A Single Primary Site Obstruction May Lead to Sleep-Disordered Breathing in Multiple Sites: An Animal Model

Objectives: This study aimed to investigate the dynamic upper airway changes occurring in an obstructive sleep apnea (OSA) rabbit model using dynamic computerized tomography (CT). Methods: In this study, 2.5 U of botulinum toxin type A was injected into the genioglossus to paralyze the tongue in the OSA group (n = 7). The control group was injected with normal saline (n = 7). Apnea-hypopnea index was measured using ApneaLink at baseline and at 1, 2, 3, 4, 6, and 8 weeks post-injection. Anterior to posterior (AP) and transverse diameters at the levels of the palate and tongue base were measured using a dynamic CT at baseline and at 1 and 2 weeks post-injection. Results: The success rate of OSA induction was higher in the OSA group (P = .02). In the OSA group, transverse and AP diameters at the palate level and AP diameter at the tongue base level significantly decreased 2 weeks post-injection (P = .01). Conclusions: A single obstruction site may constitute the primary pathogenesis in some OSA patients, even when the involvement of multiple sites is indicated. These findings may contribute to the identification of OSA pathogenesis and improve the planning of treatment based on the primary cause of OSA.