Tongue Base Ultrasound: A Diagnostic Tool for Predicting Obstructive Sleep Apnea

OBJECTIVES: We assessed the value of an ultrasound (US) examination in the diagnostic workup of patients with sleep-related breathing disorders by correlating US measurements with known parameters for the presence and severity of obstructive sleep apnea. METHODS: Forty-one male patients who complained of snoring and/or daytime somnolence participated. The diagnostic protocol included history-taking, physical examination, polysomnography, and transcervical US examination of the tongue. The US results were compared with all of the other parameters. RESULTS: The US imaging was reliable for demonstrating anatomic structures of the tongue base, discriminating between muscle, mucosa, and blood vessels. The lingual arteries were clearly visualized entering the tongue base at its lower lateral borders. There was a significant relationship between the severity of sleep-related breathing disorders (measured by polysomnography) and the width of the lower tongue base (measured as the distance between the lingual arteries). The distance between the lingual arteries also correlated with physical examination findings and patient complaints of daytime somnolence and the sensation of choking during the night. CONCLUSIONS: Tongue base width, measured by US, may influence the severity of obstructive sleep apnea. This is the first demonstration of the possible role of US examination, an inexpensive, noninvasive, and non-irradiating office procedure, in the diagnostic workup for sleep-related breathing disorders.