Cognitive correlates of CSF biomarkers in Frontotemporal dementia

Objective In this study we investigated the relationships between CSF biomarkers (tau and amyloid beta1-42 (Aβ1-42)) and cognition or behaviour in patients with Frontotemporal dementia (the behavioural 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 behaviour were assessed with linear regression analysis. Results After correction for age, gender and education, CSF tau levels were found to be negatively related to the visual association test (VAT) (standardized β =-0.3, p < 0.05), whereas CSF Aβ1-42 levels were found to be positively related to the mini-mental-state examination (MMSE) (β = 0.3, p < 0.05), the frontal assessment battery (FAB) (β = 0.5, p < 0.05) and digit span backwards (β = 0.3, p = 0.01). We did not find relations between CSF biomarkers and behaviour (measured by the neuropsychiatric inventory (NPI)). After excluding all patients with a CSF biomarker profile often seen in AD (high levels of tau and low levels of Aβ1-42), we still found relations between CSF Aβ1-42 levels and VAT naming (β = 0.4, p < 0.05) as well as between CSF Aβ1-42 levels and the FAB (β = 0.5, p < 0.05), but there was no relation between CSF tau and cognition. Conclusion Low CSF Aβ1-42 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 Aβ1-42 in bvFTD. 99 Introduction Frontotemporal dementia (behavioural variant, bvFTD), the most common form of frontotemporal lobar degeneration (FTLD), is a heterogeneous disorder, both clinically and neuropathologically. Clinically patients present with behavioural change often combined with executive dysfunction and language dysfunction