The timely introduction of non-invasive ventilation (NIV) is extremely relevant in the multidisciplinary management of patients affected by amyotrophic lateral sclerosis (ALS) and is based on the proper identification of red flags for early diaphragmatic exhaustion. Polygraphic sleep recording may provide insightful information on the ongoing respiratory impairment; in particular, atypical breathing patterns need to be recognized, as the application of current guidelines for sleep-related hypoxemia or sleep apnea may be insufficient for detecting early signs of diaphragmatic fatigue. We report the case of a 51-year-old man affected by ALS who was asymptomatic for breathing impairment, but whose nocturnal polysomnographic recording, despite not significant for obstructive sleep apnea nor for conventional hypoventilatory patterns, strongly suggested initial respiratory failure, as lately confirmed by the pulmonary follow-up. We discuss the advantages of including sleep recording in the clinical work-up of patients affected by ALS.

OBJECTIVE: The authors present the clinical practice guidelines of the French Society of Oto-Rhino-Laryngology and Head and Neck Surgery (SFORL) concerning the role of the ENT specialist in the management of pediatric obstructive sleep apnea hypopnea syndrome (POSAHS). Part 3 is dedicated to the place of sleep recordings in the diagnosis of POSAHS.
METHODS: A multidisciplinary work group was commissioned to carry out a review of the scientific literature on the above topic. Based on the articles retrieved and the group members\' individual experience, guidelines were drafted and graded as A, B or C or Expert Opinion by decreasing level of evidence, then reviewed by an editorial group independent of the work group.
RESULTS: Sleep recordings are presented according to the American Sleep Disorders Association\'s classification as type 1, 2, 3 or 4. Their modalities, interpretation, indications, advantages and limitations are detailed.

Imprinting disorders (ID), such as Prader-Willi syndrome (PWS), are associated with sleep-disordered breathing (SDB). No data are available for Silver-Russell syndrome (SRS), another ID that shares clinical features with PWS, although many patients describe excessive daytime sleepiness, disturbed sleep, and snoring. The aim of this study was to characterize sleep in children with SRS and to evaluate the impact of recombinant growth hormone (rGH) therapy.
We performed a retrospective analysis of sleep recordings in 40 patients with molecularly proven SRS (methylation anomaly in 11p15 [n = 32] or maternal uniparental disomy of chromosome 7 [n = 16]). Sleep recordings were either by means of polygraphy or polysomnography (PSG) (n = 16). A total of 34 patients received rGH therapy.
We collected 61 sleep recordings. The mean apnea-hypopnea index (AHI) was 3.4 events/h (0-12.4), with a mean central AHI of 0.5 events/h (0-2.4). SDB was identified in 73.8% (n = 45) of the recordings and was severe in 4.9%. SDB was present in 86.4% of patients before rGH therapy and was severe in 13.6%. AHI worsened for 5 of 12 patients with sleep recordings before and after rGH therapy initiation, reaching mild impairment. The mean rGH dose was 32.3 μg/kg/(12.9-51.4), with a mean insulin-like growth factor 1 plasma level of 1.7 SDS (-1.9 to 6.6).
Most patients with SRS present with SDB with an obstructive profile, possibly explained by narrowing of the airways and lymphoid organ hypertrophy. We recommend systematic ear-nose-throat evaluation of SRS patients and PSG if there are clinical anomalies, preferably before initiating rGH therapy, to monitor and adapt the management of patients with SDB.

There exists a technological momentum towards the development of unobtrusive, simple, and reliable systems for long-term sleep monitoring. An off-the-shelf commercial pressure sensor meeting these requirements is the Emfit QS. First, the potential for sleep apnea screening was investigated by revealing clusters of contaminated and clean segments. A relationship between the irregularity of the data and the sleep apnea severity class was observed, which was valuable for screening (sensitivity 0.72, specificity 0.70), although the linear relation was limited ( R 2 of 0.16). Secondly, the study explored the suitability of this commercial sensor to be merged with gold standard polysomnography data for future sleep monitoring. As polysomnography (PSG) and Emfit signals originate from different types of sensor modalities, they cannot be regarded as strictly coupled. Therefore, an automated synchronization procedure based on artefact patterns was developed. Additionally, the optimal position of the Emfit for capturing respiratory and cardiac information similar to the PSG was identified, resulting in a position as close as possible to the thorax. The proposed approach demonstrated the potential for unobtrusive screening of sleep apnea patients at home. Furthermore, the synchronization framework enabled supervised analysis of the commercial Emfit sensor for future sleep monitoring, which can be extended to other multi-modal systems that record movements during sleep.

