Pediatric Headache
segunda-feira, 12 de dezembro de 2011

Background

Headache is one of the most common patient complaints. Around 20% of outpatient visits to primary care physicians are due to headaches. In tertiary headache referral centers, more than 90% of patients are diagnosed with migraine.

In 1962, Bille investigated the incidence of headaches in 9000 school-aged children in Sweden.[1] Bille estimated that by age 6 years, 39% of children had suffered from headache. This figure dramatically increased to 70% by age 15 years. Other studies have reported similar trends with an incidence as high as 82%. More recently, a study performed in Taiwan showed that approximately 85% of children aged 13-15 have had headaches.[2] Other studies show that up to 51% of children aged 7 years and 57-82% of adolescents aged 15 years report recurrent headaches.[3, 4] Headaches have a significant impact on the lives of children and adolescents, resulting in school absence, decreased extracurricular activities, and poor academic achievement.

The prevalence of migraines in the adolescent population has been estimated worldwide to be around 4-10%[5, 6, 7] .

To properly manage childhood headache, physicians must understand the common headache patterns and the signs and symptoms that may indicate serious intracranial disease. Treatment of pediatric headaches is complicated by unanswered questions regarding the safety and efficacy of adapting adult pharmacologic therapy to the diverse pediatric population.

Classifying Pediatric Headaches

The International Headache Society published diagnostic criteria and a classification scheme for headaches in general.[8] Pediatric migraine is now distinctly recognized among the primary headache disorders. Grouping headaches into 2 general categories (primary and secondary) based on etiology is beneficial, as it facilitates proper evaluation and treatment.

Secondary headaches are associated with underlying CNS pathology. The most common primary headaches in pediatrics include migraine and tension-type headache, now felt to be the more severe and milder end of a spectrum of manifestations of similar pain mechanisms. These 2 types of headaches can be episodic or considered chronic daily headache (if present 15 or more days per month for 3 or more months).

Migraine headaches

These headaches constitute most of primary childhood headaches. More than 90% of patients who present to a neurologist complaining of headache are estimated to have a migraine (Rothrock, personal communication, 2006). Migraine can be divided into 2 groups: migraine with aura, and migraine without aura. Following are the diagnostic criteria as per the International Headache Society.[8]

Migraine without aura

At least 5 attacks fulfilling the following criteria:

Migraine with aura

In addition to above criteria, at least 2 attacks fulfilling at least 3 of the following criteria:

In practice, pediatric migraines are often bilateral, and clear localization of the pain can be difficult to obtain from children. Migraines in children are often of shorter duration than in adults. Migraine with aura is seen in 14-30% of children with migraine. Typical auras are spots, colors, image distortions, or visual scotoma. Migraine without aura comprises most of childhood migraine headaches. They are frequently preceded by a behavioral prodrome with mood changes or withdrawal from activity.

Migraine variants are headaches that are accompanied or manifested by transient neurologic symptoms. These symptoms may occur immediately before, during, or after the headache. In some situations, the headache may be mild or nonexistent.

Hemiplegic migraine and basilar artery migraine are typical examples of migraine with aura. Hemiplegic migraine, while unusual, is seen more commonly in children than in adults. These are characterized by abrupt onset of hemiparesis, which usually is followed by a headache. Hemianesthesia may also precede a headache. Basilar artery migraines are more common in girls. They are characterized by dizziness, weakness, ataxia, and severe occipital headache (with vomiting).

Ophthalmoplegic migraine may occur at any age and is usually associated with orbital or periorbital pain as well as third, fourth, or sixth cranial nerve involvement. The headache resolves in hours, but the ophthalmoplegia may last for days. The International Classification of Headache Disorders, 2nd Edition now classifies ophthalmoplegic migraine as a neuralgia.[8]

Less common presentations have also been described in which head pain is not a prominent feature. The "Alice in Wonderland" syndrome is characterized by distortions of vision, space, and/or time. Patients may note micropsia and/or metamorphopsia as well as other sensory hallucinations. Confusional migraine seen in juvenile patients is characterized by impairment of sensorium, agitation, and lethargy, which sometimes progress to stupor. Focal neurologic deficits, such as aphasia, anisocoria, and memory deficits, may also be seen.

In addition to these variants, several other syndromes have been recognized. Benign paroxysmal torticollis of infancy and benign paroxysmal vertigo of childhood are characterized by recurrent episodes of a head tilt, and vertigo and ataxia, respectively. The torticollis typically occurs during the first year while the vertigo occurs in young children (usually aged 2-3 y). Cyclic vomiting and recurrent abdominal pain frequently are considered migraine variants. Before diagnosing either of these entities, primary gastrointestinal diseases must be excluded.

