Catathrenia is a loud expiratory moan during sleep that is a social embarrassment and is sometimes confused with central apnea on polysomnography. It affects about 4% of adults, but cases are rarely referred to sleep centers. Catathrenia affects males and females, children and adults, who are usually young and thin. A \"typical\" catathrenia begins with a deep inhalation, followed by a long, noisy exhalation, then a short, more pronounced exhalation, followed by another deep inhalation, often accompanied by arousal. The many harmonics of the sound indicate that it is produced by the vocal cords. It is often repeated in clusters, especially during REM sleep and at the end of the night. It does not disturb the sleepers, but their neighbors, and is associated with excessive daytime sleepiness in one-third of cases. The pathophysiology and treatment of typical catathrenia are still unknown. Later, a more atypical catathrenia was described, consisting of episodes of short (2 s), regular, semi-continuous expiratory moans during NREM sleep (mainly in stages N1 and N2) and REM sleep, often in people with mild upper airway obstruction. This atypical catathrenia is more commonly reduced by positive airway pressure and mandibular advancement devices that promote vertical opening.

Purely prepontine arachnoid cysts not extending into the suprasellar region in neonates are rare. Herein, we report a purely prepontine arachnoid cyst in a neonate which caused central apnea and was successfully treated with microscopic cyst fenestration and C1 laminectomy.

OBJECTIVE: The purpose of this review is to discuss the pathogenesis, clinical manifestations, diagnosis and treatment, including areas of controversy and uncertainty.
RESULTS: Central apnea may be due to hypoventilation or to hypocapnia following hyperventilation. The occurrence of central apnea initiates a cascade of events that perpetuates breathing instability, recurrent central apnea and upper airway narrowing. In fact, breathing instability and upper airway narrowing are key elements of central and obstructive apnea. Clinically, central apnea is noted in association with obstructive sleep apnea, heart failure, atrial fibrillation, cerebrovascular accidents tetraplegia, and chronic opioid use.Management strategy for central apnea aim to eliminate abnormal respiratory events, stabilize sleep and alleviate the underlying clinical condition. Positive pressure therapy (PAP) remains a standard therapy for central as well as obstructive apnea. Other treatment options include adaptive-servo ventilation (ASV), supplemental oxygen, phrenic nerve stimulation, and pharmacologic therapy. However, ASV is contraindicated in patients with central sleep apnea who had heart failure with reduced ejection fraction, owing to increased mortality in this population.
CONCLUSIONS: There are several therapeutic options for central apnea. Randomized controlled studies are needed to ascertain the long-term effectiveness of individual, or combination, treatment modalities in different types of central apnea.