Sleep-disordered breathing in multiple-system atrophy

Multiple-system atrophy (MSA) is characterized by progressive autonomic failure with cerebellar, pyramidal and extrapyramidal signs. In MSA patients laryngoscopy often reveals unilateral or bilateral abductor vocal fold palsies. Snoring is very common. However, assessment of sites of obstruction and their severity is needed. We report our clinical experience in managing a 56-year-old, obese male MSA patient (1.76 m height, 100 kg weight, BMI 32.3 kg/m(2)) who was admitted for evaluation of snoring and excessive daytime sleepiness. Endoscopy while awake demonstrated an incomplete abductor vocal fold palsy. Polysomnography confirmed heavy snoring with arousals (11.1/h) and an RDI of 1.4/h. Sleep efficiency was low (51.9%) due to long intermittent awake periods. Sleep videoendoscopy of the upper airway proved the entire pharynx to be open during REM and non-REM sleep. During inspiration fluttering movements of the vocal cords caused the snoring. This was regularly terminated by arousals. The further treatment is discussed. In general, glottic snoring without daytime strider is rare and has only been described in MSA patients. However, certain of these patients will also be pharyngeal snorers. The source of the sound and site of obstruction can only be diagnosed by sleep videoendoscopy.