Migraine is a genetically influenced complex neurological disorder characterized by episodes of moderate-to-severe headache, most often unilateral and generally associated with nausea and light and sound sensitivity. Other characterizing symptoms may include nausea, vomiting, cognitive dysfunction, allodynia, and dizziness. Exacerbation of headache symptoms during physical activity is another distinguishing feature. Up to one-third of migraine sufferers experience aura: a premonitory period of sensory disturbance widely accepted to be caused by cortical spreading depression at the onset of a migraine attack. Although primarily considered to be a headache disorder, migraine is highly heterogenous in its clinical presentation and is better thought of as a spectrum disease rather than a distinct clinical entity. Disease burden can range from episodic discrete attacks, consisting of as little as several lifetime attacks, to chronic disease.
Headache, also known as cephalalgia, is the symptom of pain in the face, head, or neck. It can occur as a migraine, tension-type headache, or cluster headache. There is an increased risk of depression in those with severe headaches.
The sympathetic nervous system (SNS) is one of the three divisions of the autonomic nervous system, the others being the parasympathetic nervous system and the enteric nervous system. The enteric nervous system is sometimes considered part of the autonomic nervous system, and sometimes considered an independent system.
Triptans are a family of tryptamine-based drugs used as abortive medication in the treatment of migraines and cluster headaches. This drug class was first commercially introduced in the 1990s. While effective at treating individual headaches, they do not provide preventive treatment and are not considered a cure. They are not effective for the treatment of tension–type headache, except in persons who also experience migraines. Triptans do not relieve other kinds of pain.
Sensory neurons, also known as afferent neurons, are neurons in the nervous system, that convert a specific type of stimulus, via their receptors, into action potentials or graded receptor potentials. This process is called sensory transduction. The cell bodies of the sensory neurons are located in the dorsal ganglia of the spinal cord.
Referred pain, also called reflective pain, is pain perceived at a location other than the site of the painful stimulus. An example is the case of angina pectoris brought on by a myocardial infarction, where pain is often felt in the left side of neck, left shoulder, and back rather than in the thorax (chest), the site of the injury. The International Association for the Study of Pain has not officially defined the term; hence, several authors have defined it differently. Referred pain has been described since the late 1880s. Despite an increasing amount of literature on the subject, the biological mechanism of referred pain is unknown, although there are several hypotheses.
A thunderclap headache is a headache that is severe and has a sudden onset. It is defined as a severe headache that takes seconds to minutes to reach maximum intensity. Although approximately 75% are attributed to "primary" headaches—headache disorder, non-specific headache, idiopathic thunderclap headache, or uncertain headache disorder—the remainder are secondary to other causes, which can include some extremely dangerous acute conditions, as well as infections and other conditions. Usually, further investigations are performed to identify the underlying cause.
Moyamoya disease is a disease in which certain arteries in the brain are constricted. Blood flow is blocked by constriction and blood clots (thrombosis). A collateral circulation develops around the blocked vessels to compensate for the blockage, but the collateral vessels are small, weak, and prone to bleeding, aneurysm and thrombosis. On conventional angiography, these collateral vessels have the appearance of a "puff of smoke".
Neuralgia is pain in the distribution of a nerve or nerves, as in intercostal neuralgia, trigeminal neuralgia, and glossopharyngeal neuralgia.
Anisocoria is a condition characterized by an unequal size of the eyes' pupils. Affecting up to 20% of the population, anisocoria is often entirely harmless, but can be a sign of more serious medical problems.
Isometheptene is a sympathomimetic amine sometimes used in the treatment of migraines and tension headaches due to its vasoconstricting properties; that is, it causes constriction (narrowing) of blood vessels. Along with paracetamol and dichloralphenazone, it is one of the constituents of Amidrine.
Mixed tension migraines are also known as mixed migraines or mixed headaches. They combine characteristics of tension headaches and migraines.
