# Utility of the Rowland Universal Dementia Assessment Scale and INECO Frontal Screening for differentiating dementia subtypes between Alzheimer's disease and Parkinson's disease dementia

## TL;DR

This study shows that two brief cognitive tests, RUDAS and IFS, can effectively differentiate between dementia subtypes like Alzheimer's and Parkinson's disease dementia, especially in resource-limited areas.

## Contribution

The study demonstrates the diagnostic utility of RUDAS and IFS in distinguishing dementia subtypes in a Latin American setting.

## Key findings

- RUDAS and IFS showed 100% specificity in differentiating dementia from normal cognition, unlike MMSE.
- IFS detected early cognitive changes in Parkinson's disease with high statistical significance.
- RUDAS effectively distinguished Alzheimer's disease and Parkinson's disease dementia using memory and visuospatial tasks.

## Abstract

Time to dementia diagnosis is a major barrier to effective care, particularly in resource-limited settings such as Latin America. Barriers to timely dementia diagnosis include the lack of access to comprehensive neuropsychological testing, cognitive specialists, and advanced diagnostic tools. Brief cognitive assessments, such as the Rowland Universal Dementia Assessment Scale (RUDAS) and INECO Frontal Screening (IFS) offer promise for diverse populations, and may help in specific dementia subtypes, including Alzheimer's disease (AD) and Parkinson's disease dementia (PDD).

This study evaluates the efficacy of RUDAS and IFS in comparison to the Mini-Mental Status Exam (MMSE).

A total of 243 participants (70 normal cognition Controls, 62 PD with normal cognition, 46 PDD, and 75 AD) were recruited as part of an observational cross-sectional study at a cognitive clinic in Peru. Diagnosis was based on clinical criteria and confirmed with a comprehensive neuropsychological battery. Participants underwent cognitive assessment using RUDAS, IFS, and MMSE.

Both RUDAS and IFS differentiated dementia from normal cognition groups with 100% specificity, compared to 53% for MMSE. The IFS identified early cognitive changes in PD (median score: PD = 24; Controls = 27, p < 0.001). RUDAS was particularly effective in distinguishing AD and PDD using the memory and visuospatial tasks.

These results suggest that RUDAS and IFS can enable faster and clearer diagnoses for dementia subtypes, offering clinicians and community health workers practical tools to improve care in resource-limited settings where comprehensive evaluations are not always feasible.