Chapter 10. Headache

Headache is defined as pain located at any part of the head, but not necessarily in a specific nerve distribution. Headaches can be primary or secondary. Primary headaches cannot be attributed to another medical, systemic, or intracranial disorder. A common primary headache is migraine. The criteria for pediatric migraine include at least five attacks lasting between 1 and 72 hours, at least one associated symptom (photophobia, phonophobia, vomiting, nausea) and at least two of the following major criteria: unilateral or bilateral location (i.e., bifrontal or bitemporal as opposed to global); pulsating or throbbing quality; moderate to severe intensity; and worsened headache by physical activity.1 Secondary headaches are caused by intracranial or medical/systemic disorders.2 For example, a child with brain tumor and headache has a secondary headache. When fever and headache occur simultaneously, the headache is almost universally a secondary headache.

The ability to classify a headache as primary or secondary may not be readily apparent during the initial evaluation, therefore also categorizing the temporal characteristics of the headache is a useful way to approach pediatric headache. Headaches can be subdivided into acute, acute recurrent, chronic nonprogressive, and chronic progressive. Acute headache occurs without a prior history of similar episodes, whereas acute recurrent headaches have more stereotyped symptoms that return after periods of being symptom free. The headache that increases in severity over time is termed chronic progressive. The severity and frequency of pain may wax and wane in chronic progressive headache, but the overall trend demonstrates progression of symptoms. Chronic nonprogressive headaches occur on a nearly daily basis and do not significantly change in severity, and are typically less severe than chronic progressive headaches.

In patients without a prior history of severe headache, the acute headache is concerning to the family and the practitioner. The acute headache occurring concurrently with a systemic (e.g., viral, bacterial, etc.) or localized illness (e.g., sinusitis, otitis media, pharyngitis) is generally due to the accompanying fever or inflammation and represents the most common type of secondary headache presenting to the emergency department.3–5 However, in a child with fever, any suspicion of central nervous system involvement including a change in mental status, seizure, or meningismus should raise the suspicion of an intracranial infection. Hydrocephalus should be the primary concern in all patients with an indwelling ventricular-peritoneal shunt who present with an acute headache and in patients whose headache is accompanied by double vision or episodes of transient visual loss. Other causative factors to consider in the evaluation of the acute headache include medications, toxins, trauma, seizure, or hypertension. Special consideration should be given to all patients presenting with acute headache that have an active or past significant medical history including leukemia, lymphoma, SLE, sickle cell disease, or HIV. Table 10–1 lists the differential diagnosis of headache based on temporal characteristics.

Acute recurrent headaches typically have similar characteristics that return after a period of being symptom free. Migraine headache is the most common acute recurrent headache. While most adult migraine is unilateral, younger children can have bilateral headache that later in adolescence becomes unilateral. When acute or acute recurrent headaches have accompanying neurologic abnormalities (i.e., weakness, aphasia, or change in mental status), the differential diagnosis should always include stroke, complicated migraine, and seizures. Aura consisting of visual, sensory, or speech disturbances can precede migraine headaches. Positive visual symptoms such as bright spots/lines or colorful scotoma are reassuring, whereas negative symptoms (i.e., visual field cut) are concerning. Children with headache and focal neurologic symptoms should always be examined by a pediatric neurologist.

The chronic progressive headache deserves prompt medical attention, especially in the setting of an abnormal neurologic examination as it most often indicates an elevation in intracranial pressure (ICP) or significant intracranial pathology. Any child with a headache that is increasing in severity and has an abnormal neurologic examination needs emergent imaging. Worsening of headache severity by lying flat should raise the suspicion of increased ICP. Headache is present in half the children presenting with brain tumor, but it is almost always associated with an abnormal neurologic examination.6 Idiopathic intracranial hypertension (IIH), previously known as pseudotumor cerebri, is another common cause of chronic progressive headache that can also have accompanying abducens (sixth cranial nerve) palsy, decreased visual acuity, visual obscurations, decreased visual fields, or ringing in the ears.7 Papilledema in the setting of an elevated CSF opening pressure with normal neuroimaging, serum, and CSF studies confirm the diagnosis of intracranial hypertension. When increased ICP is found, a search for contributing factors such as mastoiditis, sinus venous thrombosis, cryptococcus, lyme meningitis, chronic meningitis, or medications (oral contraceptives, tetracycline, Retin-A, chronic steroid use) should be undertaken. Children with cerebral venous thrombosis commonly present with both systemic symptoms and focal neurologic signs.8 Risk factors for cerebral venous thrombosis include head and neck infections, acute systemic illness, dehydration, iron-deficient anemia, chronic systemic disease (e.g., connective tissue, hematologic, cardiac, or oncologic), or prothrombotic states.8,9

