HEADACHES IN CHILDREN

By Walter J. Molofsky, M.D.
associate chairman, department of neurology

OVERVIEW
Chronic recurrent headaches are a common complaint in both pediatric and adult medical practices. They occur in approximately 30% to 40% of women and 20% of men. It is estimated that half of all adult migraine patients experience migraines before age 15, some as young as two to three years of age. Epidemiological studies indicate that approximately 5% to 8% of children have migraine head-aches and at least half have complained of severe headaches before their mid-teens. Children as young as one to two years of age can have migraine headache syndromes, though the symptoms are often not recognized as being a migraine. Symptoms can include irritability, head-banging, head holding, pallor, sensitivity to light, sounds and smells, sleep disorders, behavioral change, unexplained vomiting and stomach pain.The overwhelming majority of children (newborn to 18 years) seen with recurrent headaches have either a migraine headache, tension headache or analgesic abuse headache. It is rare that a recurrent headache is due to intracranial lesion or abnormality, however, these must be considered during the initial evaluation.The key managing children with chronic headaches is to determine the type of headache the child has and attempt to alleviate the frequency and severity of the head pain. This is best accomplished by taking a detailed history and conducting an office examination.

CLASSIFICATION
The current classification of headaches was developed by the International Headache Society in 1988. This classification includes migraine with and without aura, tension-type headache and cluster headaches. The remainder of the headache syndromes are associated with intracranial, craniofacial and/ or systemic disorders that can secondarily result in headaches. The classification is continually being modified particularly in the pediatric age group where many of the syndromes differ in their clinical characteristics from adults.

CLINICAL FEATURES
Migraine is one of the more specific headache syndromes that occur in eight percent of children under the age of 15. Almost 80 percent of migraine attacks will be without aura (common migraine) and 15 to 20 percent will have a "classical" migraine with an aura. The aura typically precedes the headaches by 30 to 60 minutes. An aura may include symptoms such as heightened or dulled perception, irritability, food cravings, speech problems, flashing lights, visual scatoma, sensory complaints, "pins and needles" sensation or numbness, focal weakness, ataxia and other abnormalities. The child can be confused. His/her own motor coordination can be thrown off. Objects may sometimes appear larger or smaller. Small children may show a change in behavior or unexplained vomiting. Occasionally, it can even look as if the child has had a stroke, but the symptoms usually abate.

The headache is usually very debilitating, often unilateral and characterized by a pulsing pain behind the eye. The headache classically lasts from two to 24 hours. After the pain subsides, the patient feels "normal." Migraine headaches generally do not occur daily but are an episodic disorder which may occur as often as 10 to 15 times a month.

Seizures, strokes and transient ischemic attacks need to be considered when evaluating a patient for migraine. In general, the normal interictal state, the absence of focal neurological findings, the presence of a strong family history and the nature of the spells themselves, allow an appropriate diagnosis.The pathophysiology of migraine remains unclear. Several theories speculate that migraine is caused by a combination of vasoconstriction and vasodilation of blood vessels in the brain. Recent blood flow studies indicate that the variation in blood flow may not be severe enough to be the cause of the aura or the headache. Electrical depression may also cause the onset of a migraine. Recent theories have focused on dysfunction of the 5-hydroxytryptamine (5-HT) system in the brainstem. This is supported by the efficacy of several medications that work as an agonist at the 5-HT receptor in the brainstem. These medications have afforded dramatic improvements in treatment.

Tension headaches are the most common recurrent headaches experienced by children. Approximately 90 percent of recurrent headaches fall into this category and approximately 15 percent occur in children under the age of 10. Clinically, they are dull, persistent and bilateral and cause a feeling of pressure or constriction around the head. Tension headaches are often associated with stress factors and may last a half hour to many days. If the headaches occur more than 15 times a month they are classified as chronic tension headaches. Depression and anxiety are often associated with these headaches and should be explained to children and their families. They may be exacerbated by stress and psychological factors.

The differential diagnosis of tension- type headache centers on distinguishing it from true migraine headaches. Focal and general systemic problems need to be eliminated. The patient's psychosocial history must be reviewed, as well.

One of the most common factors responsible for the continuation of these headaches is the development of a drug rebound headache through the overuse of analgesics. Patients with almost any type of headache, particularly migraine or tension headaches, may develop this type of headache. The pain is described as a daily headache consisting of a bandlike pain around the head and the history will show that these patients are self-medicating every three to five hours with a variety of analgesics. They initially prove helpful in alleviating the headache, but, after several days are actually responsible for the ongoing headache pain itself. These patients need to be managed carefully with a program of drug withdrawal often in an in-patient setting. The success rate can be high if the patient can be weaned off the medication.

CLINICAL EVALUATION
When a patient is first seen in the office, the examination should include a detailed history, general and neurological examination and ordering of necessary laboratory tests.A detailed comprehensive history is important to establish the etiology of the headache. If possible, the child should be interviewed without his/her parent. Children often give a more candid history of what occurred during their headache experience when allowed to speak one-on-one with the physician. The headache history should begin by asking for a precise description of the headache.

The following features should be evaluated:
1) Date, circumstances and onset
2) Character and severity of pain
3) Duration of attacks
4) Location of pain, generalized or localized and any radiation
5) Frequency of attacks
6) Seasonal variations
7) Preceding or accompanying neurological and/or physical symptoms
8) Evolution in symptoms
9) Precipitating factors
10) Measures of relief
11) Family history
12) Occupation
13) Sleep patterns
14) Emotional profile
15) Current and past treatments, including over-the-counter analgesics
16) Impairment impact
17) Menstrual and obstetric history
18) Medical and surgical history
19) Disease of the eyes, ears, nose, throat, teeth and neck
20) Allergies

The physical examination should include:

1) General survey and physical examination, including vital signs, cardiac and pulmonary status
2) Mental status
3) Special attention should be paid to palpation/percussion of the cranium, jaw, neck, oral cavity, ears and sinuses
4) Cervical spasm, rigidity may indicate muscle and spinal disease of the neck that is a cause of chronic head and neck pain
5) Cranial nerves with special attention paid to funduscopic exam and testing of visual acuity
6) Motor functions
7) Sensory exam
8) Deep tendon reflexes
9) Cerebellar exam