Increased Cortical Activity that causes headaches is increased with sleep apnea.

A recent study in Sleep Med on altered Cortical Excitability in sleep apnea concluded that " This TMS-based study suggests that untreated severe OSAS patients have imbalanced cortical excitabilities that enhanced inhibition or decreased brain excitability when awake during the day." This may be a major cause of chronic headaches or migraines or other biochemical imbalances leading to stress