Cognitive characterization of the behavioral variant of frontotemporal dementia using the Neuronorma battery

Abstract

Background

Frontotemporal dementia (FTD) is a neurodegenerative disorder characterized by progressive behavioral changes, executive dysfunction, and language impairment. The behavioral variant (bvFTD) is the most common form and often overlaps clinically with psychiatric disorders and Alzheimer's disease (AD), complicating early diagnosis. Neuropsychological assessment is therefore essential, yet standardized tools for bvFTD are limited.

Objective

This study aimed to characterize the cognitive profiles of bvFTD across prodromal and demented stages using the Neuronorma neuropsychological battery.

Methods

We analyzed clinical and neuropsychological data from 122 bvFTD patients, including 35 prodromal (Clinical Dementia Rating (CDR) 0.5) and 87 demented (CDR>0.5) cases. Cognitive domains assessed were attention, executive function, memory, verbal fluency, naming, and visuospatial abilities, with impairment defined using two Z-score thresholds (≤ −1 and ≤ −1.67). Patient performance was compared to age-, sex-, and education-matched healthy controls.

Results

We found frequent deficits in executive function, semantic fluency, verbal and visual memory, and visuospatial abilities, even among prodromal patients. Multi-domain impairment predominated in demented cases, whereas prodromal profiles were heterogeneous, occasionally presenting isolated memory deficits. Comparison with matched controls confirmed significant differences across most tests, with large effect sizes in memory, executive function, attention, and verbal fluency.

Conclusions

These findings support the use of the Neuronorma battery for the cognitive assessment of bvFTD, from the prodromal stages. Furthermore, the presence of non-executive cognitive deficits in bvFTD highlights the need for comprehensive cognitive profiling in differential diagnosis.