Migraine surgery is a surgical operation undertaken with the goal of reducing or preventing migraines. Migraine surgery most often refers to surgical nerve decompression of one or several nerves in the head and neck which have been shown to trigger migraine symptoms in many migraine sufferers. Following the development of nerve decompression techniques for the relief of migraine pain in the year 2000, these procedures have been extensively studied and shown to be effective in appropriate candidates. The nerves that are most often addressed in migraine surgery are found outside of the skull, in the face and neck, and include the supra-orbital and supra-trochlear nerves in the forehead, the zygomaticotemporal nerve and auriculotemporal nerves in the temple region, and the greater occipital, lesser occipital, and third occipital nerves in the back of the neck. Nerve impingement in the nasal cavity has additionally been shown to be a trigger of migraine symptoms.
Vascular myelopathy refers to an abnormality of the spinal cord in regard to its blood supply. The blood supply is complicated and supplied by two major vessel groups: the posterior spinal arteries and the anterior spinal arteries—of which the Artery of Adamkiewicz is the largest. Both the posterior and anterior spinal arteries run the entire length of the spinal cord and receive anastomotic (conjoined) vessels in many places. The anterior spinal artery has a less efficient supply of blood and is therefore more susceptible to vascular disease. Whilst atherosclerosis of spinal arteries is rare, necrosis in the anterior artery can be caused by disease in vessels originating from the segmental arteries such as atheroma or aortic dissection.
Umbellulone is a headache-inducing monoterpene ketone found in the leaves of the tree Umbellularia californica, sometimes known as the "headache tree".
The trigeminovascular system (TVS) refers to neurons and their axonal projections within the trigeminal nerve that project to the cranial meninges and meningeal blood vessels residing on the brain's surface. The term, introduced in 1983 denotes also the neuropeptides contained within axons that are released into the meninges to target vessels and surrounding cells.
A hypothermia cap is a therapeutic device used to cool the human scalp. Its most prominent medical applications are in preventing or reducing alopecia in chemotherapy, and for preventing cerebral palsy in babies born with neonatal encephalopathy caused by hypoxic-ischemic encephalopathy (HIE). It can also be used to provide neuroprotection after cardiac arrest, to inhibit stroke paralysis, and as cryotherapy for migraine headaches.
Migraine treatment may be either prophylactic (preventive) or abortive (rescue) or acute. Prevention is better than cure, so the ideal treatment goal is to prevent migraine attacks. Because migraine is an exceedingly complex condition, there are various preventive treatments which have their effect by disrupting different links in the chain of events that occur during a migraine attack. As rescue treatments also target and disrupt different processes occurring during migraine, these are summarized, with their relative merits and demerits.
Migraine is often hereditary. It is estimated that 60% of migraine cases are caused by genetics. The role of natural selection in the development of migraines is not known. Fitness-impairing disorders, including migraines, tend to disappear as a result of natural selection, and their frequency decreases to near the rate of spontaneous mutation. However, it is estimated that migraines affect 15-20% of the population and is increasing. This could suggest that a central nervous system (CNS) susceptible to severe, intermittent headache has been linked to an important survival or reproductive advantage. Five possible evolutionary explanations exist: i) migraine as a defence mechanism, ii) migraine as a result of conflicts with other organisms, iii) migraine as a result of novel environmental factors, iv) migraine as a compromise between genetic harms and benefits, and v) headache as a design constraint. These considerations allow the treatment and prevention of migraine to be approached from an evolutionary medicine perspective.
Recurrent painful ophthalmoplegic neuropathy (RPON), previously known as ophthalmoplegic migraine (OM), is a rare neurological disorder that is characterized by repeated headache attacks and reversible ipsilateral paresis of one or more ocular cranial nerves (CN). Oculomotor nerve (CNIII) is by far the most common cranial nerve involves in RPON, while abducens nerve (CNVI) and trochlear nerve (CNIV) involvements are also reported. Globally, RPON was estimated to have an annual incidence rate of 0.7 per million as of 1990, no further epidemiological studies have been conducted. It occurs more often in children and females.
