['To investigate whether cerebrospinal fluid (CSF) biomarkers of neurodegeneration are altered in narcolepsy in order to evaluate whether the hypocretin deficiency and abnormal sleep-wake pattern in narcolepsy leads to neurodegeneration.', 'Twenty-one patients with central hypersomnia (10 type 1 narcolepsy, 5 type 2 narcolepsy, and 6 idiopathic hypersomnia cases) aged 33 years on average, and with a disease duration of 2-29 years, and 12 healthy controls underwent CSF analyses of levels of β-amyloid, total tau protein (T-tau), phosphorylated tau protein (P-tau181), α-synuclein, neurofilament light chain (NF-L), and chitinase 3-like protein-1 (CHI3L1).', 'Levels of β-amyloid were lower in patients with type 1 narcolepsy (375.4 ±143.5 pg/ml) and type 2 narcolepsy (455.9 ± 65.0 pg/ml) compared with controls (697.9 ± 167.3 pg/ml, p < 0.05). Furthermore, in patients with type 1 narcolepsy, levels of T-tau (79.0 ± 27.5 pg/ml), and P-tau181 (19.1 ± 4.3 pg/ml) were lower than in controls (162.2 ± 49.9 pg/ml and 33.8 ± 9.2 pg/ml, p < 0.05). Levels of α-synuclein, NF-L, and CHI3L1 in CSF from narcolepsy patients were similar to those of healthy individuals.'] Are cerebrospinal fluid biomarkers of neurodegeneration decreased or normal in narcolepsy?