Current Practice Headache in children

Occurrence Periodic Continuous Periodic or continuous Nocturnal/early morning Quality Throbbing Pressure, aching, tightness Pressure, throbbing, aching, tightness. Sometimes localized. Associated symptoms Gastrointestinal. –anorexia, nausea, vomiting, abdominal pain. Visual-photophobia, blurred vision, scotoma Others-vertigo, syncope Convulsions-rare Feverrare Anxiety Depression May include any symptoms listed under vascular or psychogenic headings. Evidence of infection as in sinusitis.


Introduction
Headache is a common childhood complaint.Population-based studies have shown that 66% of all children between 5 and 15 years of age had at least one episode of headache during a 1-year period and in 22% the headache was severe enough to interfere with daily activities 1 .

Categorization of headache
There are three main categories of headache in childhood viz.vascular, psychogenic and organic 2,,3 .By careful history taking and examination one could differentiate these categories to a certain extent (Table 1).Headaches can also be categorized as acute, recurrent or chronic in nature.In chronic headaches children present with at least 3 months' history of constant headache or a headache with a fluctuating intensity, but with no periods of complete recovery.These are rare in children but may be the presenting clinical manifestation of intracranial tumours 5 .
In recurrent headaches a history of at least 6 months of recurrent episodes is common.The attacks of headache are clearly separated by periods of complete normality.In a population-based study, migraine (with or without aura) was the most common cause of recurrent headache in school children accounting for 77.2% of cases 1 .Other causes were: tension headache in 11.7%, non-specific headache in 9.7% and headache associated with specific illnesses such as asthma, hay fever, allergy and constipation in 1.5% 1 .

Evaluation of headache
The following features in the history and examination may help the paediatrician to decide on further investigations 6 .

Investigations
Investigations are only required in the minority of children with chronic or recurrent headache.Lumbar puncture may be needed at times to rule out entities such as pseudotumor cerebri or if there is some concern about an infectious process 7 .Electroencephalography should be reserved for patients with alteration of mental status, loss of consciousness or entities suggestive of the epilepsy syndrome 7,8 .Computed tomography (CT) and magnetic resonance imaging (MRI) are safe, rapid and accurate methods for evaluating intracranial content if and when an intracranial disorder is suspected 7,9 .For acute evaluation of headaches, CT is performed easily and rules out most intracranial pathology.Abnormalities of the posterior fossa can however be missed on CT scan 7 .MRI is recommended for patients whose history is suggestive of a vascular event, a space-occupying lesion or posterior fossa abnormality 7,10 .

Migraine
Migraine is the commonest basis of recurring headache in childhood.It is a neuromuscular syndrome that leads to a generalized vasomotor instability and vulnerability to multiple extraneous factors 11 .It is estimated that around 1 in 10 school children suffer from migraine 1 .The aetiology of migraine is not known but it has a familial tendency.Both migraine without aura and migraine with aura are inherited disorders 12 .The International Headache Society (IHS) classified migraine into 2 major forms: migraine without aura and migraine with aura 2 .Less common forms such as abdominal migraine and cyclical vomiting syndrome were also recognized and defined 2 .Criteria have been established by the IHS for the diagnosis of the various forms of migraine 2 .75-85% of children suffer from migraine without aura 1 .Both major forms of migraine may be present in the same patient 1 .Boys and girls under the age of 12 years are almost equally affected with migraine but in children older than 12 years migraine is commoner in girls than in boys 1 .
Migraine headache is typically recurrent in nature with complete recovery between attacks.Stress and anxiety are the most commonly identified trigger factors 11 .Only 10-15% of patients can identify a certain type of food, such as cheese, chocolates and caffeine-containing drinks, as a trigger factor 11 .Aura symptoms, if present, precede the onset of headache and are commonly visual in nature (blurred vision, tunnel vision, blind spots (scotomata) or zigzag coloured lines in front of the eyes) 11 .Rarely, the aura symptoms are sensory (tingling or numbness), motor (hemiplegia or speech disturbances), autonomic or non-specific 11 .During the attack of migraine the child is pale, quiet and wants to be left alone.He refuses food and drink, feels nauseated and may vomit.Light, noise, smell and exercise may aggravate pain.Dizziness, abdominal pain, visual disturbances and sensory or motor deficits may be associated 11 .Some patients describe unusual visual hallucinations or distortion of images or both called the Alice in wonderland syndrome 13 .

Complicated migraine
• Basilar migraine -clinical features of migraine are dominated by transient symptoms of cerebellar and brainstem dysfunction such as vertigo, ataxia, visual field defects, motor deficits, dysphasia and confusion.These features are attributed to vascular constriction of the basilar artery 11 .
• Confusional migraine-attacks of migraine triggered by minor head injury.Clinical features include an aura, followed by headache, drowsiness, irritability, agitation, disturbed speech, aggressive behaviour and amnesia 11 .
• Ophthalmoplegic migraine-migraine attacks complicated by paralysis/paresis of the extraocular muscles, ptosis and pupillary dilatation but with no associated confusion or loss of consciousness 11 .
• Hemiplegic migraine -attacks of migraine complicated by unilateral weakness, impaired speech or unilateral sensory loss 11 .

Differentiation of epilepsy and migraine 8
This is shown in Table 2. Propanolol was shown to reduce the frequency of migraine attacks in a double-blind placebocontrolled trial 14 .However, propanolol should not be used in children with a history of wheezing.

Table 2
71racetamol and ibuprofen are the first line of treatment11.Domperidone, metoclopramide or prochloperazine may alleviate nausea and vomiting during migraine attacks.Concerns about possible dystonic reactions may preclude the use of metoclopramide & prochloperazine11.Ergotamine preparations could be used in children but can cause adverse effects such as prolonged vasoconstriction.Propranalol is not used for acute attacks in children.Sumatriptan, a selective 5 HT agonist, is effective in adults but its efficacy in children is not yet proven7.3.Interval treatment -is only indicated if acutetreatment is unsuccessful and migraine attacks are frequent (more than 2 attacks per month).