Migraine in Children

Migraine is a recurrent headache that occurs with or without aura and lasts in children from 30 minutes to 48 hours. It is the most common cause of primary headache in children. It differs from migraine in adults and is likely to be under diagnosed. It is an important cause of disability and a significant cause of school absence in children.¹

Although there are many common features with adult migraine (see Migraine and Migraine management) this article highlights aspects important in childhood migraine.

Childhood migraine may present in a similar way to migraine in adults but non headache and neurological symptoms (aura) may be more prominent than the headache.
No formal classification of headaches specific to children exists. The International Classification of Headache Disorders (ICHD) from the International Headache Society (IHS) defines migraine and recognises the childhood variants in its classification:²

There are few studies using IHS criteria to give reliable data, but studies show:

• Migraine is common in children affecting between 5-10% of school aged children¹
• Average age of onset is 6³
• It is rare under age 2 years
• Migraine usually starts under age 20 with 20% having a first attack under age 5 years
• Childhood migraine often stops for a few years after puberty with 62% migraine free for at least 2 years³
• Prevalence of migraine rises during childhood, reaching a peak at age 44 years and tailing off in both sexes after age 50 years³
• Migraine begins earlier in boys and is more common in boys until age 12 years¹
• After the menarche migraine is more common in girls
• In 23% of people migraine had ceased by age 25 years.³

The diagnosis in children is more difficult because:

• The condition is defined by subjective symptoms
• The prominence of non headache symptoms
• The increased likelihood that it is a new diagnosis.

Any difficulty with diagnosis can exacerbate parental anxiety. Modifications to IHS criteria have been suggested and are incorporated below.⁴

Modified IHS criteria (note shortened duration from adult 4-72 hours)

• Preschool children with migraine may look ill with abdominal pain and vomiting relieved by sleep.
• Preschool children may exhibit pain with changes in behaviour (irritability, crying, seeking out a darkened room).
• 5-10 year olds often have bilateral pain with abdominal cramps and vomiting. They usually sleep within an hour of onset.
• Location and intensity of headache may alter within and between attacks.
• Intensity and duration of headache increase with age and become more usually unilateral.
• A family history is common in migraine patients.

Migraine without aura

Most migraine (about 80%) is of this type. It is worth reviewing the typical phases of an attack with parents so that changes in behaviour and mood can be put in context:

• Premonitory symptoms (changes in mood, appetite, thirst, arousal etc)
• Headache lasting 30 minutes-48 hrs in children. This may be the only phase the patient is aware of. In children the pain may be bilateral and is not always throbbing or pulsating in nature.
• Accompanying symptoms occur and are prominent in children- such as sensitivity to light (photophobia), sounds (phonophobia) and smells, gastrointestinal disturbance, tiredness etc.
• Postdromes (fatigue, depression).

Migraine with aura

14-30% of migraine in children is of this variety. The aura may follow premonitory symptoms and may or may not be followed by headache.

• The aura may suggest cortical dysfunction (visual, sensory, motor, speech or language disturbance, cognitive impairment including confusion), or brainstem dysfunction (loss of consciousness, vertigo, ophthalmoparesis).
• Children may find it difficult to describe the aura.
• The aura are often more distressing than the headache in children.
• Visual aura are the most common (blurred vision, fortification spectra, scotomata, micropsia, macropsia, dysmorphopsia etc).
• Children who eventually develop migraine with aura usually present earlier than children experiencing migraine without aura.

Some of the less common migraine variants are listed to illustrate diagnostic difficulty and invariably require specialist referral:

Aura without headache

• Visual aura are the most frequent.
• Consider other diagnoses especially if never followed by headache.

Hemiplegic migraine

• A dramatic presentation
• Hemiplegia or hemiparesis may precede or accompany the less dramatic headache
• There is usually a family history.

Basilar migraine

• Aura followed by dizziness, syncope and minimal headache
• Most often seen in adolescent girls.

Ophthalmoplegic migraine

• Disorders of eye movement or pupillary response precede the headache.

