Migraine cannot be diagnosed clearly by neuroimaging yet. Neuroimaging, like MRI, is done to exclude other conditions associated with headache, like a blood clot in the brain. Migraine diagnosis is based on history. The clinical criteria to confirm migraine are:
Migraine without aura
At least 5 headache attacks (in 15 days or more per month for more than 3 months) fulfilling 2 to 4 of the criteria given below.
Headache lasting 4 to 72 hours
The headache has at least 2 of the following characteristics: one-sided location, pulsating quality, moderate to severe intensity or aggravated by or causing avoidance of routine physical activity.
During the headache, at least one of the following occurs: nausea and/or vomiting, photophobia (sensitivity to light) or phonophobia (sensitivity to sound)
The headache cannot be attributed to any other disorder
Migraine with aura
At least 2 headache attacks fulfilling 2 to 4 of the criteria below.
An aura consisting of at least one of the following: visual disturbances, tingling sensation or slurred speech. There will be no motor weakness and the symptoms will last only for about 2 mins.
At least 2 of the following characteristics: (1) homonymous visual symptoms and/or unilateral sensory symptoms. This means the same part of the visual field is affected, for example, the right half of both eyes or left half of both eyes affected and/ or same side of the body will suffer from sensory symptoms like twitching or numbness (2) gradual development of at least one aura over 5 minutes or more and/or different aura symptoms occurring in succession over 5 minutes and more (3) each symptom lasts longer than 5 minutes but not longer than 60 minutes.
The headache fulfils 2 to 4 of the following criteria:
- Headache lasting 4 to 72 hours
- The headache has at least 2 of the following characteristics: one-sided location, pulsating quality, moderate to severe intensity or aggravated by or causing avoidance of routine physical activity.
- During the headache at least one of the following occurs: nausea and/or vomiting, photophobia (sensitivity to light) or phonophobia (sensitivity to sound)
- The headache cannot be attributed to any other disorder
Apart from patient history, the patient should maintain a pain diary in which he/she records the duration, intensity, features of headache and other associated symptoms.