Cognitive correlates of cerebrospinal fluid biomarkers in frontotemporal dementia

Objective: In this study we investigated the relationships between cerebrospinal fluid (CSF) biomarkers (tau and amyloid-beta(1-42) [A beta(1-42)]) and cognition or behavior in patients with frontotemporal dementia (the behavioral variant, bvFTD). Methods: We included 58 patients with bvFTD. All patients underwent a neuropsychological assessment and lumbar puncture. Relationships between CSF biomarkers and cognition or behavior were assessed with linear regression analysis. Results: After correction for age, sex, and education, CSF tau levels were found to be negatively related to the Visual Association Test (standardized beta = -0.3, P < .05), whereas CSF A beta(1-42) levels were found to be positively related to the Mini-Mental State Examination (beta = 0.3, P < .05), the frontal assessment battery (beta = 0.5, P < .05), and digit span backwards test (beta = 0.3, P = .01). We did not find relations between CSF biomarkers and behavior (measured by the neuropsychiatric inventory). After excluding all patients with a CSF biomarker profile often seen in Alzheimer's disease (high levels of tau and low levels of A beta(1-42)), we still found relations between CSF A beta(1-42) levels and Visual Association Test object naming (beta = 0.4, P < .05), as well as between CSF A beta(1-42) levels and the frontal assessment battery (beta = 0.5, P < .05, but there was no relation between CSF tau and cognition. Conclusion: Low CSF A beta(1-42) levels are associated with worse general cognitive function and worse executive function in patients with bvFTD. Our results provide circumstantial evidence for a pathophysiological role of A beta(1-42) in bvFTD. (C) 2013 The Alzheimer's Association. All rights reserved.