Relationship of nasal continuous positive airway pressure to periodic limb movement disorder in a patient without sleep apnea.

The treatment of sleep apnea with nasal continuous positive airway pressure (CPAP) occasionally has been associated with the appearance of periodic limb movement (PLM) disorder, but it has not been clear whether CPAP induces PLM, or whether the PLM is simply disguised until apnea is treated. We report the emergence of PLM after the inadvertent application of CPAP in a patient without sleep apnea.