Tension-type headaches

Tension-type headaches are benign, described as a bandlike sensation around the head, and may be associated with neck and/or shoulder pain. These headaches are often worse as the day progresses, but can last for days and may be associated with stressful events at home or school. Sleep may relieve the headache temporarily.

Approach to Headaches in Children

While the minority of headaches in children are due to serious underlying pathology, early recognition is paramount for appropriate diagnosis and management. Structural headaches frequently are caused by space-occupying lesions, inflammation, and/or an increase in intracranial pressure. Frequently, neurosurgical intervention is needed.

While no single sign or symptom indicates a structural etiology, several signs and symptoms warrant further investigation. Headaches due to increased intracranial pressure may be worse in the morning and improve as the day progresses or may be aggravated by sneezing, coughing, or straining. Headaches persistently localized to the occipital region warrant attention (as do any focal neurologic signs or symptoms with or without headache). Worsening of headache severity and/or frequency (especially with rapid progression) may also suggest an intracranial pathologic process, as may any significant change in a previously diagnosed headache syndrome. Failure of an adequate trial of headache therapy may imply an incorrect diagnosis.

Besides being classified on the basis of associated symptoms, headaches can also be classified by their temporal pattern: acute, acute recurrent (episodic), chronic nonprogressive, and chronic progressive.

Acute headache is defined as a recent onset of headache with no prior history of similar episodes. Establishing whether any neurologic symptoms accompany this headache is very important. The differential of acute headache includes systemic infection, trauma, CNS infection, or first episode of migraine. Similar headaches that recur as often as several times a month with intervening symptom-free intervals are classified as acute recurrent headaches (usually migraine).

Chronic nonprogressive headaches differ from acute recurrent headaches by their greater frequency and persistence for years with no associated neurologic symptoms or change in headache severity. Chronic nonprogressive headaches may have emotional or behavioral components. A common headache in this category is tension-type headache. An important newly recognized diagnostic entity that also occurs with this temporal pattern is chronic daily headache (CDH). CDH was first described in adults who reported daily or nearly daily headaches. It was soon recognized that, although patients were similar in the number of headaches experienced, the characteristics of their headaches fell on a continuum between migraine and tension-type headache. Recent work has demonstrated a similar spectrum in children. The most common CDH pattern is superimposition of migraines on a background pattern of frequent tension headaches.

Chronic progressive headaches also occur at least several times a week, but unlike the nonprogressive variety, these headaches increase in frequency and/or severity with time. As already discussed, the changing headache pattern should alert the care provider to the possibility that these headaches are secondary to a structural etiology.

Imaging

While imaging studies are not needed for every child who complains of headache, neuroimaging should be performed when the caregiver has any suspicion or concern that the headache may have a structural etiology. Given the broad differential of structural headaches and the imaging choices that are available, many practitioners are unsure which imaging modality will yield the most information in a cost-effective manner.

Magnetic resonance imaging (MRI) is generally more costly, takes longer, and may require sedation. Its superior imaging capabilities offer detailed structural definition overall. Visualization of the posterior fossa in particular is superior to that of CT. Gadolinium enhances MRI sensitivity to vascular lesions and those that disrupt the blood-brain barrier.

Computed tomography (CT) brain scan with contrast can define most structural lesions. A CT scan without contrast is somewhat more limited in its sensitivity, although it can define hydrocephalus and hemorrhage easily.

All patients who present with any features of a structural headache should undergo high-quality imaging, preferably an MRI with gadolinium enhancement. In less suggestive clinical situations or for parental or patient reassurance, routine MRI or high-quality CT with contrast is sufficient. Routine noncontrast CT should be reserved for more acute situations in which time is crucial and intracranial hemorrhage is suspected.

If the patient has had headaches for a long time (months to years) and the neurologic examination is normal, the likelihood of this patient of harboring any serious intracranial pathology is minimal and neuroimaging studies should not be performed routinely.

Treating Primary Headache

Much less data are available for the pediatric age group than for adults.[9] No drug has US Food and Drug Administration (FDA) approval in this population. The first step is to reassure that the headache is not due to a brain tumor or another CNS pathology. Reassure the parents and patient that the headache process is benign and not progressive. Review with them the headache pattern, associated symptoms such as nausea, dizziness, and photophobia, and the benign nature of the physical examination (including funduscopy). An imaging study also can be reassuring to the family. This simple but crucial review will help alleviate stress and worry, which may contribute to the patient's symptoms and parent's anxiety. Realizing that the pain, although unpleasant, is not life-threatening often allows the patient and parents to apply healthier coping strategies.

