Chapter 136: Headache in Children

Headache is pain in the scalp and cranium. Headaches in children can be mild, refractory, or life threatening, and can represent an acute, subacute, or chronic process. Sustained or recurrent headaches can greatly impact school performance and may even induce behavioral disturbances.¹ Headache accounts for approximately 1% of all pediatric ED visits.^2,3 Headaches increase in prevalence as a child ages; 30% to 60% of children through adolescence experience headaches.^4,5 The most common causes of headache are viral and respiratory illnesses (28.5%),^2,6 posttraumatic headache (20%), possible ventriculoperitoneal shunt malfunction (11.5%), and migraine (8.5%).³ Serious causes of headache are reported in 4% to 6.9% of children and include subdural hematoma, epidural hematoma, proven ventriculoperitoneal shunt malfunction, brain abscess, pseudotumor cerebri, and aseptic meningitis.^2,3 Factors correlated with dangerous conditions include preschool age, recent onset of pain, occipital location, and the child's inability to describe the quality of the headache. Emergent neurosurgical conditions in children with headache are generally predicted by the presence of focal neurologic signs.⁷

The pathophysiology of headaches is complex and varies according to cause. The cranium, most of the overlying meninges, brain, ependymal lining, and choroid plexus do not possess pain receptors.^6,8,9 Extracranial pain may arise from cervical nerve roots, cranial nerves, or extracranial arteries, and intracranial pain may arise from intracranial venous, arterial, or dural structures. Cranial nerve or root pain can radiate to the occiput, ear, retroauricular areas, or throat.^9,10

HEADACHE CLASSIFICATION

Headaches are classified as primary or secondary based on the underlying cause. Primary headaches are physiologic or functional and are typically self-limited. They are often recurrent and are usually associated with normal findings on physical examination. Their diagnosis is typically based on recurrent symptoms, and they include migraine, tension, cluster, and chronic daily headaches. Migraine headaches are common and account for about 75% of primary pediatric headache disorders seen in the ED.⁷

Specific underlying causes are identifiable for secondary headaches (Table 136-1), which are usually, but not always, anatomic in nature. Causes include brain tumors, vascular malformations, and intracranial abscesses; craniofacial problems, such as sinusitis, dental abscesses, or otitis; systemic disorders, such as lupus cerebritis; and exposure to toxic substances, such as carbon monoxide, lead, or cocaine. Although primary headaches can be disabling, secondary headaches result in morbidity and mortality if not treated.

The International Headache Society provides one method for headache classification (http://ihs-classification.org/en/). Table 136-2 associates temporal patterns of headache with possible diagnoses.

Obtain a thorough history from all possible sources (child, parents, and other caretakers available) in order to help identify or exclude more worrisome secondary causes of headache (Table 136-1). Enquire about the child's personal and family medical histories. Elicit characteristic features of the headache. Obtain details as to whether the child or family has a history of headaches and whether the current headache is similar to past attacks.

AGE OF FIRST OCCURRENCE OR PATTERN OF PREVIOUS OCCURRENCES

The prevalence of migraine headaches increases with the child's age, and a pattern of prior occurrences suggests primary headache.^3,4,11 Although migraine headaches are unusual in preschool-age or younger children (<5 years old), they are becoming increasingly recognized in this young age group.¹² Complex migraines (hemiplegic, confusional, or basilar type) may have their onset at a young age as well; however, incapacitating headache in a young child, especially when associated with vomiting or gait changes, suggests an intracranial mass with an infratentorial location being the most common location.¹³ Predictors of a surgical space-occupying lesion include headache of <6 months' duration, sleep-related headache, vomiting, confusion, absence of visual symptoms, absence of family history of migraine, and abnormal findings on neurologic examination.¹⁴

HEADACHE PRECIPITANTS

Viral illnesses and fever are among the most common causes of headache in children, and the associated headaches are most frequently frontal or temporal.^2,6,8 A history of trauma may suggest posttraumatic headache or traumatic brain injury. Posttraumatic headaches may be chronic as well.¹⁵ Migraines, more common and better studied in adults and adolescents, may be accompanied by premonitory symptoms (prodromes such as fatigue, mood changes, or GI symptoms) and have identifiable triggers.¹⁶ Children with prodromes tend to have more characteristic triggers as a whole, which may include specific foods (e.g., chocolate or monosodium glutamate), stress, light, specific odors, and weather changes.^8,12 Headaches are among the most commonly reported symptoms in toxic exposures such as carbon monoxide poisoning.¹⁷ Additional precipitants include medications (e.g., methylphenidate, steroids, oral contraceptives, and anticonvulsants), infection (e.g., sinusitis, pharyngitis, or meningitis), hypertension, anemia, and substance abuse (e.g., cocaine).¹⁸

