Diagnosing Migraine (I.H.S Criteria)
The International Headache Society (I.H.S) criteria for diagnosing Migraine are both inclusive (certain features must be present) and exclusive (secondary headaches must first be ruled out). The criteria are outlined below. Please note that none of the features, even headache,are compulsory in order to make a diagnosis so the criteria should be used with a certain flexibility in practice.
Criteria for Diagnosing Migraine Without Aura
A. At least five attacks fulfilling B-D
B. Attacks lasting 4-72 hours if untreated or unsuccessfully treated
C. Headache has at least two of the following characteristics
- Unilateral location
- Pulsating quality
- Moderate or severe pain intensity
- Aggravation by or causing avoidance of routine physical activity
D. During headache, at least one of the following
- Nausea and / or vomiting
- Photophobia / Phonophobia
E. Headache not attributable to any other disorder
Criteria for Diagnosing Migraine With Aura
A. At least two attacks fulfilling criteria B-D
B. Aura consisting of at least one of the following, but no motor weakness:
- Fully reversible visual symptoms including positive features (e.g. flickering lights, spots or lines) and /or negative features (i.e. loss of vision)
- Fully reversible sensory symptoms including positive features (i.e. pins and needles) and / or negative features (i.e. numbness)
- Fully reversible dysphasic speech disturbance
C. At least two of the following:
- Homonymous visual symptoms and / or unilateral sensory symptoms
- At least one aura symptom develops gradually over ≥5 minutes and / or different aura symptoms occur in succession over ≥5 minutes.
- Each symptom lasts ≥5 and ≤60 minutes
D. Headache fulfilling criteria B-D for Migraine without Aura begins during the aura or follows aura within 60 minutes
E. Headache not attributed to another disorder
Rare forms of Migraine
1-3% of all migraine does not fit the standard diagnostic criteria for ‘Migraine with Aura’ or ‘Migraine without Aura’.
Basilar artery migraine is a rare form of Migraine with Aura seen most commonly in young women and has an aura that is believed to be due to vertebro-basilar ischaemia.
Features of the aura may include:
- bilateral visual impairment or sensory symptoms
The headache associated with Basilar migraine is usually occipital.
Hemiplegic Migraine is a rare form of Migraine and has two separate variations:
Familial Hemiplegic Migraine (FHM) – which is a genetic condition linked to mutations of specific genes on chromosomes 1 and 19
Sporadic Hemiplegic Migraine (SHM) – has no genetic link
Both FHM and SHM usually begin in childhood and cease during adult years. They also share the same symptoms. Because the symptoms are also indicative of vascular disease, a full neurological examination is necessary to rule out other causes and confirm the diagnosis
In addition to the symptoms of typical migraine, the following symptoms may present:
- Episodes of prolonged aura (up to several days or weeks)
- Impaired consciousness ranging from confusion to profound coma
- Headache, which may begin before the hemiplegia or be absent
In this condition a patient, often with a previous history of migraine, suffers an unrelenting migraine (>72 hours) which is refractory to conventional therapy. The pain is severe, unilateral and throbbing.
Retinal Migraine is a rare form of migraine in which the patient experiences vascular spasm affects the vessels supplying blood to the eye, resulting in a fully reversible visual loss. Retinal migraine is a diagnosis of exclusion and embolic and other vascular diseases need to be ruled out.