Rapidly progressive dementia besides prion diseases: a multicentric tertiary hospital study

Background: Several diseases may cause rapidly progressive dementia (RPD). Reference centers for Creutzfeldt–Jakob disease reported prion diseases as the main cause of RPD. Alternatively, tertiary centers found high frequencies of nonprion diseases causing RPD, including several potentially treatable disorders.

Objective: This study aimed to identify the etiologies of RPD among inpatients from four tertiary centers in Florianópolis, Brazil.

Methods: Medical records of patients hospitalized from 2001 to 2020 were reviewed. Those meeting criteria for RPD were selected. RPD was characterized when (1) the criteria of the National Institute on Aging–Alzheimer’s Association for dementia were met and (2) the disease duration was 730 days or less. All etiological diagnoses were revised according to established clinical criteria.

Results: One hundred four patients with RPD were identified. The most frequent etiologic groups were dementias of vascular origin (N = 27, 26.0%), nonprion degenerative diseases (N = 24, 23.0%), and mixed dementias (N = 9, 8.7%). Eight patients (7.7%) had prion diseases. Ten patients (9.6%)—diagnosed with autoimmune disorders, infectious disorders, neoplasia, or posterior reversible encephalopathy syndrome—clinically improved.

Conclusions: Dementias of vascular origin were the most frequent cause of RPD in our sample, followed by nonprion degenerative diseases. Prion diseases were less common, though still a major etiologic group of RPD. A considerable group of RPD cases showed clinical improvement. Thorough investigation of RPD is crucial for the identification of potentially reversible etiologies.