In recent years, an abnormality of sleep has been described that explains why some patients have daytime hypersomnolence. This disorder is characterized by nocturnal sleep arousals resulting from periodic apneas that disrupt sleep as frequently as several hundred times each night. These numerous sleep interruptions deprive the patient of normal sleep and are thought to be the cause of the daytime hypersomnolence. This sleep abnormality has been accurately termed the "sleep apnea syndrome" by the Stanford University sleep research group.1 The apneas result mainly from intermittent upper airway obstruction. The arousal is accompanied by a snort or loud snoring (inspiration against a partially obstructed upper airway). The hypotonic upper airway then regains some of its normal tone during this arousal allowing for normal breathing and the return to normal sleep. These cycles of obstructive apneas leading to arousal recur throughout the night.
Men are most frequently affected but are