Causes of persistent obstructive sleep apnea despite previous tonsillectomy and adenoidectomy in children with down syndrome as depicted on static and dynamic cine MRI

OBJECTIVE. Our purpose was to evaluate the causes of persistent obstructive sleep apnea despite previous tonsillectomy and adenoidectomy in children with Down syndrome as depicted on cine MRI. MATERIALS AND METHODS. Cine MRI studies performed to evaluate persistent obstructive sleep apnea despite previous tonsillectomy and adenoidectomy were reviewed. MRI was performed under sedation and included cine MR images (fast gradient-echo) obtained in the midline sagittal plane and in the axial plane at the base of the tongue and T1-weighted spin-echo and fast spin-echo inversion recovery images in the axial and sagittal planes. Imaging parameters reviewed included static and dynamic diagnoses made, frequency of recurrence and diameter of tonsillar tissue, and tongue morphology. RESULTS. Twenty-seven patients were identified (mean age, 9.9 years). Diagnoses included glossoptosis in 17 patients (63%), hypopharyngeal collapse in six (22%), recurrent and enlarged adenoid tonsils in 17 (63%), enlarged lingual tonsils in eight (30%), and macroglossia in 20 (74%). Of the 20 patients with macroglossia, 11 (55%) had absence of the normal median sulcus and 12 (60%) had evidence of fatty infiltration of the tongue musculature. CONCLUSION. Persistent obstructive sleep apnea in children with Down syndrome who have undergone previous adenoidectomy and tonsillectomy has multiple causes. The most common causes include macroglossia, glossoptosis, recurrent enlargement of the adenoid tonsils, and enlarged lingual tonsils.