Diagnosis and treatment of rapidly progressive dementias

Abstract

Rapidly progressive dementias are conditions that typically cause dementia over weeks or months. They are a particular challenge to neurologists as the differential diagnosis often is different from the more typical, slowly progressive dementias. Early and accurate diagnosis is essential, as many of the etiologies are treatable. The information in this review is in part based on experience through our rapidly progressive dementia program at the University of California San Francisco, Memory and Aging Center. As treatment of a rapidly progressive dementia is entirely dependent on the diagnosis, we present a comprehensive, structured, but pragmatic approach to diagnosis, including key clinical, laboratory, and radiologic features. For the 2 most common causes of rapid dementia, treatment algorithms for the autoimmune encephalopathies and symptomatic management for the neurodegenerative causes are discussed.

Figure 1. Suggested diagnostic tests for initial rapidly progressive dementia evaluation

ANA = antinuclear antibody; ANCA = anti-neutrophil cytoplasmic antibody; anti-TG = anti-thyroglobulin; anti-TP = anti-thyroperoxidase; CRP = C-reactive protein; ESR = erythrocyte sedimentation rate; NSE = neuron-specific enolase; RF = rheumatoid factor. Modified from Geschwind et al.

Figure 2. Proposed non–evidence-based treatment algorithm for autoimmune paraneoplastic and non-paraneoplastic encephalopathies

Adapted from Mckeon et al.

Figure 3. Proposed management algorithm for more common neurodegenerative causes of RPD

AD = Alzheimer disease; bvFTD = behavioral variant frontotemporal dementia; CJD = Creutzfeldt-Jakob disease; LBD = Lewy body dementia; RPD = rapidly progressive dementia. Quinacrine failed to show benefit in a clinical trial. LBD management adapted from: Boeve BF (2005), Clinical, diagnostic, genetic and management issues in dementia with Lewy bodies, Clin Sci 109(4), 343–354.