[Improvement of obstructive sleep apnea by uvulopalatopharyngoplasty and tonsillectomy in a case of Duchenne muscular dystrophy]

A 10-year-old boy with Duchenne muscular dystrophy (DMD) underwent uvulopalatopharyngoplasty and tonsillectomy for obstructive sleep apnea (OSA). He has snored loudly during nocturnal sleep since infancy, and OSA developed one and a half years after he was wheel chair-bound at 8 years. Magnetic resonance imaging (MRI), conventional spirometry and overnight polysomnography were performed before and after the surgery. MRI before surgery revealed moderate tonsillar hypertrophy and a long uvula which narrowed the upper airway. After the surgery, his vital capacity (VC) was not changed (% VC; from 77 to 78%), but forced expiratory volume (FEV) was improved (FEV 1.0%; from 75 to 86%). A preoperative apnea index of 32.8/hour decreased to 0.8/hour postoperatively. REM-related falls in HbSaO2 improved remarkably. The present case suggests that subjects with DMD with tonsillar hypertrophy and a redundant uvula tend to develop noctrurnal OSA earlier than DMD cases with a normal tonsil and uvula. Assessment of respiratory function, particularly FEV 1.0%, is important for determining surgical indication of OSA in patients with DMD.