Central Sleep Apnea Syndromes Differential Diagnoses

Updated: Aug 25, 2020
  • Author: Kendra Becker, MD, MPH; Chief Editor: Zab Mosenifar, MD, FACP, FCCP  more...
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Diagnostic Considerations

This discussion includes the differentiation of central sleep apnea from non–central sleep apnea conditions.

Obstructive sleep apnea

This is a sleep disorder in which recurrent complete or partial upper airway obstruction produces snoring, oxygen desaturations, and numerous arousals. The repetitive upper airway collapse occurs during sleep because negative pressure generated during inspiration is not effectively counteracted by splinting by pharyngeal dilators, especially when narrowing occurs as a result of excessive soft tissue or vulnerable craniofacial anatomy. Patients may report loud snoring, witnessed apneas, and excessive daytime sleepiness. Physical examination characteristics often include a crowded oropharynx, increased neck and waist circumferences, and increased body mass index. Further, polysomnography (PSG) demonstrates prominent snoring and obstructive respiratory events (airflow is absent but ventilatory effort persists, as opposed to absent ventilatory effort in central sleep apnea) (see the image below).

Obstructive sleep apnea (OSA): This polysomnogram Obstructive sleep apnea (OSA): This polysomnogram demonstrates typical hypopneas occurring in OSA prior to continuous positive airway pressure titration. In OSA, airflow is absent or reduced, but ventilatory effort persists.

Pseudocentral sleep apnea

Patients with diaphragmatic paralysis and other neuromuscular diseases, who are dependent on accessory muscles of breathing to maintain ventilation, may appear to have central apneas during rapid eye movement (REM) sleep. This is due to the REM atonia of skeletal muscles. Many of these patients actually have obstructive sleep apnea but do not have enough diaphragmatic excursions to be recorded by the piezoelectric belts used during routine PSG. A history of neuromuscular disease and worsening of central apneas during REM sleep should alert to the possibility of pseudocentral apnea.

Sleep-related hypoventilation syndrome

Sleep-related hypoventilation with central sleep apneas can be observed in many conditions, such as neuromuscular weakness or chronic obstructive pulmonary disease. These conditions are characterized by a history of a preexisting disorder of hypoventilation, elevated resting PaCO2, and severe oxygen desaturation during sleep, which is more prominent during REM sleep in contrast to primary central sleep apnea and Cheyne-Stokes breathing-central sleep apnea (CSB-CSA), which are mostly observed during NREM sleep.