1. What is the impact of the headache on the sufferer's daily life? (high impact = migraine or chronic daily headache; low impact = acute tension-type headache)

2. How many days of headache does the patient have every month? (> 15 days = chronic headache; </= 15 days = intermittent migraine)

3. For patients with chronic daily headache, on how may days per week does the patient take analgesic medications? (> 2 = analgesic-dependent headache; </= 2 = non-analgesic-dependent headache)

4. For patients with migraine, does the patient experience reversible sensory symptoms associated with their attacks? (yes = migraine with aura; no = migraine without aura. N.B. Aura occurs in only about 10% of migraine attacks, and most sufferers also experience attacks of migraine without aura.)

In addition, sinister headache should be excluded before asking the questions. Points indicating sinister headaches requiring referral include new-onset, acute headaches associated with a range of other symptoms (e.g. rash, neurological deficit, vomiting and pain or tenderness, accident or head injury, infection or hypertension) and neurological change/deficit does not disappear when the patient is pain-free between headache attacks. Also, once a pattern of chronic headaches is established (Question 2), the physician should investigate whether short-lasting headaches (e.g. cluster headache or short, sharp headaches) are the cause (Table 2).^[21]

Formal Differential Diagnosis

The key question to ask is Question 1, the impact of the headache to the patient's daily life. Any high impact, intermittent headache can be given a default diagnosis of migraine. Further questioning can then be used, if necessary, to confirm the diagnosis:

• The full IHS diagnostic criteria can be used if desired.^[26]

• As an alternative, the physician can elicit the following information, which incorporates key features of the IHS criteria:

Headache Characteristics

• Does the headache last between 4 hours and 3 days?

• Does the patient feel well between attacks?

• Is the headache a throbbing, pulsating pain?

• Is the headache located on one side of the head at any stage?

Non-headache Associated Symptoms

• Does the patient suffer from wavy lines, flashing lights or blind spots affecting their vision before or during the headache?

• Does the patient feel sick or vomit during their headaches?

• Does the patient feel that they want to avoid light and/or noise during their headaches?

Headache Impact

• Does the patient usually sit or lie quietly when they have a headache?

• Is the patient prevented from, or have difficulties in, conducting their normal daily activities (employment, unpaid work and leisure activities) when they have a headache?^[22]

(A 'yes' answer to most, or all, of these queries is indicative of a migraine diagnosis.)

http://www.medscape.com/viewarticle/446557_8