Nocturnal cluster headache associated with sleep apnea. A case report.

We describe a 49-year-old man with chronic cluster headache unresponsive to all medications. Following investigation in the sleep lab he was found to have obstructive sleep apnea (OSA) with associated oxygen desaturations during rapid eye movement (REM) sleep. He awakened during one of these episodes with a typical headache. Treatment with nasal CPAP abolished his OSA and desaturations, and largely abolished his headaches. He then developed central apneas during REM sleep. Further treatment with BiPAP, with a set backup rate, abolished both the apneas and the headaches. We conclude that there may be a link between nocturnal cluster headaches and sleep apnea.