Snoring and Obstructive Sleep Apnea: Patient s Guide to Minimally Invasive Treatments Chapter 2 CAUSES OF SNORING AND SLEEP APNEA We inhale air through our nose and mouth. From the nostrils, air flows through our nose over the hard and soft palate in a manner guided by our sinuses and nasal structures. When the air hits the back of our nasal passage it flows over the soft palate and through a small tunnel (choana) where it enters the end of the nasal cavity (nasopharynx) [FIGURE 1]. From the nasopharynx, air flows downward towards the windpipe (trachea) and into the lungs. Along this route air travels past the internal tissues of the neck and the voice box (larynx). Air is also inspired through the mouth. When air enters the mouth it flows over the soft tissues of the tongue and between the root, or base, of the tongue and the soft palate and uvula above. Air then flows into the back of the throat (oropharynx) where it meets up with air from the nose on the way down to the voicebox, windpipe, and lungs. FIGURE 1 Sagittal CT view of a patient s nasal airway. Note the airflow (dotted arrows) into the nasal opening, over the inferior turbinate, back in to the nasopharynx and down into the oropharynx (throat). Note how the air passes over the inferior turbinate (triangle), hard palate
(rectnagle), and soft palate (oval) and then just in front of the nasopharynx/adenoid area (star) before heading down into the throat. Snoring is commonly associated with abnormalities of the soft palate or uvula. An overly long or floppy soft palate may vibrate irregularly with airflow. This abnormal vibration makes a sound snoring. Other sources may also contribute to snoring and, for this reason, careful and complete evaluation is imperative in order to direct effective treatment. Nasal sources (deviated septum, inferior turbinate hypertrophy, polyps, chronic and allergic nasal congestion) [FIGURE 2, 3, 4, & 7], nasopharyngeal sources (enlarged adenoids and nasopharyngeal growths) [FIGURE 5, 6] oral sources (enlarged tongue base, small jaw, enlarged uvula or tonsils), and throat and neck sources (floppy neck soft tissues) may all contribute to snoring and to sleep apnea. In some cases, snoring may be increased by alcohol consumption late at night (which causes your throat to relax and become more floppy). Obstructive sleep apnea (OSA) may similarly be related to obstruction along the airflow pathway. Common oral sites include the tongue base, soft palate, uvula, mandible (jaw), and tonsils. Nasal and nasopharyngeal sources may also play a role. Specifically, the adenoids, septum, and inferior turbinates should all be carefully evaluated. More inferiorly, the soft tissues of the neck may be predisposed to collapse and obstruction. 9
FIGURE 2 Endoscopic view into the left nasal cavity shows obstruction of the nasal airway (triangle) by the deviated nasal septum (star). Obstruction leads to turbulent nasal airflow. FIGURE 3 Intraoperative view of the patient in FIGURE 2 shows the wide open nasal airway (triangle) after straightening of the deviated septum. 10
FIGURE 4 Endoscopic view into the right nasal cavity shows obstruction of the nasal airway (arrow) by the enlarged right inferior turbinate (traingle). The nasal septum is also seen (star). 11
FIGURE 5 Endoscopic view into the right nasal cavity shows near complete obstruction of the nasal airway by a large nasopharyngeal mass (arrow). The mass turned out to be a large fluid filled cyst. Nasal floor (triangle) and nasal septum (start) are identified. 12
FIGURE 6 Endoscopic view into the right nasal cavity after the cyst seen in FIGURE 5 has been decompressed. The airway (arrow) is now wide open. Nasal floor (triangle) and nasal septum (start) are identified. 13
FIGURE 7 Endoscopic view into the left nasal cavity shows a large polyp (star) blocking the nasal and sinus cavities. 14