This is the second most commonly seen form of migraine: patients who primarily suffer from migraine with aura may also have attacks of migraine without aura. According to the International Classification of Headache Disorders^[11] it is a recurrent disorder manifesting in attacks of reversible focal neurological symptoms that usually develop gradually over 5-20 minutes and last for less than 60 minutes. Headache with the features of "migraine without aura" usually follows the aura symptoms. Less commonly, the aura may occur without a subsequent headache or the headache may be non-migrainous in type.

In order to diagnose migraine with aura, there must have been at least 2 attacks not attributable to another cause that fulfill the following criteria:

1. Aura consisting of at least one of the following, but no muscle weakness or paralysis:

• Fully reversible visual symptoms (e.g. flickering lights, spots, lines, loss of vision)
• Fully reversible sensory symptoms (e.g. pins and needles, numbness)
• Fully reversible dysphasia (speech disturbance)

2. Aura has at least two of the following characteristics:

• Visual symptoms affecting just one side of the field of vision and/or sensory symptoms affecting just one side of the body
• At least one aura symptom develops gradually over more than 5 minutes and/or different aura symptoms occur one after the other over more than 5 minutes
• Each symptom lasts from 5-60 minutes

Where these criteria are not fully met, a diagnosis of "probable migraine with aura" may be considered, although other neurological causes must also be excluded. If the picture complies with the criteria but includes one-sided muscular weakness or paralysis, a diagnosis of "sporadic hemiplegic migraine" or "familial hemiplegic migraine" should be considered.

Aura phase

For the 20-30%^[5][6] of migraineurs who suffer migraine with aura, the migraine aura comprises focal neurological phenomena that precede or accompany the attack. They appear gradually over 5 to 20 minutes and generally last less than 60 minutes. The headache phase of the migraine attack usually begins within 60 minutes of the end of the aura phase, but it is sometimes delayed up to several hours, and it can be missing entirely. Symptoms of migraine aura can be visual, sensory, or motor in nature.^[7]

Visual aura is the most common of the neurological events. There is a disturbance of vision consisting usually of unformed flashes of white and/or black or rarely of multicolored lights (photopsia) or forma­tions of dazzling zigzag lines (scintillating scotoma; often arranged like the battlements of a castle, hence the alternative terms "fortification spectra" or "teichopsia"). Some patients complain of blurred or shimmering or cloudy vision, as though they were look­ing through thick or smoked glass, or, in some cases, tunnel vision and Hemianopsia. 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.

Other symptoms of the aura phase can include auditory or olfactory hallucinations, aphasia, vertigo, tingling or numbness of the face and extremities, and hypersensitivity to touch.

The diagnosis of migraine without aura, according to the International Headache Society, can be made according to the following criteria, the "5, 4, 3, 2, 1 criteria":

• 5 or more attacks
• 4 hours to 3 days in duration
• 2 or more of - unilateral location, pulsating quality, moderate to severe pain, aggravation by or avoidance of routine physical activity
• 1 or more accompanying symptoms - nausea and/or vomiting, photophobia, phonophobia

For migraine with aura, only two attacks are required to justify the diagnosis.