Analysis of a case series of behavioral variant frontotemporal dementia: emphasis on diagnostic delay

Despite many advances in the characterization of the behavioral variant of frontotemporal dementia (bvFTD), the diagnosis of this syndrome poses a significant challenge, while delays or diagnostic mistakes may impact the proper clinical management of these patients.

To describe the clinical profile at first evaluation of a sample of patients with bvFTD from a specialized outpatient neurological unit, with emphasis on the analysis of the delay between the onset of symptoms and diagnosis.

We selected 31 patients that fulfilled international consensus criteria for possible or probable bvFTD. Patients' medical admission sheets were thoroughly reviewed.

Patients' mean age was 67.9±8.2 years; 16 (51.6%) were men. Mean number of years of formal education was 7.7±4.0 years. Mean age at onset was 62.2±7.7 years, indicating a mean of 5.8 years of diagnostic delay. Thirteen patients (41.9%) presented with initial behavioral complaints only, eleven patients (35.5%) had mixed behavioral and memory complaints, five patients (16.1%) presented with memory complaints only, and two patient (6.4%) had behavioral and speech problems. Nine patients (29%) were admitted with alternative diagnoses. Mean and standard deviation scores for the mini-mental state examination, animal category fluency and memory test for drawings (five-minute delayed recall) were 19.3±6.3, 8.3±4.1and 3.7±2.7, respectively.

Most patients from this sample were evaluated almost six years after the onset of symptoms and performed poorly on both cognitive screening tests and functional evaluation measures.