Central apnea

Central sleep apnea syndrome (CSAS) refers to the absence of airflow through the upper airway for more than 10 seconds without chest and abdominal breathing movements. CSAS is rare and can coexist with obstructive sleep apnea syndrome (OSAS). It can occur in any sleep phase, but the obvious abnormality is only seen in slow phase sleep (NREM, also known as normal phase sleep and slow wave sleep). CSAS can exist alone or coexist with central nervous system diseases such as brain stem trauma, tumors, infarction, and infection. Cases have also been reported to be associated with neuromuscular diseases such as polio and myotonic dystrophy. Appropriate ventilation can be maintained when awake, but abnormal sleep central regulation occurs during sleep, and central (or obstructive) apnea occurs.