUSIONS
  Immune-mediated diseases were the most common cause of RPD in this series. Timely evaluation and diagnosis along with institution of appropriate therapy are required in RPD, especially in view of potentially reversible causes.
authors.affiliation: Department of Neurology, Hospital das Clínicas, Medical School, University of São Paulo, Brazil.
authors.forename: Adalberto
authors.initials: A
authors.lastname: Studart Neto
authors.forename: Herval R
authors.initials: HR
authors.lastname: Soares Neto
authors.forename: Mateus M
authors.initials: MM
authors.lastname: Simabukuro
authors.forename: Davi J F
authors.initials: DJF
authors.lastname: Solla
authors.forename: Márcia R R
authors.initials: MRR
authors.lastname: Gonçalves
authors.forename: Ida
authors.initials: I
authors.lastname: Fortini
authors.forename: Luiz H M
authors.initials: LHM
authors.lastname: Castro
authors.forename: Ricardo
authors.initials: R
authors.lastname: Nitrini
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001938:Brazil / Q000453:epidemiology; D007562:Creutzfeldt-Jakob Syndrome / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000523:psychology; D003430:Cross-Sectional Studies; D003704:Dementia / Q000000981:diagnostic imaging* / Q000453:epidemiology* / Q000523:psychology; D018450:Disease Progression; D006757:Hospital Units / Q000639:trends; D006801:Humans; D008875:Middle Aged; D019636:Neurodegenerative Diseases / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000523:psychology; D009462:Neurology / Q000639:trends*; D015995:Prevalence; D012189:Retrospective Studies; D062606:Tertiary Care Centers / Q000639:trends*; D013997:Time Factors; D055815:Young Adult