Sleep apnea syndrome in Thomsen's disease. A case report.

The authors describe the occurrence of a sleep-induced apnea syndrome with daytime hypersomnolence in a patient suffering from Thomsen's disease. Polysomnography showed, during the whole sleep, repetitive obstructive, and rarely mixed, apneas. The patient also had daytime alveolar hypoventilation, primarily obstructive, and waking chronic hypercapnia. Long-term diphenylhydantoin therapy relieved not only myotonia, but sleep-induced apneas, daytime sleepiness and waking breathing as well. This result, together with some EMG features recorded during sleep and with daytime obstructive hypoventilation, suggests that myotonia could be one of the pathogenic factors involved in nocturnal upper airway stenosis.