Unraveling sleep respiratory dysfunction in amyotrophic lateral sclerosis: Beyond the apnea-hypopnea index and sleep-related hypoxia.

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.

The Contribution of Sleep Texture in the Characterization of Sleep Apnea.

Obstructive sleep apnea (OSA) is multi-faceted world-wide-distributed disorder exerting deep effects on the sleeping brain. In the latest years, strong efforts have been dedicated to finding novel measures assessing the real impact and severity of the pathology, traditionally trivialized by the simplistic apnea/hypopnea index. Due to the unavoidable connection between OSA and sleep, we reviewed the key aspects linking the breathing disorder with sleep pathophysiology, focusing on the role of cyclic alternating pattern (CAP). Sleep structure, reflecting the degree of apnea-induced sleep instability, may provide topical information to stratify OSA severity and foresee some of its dangerous consequences such as excessive daytime sleepiness and cognitive deterioration. Machine learning approaches may reinforce our understanding of this complex multi-level pathology, supporting patients' phenotypization and easing in a more tailored approach for sleep apnea.

Sleep macro- and micro-structure in autoimmune encephalitis: single case report from the subacute phase of the disease to the follow-up.

Sleep disorders are frequently described in autoimmune encephalitis (AE); however, data on sleep texture are fragmentary. We analyzed the polysomnography of a woman affected by AE, and we performed cyclic alternating pattern (CAP) scoring during the subacute phase of the disease and at follow-up. The first polysomnography showed deviations both at macro and microstructure levels, with a marked reduction of CAP rate compare to healthy sleepers (20.8% vs 33%). After 6-months sleep macrostructure improved, whilst CAP parameters remained abnormal. This is the first polysomnographic analysis, comprehensive of microstructural data, performed in AE. We briefly discuss the results.

Obstructive sleep apnea, cpap and COVID-19: a brief review.

Obstructive sleep apnea (OSA) is a broadly diffused curable chronic low-grade inflammatory disease sharing impressive clinical and pathogenetic features with Covid-19. Moreover, a potential role of OSA as a detrimental factor for Covid-19 severity has been hypothesized. Continuous positive airway pressure (CPAP) is the mainstay treatment for moderate-severe OSA, but the beneficial effects of ventilation strongly depend on medical expertise and on the patient's adherence and compliance. Although several papers have analyzed the overlaps and outcomes of OSA and Covid-19, limited attention has been dedicated to ventilatory adherence and management of  OSA cohorts exposed to Covid-19. We briefly review the literature data, pointing out the main risks and benefits of CPAP for OSA patients in the pandemic setting.