**4.1 Primary headaches associated with sleep disorders**

Migraine with and without aura. Migraine is defined as uni- or bilateral, moderate to severe headache associated with photophobia, phonophobia, and nausea and/ or vomiting, and aggravated by activity. Migraine is reciprocally intertwined with sleep patterns. Too much or too little sleep at night or irregular sleeping pattern (circadian rhythm disorders or sleep fragmentation) are all common migraine triggers. Meanwhile, sleep may have a curative effect on the migraine headaches—the so-called "healing naps" (2). Nearly 90% of episodic migraineurs who complain of poor sleep quality and poor night sleep, have more severe migraine and increased daily burden [17]. Sleep hygiene could be a trigger or relieving factor for migraine chronicity, depending on whether it is poor or good, respectively [18]. Poor sleep quality and/or duration is a trigger for migraine [19] and causes increase in migraine frequency [20]. Similarly, Korean study showed increase in frequency of migraine in patients with poor sleep [21]. Migraine is related to several sleep disorders, such as insomnia, OSA, parasomnias, sleep-related movement disorders, REM-sleep related disorders [22]. Half to two-thirds of migraineurs suffer from insomnia [23]—the most common sleep disorder, and migraineurs have a 3-fold increase in daytime sleepiness [24]. Insomnia is more common in patients with chronic

migraine (with at least 15 headaches per month) than in patients with episodic migraine [25]. Migraine is closely linked to insomnia as they trigger or aggravate each other [26, 27]. CBT for insomnia improves headache frequency [28]. One third of patients with the refractory chronic daily headache is diagnosed with OSA [29]. There is strong comorbidity between migraine and OSA [2] and patient with migraine who are compliant with CPAP have lower incidence of headaches. The use of opioids for management of headaches is not recommended, but they are still often used, and are also associated with central sleep apnea [30] with increase in nocturnal hypoxemia [31]. Patient with more nocturnal migraines are usually older, have longer history of migraine and shorter sleep time, probably related to more sleep fragmentation often seen in older individuals [32]. There is also connection between migraine and RLS with an increase in frequency of RLS in migraines, and also RLS is more severe in patients with migraine [33], REM sleep behavior disorder (RBD) is more frequent in migraine patients [34] and these patients have severe headache-related disability and insomnia. Migraines is also associated with bruxism and somnambulism in children [35].

Cluster headaches: are severe to very severe unilateral headaches, periorbital and temporal in distribution, lasting between 30 and 180 min, frequency of 1–8 headaches per day, and associated with conjunctival injection (red eye), increased lacrimation, rhinorrhea, and restlessness. Circadian and circannual periodicity is a hallmark of cluster headache. Two thirds of headaches occur at night between 9 PM and 10 AM. Cluster headaches are linked to REM sleep and to sleeping late in the morning—which has more REM sleep. The fact that individuals with cluster headaches have lucid recall of dreams 2 hours into sleep support the REM sleep association with CH. Patient with cluster headaches have a high incidence of OSA. A study showed over 8-fold increased risk for OSA in patients with cluster headache, and that risk increases further up to 24-fold in patients with an elevated body mass index of greater than 25 kg/m2 [36].

Paroxysmal hemicrania (PH) is unilateral headache, side-locked (occurring on the same side), short-lasting, average duration of 30 minutes, occurring multiple times a day (up to 40 attacks a day), associated with autonomic features (conjunctival injection, lacrimation, rhinorrhea, ptosis, etc.) which primarily affects women. PH often occurs at night and is associated with REM sleep and occurs only during REM sleep [37].

Hypnic headaches (HH) mainly affects elderly male patients, and presents with mild to moderate bilateral headache, which awake patients from sleep, usually between 1 and 3 AM. It was believed to be related REM sleep, but recent studies revealed that its occurrence is more common during NREM sleep [37].

