المتخصصون في المجالات الطبية

April 24, 2026

A multicenter study led by Mayo Clinic researchers has established an evidence-based definition for rapidly progressive dementia (RPD). As described in Neurology, the definition clearly distinguishes individuals with a broad spectrum of causes of RPD, supporting early diagnosis.

RPD accounts for only 3% to 4% of dementia cases but poses significant clinical challenges, due to the wide differential diagnosis and the need to quickly identify causes that might respond to treatment. The lack of a standardized definition of RPD also precludes multisite studies and complicates the generalization of published findings.

The researchers sought to determine whether a standardized definition based on the Clinical Dementia Rating (CDR) could reliably identify individuals with RPD early in the symptomatic course of disease. The study used the CDR classifications of dementia, defining RPD as dementia developing within one year, or incapacitation within two years, of symptom onset.

The performance of the researchers' CDR-based definition of RPD was evaluated in two independent cohorts: patients with suspected RPD who were prospectively assessed at two academic centers (RaPID cohort) and participants whose data from the National Alzheimer's Coordinating Center (NACC) dataset were retrospectively assessed. The researchers compared characteristics and rates of progression between typically progressive dementia and RPD.

Key findings:

• In the RaPID cohort, 74.6% of patients met the CDR-based RPD definition. Autoimmune (29.7%), neurodegenerative (27.6%) and prion diseases (18.9%) predominated.
• Among the 20,418 NACC participants with cognitive impairment, 4.1% met the CDR-based RPD definition. Neurodegenerative diseases predominated, especially Alzheimer's disease.
• The proposed RPD definition was readily applied across multiple sites and settings — including inpatient and outpatient populations — and identified common and rare causes of RPD.
• Most individuals with RPD were identified within six months of symptom onset.

"Our proposed RPD definition supports early diagnosis with minimal resource requirements," says Gregg S. Day, M.D., a behavioral neurologist at Mayo Clinic in Jacksonville, Florida, and the study's senior author. "Early diagnosis of RPD provides the opportunity for systematic screening for a specific cause that potentially could be treated."

He notes that multicenter studies are essential to study the factors that drive neuropathologic progression in RPD. "Patients with RPD present unique clinical challenges," Dr. Day says. "There is a clear need for a standardized definition of RPD that can be broadly and consistently applied in clinical settings and across research centers."

For more information

Satyadev N, et al. Standardizing 'rapid': Applying the Clinical Dementia Rating to define rapidly progressing dementia. Neurology. 2026;106:e214439.

Refer a patient to Mayo Clinic.