Migraines: The Headache Is Only Half the Story

By Gennady Gelman, MD

Migraine is a word that is half right. It means “half a head.” Many attacks involve both halves. Some involve no head pain at all. And the disorders that now officially carry the Greek name for “half a head” are not migraine. To see how that happened, start with the word and follow it.

Take the word apart

Migraine descends, by a winding route through Latin and French, from Greek hēmikrania: hēmi-, half, and kranion, skull or head. You likely already know hemi- from hemisphere (half a sphere), hemiplegia (paralysis of one side), and hemithorax (one side of the chest). Cranium is the bony case around the brain. The board game Cranium promises to exercise what is inside the box; strictly speaking, it is named for the box.

The word appears in Galen’s surviving second-century writings. Aretaeus of Cappadocia, who may have written before Galen, used a near relative, heterocrania, “the other side of the head.” From there the word wore down in the mouths of Latin and French speakers. The unstressed first syllable dropped off, the c softened to a g, and hemicrania became migranea, then French migraine. Losing the front of a word has its own Greek name: aphaeresis, “a taking away.” Aphaeresis is also the term to separate a blood component from whole blood, the rest is usually returned to the body. 

English borrowed the modern spelling from French in the eighteenth century; an earlier medieval borrowing survives as megrim (Fig. 1). Physicians meanwhile kept the plainer Greek cephalalgia (kephalē, head, and algos, pain), literally just “headache,” and the English-speaking public said “sick headache.”

The half-head names went to someone else

Here is the irony. The International Classification of Headache Disorders (ICHD-3) still uses the Greek word, but not for migraine. Paroxysmal hemicrania (described by Sjaastad and Dale in 1974) and hemicrania continua (Sjaastad and Spierings, 1984) are strictly one-sided headaches, grouped with cluster headache among the trigeminal autonomic cephalalgias, and defined in part by an absolute response to indomethacin. They earned the literal name. 

The name promises one side, but one side is just one feature among several to choose from.

So the name records an old observation, head pain that often favors one side, rather than a definition. A migraine can hurt on both sides, switch sides, or never hurt at all. The last case, typical aura without headache, has its own ICHD code.

Before and after

Many attacks begin well before the pain. Hours or even a day or two ahead, someone may yawn repeatedly, feel unusually tired, crave a food, notice a stiff neck, or struggle to concentrate. This is the prodrome. Pro- means before; Greek dromos is a running course. A prodrome “runs before.”

That matters clinically. If someone craves chocolate and then develops a headache, chocolate may have triggered it, or the craving may tell us the attack had already begun. Both possibilities deserve more care than a universal forbidden-food list.

Dromos is a busy root. After the pain comes the postdrome, the “migraine hangover” of fatigue and poor concentration. That word is a modern hybrid, Latin post bolted to Greek dromos. Purists call such crossbreeds barbarisms, in the good company of television and automobile.

A breeze, a wall, and a sparkling darkness

Aura is Greek for a breeze or a breath of air. The medical use began with epilepsy: Galen credited his teacher Pelops with the term, after a patient described a cold breeze rising up his leg before a seizure. Nineteenth-century physicians carried the word over to migraine, where it now means fully reversible visual, sensory, or language symptoms that build gradually, usually over 5 to 60 minutes. Most attacks have none.

The most familiar aura has two names, both drawn from the same image. As it expands, the shimmering zigzag edge reminded Victorian observers of the star-shaped ramparts of a fortified town seen from above. English gave it the fortification spectrum; Greek gave it teichopsia (teichos, wall, and opsis, sight). In 1870 the physician Hubert Airy drew his own aura in sequence for the Royal Society; his father, the Astronomer Royal George Airy, had the same visions and called them “Norman arches.”

Behind the zigzag lies a scotoma, from skotos, darkness: the blind patch the aura leaves behind. Put the words together and the common clinical term, scintillating scotoma, is a small oxymoron: a sparkling darkness. The leading explanation is cortical spreading depression, a slow wave of neuronal depolarization followed by suppressed activity, crossing the visual cortex at a few millimeters per minute. Depression here means a fall in electrical activity, as Leão meant when he named it in 1944, not a mood.