TIME AND MODE OF ONSET

Headache coinciding with the onset of fever suggests inflammation of some sort, typically infectious (e.g., sinusitis, pharyngitis, otitis, or meningitis), or may be associated with a more general viral syndrome. Abrupt occurrence of severe headache due to a serious underlying condition, such as a brain tumor or intracranial hemorrhage, is typically associated with one or more objective findings on neurologic examination (e.g., altered mental status, ataxia, nuchal rigidity, papilledema, or hemiparesis).^7,8 Cluster headaches also tend to develop acutely, whereas tension headaches have a more subacute onset. Hormonal cycles can trigger migraine headaches in adolescent females. Migraine headaches in children typically start relatively abruptly, intensify over several minutes, and then reach full intensity in about an hour.¹⁹ Young children often have headaches that begin in the late afternoon.

LOCATION OF HEADACHE

In a cohort of children with headaches presenting to a pediatric ED, only 27.5% of patients could identify a precise location of the pain. Among children with intracranial diseases, most either were unable to indicate the location of the pain or had an occipital headache.^7,20 Medications, hypertension, and basilar-type migraines can also cause headaches in the occipital region. Pain at the vertex can be seen with sphenoid sinusitis. Ethmoid, maxillary, and frontal sinus infections tend to cause retro-orbital pain, as does meningitis (along with fever and neck stiffness) and dural sinus thrombosis. Pain seemingly in, around, or in front of the ear (or entire temporal region) is often seen with temporomandibular joint dysfunction and can be reproducible on exam. Migraine headaches are usually unilateral and involve the frontal or temporal region in adolescents. However, in younger children, they are usually bifrontal or generalized. Only about a third of children have unilateral migraines.¹⁹ Tension headaches tend to have the greatest variability in location. They may be generalized, frontal, or even occipital/posterior cervical. Occipital location in children is a red flag that should be investigated further before attributing to a primary headache disorder.

QUALITY OF HEADACHE

Younger children and many developmentally normal, otherwise healthy children may have a difficult time describing the quality of their headaches. An ability to describe pain quality or a description of the headache as having a pulsating quality is more frequently associated with benign headaches. An inability to describe the pain or a description of the headache as constrictive indicates a greater likelihood of a more serious cause.^7,8,20 Many different qualities of pain can be identified: stabbing or hyperesthetic pain has been associated with herpes zoster; aching pain with tension headaches, meningitis, or encephalitis; and constant pain with sinusitis in all locations. A pulsating quality is one of the diagnostic criteria for migraine headache set forth by the International Headache Society but can also be seen with headaches caused by hypertension or intracerebral hemorrhage.²¹ The International Headache Society criteria for migraine were developed for the adult population, but children present differently. In particular children, may have shorter headaches and in different locations. Diagnostic criteria for pediatric migraine are presented in Tables 136-3 and 136-4.²² Although these diagnostic criteria rely on recurrent attacks, in an ED, a child may present with a first migraine headache due to intractable pain. One study investigated the utility of applying the International Headache Society criteria in the ED without the "recurrent" requirement ("Irma Criteria") and found the criteria to be quite sensitive in diagnosing first-time migraines when followed long term using the original International Headache Society criteria as the gold standard.²³

SEVERITY OF HEADACHE

The severity of a headache is neither a sensitive nor a specific characteristic in determining cause. Patients with tension headaches can complain of terrible pain, whereas a child with a brain tumor may complain of mild to moderate pain. Nonetheless, complaints of very intense pain should be taken seriously and assessed in context with other historical elements.⁷ Ask about and document presenting pain assessments in children with primary headache disorders because treatment end points will be dictated by improved pain scores in the ED.

DURATION OF HEADACHE

Although the duration of a headache is not particularly useful in assessing the majority of headaches, the International Headache Society definition of migraines requires a duration of symptoms of 4 to 72 hours²¹ in adults, but the duration may be less (1 to 48 hours)²² in children (Tables 136-3 and 136-4). A migraine that lasts >72 hours is known as status migrainosus. Children can sometimes come to the ED with this condition and should be treated appropriately.