Sleep, darkness, and a quiet room are essential in managing acute migraine and tension-type headache. Stress, both as an etiology and as a consequence of headache, is a logical target for nonpharmacologic therapy. Encourage scheduled times for meals, bedtime, relaxation, and exercise. Relaxation techniques and biofeedback may prove beneficial. Individual treatment decisions should be based on the age of the child and receptiveness to behavioral techniques. Behavioral techniques can be highly effective for migraine and tension-type headaches. More focus is also being made toward the use of complementary/alternative therapies such as acupuncture.

Psychotherapy is indicated for any patient under significant stress. Consider family therapy in situations that involve divorce or illness of a sibling, or when the family unit is a contributing factor. Eliminate identified precipitants. Alcohol, drugs, or caffeine may trigger headaches. Encourage appropriate lifestyle changes. The role of diet in headaches remains controversial. However, if a given food or beverage is associated with headaches, its avoidance has an obvious and significantly positive impact.

A study by Milde-Busch et al linked obesity and physical inactivity to childhood and adolescent headache disorders.[10] A lifestyle that includes physical exercise improves the quality of life of these patients in more than one way.

Factors that precipitate migraine

  • Common factors

    • Stress/anxiety
    • Menstruation
    • Oral contraceptives
    • Physical exertion/fatigue
    • Lack of sleep (sleep apnea may also be a primary cause of headache)
    • Glare
    • Hunger
    • Foods/beverages with nitrates, glutamate, caffeine, tyramine, salt

  • Less common factors

    • Reading/refractive error
    • Cold foods
    • High altitude
    • Drugs - Nitroglycerin, indomethacin, hydralazine

     

    Pharmacologic Treatment of Migraine

    Abortive Therapy

    Abortive therapy uses medications to interrupt a headache after its onset. All abortive medications carry a risk of medication overuse headache (MOH) with excessive use in patients with frequent headaches.

    Sumatriptan (Imitrex)

    Sumatriptan (Imitrex), a 5-HT1 receptor agonist that causes vasoconstriction among other actions, is effective in aborting migraine (about 70% efficacy in adults).

    • It is available as an oral tablet, nasal inhalant, or subcutaneous patient autoinjection system (vials for injection).
    • The injected form of sumatriptan works faster than the nasal spray or the oral form.
    • Adverse effects of sumatriptan include tingling, dizziness, warm sensations, chest pain, and cardiac arrhythmias.
    • Sumatriptan is absolutely contraindicated for patients with cardiac disease, uncontrolled hypertension, hemiplegic and basilar migraines, or pregnancy.
    • Recommended adult doses are 25-100 mg orally or 6 mg subcutaneously. Both routes may be repeated after 2 hours. Maximum daily adult oral dose should not exceed 300 mg.
    • In children aged 12-17 years, controlled clinical trials with oral sumatriptan failed to show efficacy. This is probably due to high placebo effect observed in pediatric migraine trials. This means that children seem to respond well to placebo, therefore obscuring the response to active medication. Pediatric and adolescent studies indicate efficacy with the nasal spray form of this medication.[11]
    • Subcutaneous sumatriptan has been effective, although the manufacturer does not recommend use in patients who are younger than 18 years.
    • In children, the trial subcutaneous dose is 0.1 mg/kg/dose.
    • Current autoinjection sumatriptan is available in 6 mg and 4 mg unit doses.

    Several other members of the triptan family are approved by the FDA to be used as abortive therapy in the treatment of adult migraine. A study by Linder et al provided evidence that almotriptan (Axert) is effective and well tolerated in adolescents with migraines; the drug gained FDA approval for this indication shortly after the study.[12] Clinicians usually use almotriptan and other triptans in their daily clinical practice, even if they are not indicated by the FDA. These include, in no specific order, naratriptan (Amerge), eletriptan (Relpax), frovatriptan (Frova), rizatriptan (Maxalt), and zolmitriptan (Zomig).

    Clinical trials of some of these medications in children are currently under way.

    For years in the author's practice, if children and adolescents do not respond to NSAIDs or other OTC analgesics, he has treated them with triptans.

    Isometheptene (Midrin) and ergotamines

    Isometheptene (Midrin) and ergotamines are also available for abortive therapy for migraines. Nevertheless, the scientific evidence of their efficacy is lacking. Many clinicians have used these medications with success. Midrin was pulled out of the US market in 2011. They are most effective when administered at aura onset or at the start of the headache. Because aura is less common in pediatric migraine and children may be less able to communicate early symptoms of a headache, administering these abortive therapies at the appropriate time can be difficult.

    Ergotamines generally are not used for young children (aged 6 y or younger) and may cause gastrointestinal upset.

    Analgesics

    Analgesics such as acetaminophen and NSAIDs can be used as abortive therapy, and they seem to be particularly effective in the pediatric population. They can be obtained without prescription. Less risk of medication overuse headache (rebound or withdrawal headache) may be seen with long-acting NSAIDs such as naproxen sodium.

