Chronic Migraine

Neurology

Description

Chronic migraine is a primary headache disorder defined by the International Classification of Headache Disorders, 3rd edition, as headache occurring on 15 or more days per month for longer than three consecutive months, of which at least 8 days each month have migraine features such as unilateral throbbing pain, photophobia, phonophobia, nausea, or aura. It represents the most disabling end of the migraine spectrum, affecting about 1–2 % of the general population—predominantly women in their reproductive years—and accounting for a disproportionate share of migraine‐related healthcare use, lost productivity and diminished quality of life.

Symptoms

Core manifestations are daily or near-daily head pain varying in intensity, location and character, often superimposed by disabling migraine attacks with throbbing unilateral pain, nausea, vomiting, photophobia and phonophobia. Cognitive fog, dizziness, osmophobia, cutaneous allodynia, neck stiffness and mood lability are common interictal complaints. Up to one third experience reversible visual, sensory or language aura preceding some attacks. Many patients develop refractory insomnia, social withdrawal and reduced physical activity.

Risk Factors

Female sex, family history of migraine, high baseline attack frequency, obesity, obstructive sleep apnoea, depression, anxiety, stressful life events, medication-overuse headache (regular intake of simple analgesics > 15 days/month or triptans/opioids > 10 days/month), insufficient sleep, caffeine overuse, persistent neck pain, low socioeconomic status and head trauma accelerate progression from episodic to chronic migraine. Oestrogen fluctuations, especially perimenstrual decline or hormonal therapy changes, precipitate chronification in susceptible women.

Diagnosis

Diagnosis is clinical, requiring a detailed history that confirms frequency criteria, migraine features and absence of secondary causes. A structured headache diary documenting attack days, analgesic use and triggers aids classification. Neurologic examination is typically normal; red-flag features (sudden onset, focal deficit, papilloedema) prompt neuroimaging with brain MRI and MR venography to exclude secondary pathology. Laboratory screening for anaemia, thyroid dysfunction and vitamin D deficiency can uncover modifiable comorbidities. The ID-Migraine and Migraine Disability Assessment (MIDAS) scales quantify impact.

Treatment

Effective management combines patient education, trigger modification, acute attack therapy and preventive pharmacotherapy. Acute therapy employs oral or nasal triptans, gepants (ubrogepant, rimegepant) or lasmiditan at attack onset, combined with NSAIDs and anti-emetics; limiting use to ≤ 10 days/month prevents medication overuse. Preventive treatment is recommended for chronic migraine irrespective of disability level. First-line options are CGRP monoclonal antibodies (erenumab 70–140 mg monthly, fremanezumab 225 mg monthly or 675 mg quarterly, galcanezumab 120 mg monthly after 240 mg loading, eptinezumab 100–300 mg IV every 12 weeks), which reduce monthly migraine days by 4–8 with rapid onset and favourable tolerability. OnabotulinumtoxinA 155–195 U every 12 weeks using the PREEMPT protocol is FDA-approved and effective, particularly in patients with pericranial muscle tenderness. Oral preventives (topiramate 50–100 mg/day, valproate 500–1000 mg/day, amitriptyline 10–50 mg at night, propranolol 80–160 mg/day, candesartan 8–32 mg/day) remain valuable when cost or access limits newer agents but require titration and monitoring of side effects. Rimegepant or atogepant taken daily offers dual acute-preventive benefit. Emerging therapies include sphenopalatine ganglion stimulation, transcranial magnetic stimulation, occipital nerve stimulation and small-molecule PACAP receptor antagonists. Non-pharmacologic measures—regular aerobic exercise within pain-free limits, cognitive-behavioural therapy, biofeedback, mindfulness, sleep hygiene, weight reduction, magnesium (400 mg), riboflavin (400 mg) and co-enzyme Q10 (100–200 mg) supplementation—complement drug therapy.

Outlook

With a multimodal regimen roughly two thirds of patients achieve ≥ 50 % reduction in monthly migraine days, improved function and reversal to episodic status. Nevertheless, chronic migraine can fluctuate and relapse, particularly with ongoing stress, hormonal change or medication overuse. Early aggressive prevention, management of comorbid insomnia, depression and obesity and strict limitation of acute medications offer the best prospects for sustained remission.

Complications

Medication-overuse headache, depression, generalised anxiety, sleep disorders, chronic pain syndromes, functional gastrointestinal disorders, cardiovascular disease associated with triptan or ergot overuse in susceptible patients, and social or occupational disability are the main sequelae of uncontrolled chronic migraine.

Prevention

Primary prevention focuses on smoking cessation, weight management, regular moderate exercise, balanced Mediterranean-style diet, avoidance of excessive caffeine and alcohol, consistent sleep and stress management. Early treatment of frequent episodic migraine with appropriate preventives may forestall chronification. Vaccination and hand hygiene reduce viral triggers of escalation.

Support

Keeping a detailed headache diary to identify triggers, adhering to regular sleep–wake schedules, maintaining hydration, spacing meals, limiting caffeine to < 200 mg/day, performing low-impact exercise, practising relaxation breathing and scheduling periodic follow-up visits help sustain control. Family members can assist by learning rescue-medication protocols and providing a dark, quiet environment during attacks. Workplace accommodations such as flexible hours, reduced screen glare and scheduled breaks may prevent exacerbations.