ALLEVIATING AND EXACERBATING FACTORS

Patients with a sense of restlessness or agitation are more likely to have cluster headaches (more rare in children; Table 136-5).²¹ They may pace about the room or rock back and forth in a chair. In contrast, patients with migraines typically prefer silence and darkness because the lack of stimulation provides some relief, and photophobia/phonophobia are part of the diagnostic criteria for migraine headache (Table 136-3).^21,22 Tension headaches can be frequent and frustrating but tend not to be aggravated by routine physical activity (Table 136-6).²¹ Positional preferences (such as a head tilt) may be noted in children with space-occupying lesions, in order to avoid positions that increase intracranial pressure or exacerbate diplopia caused by cranial nerve dysfunction. In addition, children with increased intracranial pressure may be unable to look up or may avoid the Valsalva maneuver (e.g., defecation or coughing). Analgesic rebound headaches worsen when the patient goes a certain period of time without taking long-term pain medication or overuses analgesics.

ASSOCIATED SYMPTOMS

Eliciting associated symptoms can help narrow the differential diagnosis. Migraine headache with aura, by definition, is associated with visual, sensory, or speech disturbances (all fully reversible; Table 136-4).²² Specific symptomatology may distinguish between types of migraines such as confusional (e.g., distortions of visual size, space, or time) and hemiplegic (e.g., transient hemiparesis or aphasia). Hemiplegic migraines are uncommon, so think carefully about other causes of neurologic deficits when contemplating the differential diagnosis. Abdominal pain, nausea, or vomiting may occur along with migraine headache.¹⁰ Cluster headaches can be associated with multiple ipsilateral symptoms (Table 136-5).²¹ Headache with effortless vomiting but no GI complaints is characteristic of elevated intracranial pressure.⁷ Irreversible and progressive defects in visual acuity and diplopia are more suggestive of pseudotumor cerebri. Seizures and headache may indicate traumatic brain injury, concussion, arteriovenous malformation, subarachnoid hemorrhage, or tumor. A headache with fever and focal neurologic signs (with or without seizure) may suggest an intracranial abscess, encephalitis, or meningitis (especially with neck stiffness). Children who present with headache, altered mental status, and seizures must be evaluated for meningoencephalitis from herpes simplex virus.²⁵

MEDICAL HISTORY

Headaches should be considered both independently and within the context of the child's medical history because secondary headaches can occur even when there is a history of primary headaches. It is helpful if a child has a history of similar headaches, but a first-time headache does not preclude a primary headache disorder as described previously.²³ Concurrent chronic illness may predispose the patient to unique headaches (e.g., those associated with ventriculoperitoneal shunt malfunction or infection), headaches from infection (e.g., related to anatomic defects predisposing to meningitis or acute illness with sinusitis leading to brain abscess), or headaches caused by intracranial hemorrhage (e.g., due to hemophilia or anatomic arteriovenous anomalies). Although the ED is a location for acute care, taking a history regarding psychological factors can be important, because children have been shown to have psychosomatic headaches as well.²⁶

FAMILY HISTORY

Headaches occur more often in children who have a family history of headaches in either first- or second-degree relatives.²⁷ This association is particularly true for children with migraines (family history of migraines in up to 90% of cases). Children with cluster headaches rarely have a family history of similar headaches (about 7%). Children with a parent who experienced a subarachnoid hemorrhage are at a four times greater risk of this type of intracranial bleed than the general population. Predisposing genetic disorders may provide some clue to a familial link in headaches (e.g., bleeding diathesis, familial dyslipidemias, or atherosclerotic events).

The physical examination and history will help to distinguish benign from life-threatening headaches (Table 136-7). However, examination findings may be normal even if the history suggests a secondary headache. A careful neurologic examination with attention to cranial nerves, gait, strength, and mental status is essential to exclude secondary headache (Table 136-8). Focal neurologic findings or gait instability are associated with secondary causes of headache. Additional examination clues to secondary headache are listed in Table 136-8.

No specific laboratory testing or radiologic imaging is needed for primary headache because the diagnosis is clinical and made by history. Imaging studies are not needed for primary headache when the findings of the neurologic examination are normal. Despite the importance of history and examination, one study reported that almost 40% of all children with headache who were evaluated in the ED underwent head imaging with radiation.²⁸

If secondary headache is a consideration, obtain laboratory evaluation and imaging dictated by results of the history and physical examination. Blood tests that may be useful in specific clinical situations include CBC, serum glucose level, electrolyte levels, renal function tests, liver function tests, blood culture, and drug screen. Perform a lumbar puncture if meningitis or encephalitis is suspected, and send cerebrospinal fluid for Gram stain, culture, appropriate viral studies, glucose, protein, and cell count. If pseudotumor cerebri is suspected, perform a lumbar puncture with the patient in the lateral decubitus position and measure the opening pressure. A lumbar puncture may also be needed to rule out a subarachnoid hemorrhage if there is a high level of suspicion but the findings of a CT scan of the brain are normal.^29,30 Focal neurologic deficits or signs of increased intracranial pressure warrant a CT scan prior to lumbar puncture; however, clinical signs of probable impending herniation are the best indicators of when to delay a lumbar puncture, even in the setting of normal CT scan results.³¹

IMAGING

Consider imaging in children with abnormal findings on neurologic examination, altered mental status, or concurrent seizures, or if medical history indicates the recent onset of severe (worst) headache, a change in the type of headache, or associated features that suggest neurologic dysfunction.^10,32,33,34 There is a very low incidence of positive findings on neuroimaging studies in children with headache who have normal findings on physical examination.^{35,36,37,38,39} Imaging is not indicated in children with recurrent headaches and normal findings on neurologic examination.

