Clinical Manifestations

Frontotemporal lobar degeneration (FTLD) includes behavioral variant frontotemporal dementia (bvFTD), nonfluent and semantic variants of primary progressive aphasia (nfvPPA, svPPA), progressive supranuclear palsy (PSP), corticobasal degeneration (CBD), and frontotemporal dementia associated with motor neuron disease (FTD-MND). These syndromes are associated with prolonged time to diagnosis, impacting patient care and family outcomes. While diagnostic timelines have been studied in other regions, data from Latin America remain limited. Addressing this gap is essential to identify barriers and improve timeliness of diagnosis and treatment strategies.

We analyzed 415 cases (mean age 66.5 ± 8.2 years) from the RedLat consortium (2021-2024): bvFTD (n =  232, 55.9%), svPPA (n =  68, 16.4%), nfvPPA (n =  33, 8%), non-specified PPA (nsPPA; n =  13, 3.1%), PSP (n =  32, 7.7%), CBS (n =  22, 5.3%), FTD-MND (n =  7, 1.7%), and non-specified FTD (n =  8, 1.9%). Time to diagnosis was defined as the interval from first reported symptom (TDFRS) and first FTLD-criteria symptom (TDFCS) to diagnosis. Clinical and sociodemographic factors influencing these timelines were also assessed.

Diagnostic timelines varied substantially. The most prevalent phenotype, bvFTD, had a mean (±SD) TDFRS of 3.54 ± 3.61 years and TDFCS of 3.09 ± 2.76 years. In contrast, svPPA (TDFRS = 3.47 ± 3.56; TDFCS = 3.08 ± 2.73) and PSP (TDFRS = 3.00 ± 2.64; TDFCS = 2.68 ± 1.94) showed similar durations. FTD-MND exhibited the shortest timeline, with a mean duration of 1.29 ± 1.38 years for both TDFRS and TDFCS. Younger age at onset and lower education levels were associated with longer diagnostic timelines.

This study highlights substantial variability in diagnostic timelines across FTLD phenotypes in Latin America. The longest timelines were seen for bvFTD, while FTD-MND had the shortest. Younger patients and those with lower education faced greater challenges in obtaining timely diagnoses, suggesting sociodemographic disparities. These findings emphasize the need for targeted interventions, including increased clinical awareness, improved access to specialized care, and strategies to address disparities, optimizing the diagnostic process and outcomes for patients and families.