Persistence of Apnea in Wakefulness in a Patient with Postradiation Pharyngitis

We report on a patient with the onset of recurrent nocturnal awakenings associated with postawakening stridor with onset a few weeks after receiving radiation therapy to the neck. The onset of nocturnal stridor was also accompanied by complaints of snoring and excessive daytime sleepiness. Stridor did not occur during daytime wakefulness. Nocturnal polysomnography (NPSG) recorded with a calibrated pneumotachometer demonstrated snoring and severe obstructive sleep apnea (OSA) with a apnea/hypopnea index of 51 events/hr. One apneic episode persisted for 17 sec after the onset of wakefulness as evidenced by standard NPSG scoring criteria for arousals. With this event, video monitoring revealed the patient abruptly sitting upright and clutching his throat and auditory recording demonstrated stridorous sounds. During wakefulness endoscopy revealed moderate edema and erythema of the supraglottic region, epiglottis, palatine tonsils, and false and true vocal cords. Vocal cord function appeared normal. This case report represents the observation of two rare findings in a single patient, persistence of apnea in wakefulness, and OSA onset following neck irradiation. We review the literature on the persistence of apnea in wakefulness and discuss possible mechanisms for its occurrence in this patient.