Accuracy of the Clinical Evaluation for Frontotemporal Dementia

BACKGROUND: Without a definitive clinical test, the early diagnosis of frontotemporal dementia (FTD) can be difficult. OBJECTIVE: To evaluate the accuracy of the clinical evaluation for FTD. DESIGN: Retrospective assessment of consensus criteria for FTD, neuropsychological measures, magnetic resonance images, and single-photon emission computed tomography/positron emission tomography (SPECT/PET) scans at baseline compared with a standard of subsequent clinical diagnosis after follow-up and reevaluation to year 2. SETTING: University hospital. PATIENTS: A total of 134 patients referred for clinical evaluation of suspected FTD. These patients had 1 or more core or supportive features of FTD in the absence of another etiology on initial assessment. MAIN OUTCOME MEASURES: Sensitivities, specificities, and predictive values of consensus criteria for FTD, magnetic resonance images, and SPECT/PET scans at initial assessment. RESULTS: The sensitivities and specificities for the diagnosis of FTD were 36.5% and 100.0% for consensus criteria, 63.5% and 70.4% for magnetic resonance images, and 90.5% and 74.6% for SPECT/PET scans, respectively. With a previous prevalence of nearly 50% for FTD, the positive predictive value was greatest for consensus criteria (100.0%), and the negative predictive value was greatest for SPECT/PET (89.8%). The initial neuropsychological results did not distinguish FTD, but the pattern of progression (worse naming and executive functions and preserved constructional ability) helped establish the diagnosis at year 2. CONCLUSIONS: Consensus criteria for FTD and neuropsychological measures lacked sensitivity for FTD; however, neuroimaging, particularly functional brain studies, greatly increased the sensitivity of detecting FTD. The clinical diagnosis of FTD needs to combine neuropsychiatric features with SPECT or PET findings while following the changes on neuropsychological tests.