Electroencephalography (EEG) recordings represent a vital component of the assessment of sleep physiology, but the methodology presently used is costly, intrusive to participants, and laborious in application. There is a recognized need to develop more easily applicable yet reliable EEG systems that allow unobtrusive long-term recording of sleep-wake EEG ideally away from the laboratory setting. cEEGrid is a recently developed flex-printed around-the-ear electrode array, which holds great potential for sleep-wake monitoring research. It is comfortable to wear, simple to apply, and minimally intrusive during sleep. Moreover, it can be combined with a smartphone-controlled miniaturized amplifier and is fully portable. Evaluation of cEEGrid as a motion-tolerant device is ongoing, but initial findings clearly indicate that it is very well suited for cognitive research. The present study aimed to explore the suitability of cEEGrid for sleep research, by testing whether cEEGrid data affords the signal quality and characteristics necessary for sleep stage scoring. In an accredited sleep laboratory, sleep data from cEEGrid and a standard PSG system were acquired simultaneously. Twenty participants were recorded for one extended nocturnal sleep opportunity. Fifteen data sets were scored manually. Sleep parameters relating to sleep maintenance and sleep architecture were then extracted and statistically assessed for signal quality and concordance. The findings suggest that the cEEGrid system is a viable and robust recording tool to capture sleep and wake EEG. Further research is needed to fully determine the suitability of cEEGrid for basic and applied research as well as sleep medicine.

Traumatic brain injury (TBI) is a major cause of persistent disabilities such as sleep-wake disorders (SWD). Rodent studies of SWD after TBI are scarce, however, because of lack of appropriate TBI models reproducing acceleration-deceleration forces and compatible with electroencephalography/myography (EEG/EMG)-based recordings of vigilance states. We therefore adapted the Marmarou impact acceleration model to allow for compatibility with EEG-headset implantation. After implantation of EEG/EMG electrodes, we induced closed TBI by a frontal, angular hit with a weight-drop device (56 rats, weight 2500 g, fall height 25 cm). Subsequently, we tested our model\'s usefulness for long-term studies on a behavioral, electrophysiological, and histological level. Neurological, motor, and memory deficits were assessed with the neurological severity score, open field, and novel object recognition tests, respectively. EEG/EMG recordings were performed in both Sham (n = 7) and TBI (n = 7) rats before and 1, 7, and 28 days after trauma to evaluate sleep-wake proportions and post-traumatic implant stability. Histological assessments included hematoxylin and eosin staining for parenchymal damage and hemorrhage and amyloid precursor protein staining for diffuse axonal damage. All rats survived TBI without major neurological or motor deficits. Memory function was impaired after TBI at weeks 1, 2, and 3 and recovered at week 4. EEG implants were stable for at least 1 month and enabled qualitative and quantitative sleep analyses. Histological assessments revealed no major bleedings or necrosis but intense diffuse axonal damage after TBI. This approach fulfills major pre-conditions for experimental TBI models and offers a possibility to electrophysiologically study behavioral states before and after trauma.

Transgenic animal models of Alzheimer\'s disease (AD) are widely used to investigate mechanisms of pathophysiology and cognitive dysfunctions. A model with a very early development of parenchymal plaque load at the age of 2months is the 5xFAD mouse (Tg6799, Oakley et al. 2006). These 5xFAD mice over-express both human amyloid precursor protein (APP) and human presenilin 1 (PS1). Mice from this line have a high APP expression correlating with a high burden and an accelerated accumulation of the 42 amino acid species of amyloid-β (Aβ). The aim of this study was the behavioral and functional investigations of 5xFAD males because in most studies females of this strain were characterized. In comparison to literature of transgenic 5xFAD females, transgenic 5xFAD males showed decreased anxiety in the elevated plus maze, reduced locomotion and exploration in the open field and disturbances in learning performance in the Morris water maze starting at 9months of age. Electroencephalogram (EEG) recordings on 6month old transgenic mice revealed a decrease of delta, theta, alpha, beta and gamma frequency bands whereas the subdelta frequency was increased. EEG recordings during sleep showed a reduction of rapid eye movement sleep in relation to the amount of total sleep. Thus, 5xFAD males develop early functional disturbances and subsequently behavioral deficits and therefore they are a good mouse model for studying Alzheimer\'s disease.