What causes migraines and how are they treated?

Causes and Treatment of Migraines

Migraine is a disabling primary headache disorder caused by a complex interplay of genetic and environmental factors, involving activation of the trigeminovascular system and cortical spreading depression, which requires a comprehensive treatment approach including both acute and preventive therapies. 1, 2

Causes of Migraine

Pathophysiology

• Migraine involves peripheral and central activation of the trigeminovascular system, with cortical spreading depression thought to be the underlying neurophysiological substrate of migraine aura 1
• Genetic factors play a significant role, with multiple genetic variants identified that increase susceptibility to migraine 3, 4
• Neuroimaging studies have identified involvement of specific brain regions including the cortex, cerebellum, and subcortical areas in migraine pathophysiology 3
• Migraine should be understood as a neurological disorder with a biological basis, with associated functional and structural changes within the nervous system 1

Triggers and Predisposing Factors

• Environmental, psychological, and internal triggers can precipitate migraine attacks 1
• Common triggers include stress, hormonal changes (particularly menstruation), poor sleep quality, and certain foods 1
• Predisposing factors increase susceptibility to migraine attacks and include poor physical fitness and chronic stress 1
• True trigger factors are often self-evident but their role is sometimes overemphasized in migraine management 1

Diagnosis of Migraine

Clinical Features

• Recurrent attacks of headache with moderate to severe intensity, often with accompanying symptoms 1
• Approximately one-third of individuals experience aura, which manifests as transient focal neurological symptoms (most commonly visual disturbances) 1
• Common associated symptoms include photophobia, phonophobia, nausea, and vomiting 1
• Prodromal symptoms before pain onset can include depressed mood, yawning, fatigue, and food cravings 1

Diagnostic Approach

• Diagnosis is primarily clinical, based on medical history and application of diagnostic criteria 1
• Rule out secondary causes of headache through appropriate examination 1
• Neuroimaging is only indicated when a secondary headache disorder is suspected 1
• Consider differential diagnoses including tension-type headache, cluster headache, and secondary headache disorders 1

Treatment of Migraine

Acute Treatment

• First-line medications include NSAIDs (acetylsalicylic acid, ibuprofen, or diclofenac potassium) for mild to moderate attacks 1
• Second-line medications are triptans, which should be offered to patients for whom over-the-counter analgesics provide inadequate relief 1
• Triptans are most effective when taken early in an attack while the headache is still mild, but should not be used during the aura phase 1
• Combination of a triptan with a fast-acting NSAID may provide better relief than either medication alone 1
• Caution is needed with triptans in patients with cardiovascular risk factors due to potential vasoconstrictive effects 5

Preventive Treatment

• Preventive therapy should be considered if the patient has more than two headaches per week 1
• Options include beta-blockers, antidepressants, anticonvulsants, and newer CGRP monoclonal antibodies 1, 6
• Exercise has been shown to be effective for migraine prevention, with studies showing that exercising for 40 minutes three times a week can be as effective as some medications 1
• Medication overuse should be avoided as it can lead to medication overuse headache, which presents as increased frequency of migraine attacks 5

Non-Pharmacological Approaches

• Cognitive-behavioral therapy (CBT) and biofeedback should be offered to all patients 1
• Other effective non-pharmacological therapies include relaxation training, meditative therapy, progressive muscle relaxation, and visualization/guided imagery 1
• Patient education is essential - patients should understand that migraine is a neurological disorder with a biological basis 1
• Lifestyle modifications addressing sleep, stress, and physical activity can be beneficial 1

Special Populations

Children and Adolescents

• Migraine attacks in children are typically shorter than in adults and often present with bilateral rather than unilateral pain 7
• Gastrointestinal symptoms like nausea and vomiting are commonly prominent in children 7
• Ibuprofen is recommended as first-line medication for children, with dosing appropriate for body weight 7
• Bed rest alone may be sufficient for children with short-duration attacks 7

Pregnant and Breastfeeding Women

• Paracetamol is the safest option for acute treatment during pregnancy 1
• Preventive treatments should be avoided if possible during pregnancy 1
• Special consideration is needed for women with menstrual migraine, as attacks are often predictable and preventable 1

Management Strategy

Monitoring and Follow-up

• Use headache calendars to track frequency, intensity, and response to treatments 1
• Regularly assess effectiveness and adverse events of prescribed medications 1
• When treatment outcomes are suboptimal, review diagnosis, treatment strategy, dosing, and adherence 1
• Establish realistic expectations - patients should understand that the road to recovery may be long but achievable 1

Addressing Complications and Comorbidities

• Recognize and manage medication overuse headache by withdrawing overused medications 1
• Consider referral to specialists for patients with chronic migraine (≥15 headache days per month) 1
• Identify and appropriately treat comorbid conditions such as depression, anxiety, and cardiovascular disorders 1
• Maintain stability of effective treatment in primary care and react promptly to changes in the patient's condition 1