migraine

migraine
Name	Migraine
Field	Neurology

migraine. A migraine is a common, complex neurological disorder characterized by recurrent, often severe headaches and associated sensory disturbances. It is recognized as a leading cause of disability worldwide by organizations like the World Health Organization. The condition involves intricate interactions within the brainstem, cerebral cortex, and the trigeminovascular system.

Signs and symptoms

The classic manifestation involves a severe, throbbing headache, typically unilateral, often accompanied by photophobia, phonophobia, and nausea. Many individuals experience a prodrome phase with symptoms like yawning or food cravings hours before the headache. A distinctive feature for some is the aura, a transient neurological phenomenon involving visual disturbances such as scintillating scotoma or sensory changes, believed to originate from cortical spreading depression in the occipital lobe. The headache phase can last from 4 to 72 hours and may be exacerbated by physical activity, with the subsequent postdrome phase often described as a "hangover"-like state.

Causes and mechanisms

The exact etiology remains an active area of research in neurology, but it is understood to involve a combination of genetic and environmental factors. The pathophysiology is linked to abnormal neuronal excitability and a wave of cortical spreading depression that activates the trigeminovascular system, leading to neurogenic inflammation and pain. Key neurotransmitters implicated include calcitonin gene-related peptide and serotonin. Genetic studies, including those by the International Headache Society, have identified several susceptibility loci, and hormonal fluctuations, particularly involving estrogen, are a major trigger, explaining higher prevalence in women. Common triggers reported by patients include stress, specific foods, changes in sleep patterns, and environmental factors like bright lights.

Diagnosis

Diagnosis is primarily clinical, based on patient history and the exclusion of other causes, following criteria established by the International Classification of Headache Disorders. There is no specific confirmatory test like MRI or CT scan, but these imaging tools are used to rule out other conditions such as brain tumor or subarachnoid hemorrhage. A thorough neurological examination is essential. For chronic cases, clinicians may use diaries to track frequency and triggers, differentiating it from other headache disorders like tension-type headache or cluster headache.

Prevention

Preventive strategies are recommended for individuals with frequent or severe attacks. Pharmacological prophylaxis includes medications such as topiramate, propranolol, amitriptyline, and the newer class of CGRP monoclonal antibodies like erenumab. Non-pharmacological approaches are equally critical and involve identifying and avoiding individual triggers, maintaining regular sleep schedules, and practicing stress-reduction techniques like cognitive behavioral therapy or biofeedback. Lifestyle modifications, including regular aerobic exercise and dietary consistency, are also advocated by organizations like the American Headache Society.

Management

Acute treatment aims to stop or alleviate the pain and associated symptoms. First-line medications include NSAIDs such as ibuprofen and naproxen, and specific triptans like sumatriptan and rizatriptan. For nausea, antiemetics like metoclopramide are used. In refractory cases, dihydroergotamine or newer gepants like ubrogepant may be administered. Non-pharmacological management during an attack includes resting in a dark, quiet room. For chronic migraine, defined by the Food and Drug Administration as headaches on 15 or more days per month, treatments include onabotulinumtoxinA injections and the preventive medications listed above.

Epidemiology

Migraine is a highly prevalent disorder, affecting an estimated 12% of the global population, according to the Global Burden of Disease Study. It is about three times more common in women than in men, a disparity largely attributed to hormonal factors. Prevalence peaks in mid-life, during the most productive years, contributing significantly to economic burden through lost workdays and reduced productivity. The condition is observed across all geographic regions and ethnic groups studied, though prevalence rates can vary. Its high disability burden ranks it among the top causes of years lived with disability worldwide.

Category:Neurological disorders Category:Headaches