Paroxysmal headache lasting 4-72 hours. Episodes vary in frequency from more than once a week to less than one per year with symptoms abating completely between attacks. Prodromes consisting of non-specific symptoms occur frequently hours to days before headache. Most frequent sub-types are:

• Without aura - (common migraine) defining over 80% of attacks
• With aura - (classic migraine) characterized by focal disruption of neurological function begins and ends prior to headache onset
• Variants of migraine include:
  • Transformed migraine - chronic headache pattern evolving from episodic migraine. Migraine-like attacks are superimposed on a daily or near-daily headache pattern, e.g., tension headache.
  • Basilar migraine - occipital headache, with aura symptoms of dysarthria, vertigo, tinnitus, ataxia, and bilateral paresis or bilateral paresthesias
  • Hemiplegic migraine - aura consisting of hemiplegia and/or hemiparesis
  • Ophthalmoplegic - palsy of the ipsilateral third cranial nerve during the headache phase
  • Retinal - symptoms of retinal vascular involvement during headache
  • Childhood periodic syndromes - (migraine equivalents) recurrent often cyclic episodes of symptoms
  • Status migrainous - persistent migraine which does not resolve spontaneously
  • Migrainous stroke - persistent or permanent neurologic deficits persisting beyond migraine attack usually with neuro-imaging changes
• System(s) affected: Nervous, Musculoskeletal, Cardiovascular, Gastrointestinal
• Genetics: > 80% of patients have positive family history. Identification of a chromosomal abnormality has been confirmed in familial hemiplegic migraine.
• Incidence/Prevalence in USA:
  • Adults: 17.6% of females, 5.6% of males
  • Childhood unknown; may be significant
• Predominant age: Childhood; increase in early adolescence, through 30s and 40s; decreases with age, attacks may persist into mature adulthood
• Predominant sex:
  • Male ≥ Female in childhood
  • Female > Male (3:1) after menarche to mid-adult life
  • Female > Male (2:1) in postmenopausal female populations

Five phases of a migraine; symptoms vary from patient to patient or from attack to attack within the same individual

• Prodrome (experienced by 50-80% of patients): A variety of "warnings" that precede migraine, frequently characterized by mood disruptions (e.g., euphoria, irritability, depression), fatigue, muscle tension, food craving, bloating, yawning, or subtle disruption of sensory processing. These symptoms are often not recognized by patients as associated with migraine.
• Aura: Visual disruptions are most common, including scotoma, hemianopsia, fortification spectra, geometric visual patterns, and occasionally hallucinations. Somatosensory disruption in face or upper extremities is also common. Headache typically begins within 1 hour of aura resolution.
• Headache: Unilateral (30-40% bilateral), throbbing (40% non-throbbing) pain of 4-72 hours; intensified by movement; associated with systemic manifestations, e.g., Nausea (87%), Vomiting (56%), Diarrhea (16%), Photophobia (82%), Phonophobia (78%), Muscle tenderness (65%), Lightheadedness (72%), Vertigo (33%).
• Headache termination: Untreated, usually occurs with sleep; occasionally, vomiting or strong emotional experiences abort headache
• Postdrome: Headache pain resolved but another manifestation lingers on, such as food intolerance, impaired concentration, fatigue, muscle soreness

• Exact etiology unknown; appears to be a genetically linked, neuronal disease with vascular disruption as an epiphenomenon of underlying neurochemical disruption
• Serotonin and norepinephrine metabolism abnormalities may play a role
• Neurogenic inflammation and regional disruption of cerebral and/or extracranial blood flow may explain some clinical features

• Specific foods, alcohol, missing meals, menstrual cycle, excessive sleep, fatigue, emotional stress, let down (relief of stress)
• Medications (estrogen replacement, BCP's, vasodilators)
• Family history of migraine
• Female gender
• Young age
• History of childhood cyclic vomiting, cyclic abdominal pain, motion sickness