Daytime sleep state misperception in a tertiary sleep centre population.

STUDY OBJECTIVES: Sleep state misperception is common in various sleep disorders, especially in chronic insomnia with a prevalence ranging between 9-50%. Most prior studies used nocturnal polysomnography (PSG) for the identification of sleep state misperception during nighttime. Our objective was to assess sleep state misperception during daytime in people with sleep disorders with excessive daytime sleepiness (EDS). METHODS: In this prospective observational study, we assessed the occurrence of, and factors influencing sleep state misperception in consecutive patients undergoing a routine multiple sleep latency test (MSLT) in a tertiary sleep-wake centre included between 2014 and 2017. Mixed models were applied to assess the influence of patients' clinical data on sleep state perception. RESULTS: People with narcolepsy type 1 (NT1, n = 33) and type 2 (NT2, n = 14), idiopathic hypersomnia (IH, n = 56), obstructive sleep apnea (OSA, n = 31) and insufficient sleep syndrome (ISS, n = 31) were included. The prevalence of both classical and reverse sleep state misperception did not differ between the sleep disorders (mean 25%, range 8-37%) after correction for sleep stage, sleep onset latency and age. Longer sleep onset latency and reaching only non-rapid eye movement (REM) sleep stage 1 were significant predictors for classical sleep state misperception. CONCLUSIONS: Sleep state misperception is common in people with NT1 and NT2, IH, OSA, and ISS. Classical sleep state misperception is more frequent in patients with longer sleep onset latencies who only reach non-REM sleep stage 1 during a nap.

H1N1 hemagglutinin-specific HLA-DQ6-restricted CD4+ T cells can be readily detected in narcolepsy type 1 patients and healthy controls.

Following the 2009 H1N1 influenza pandemic, an increased risk of narcolepsy type 1 was observed. Homology between an H1N1 hemagglutinin and two hypocretin sequences has been reported. T cell reactivity to these peptides was assessed in 81 narcolepsy type 1 patients and 19 HLA-DQ6-matched healthy controls. HLA-DQ6-restricted H1N1 hemagglutinin-specific T cell responses were detected in 28.4% of patients and 15.8% of controls. Despite structural homology between HLA-DQ6-hypocretin and -H1N1 peptide complexes, T cell cross-reactivity was not detected. These results indicate that it is unlikely that cross-reactivity between H1N1 hemagglutinin and hypocretin peptides presented by HLA-DQ6 is involved in the development of narcolepsy.