Cerebrospinal fluid biomarkers of neurodegeneration in narcolepsy type 1

Study Objectives To measure the levels of five neurodegenerative biomarkers in the cerebrospinal fluid (CSF) of patients with narcolepsy type 1 (NT1) with variable disease duration. Methods Following a standardized protocol of CSF collection and storage, we measured CSF total- and phosphorylated-tau, amyloid-beta 1-40 and 1-42, and neurofilament light chain (NfL) proteins in 30 nonneurological controls and 36 subjects with NT1, including 14 patients with recent disease onset (i.e. <= 12 months, short disease duration group). Results CSF levels of all biomarkers were similar in NT1 subjects and controls. The comparison between NT1 with short and long disease duration only revealed slightly higher levels of CSF amyloid-beta 1-40 in the former group (median 9,549.5, interquartile range [IQR] 7,064.2-11,525.0 vs. 6,870.0, IQR 5,133.7-9,951.2, p = 0.043). CSF storage time did not influence the levels of the tested biomarkers. Conclusions The measurement of CSF total-tau, phosphorylated-tau, amyloid-beta 1-40 and 1-42, and NfL proteins is not informative in NT1.