Exploding head syndrome (EHS) was originally classified as a sleep disorder, which occurs during transition from wakefulness to sleep. Patients report hearing extremely loud or explosive noise, which is nonpainful, but is often associated with significant apprehension [37]. Recently, EHS was reported as an aura of migraine with brainstem aura while patient was fully awake [38]. Previously, EHS was reported as an aura of other type of migraine [39].

Tension-type headache is the most common type of headaches, which are known as "featureless" headache, in contradistinction to migraine TTH are not usually associated with photophobia, phonophobia, or nausea. Insomnia often triggers or aggravates TTH, whereas sleep may relieve them [40]. Insufficient sleep or oversleeping may trigger TTH [41, 42]. Headaches, sleep disorders and depression may share common brain mechanisms, e.g. dysregulation of serotonin, melatonin and hypothalamic dysfunction and management of sleep disorders and depression is essential for the adequate control of the TTH.

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*Comorbid Sleep Disorders and Headache Disorders DOI: http://dx.doi.org/10.5772/intechopen.93358*

**4.2 Secondary headaches associated with sleep disorders**

intracranial pressure, and poor sleep quality [43–45].

2–3 months, with re-evaluation after that.

magnesium oxide and vitamin B2 (riboflavin) [46].

quality [2, 3, 9].

**5. Treatment**

Sleep-apnea-syndrome related headaches; presents with awakening headaches (headaches on awakening rather than headaches that awaken patients from sleep). These headaches start in the morning and resolve 30 min after awakening. They are bilateral frontal headaches, squeezing in character, and daily or almost daily. There is no associated photophobia, phonophobia, or nausea. These headaches are most commonly caused by obstructive sleep apnea (occur in 18–60% of patient with OSA) but also central sleep apnea and hypoventilation. Awakening headaches affects 4–6% of the general population and 18% of patients with insomnia. OSArelated headaches may also present with migraines features, chronic daily headache, or be similar to TTH [40–42]. The pathogenesis of the awakening headaches related to the OSA, is probably associated with hypercapnia, vasodilatation, elevated

Medication overuse headaches (MOH) is also associated with sleep disorders:

MOH is a secondary form of headache triggered by the frequent use of acute pain medication for management headaches. MOH is associated with poor sleep

The treatment is mainly targeted to relieve pain and associated features of headache. In case of migraine, the treatment has undergone major advances with the development of new specific anti-migraine therapies and more treatments are in development. If not a migraine- specific medication, treatment should be selected based on patient comorbidities, in order to address more than one problem at the same time. Medication should be initiated at the lowest dose with gradual increase of the dose to an effective range, while monitoring the response and potential adverse effects. Treatment, if well tolerated, should be continued for at least

Migraine treatment algorithm is mainly divided into pharmacological interventions and nonpharmacological interventions. Among the pharmacological interventions the paradigm of treatment is based on preventative and acute/rescue therapy. Options included on the preventative armamentarium are oral antihypertensive (beta blockers, calcium blockers, ACEI/ARB), anti-depressants (SNRI/TCA), anticonvulsants (valproate, topiramate), Botox injections, CGRP mAB. Options for the acute treatment of migraine include triptans, Dihydroergotamine, Ergotamine, Neuroleptics, NSAIDs, and newer categories of recently FDA-approved gepants (ubrogepants) and ditans (lasmiditan). Among nonpharmacological interventions there are psychological interventions, including cognitive behavioral therapy (CBT), relaxation therapy and biofeedback. Neuromodulation including transcranial magnetic stimulation (TMS), Cefaly device, noninvasive vagus nerve stimulator GammaCore, remote electrical neuromodulation (REM), and acupuncture. Lifestyle modifications, including regular sleep and healthy diet, good hydration, management of triggers and stress management and use of supplements/vitamins, such as

Acute treatment for cluster headache is mainly based on high flow oxygen and fast acting triptans, such as Sumatriptan and Zolmitriptan, available in injectable form and/or nasal spray. Inhalation of 100% oxygen by nonrebreather mask at a rate of 12–15 L/m for 10–15 minutes is used as a first line therapy. Acute therapy for cluster headaches requires fast acting routes of administration with subcutaneous triptans as
