Assessment of the suitability of using a forehead EEG electrode set and chin EMG electrodes for sleep staging in polysomnography

Abstract

Summary Recently, a number of portable devices designed for full polysomnography at home have appeared. However, current scalp electrodes used for electroencephalograms are not practical for patient self‐application. The aim of this study was to evaluate the suitability of recently introduced forehead electroencephalogram electrode set and supplementary chin electromyogram electrodes for sleep staging. From 31 subjects (10 male, 21 female; age 31.3 ± 11.8 years), sleep was recorded simultaneously with a forehead electroencephalogram electrode set and with a standard polysomnography setup consisting of six recommended electroencephalogram channels, two electrooculogram channels and chin electromyogram. Thereafter, two experienced specialists scored each recording twice, based on either standard polysomnography or forehead recordings. Sleep variables recorded with the forehead electroencephalogram electrode set and separate chin electromyogram electrodes were highly consistent with those obtained with the standard polysomnography. There were no statistically significant differences in total sleep time, sleep efficiency or sleep latencies. However, compared with the standard polysomnography, there was a significant increase in the amount of stage N1 and N2, and a significant reduction in stage N3 and rapid eye movement sleep. Overall, epoch‐by‐epoch agreement between the methods was 79.5%. Inter‐scorer agreement for the forehead electroencephalogram was only slightly lower than that for standard polysomnography (76.1% versus 83.2%). Forehead electroencephalogram electrode set as supplemented with chin electromyogram electrodes may serve as a reliable and simple solution for recording total sleep time, and may be adequate for measuring sleep architecture. Because this electrode concept is well suited for patient's self‐application, it may offer a significant advancement in home polysomnography.

Machine‐learning‐derived sleep–wake staging from around‐the‐ear electroencephalogram outperforms manual scoring and actigraphy

“…We hypothesize that this is because of the different EEG characteristics between brief arousals and "proper" wake EEG. The WASO-related problems were also observed in other studies; see Myllymaa et al (2016), Popovic, Khoo, and Westbrook (2014) and Griessenberger, Heib, Kunz, Hoedlmoser, and Schabus (2013). However, the current results clearly demonstrate that compared with actigraphy, the automatic cEEGrid-based classifiers perform significantly better in sleep-wake assessment, besides offering the opportunity to detect different sleep stages.…”

Screen‐printed ambulatory electrode set enables accurate diagnostics of sleep bruxism

“…Furthermore, sleep stages, RMMA and arousal events were determined by only one scorer. However, determination of TST by sleep stage scoring with AES has been shown to be accurate and the variance between scorers to be small in a larger study examining the sleep stage scoring with AES (Myllymaa et al ., ). Also, inter‐rater agreement of RMMA scoring is very high (Dutra et al ., ).…”

“…Two equal sized groups, a bruxer group and a control group (n = 6 in both), were formed from an original study group of 31 volunteers (Myllymaa et al, 2016). Twenty-two of the subjects were self-proclaimed bruxers and nine were supposedly healthy controls.…”

“…Recently, the authors have introduced a silver ink screen-printed and hydrogel-coated electrode set (Lepola et al, 2014) for emergency assessment of EEG in patients with altered mental state (Muraja-Murro et al, 2015). The electrode set is easy and quick to attach to the skin (Lepola et al, 2014), and it is also suitable for assessment of TST by sleep stage scoring (Myllymaa et al, 2016). The set includes electrodes placed near masseter muscles, generally used for RMMA recognition (Carra et al, 2012;Lavigne et al, 1996).…”

Sleep research in the near future: a passing outlook

“…In the first paper addressing these issues, the montage used consists of a printable electrode set of 10 EEG electrodes, two EOG electrodes, two ground electrodes and two reference electrodes (Myllymaa et al ., ). A comparison between sleep scoring based on this montage and a standard montage in 31 participants yielded excellent agreement [intraclass correlation (ICC) > 0.8] for total sleep time, wake after sleep onset, REM sleep and N3, with slightly poorer agreement for N1, N2 and the latency to sleep onset and REM sleep.…”