Stört die kontinuierliche, nicht-invasive Blutdruckmessung bei Patienten mit primärem Restless-Legs-Syndrom den Schlaf? Beurteilung mittels EEG-Spektralanalyse

The relevance of nocturnal blood pressure measurement in relation to cardiovascular risk, blood pressure changes during apnea phases, and PLMS in restless legs syndrome is well established in the literature. Features of high-quality blood pressure measurement include valid measurement results, as well as a high temporal resolution to record short-term blood pressure fluctuations and ensure the lowest possible influence on sleep architecture. The aim of this study is to determine whether the sleep structure is disturbed by continuous, non-invasive blood pressure measurement using PORTAPRES®. The Penáz method of blood pressure measurement used in this study is the most frequently used method for continuous, non-invasive blood pressure measurement in sleep research. Sensors are attached to two fingers. One of these sensors is used for the measurement. A noticeable pressure is exerted on this finger, and the change from one finger to the other, which occurs again and again during the measurement period (change of cuff), is clearly noticeable when awake and could have a disruptive effect on sleep. Methods This study is a retrospective analysis of polysomnographic data collected from 89 patients with idiopathic restless legs syndrome. In total, 79 subjects are included in the final evaluation. The data were collected from 2011–2012 as part of the ENCORE study. EEG spectral analysis is used to assess whether the cuff change during nocturnal blood pressure measurement using PORTAPRES® recorded any variation throughout sleep. The EEG was analysed 20 seconds before and after the cuff change. Additional variations in REM and NREM wave patterns, changes in heart rate, frequency of arousal, and sleep stage after cuff change were recorded for analysis. Results After the cuff change, increases in delta, theta, and alpha power were observed throughout sleep. The delta power had the greatest increase of the three, and increases in the beta and alpha band were observed in REM sleep. The period of time in which a significant increase in individual power could be demonstrated begins right at the moment of changing the cuff and extends up to 6 seconds after the start of the change. The vegetative response, an increase in heart rate, begins with a delay between 3 and 4 seconds and normalizes again after 10 seconds. The occurrence of arousals also increased slightly after the change. An increase in sleep stage changes cannot be demonstrated. Conclusions The results indicate that the cuff change is registered during sleep but does not lead to a relevant disturbance of sleep such as sleep fragmentation or significantly increased frequency of arousal. The increase in the delta band observed in this study can be considered a component of regulation to maintain sleep. The curve of the heart rate indicates a low vegetative response. Thus, the stimulus of changing the cuff appears to be so slight that it is possible to maintain sleep despite the change in the power of the individual frequencies and a slight vegetative reaction.