NEFL and frontotemporal dementia: Additionally, this trial’s inclusion of a variety of exploratory PD end points allowed for novel analyses comparing cortical fluorodeoxyglucose positron emission tomography (FDG-PET), clinical measures of functional FTD severity, and candidate CSF biomarkers of neuronal injury, including neurofilament light chain (NfL), amyloid β 1-42 (Aβ1-42), phosphorylated tau 181 (p-tau181), and total tau (t-tau).