Migraine is a form of primary headache disorder.
Migraine describes a recurrent moderate to severe headache commonly associated with nausea, vomiting, photophobia and phonophobia. The headache is typically unilateral and pulsating in nature lasting 4-72 hours.
There are two major types of migraine:
Migraines are one of the most common disabling conditions in the world. In the 2019 Global Burden of Disease study, headaches (primarily migraine and tension-type headache) were ranked the 14th most common cause of disability-adjusted life years.
Management involves avoidance of potential triggers and preventative medications to reduce the frequency of attacks. The migraines themselves may be treated with anti-emetics, simple analgesia and triptans. This note focuses on the diagnosis and management of migraines in adult patients.
Migraine is estimated to have a global prevalence of 1 in 7 people.
Migraines most commonly occur between the ages of 25 - 55. Females (lifetime prevalence approximately 33%) are affected more than men (lifetime prevalence approximately 13%) though frequency is equal before puberty.
The definition and classification of migraines can be taken from the International Classification of Headache Disorders 3rd edition (ICHD-3).
Migraine is typically a unilateral, pulsating headache that is accompanied by symptoms such as nausea and vomiting, photophobia and phonophobia. Attacks typically last 4-72 hours. In children and adolescents the headache is more likely to be bilateral and attacks may be shorter. Patients struggle to get comfort and will often prefer to rest or sleep in a darkened room. Migraines may be episodic or chronic:
Migraines may be associated with a preceding aura - neurological changes that precede and at times accompany the headache. Auras are highly variable, atypical auras are discussed in the red flags chapter below.
The below definitions rely on secondary causes of both aura symptoms and headache being excluded either clinically or with further investigations.
The ICHD-3 describes migraine without aura as:
Recurrent headache disorder manifesting in attacks lasting 4-72 hours. Typical characteristics of the headache are unilateral location, pulsating quality, moderate or severe intensity, aggravation by routine physical activity and association with nausea and/or photophobia and phonophobia.
A headache meets the diagnostic criteria if:
Migraine without aura is often associated with female patients menstrual cycles, the headache occurring near the onset of menstruation. A headache diary can be useful to help characterise this association.
The ICHD-3 describes migraine with aura as:
Recurrent attacks, lasting minutes, of unilateral fully-reversible visual, sensory or other central nervous system symptoms that usually develop gradually and are usually followed by headache and associated migraine symptoms.
Around a third of patients with migraine have an aura. It refers to neurological symptoms that occur hours or sometimes days prior to the migraine itself. Auras are highly variable but visual disturbances (e.g. scintillating scotoma) are most common. Others experience sensory symptoms (e.g. numbness, tingling) or dysphasia.
Though listed in the diagnostic criteria motor, brainstem and retinal are less typical and should raise suspicion for an underlying cause. See the red flags section below for more on atypical auras.
A headache meets the diagnostic criteria if:
You must consider potentially serious secondary causes of headaches and/or auras.
The NICE CKS guide of headache assessment outlines a number of circumstances when you need to consider alternative causes of a headache.
The neurological symptoms brought on by migraine with aura can be challenging to distinguish from a TIA/Stroke. The NICE CKS on Migraine specifically highlights features that should raise suspicion of a secondary cause. Auras that feature motor, brainstem or retinal symptoms are not typical. In particular NICE highlight the following symptoms that warrant consideration of urgent neurological review:
At times a typical aura may occur without a following migraine. This can be extremely challenging to differentiate from an acute neurological event (TIA / stroke). Investigation depends in part on the ‘aura’ symptoms and patient age but in general cases should be discussed and referred urgently to neurology.
NOTE: If multiple close contacts present with headache consider carbon monoxide poisoning
Treatment options include simple analgesia, triptans and anti-emetics.
Treatment is determined by the individual patients presentation, preferences and co-morbidities. Those with relatively mild symptoms may be well managed with simple analgesia +/- an anti-emetic, though if ineffective triptans can be used.
In those with more severe headaches triptans may be introduced early and often offer patients significant symptomatic relief.
KEY POINT: Migraine with aura is a contra-indication to the combined oral contraceptive pill and should be used with caution in migraine without aura due to the risk of ischaemic stroke. Where necessary the combined pill should be stopped and alternative contraceptive methods discussed.
Prevention of migraines can involve avoidance of triggers and preventative therapies.
Some patients have identifiable triggers and where possible patients should avoid these. Lifestyle factors are commonly implicated and advise should be given to maintain adequate hydration, get sufficient sleep and to stay healthy and active.
Where possible sources of stress should be avoided as well as other triggers (e.g. certain foods, smells, lights). A headache diary (maintained for at least 8 weeks) can make identification of triggers far easier.
Prophylactic medications may be given to suitable patients. It should be considered where the symptoms significantly impact quality of life and daily function, acute treatments are inappropriate or ineffective or if the patient is at risk of medication overuse headache (see below).
There are a number of medications that can be used and prior to initiation a full discussion of the possible benefits and side effects should be had. The options include:
The efficacy should be reviewed regularly. If treatment fails consider referral to neurology. After 6-12 months of effective treatment consider gradual withdrawal of preventative treatments.
Galcenezumab is a novel therapy recently made available on the NHS (NICE TA 659) for patients who:
It should only be continued if after 12 weeks:
Non-medical therapies are also available. This includes behavioural interventions (e.g. mindfulness, relaxation techniques) and acupuncture.
Medication ‘overuse’ itself has been shown to result in chronic headaches. As the name suggests this occurs when regular analgesia taken for symptomatic relief of headache causes or perpetuates the condition.
The International Headache Society defines it as 'Headache occurring on 15 or more days/month in a patient with a pre-existing primary headache and developing as a consequence of regular overuse of acute or symptomatic headache medication (on 10 or more or 15 or more days/month, depending on the medication) for more than 3 months. It usually, but not invariably, resolves after the overuse is stopped'.
Patients with menstrual-related migraine may be commenced on specific therapies if standard measures fail.
Women who have pure menstrual or menstrual-related migraine can be initiated on the standard lifestyle and trigger avoidance advice as well as standard acute treatment.
If this is ineffective NICE CKS advise the consideration of the following medications (off-label) in the absence of contraindications:
These can be taken daily on days migraine is anticipated or from two days before until three days after bleeding starts. All patients should be followed up to review efficacy of treatment.
As discussed elsewhere migraine with aura is a contraindication to the use of the combined oral contraceptive pill due to the increased risk of ischaemic stroke. The combined pill should be used with caution in those with migraine without aura, particularly if there are additional risk factors present for vascular events.
There are a number of complications that may affect those with migraines.
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