Acute confusional migraine

• Migraine before or following transient episodes of amnesia, confusion and expressive aphasia or dysphasia following minor head trauma.

Childhood periodic syndromes

Childhood periodic syndromes are often a precursor to migraine but can present a diagnostic challenge and need specialist referral. These include:

• Cyclical vomiting with migraine (periodic syndrome). This is characterised by recurrent episodes of intense vomiting occurring often at night and with complete recovery in between attacks. Girls are more affected. Stress and dietary triggers may be identified. It typically begins in toddlers and resolves by adolescence.
• Abdominal migraine. This presents typically as recurrent bouts of generalised abdominal pain associated with nausea and vomiting but no headache, followed by sleep and recovery. Typical migraines may occur separately.
• Benign paroxysmal vertigo is seen usually age 2 to 6 years and is characterised by brief episodes of vertigo and nausea with no hearing loss or loss of consciousness. More common migraine eventually ensues but referral to exclude posterior fossa tumours is required.

As can be appreciated from the wide variation in presentation of migraine and migraine variants there is in theory a long and varied list. However other possible diagnoses can be grouped under the following:

• Headache-other primary and secondary headache
• Aura- other causes of the neurological disturbance
• Non headache symptoms- other causes of for example nausea and vomiting.

These may follow history and examination, including fundoscopy and head circumference.⁵ Further investigation is not usually required but is indicated for example if:

• Neurological examination is abnormal (persistent focal signs or papilloedema)
• There is a history of seizures
• A history of head trauma
• Significant unexplained change in the pattern of headaches.

Asthma, allergies, motion sickness and seizure disorders are all more common in migraine patients.

The principles are similar to those in adult migraine management. Important differences can be highlighted:⁵

• Conservative management alone is more often effective
• Reassurance of parents is an important part of management
• Drug dosages and contraindications are different
• Children with migraine not responding to trigger avoidance and simple analgesics with or without antiemetics should be referred to a paediatrician with an interest in headache
• Management in children involves the whole family.

Non drug management

• Explanation and reassurance. This should emphasise what migraine is and how realistically attacks can be reduced. Fears about brain tumours and more serious conditions should be discussed and fears allayed.
• Identification of triggers and predisposing factors, often with a trigger/headache diary. This may be important in development of a behavioural strategy.⁶ Dietary sensitivities affect only about 20% of migraine sufferers⁷ and in children it is particularly important to identify the range of possible factors (sleep, stress, exercise, menstruation etc). Stress management has been shown to improve severity and frequency of headache.⁸
• Behavioural management strategy. This should emphasise routine around sleeping, eating and avoiding an overloaded routine to help prevent migraine as well as strategies for dealing with an attack (Lie in a cool, dark, quiet room and encourage sleep with pharmacological or non pharmacological support).

Drug intervention for acute attacks

• This should be according to the success of previous treatments and severity of attack
• Simple analgesics such as paracetamol and ibuprofen should be tried first early in the attack.⁵ Ibuprofen is likely to be more effective.^5,9 Aspirin should be avoided under age 16.
• Anti emetics may be required but are not recommended in children because of extrapyramidal side effects. These are more common in girls and when weight is less than 10kg. Combined formulations such as paramax can be used over age 12 years.
• If simple analgesics are ineffective some 5 HT 1 agonists can be used but are usually initiated by the specialist.⁷ For adolescents age 12-17 years sumatriptan nasal spray can be used.^10,11 Orally it may be less effective than in adults.¹²
• Although there is clinical consensus in treatment guidelines there is, in fact, little evidence for efficacy of simple analgesics for migraine in children.⁷

Drug intervention for prophylaxis

• This should be considered when the frequency and severity of attacks causes interference with school attendance or social life.⁵
• It should be used with acute therapy not instead of it.
• There is little evidence for efficacy of the available drugs in children. Beta- blockers^13,14,15 or pizotifen¹⁶ are used and occasionally paediatricians use sodium valproate or amitriptyline.

In one study which followed children with migraine for 40 years, 50% still had migraine at age 50 years.³ Generally migraine improves with age and often abates temporarily around adolescence.^3,17