Reduced sympathetic activity in idiopathic rapid-eye-movement sleep behavior disorder and Parkinson's disease.

Background: More than 50% of patients with idiopathic REM sleep behavior disorder (iRBD) will develop Parkinson's disease or Lewy body dementia. In a previous study, we found attenuated heart rate responses in iRBD and Parkinson's disease patients during sleep. The current study aimed to evaluate heart rate variability further in order to identify possible changes in these components during wakefulness and sleep in patients with iRBD and Parkinson's disease.

Sleep transitions in hypocretin-deficient narcolepsy.

Study Objectives: Narcolepsy is characterized by instability of sleep-wake, tonus, and rapid eye movement (REM) sleep regulation. It is associated with severe hypothalamic hypocretin deficiency, especially in patients with cataplexy (loss of tonus). As the hypocretin neurons coordinate and stabilize the brain's sleep-wake pattern, tonus, and REM flip-flop neuronal centers in animal models, we set out to determine whether hypocretin deficiency and/or cataplexy predicts the unstable sleep-wake and REM sleep pattern of the human phenotype.

Attenuated heart rate response is associated with hypocretin deficiency in patients with narcolepsy.

Study Objective: Several studies have suggested that hypocretin-1 may influence the cerebral control of the cardiovascular system. We analyzed whether hypocretin-1 deficiency in narcolepsy patients may result in a reduced heart rate response.

Design: We analyzed the heart rate response during various sleep stages from a 1-night polysomnography in patients with narcolepsy and healthy controls.

Attenuated heart rate response in REM sleep behavior disorder and Parkinson's disease.

The objective of this study was to determine whether patients with Parkinson's disease with and without rapid-eye-movement sleep behavior disorder and patients with idiopathic rapid-eye-movement sleep behavior disorder have an attenuated heart rate response to arousals or to leg movements during sleep compared with healthy controls. Fourteen and 16 Parkinson's patients with and without rapid-eye-movement sleep behavior disorder, respectively, 11 idiopathic rapid-eye-movement sleep behavior disorder patients, and 17 control subjects underwent 1 night of polysomnography. The heart rate response associated with arousal or leg movement from all sleep stages was analyzed from 10 heartbeats before the onset of the sleep event to 15 heartbeats following onset of the sleep event.

Detection of arousals in Parkinson's disease patients.

Arousal from sleep are short awakenings, which can be identified in the EEG as an abrupt change in frequency. Arousals can occur in all sleep stages and the number and frequency increase with age. Frequent arousals during sleep results in sleep fragmentation and is associated with daytime sleepiness.