Repeated polysomnography and multiple sleep latency test in narcolepsy type 1 and other hypersomnolence disorders

•Polysomnography and multiple sleep latency test were accurate in diagnosing NT1.•Patients with NT1 presented a stable prognosis and characteristic profile.•Patients with NT1 have stable electrophysiological presentation.•Patients with hypersomnolence with hypocretin-1 are complex heterogeneous disorders.•Hypersomnolence patients with normal hypocretin-1 showed poor reliability and repeatability of electrophysiological results.