Rarer auras distort size, so that objects or one’s own body seem too small or too large. In 1955 the psychiatrist John Todd named this Alice in Wonderland syndrome. Lewis Carroll had migraine; whether his auras shaped Alice is a pleasant speculation, not a finding.

Fear that isn’t fear

Photophobia and phonophobia join phōs (light) and phōnē (sound, voice) to phobos, fear. Patients are not afraid of the lamp. They find it painful or intolerable, so the accurate word would be aversion. The mechanism is not an injured optic nerve but convergence: in experimental work, retinal input and meningeal pain signals meet on the same thalamic neurons, so light turns up pain. The same logic gives osmophobia, aversion to smells (osmē).

Allodynia is allos, other, plus odynē, pain: pain from something that should not hurt. During an attack, combing hair, wearing glasses, or a ponytail can hurt. It marks sensitization and is worth asking about.

Nausea comes from Greek naus, ship: it was seasickness first. The same ship sails through nautical and astronaut. There is also a disputed but tempting theory that English noise descends, through Old French, from Latin nausea, in the sense of disturbance or annoyance. If so, the migraine patient lying in a dark room is avoiding two words from the same ship.

Family matters

The brain tissue itself has no ordinary pain receptors. The pain of migraine is carried from the meninges and their blood vessels by the trigeminal nerve. Latin trigeminus means born as triplets (tri-, three, and geminus, twin, as in the zodiac’s Gemini, not the chatbot): one nerve, three branches. Its signals run through the brainstem and thalamus to cortex, and its terminals release CGRP, which amplifies and sustains the pain.

The membrane those fibers live in is the dura mater, “hard mother,” with the pia mater, “tender mother,” lying on the brain beneath it. These terms come from Medieval Islamic clinicians who described anatomic relationships as parents and children; twelfth-century translators rendered the Arabic into Latin word for word. Other examples: abū kaʿb, “father of the ankle,” a folk name for mumps, and vessels described as sons of the root vessel.

The meninges as a group come from Greek mēninx, membrane, also the root of meningitis.

Drugs

The term drug itself likely stems from French drogue, perhaps from Dutch droog, “dry,” for the dried herbs and roots that made up most remedies. An apothecary is simply a storekeeper: Greek apothēkē, a storehouse, is also the root of boutique and bodega. They would store the dried goods required for medical remedies. Pharmacy goes back to Greek phármakon, which meant remedy, poison, and charm all at once; only in the 19th century did the word come to mean the shop. Its relative pharmakeía could mean the use of drugs or sorcery, and the King James Bible translates it as “witchcraft.”

Drug names are fossils. Several in migraine carry older theories inside them.

Triptans activate 5-HT_1B/1D receptors and constrict cranial vessels, which once seemed to confirm the vascular story written into serotonin’s name. But lasmiditan, a “ditan,” acts at 5-HT_1F without constricting vessels and still treats attacks, and gepants work without vasoconstriction too. The drugs show where an attack can be interrupted. They do not reveal where it started.

Why keep a migraine-prone brain?

An evolutionary tangent. Migraine is common and substantially heritable, and genome-wide studies show it is polygenic: many variants, each with a small effect. Something that common and that inherited invites the question of why selection kept it.

What would we call it if we discovered it today?

Try building a name from what we now know. I suggest recurrent sensory and trigeminal syndrome. Each word earns its place, and each leaves something out.

Fig. 5 · Recurrent sensory and trigeminal syndrome. More accurate than “half a head,” and nobody will ever say it.

No replacement fits, because a name is a small box for a complicated disease. Migraine, the half-word for half a head, has at least survived two thousand years.

The last word in that table is the one that fits best. We have met the hippodrome, where horses run; the palindrome, which runs back; and the prodrome, which runs before. Syndrome, syn + dromos, is things that run together, which is where the next entry begins.

Disclaimer: This article is for educational purposes only. It is not medical advice, does not establish a clinician-patient relationship, and should not replace evaluation by a qualified healthcare professional. If you have urgent, severe, new, or otherwise concerning symptoms, seek appropriate medical evaluation.