Migraine is a severe headache variable in intensity, frequency and duration, which may also involve other associated symptoms. Although it is very common, it is also very disabling for the sufferer. There are two treatment modalities, one for migraine attacks and one preventive.
Migraine: what it is and symptoms
Headache or migraine is understood as any pain or discomfort localized in the head and whose topography does not coincide with the area of distribution of the sensitive nerves that innervate the sensitive parts of the head.
It consists of attacks of headache very variable in intensity, frequency and duration, commonly unilateral and associated with nausea and vomiting, being sometimes associated with visual sensory-motor disorders of language and mood.
It is a common disease that affects 10-20% of the population, being twice as frequent in women. It is estimated that 40% of men and 50% of women have suffered from disabling headache at some time in their lives. In adolescents, 20% suffer from typical migraine.
The characteristics of migraine syndrome include:
– headache
– gastrointestinal disturbances, including anorexia, nausea, vomiting, abdominal distention, constipation, or diarrhea
– irritability
– sonophobia and photophobia
– coldness of extremities
– disorientation
– sweating
– vertigo
– auras in the form of transient loss of vision or blurring, photopsia (seeing lights or flashes) or hemianoptsia (transient blindness)
– speech disturbances
– olfactory or auditory hallucinations
– mood disturbances
Diagnosis of migraine
In order to make the diagnosis, the clinical history is essential: duration, frequency, location, character, intensity and modality of pain. Likewise, the existence of triggering factors and accompanying symptoms should also be studied, such as:
– scotomas or partial loss of visual field
– amaurosis or transient blindness
– tinnitus
– rhinorrhea
– vertigo
– focal motor and sensory disturbances
– alterations of consciousness
This will be completed with the examination by the expert in Neurology and the pertinent complementary neurological tests.
Causes of migraine
The following have been postulated as mechanisms responsible for headaches or migraines:
– Traction of the veins leading to the venous sinuses.
– traction of the great arteries of the base of the brain and its main branches.
– distension and dilatation of the intracranial arteries
– inflammation of some of the pain-sensitive structures
– direct pressure of some processes on the cranial or cervical sensory nerves
– other pain-sensitive structures, such as skin, subcutaneous cellular tissue, epicranial periosteum, paranasal sinuses, nasal cavity structures, eye structure, trigeminal, glossopharyngeal and vagus nerves.
Classification of migraine headaches
In the classification of headaches or migraines are included, in a general way:
– Common migraine
– Migraine without aura
– Migraine with visual aura, which presents different types: familial hemiplegic, basilar, visual migraine aura, aura without headache.
– Migraine accompanied by sensory-motor and language prodromes.
– Other types of migraine, such as ophthalmoplegic, retinal, migraine status migraine, cardiac migraine, atypical migraine disorder…
– Tension headache. It is one of the most frequent headaches or migraines, with triggering factors such as stress, insomnia, anxiety and a depressive component.
– Cluster headache and chronic paroxysmal hemicrania. These are major clinical challenges.
– Mixed tension and migraine headache.
– Headache associated with head injury or stroke.
– Giant cell arteritis headache of the temporal artery with risk of blindness.
– Cerebral expansive neoplastic processes, metabolic, temporomandibular dysfunction or myofascial syndrome.
– Trigeminal, glossopharyngeal, nasociliary, laryngeal, postherpetic cranial neuralgias.
Genetic factor in migraine
The genetics of migraine suggests an inheritance with an autonomic dominant trait, with 70% of patients having a family history.
Migraine patients with aura have been found to have a gene variant associated with chromosome 8 that patients with common migraine without aura do not have.
The latest genetic findings show four genes in migraine patients, which are: MEF2D, TGFBR2, PHACTR1 and ASTN2, discovered by the Vall d’Hebron Hospital Research Institute of the University of Barcelona. However, environmental, hormonal, psychological and epigenetic factors also play a major role in the development of migraine.
Migraine and Neurology
Arterial dilatation and vasospasm produced during migraines have been explained by two theories: neural and vascular.
1) Neural theory. This theory postulates that low frequency discharges in the locus ceruleus (brain region involved in panic and stress) determine a narrowing of a cerebral blood vessel (cortical vasoconstriction), causing a second wave of oligohemia or reduction of the usual amount of circulating blood.
On the contrary, high frequency discharges are the conditioners of an extracranial vasodilatation. The phenomenon of propagated oligohemia begins in the visual area, with progression towards the cortex from 2 to 34 minutes. This phenomenon of acute, intense and transient inhibition of neuronal activity has a biochemical, hemodynamic and electrophysiological expression.
The final pathway is an alteration of the vascular smooth fiber with narrowing of a blood vessel (vasoconstriction) and vasodilatation, by release of neurotransmitters, which causes the painful crisis.
2) Vascular theory. It explains the painful picture through the appearance of a serotonin-releasing factor that causes vasoconstriction and aura, and produces nausea and vomiting. The alteration in the hypothalamus and limbic system suggests the role of emotions in the triggering.
Migraine triggering factors
There are triggering factors involved in migraine attacks. They can be dietary factors, such as hunger, alcohol and tobacco. Also dietary, as foods containing thiamine, dopamine, phenylethylamine, monosodium glutamate and sodium nitrite can trigger headache pain. Sodium nitrite is found as a preservative and colorant in cured meats and sausages. Tyramine is found in aged cheeses, yogurt, overripe bananas, avocados, peanuts, pickled herring or chicken liver. Dopamine is found in the pod of thick beans and in caffeine. And, phenylethylamine is found in chocolate, cola and tea. Caffeine, on the other hand, relieves migraine.
There are also atmospheric factors, as bright clouds, snow, sun, strong smells or wind can trigger migraines. There are also emotional or behavioral factors, such as insomnia and stress.
Treatment of migraine
With regard to treatment, first of all, non-pharmacological treatment based on eliminating the triggering factors should be emphasized: leading a relaxed life with physical exercise or moderate-intensity sport and a balanced diet.
Pharmacological treatment consists of specific medication for migraine attacks and preventive treatment:
– Treatment for migraine attacks. To treat migraine there are oral, intranasal and flash profile triptans. Ergotics and derivatives are also used, but they are practically not used due to their side effects. Anti-inflammatory drugs (NSAIDs) are also effective in some cases, as well as conventional analgesics. In very intense and rebellious crises, morphine derivatives are also administered.
– Preventive treatment. It is effective in 60% of cases. Edrenergic beta-blockers, a calcium antagonist drug, sodium valproate or antidepressants are used. Acupuncture and botulinum toxin are also used in very specific cases.