Central Sleep Breathing Disorders: A Critical Evaluation of Classification and Diagnosis

This paper provides a critical analysis of several key gaps in conceptualizing central apnea, discusses potential pathways that could modify the propensity to central sleep apnea (CSA), and describes gaps in the current classification system. While intuitively appealing, the loop gain model does not account for several nonperiodic perturbations that may perpetuate central apnea. The propensity to central apnea displays marked plasticity to pharmacologic and physiologic perturbations. The role of arousals in initiating or perpetuating central apnea remains uncertain. The current ICSD-3 TR diagnostic criteria for CSA have no inherent biological or epidemiological basis and may obscure bona fide CSA that occurs with obstructive sleep apnea. Central apnea is not a single disorder but part of a panoply of conditions, thus influencing the manifestations of the clinical syndrome. It does not occur in isolation but in cycles of apnea/hypopnea alternating with hyperpnea in a closed-loop fashion.