Chapter 52 A contribution to pathophysiology of idiopathic hypersomnia

Abstract

Publisher Summary This chapter characterizes sleep and the circadian rhythm of salivary melatonin in polysymptomatic form of idiopathic hypersomnia (IH) to compare sleep and melatonin markers of the subjective night in these patients. In addition, salivary cortisol rhythm as another marker of circadian rhythmicity is discussed. Knowledge of the phase and duration of the nocturnal melatonin signal and nighttime sleep in polysymptomatic IH patients can contribute to the understanding of pathophysiology of the disease. The clinical and polysomnographic findings in the IH patients are in full agreement with the well-known literature data. To the best of present knowledge, the changes of hormonal circadian rhythms in IH patients have not yet been reported. According to the results, the melatonin rhythm as well as the cortisol rhythm in IH patients are significantly phase delayed compared with those in control subjects. Apparently, the IH patients' subjective night, determined from the elevated nocturnal melatonin levels, is phase shifted toward the morning hours. In addition, longer melatonin signal duration in IH patients has been indicated, because of a later morning melatonin decline, however, the signal lengthening is not significant. The later melatonin decline might be because either of later commands from the circadian pacemaker to switch off the melatonin production or to a change in melatonin degradation in IH patients.