Knuckle cracking at night associated with sodium oxybate treatment.

During upward titration of a dose of sodium oxybate therapy for narcolepsy with cataplexy, a 25-year-old woman was observed by her husband to have new onset of knuckle-cracking and moaning behaviors during sleep ≥1 nights each week. The patient did previously occasionally crack her knuckles during the day (but never at night). These behaviors had not been evaluated by polysomnography. After transition of care, polysomnography with video monitoring was ordered and revealed 2 knuckle-cracking episodes that developed out of stage N2 sleep and were likely a non-rapid eye movement sleep parasomnia associated with sodium oxybate treatment.