CT Scan

Reserve CT scans for instances in which there is a highly suspicious history, neurologic findings on examination are abnormal, or an intracranial hemorrhage or a space-occupying lesion is suspected. Noncontrast head CT is sensitive for detecting skull fracture and brain injury from trauma and may identify supratentorial tumors and stroke; give IV contrast if considering intracranial abscess.

MRI

A normal head CT does not exclude an intracranial mass because the posterior fossa is not well visualized. The posterior fossa is the most common location of brain tumors in children, and MRI of the brain provides better visualization of the posterior fossa. Magnetic resonance angiography and venography are useful when vascular malformations or dural sinus thrombosis is suspected. MRI may require sedation based on the patient's age. The decision to admit a child for MRI or to obtain outpatient imaging depends on the practice location and deserves a discussion with an inpatient team as well as primary care provider.

Treatment recommendations vary greatly because few evidence-based data on treatment efficacy are available.^40,41 Treat the underlying cause of secondary headache and provide analgesia for pain. Almost 30% of children presenting with headache to the ED receive opioid medications in the United States.²⁸ Do not use narcotics for primary headaches. Long-term use of narcotics can change the pain-modulatory system in the brainstem and can lead to more intense pain.

PHARMACOLOGIC TREATMENT OF PRIMARY HEADACHES

Table 136-9 lists treatment options for migraine and cluster headache treatment in the ED. Both are initially treated in the same fashion. A recent review of the available evidence in pediatric migraine suggests a treatment algorithm with dopamine antagonists and nonsteroidal anti-inflammatory agents (Table 136-10).⁴¹

The most widely studied abortive medications are the dopamine antagonists, prochlorperazine and metoclopramide. These drugs can cause dystonic or extrapyramidal reactions, which are relieved by diphenhydramine.^42,43 A second class of medications that are well studied are nonsteroidal anti-inflammatory agents, including ketorolac. Ketorolac may not be used if the patient has acutely taken a nonsteroidal anti-inflammatory agent within 6 hours. When compared to dopamine antagonists, ketorolac appears to be less effective than prochlorperazine.⁴⁴

Other options for abortive migraine therapy include the triptans, which may be given orally, intranasally, and subcutaneously. As with most pediatric migraine medications, treatment is "off-label," but a limited number of triptan agents have received Food and Drug Administration approval in adolescents. Dihydroergotamine is effective in the inpatient setting, but no studies exist on ED treatment.⁴⁵ Data are lacking in children on dexamethasone for prevention of headache recurrence.^46,47 Many emergency medicine providers use a "cocktail" of medications for migraine treatment that includes ketorolac, prochlorperazine or metoclopramide, and diphenhydramine. This combination is effective and safe.⁴⁸ In addition to administering abortive medications in the emergency department, counsel patients to identify and eliminate potential precipitating factors.

Table 136-11 lists additional treatment for cluster headaches, which includes triptans and high-flow oxygen. Consider pediatric neurology consultation to help guide the management of recalcitrant headaches.

PROPHYLACTIC TREATMENT

Children with chronic headaches that disrupt activities of daily living or school performance may benefit from prophylactic treatment. Medications for the prevention of migraines are summarized in Table 136-12. The decision to start prophylaxis should be made by the primary care physician or pediatric neurologist, in consultation with the child and the family, and should include a careful weighing of the risks and benefits of daily medication.

NONPHARMACOLOGIC TREATMENT

For tension-type headaches, biofeedback and relaxation techniques can be effective.⁴⁹ In general, 8 to 10 sessions are necessary to teach these techniques in the outpatient setting. Although acupuncture has been used to treat chronic migraine headaches in both children and adults, several randomized controlled studies failed to show benefit over placebo.

Admit children with emergent, life-threatening causes of headache to the hospital for definitive treatment and pain control. Consider admission for intractable pain. Arrange close follow-up for any child with headache discharged from the ED. Thoroughly discuss reasons for immediate return to the ED.