The migraine attack can be divided into four phases:
1. The prodrome, which occurs hours or days before the headache.
2. The aura, which immediately precedes the headache.
3. The headache phase.
4. The postdrome.(71)
The first phase or prodrome
Prodromal symptoms occur in 40% to 60% of migraineures. This phase consists of altered mood, irritability, depression or euphoria, fatigue, yawning, excessive sleepiness, craving for certain food (e.g., chocolate), and other vegetative symptoms (72, 73), all of which suggest origin of these symptoms in the hypothalamus, perhaps resulting from excessive dopamine stimulation (74). These symptoms usually precede the headache phase of the migraine attack by several hours or days, and experience teaches the patient or observant family that the migraine attack is near.
Two types of migraine prodrome may occur non-evolutive ,which precedes the attack by 48 hours and evolutive which starts 6 hours before the attack, gradually increasing in intensity and culminating in the attack (73,78)
The second phase or the aura:
The migraine aura is comprised of focal neurological phenomena that precedes or accompany the attack. They appear gradually over 5 to 20 minutes and usually subside just before the headache begins. Symptoms of migraine aura are usually sensory in nature (20, 76). They are visual in 99% and sensory in 31%. And may involve motor, language or brainstem disturbances (77). The aura symptoms usually precede the headache phase of the migraine attack but occasionally occur simultaneously. Sometimes, two aura symptoms occur in the attack, or may occur in isolation. Rarely, auras may occur repeatedly. This may be many times and as long as several months. These have been termed "migraine aura status" yet other organic causes should be considered (78)
Visual aura is the most common of the neurological events. There is a disturbance of vision consisting usually of unformed flashes of white or, rarely, of multicolored lights (photopsia) or formations of dazzling zigzag lines (arranged like the battlements of a castle, hence the term fortification spectra or teichopsia). Some patients complain of blurred or shimmering or cloudy vision, as though they were looking through thick or smoked glass. These luminous hallucinations move slowly across the visual field for several minutes and may leave scotomatous defects; the latter are usually bilateral and often homonymous (involving corresponding parts of the field of vision of each eye), pointing to their origin in the visual cortex. Visual abnormalities of retinal and optic nerve origin have also been observed (20, 79)
The somatosensory aura of migraine consists of digitolingual or cheiro-oral paresthesias, a feeling of pins-and-needles experienced in the hand and arm as well as in the ipsilateral nose-mouth area.. Paresthesia migrate up the arm, and then extend to involve the face, lips, and tongue. Paresthesias can become bilateral and may be followed by numbness and loss of positional sense. More complex symptoms include difficulties in the perception and use of the body; speech and language disturbances; states of double or multiple consciousnesses associated with de ja vu or jamais vu; and elaborate dreamy, nightmarish, trancelike, or delirious states. Motor symptoms, when they occur, are usually associated with sensory symptoms, but true weakness is rare and usually unilateral. (79)
Periodic neurologic phenomena, which may be the aura of migraine, can occur in isolation without the headache. these phenomena (scintillating scotoma, recurrent sensory, motor, and mental phenomena must be differentiated from other neurologic disorders.(79)
The third phase: the headache
The typical migraine headache is unilateral, throbbing, moderate to severe, and aggravated by physical activity (9). Not all of these features are required. The pain may be bilateral at the onset or start on one side and become generalized, usually alternates sides from one attack to the next. The onset is usually gradual. The pain peaks and then subsides, and usually lasts between 4 and 72 hours in adults and 1 and 48 hours in children. The frequency of attacks is extremely variable, from a few in a lifetime to several times a week, and the average migraineur experiences from one to three headaches a month. The head pain varies greatly in intensity. Pain is throbbing in 85 percent of cases, although throbbing pain is not diagnostic of migraine because it is often described in other headache types. (80, 75)
The pain of migraine is invariably accompanied by other features. Anorexia is common, and nausea occurs in almost 90 percent of patients, while vomiting occurs in about one third of patients. Many patients experience sensory hyperexcitability manifested by photophobia, phonophobia, and osmophobia, and seek a dark, quiet room. Blurred vision, nasal stuffiness, diarrhea, polyuria, pallor, or sweating may be noted during the headache phase. There may be localized edema of the scalp or face, scalp tenderness, prominence of a vein or artery in the temple, or stiffness and tenderness of the neck. Impairment of concentration and mood are common. Lightheadedness, rather than true vertigo, and a feeling of faintness may occur. The extremities tend to be cold and moist.(77,80)
Following the headache, during the postdrome phase, the patient may feel tired, "washed out" irritable, and listless, and may have impaired concentration, scalp tenderness, or mood changes. Some people feel unusually refreshed or euphoric after an attack, whereas others note depression and malaise (77).