    Prophylactic Therapy

    Consider prophylactic therapy when headaches are frequent enough to interfere with the patient's lifestyle. In deciding to begin prophylactic therapy, consider the risks of long-term drug use against the benefit of potential headache relief. As with abortive therapy, several classes of pharmacologic agents are available. In general, the effect of prophylactic therapy is not immediate, often taking as long as 6-8 weeks before improvement. Providing this information to the patient and parents leads to improved compliance and more realistic goals. Giving an appropriate trial before attempting a new treatment is important.

    Migraines are known to remit spontaneously during childhood in some patients. Every 6-12 months, reassess the need for continued prophylaxis. This can be achieved by tapering the medication until either the headaches resume or the patient remains headache free off therapy.

    On the other hand, parents and patients need to be aware of the fact that migraine headaches may be a lifelong condition, and they should expect that the headaches will reappear at sometime during their lifetime, especially during situations of increased stress such as puberty, marriage, or change of job.

    Beta-blockers

    Beta-blockers are commonly used as prophylactic therapy for childhood migraine. Both propranolol and nadolol are effective. Nadolol has the advantage of being longer acting (given once daily). Beta-blockers are contraindicated in patients with asthma or diabetes. They may cause depression in adolescents.

    Tricyclic agents and cyproheptadine

    Tricyclic agents (amitriptyline, nortriptyline) are frequently used for prophylactic therapy, especially in older children and adolescents. Nortriptyline tends to be less sedating than amitriptyline. Scientific evidence favors the use of amitriptyline in adults, whereas no good evidence supports the use of nortriptyline.

    Cyproheptadine (Periactin), an antihistamine/antiserotonin drug, is also used, especially in younger children. Side effects include sedation, appetite stimulation, and weight gain.

    No good scientific evidence supports the use of tricyclic agents or cyproheptadine in the pediatric population, but many clinicians have used these medications with success over decades.

    Anticonvulsants

    Anticonvulsants such as valproic acid, zonisamide, and topiramate, also have been used as prophylactic agents with reasonable success. These agents are especially useful when a seizure disorder coexists with migraines. Good scientific evidence exists behind the use of valproic acid and topiramate. That evidence is lacking for any other anticonvulsant. Although some patients on topiramate complain of cognitive changes, the authors' own experience and recent published data[13] are consistent with the fact that cognitive changes are not common and topiramate is safe and effective in the pediatric population.

    Calcium channel blockers

    Calcium channel blockers (eg, verapamil) have been used in adults for migraine prophylaxis, but their efficacy in children is variable.

     

     

    Pharmacologic Therapy of Tension Headaches and Chronic Daily Headache

    Acute tension headaches often respond to symptomatic treatments. Sleep, darkness, or a quiet room may relieve some tension headaches and acute migraines. Ibuprofen and acetaminophen are recommended to relieve headache pain. Patients who are prone to tension headaches should attempt to minimize stress and may benefit from behavioral/relaxation therapy. Avoid narcotics and other potentially addictive medications.

    The treatment of CDH combines therapies that are used for both tension and migraine headache. The patient should discontinue over-the-counter analgesics and all narcotics. Chronic intermittent analgesic use may result in medication overuse headaches. Tricyclic antidepressants appear to be most helpful for treating CDH in children. There is also data on topiramate and CDH.[14, 15, 16] Psychological, behavioral, and relaxation interventions are also beneficial. Consider using these techniques concomitantly with tricyclic antidepressants. When the CDH pattern includes well-defined migraine attacks, abortive therapy may provide symptomatic relief.

     

    Summary: Pharmacologic Treatment of Migraine

    Abortive

    • Selective agonists for serotonin 5-HT1 receptors including sumatriptan, naratriptan, zolmitriptan, rizatriptan, almotriptan, frovatriptan, and eletriptan
    • Ergots
    • Isometheptene (Midrin)
    • Analgesics such as acetaminophen and NSAIDs

    Prophylactic

    • Beta-blockers (propranolol, nadolol)
    • Tricyclics (amitriptyline, nortriptyline)
    • Cyproheptadine
    • Antiepileptic drugs (valproic acid, phenobarbital, phenytoin, topiramate)
    • Verapamil

 

 

 

Conclusion

Physician awareness is the key to properly diagnosing and treating pediatric headache. Recognition that pediatric headaches can be divided into primary and secondary groups is crucial in the approach to and treatment of childhood headaches. With recent technological and pharmacologic advances, this common pediatric problem can be addressed effectively in the majority of patients. The primary care physician can manage a significant proportion of pediatric headaches and reserve neurologic referral for complicated headache patterns, headaches refractory to treatment, and headaches with a suspected structural etiology.