HCRT and narcolepsy: Narcolepsy type 1 (NT1), also known as narcolepsy with cataplexy or hypocretin-deficiencysyndrome, is a rare chronic sleep disorder characterized by the specific and subtotal lossof hypocretin neurons, which could be immune mediated.1,2 Hypocretin-1(HCRT-1) level in the cerebrospinal fluid (CSF) of patients with NT1 is typically reduced tolow or undetectable levels already at diagnosis.