Table 1.

Models of relations between sleep and headache

1	Sleep as trigger factor for headache (excessive, reduced or disrupted, increased deep sleep)
2	Sleep as relieving factor for headache
3	Sleep disturbance as cause of headache (es. sleep apnea)
4	Headache as cause of sleep disturbance (es. attacks occurring during sleep)
5	Sleep disorders in headache patients (parasomnias, sleepwalking)
6	Sleep related headache:
	a) Temporal relationship (during or after sleep)
	b) Sleep stage relationship:
	1. REM sleep (migraine, cluster headache, chronic paroxysmal hemicrania)
	2. Slow-wave sleep (migraine)
7	Headache/sleep association:
	a) Intrinsic origin (modulation through the same neurotransmitters)
	b) Extrinsic origin (i.e. fibromyalgia syndrome)
	c) Reinforcement (bad sleep hygiene)