The chronic nonprogressive headache is generally milder in severity than acute headaches and less likely represents significant pathology. In the setting of a normal neurologic examination, a history of mild headaches without concerning features suggests chronic daily headache. There is typically a long history of headache that has been refractory to many medical treatments and/or has an emotional component.

The history and physical examination in pediatric headache is paramount (Figure 10–1). Obtaining a detailed description of the headache can be quite difficult in the uncomfortable child or adolescent. A headache history is particularly difficult in the toddler and young child. As with any medical symptom, the duration, frequency, onset (i.e., gradual versus abrupt), location, quality, severity, and temporal pattern of pain should be obtained. The presence of previous headaches with similar symptoms is the most useful as discussed in the prior section. Family history of migraine is also very reassuring. Subarachnoid hemorrhage should be considered when children complain of a sudden onset of their worst headache of life.

The headache location can be difficult to pinpoint in some children and may be referred pain from the sinuses, ear, mastoid, neck is but ascribed to the head. Headaches occurring in the occipital region are believed to be suggestive of significant pathology, but this is controversial. Although the quality of the pain (i.e., sharp, dull, pulsing) is a helpful descriptor, its usefulness in ruling out significant disease has not been shown to be helpful. Headaches that awaken a child at night or are present immediately upon awakening are two temporal patterns that should raise concern for intracranial pathology. Special attention to exacerbating factors such as worsening pain when lying flat or performing the valsalva maneuver suggests increased ICP. Headache relief with vomiting or early morning vomiting also suggests increased ICP.

Additional questions in the history should include presence of fever, localized pain, recent infection, trauma, toxin exposure, current medications, and a thorough review of any comorbid medical conditions and their treatment (i.e., congenital heart disease, genetic syndromes associated with vascular anomalies, immunodeficiency, indwelling shunts, oncology patients requiring chemotherapy, postsurgical patients, sickle cell disease, thrombophilia).

Routine vital signs, physical examination, and neurologic examination should be performed in every child presenting with headache. Special attention to the sinusus, nares, dentition, lymph system, mastoid, tympanic membrane, and nuchal rigidity may help elucidate an etiology. A complete neurologic examination should always include a funduscopic examination. If the optic disk and disk margins cannot be adequately visualized, a dilated eye examination by a neurologist or ophthalmologist might be needed in certain clinical situations. Figure 10–2 demonstrates papilledema in a child with 3 weeks of progressive headache who was found to have an elevated opening pressure on lumbar puncture and then diagnosed with idiopathic intracranial hypertension (i.e., pseudotumor cerebri).

Most laboratory tests are unhelpful in the child presenting with headache and a normal physical and neurologic examination. When indicated, etiology-specific laboratory studies can be sent based on physical examination findings. When meningitis, subarachnoid hemorrhage, or increased ICP are suspected, lumbar puncture is indicated. For cerebral and epidural abscesses, lumbar puncture should be deferred until after neurosurgical consultation. If signs of increased ICP or focal neurologic deficits are present, a noncontrast head CT should be performed prior to lumbar puncture. For suspected infections, routine CSF cultures and viral-specific CSF studies (i.e., enterovirus PCR, HSV PCR) should be sent along with routine cell counts, protein, and glucose. An opening pressure should be a part of every diagnostic lumbar puncture.10 If there exists a clinical suspicion for subarachnoid or intracerebral hemorrhage, CSF cell counts should be performed on the first and last CSF specimen tubes to evaluate clearing of blood.

Imaging the child with headache can be approached in a systematic manner. Any child with an abnormal neurologic examination or signs of increased ICP requires emergent imaging. In most cases, a nonconstrast head CT scan will be sufficient initially. Even when the neurologic examination is normal, if elements of the history are concerning (i.e., vomiting upon awakening, head trauma, worst headache of life, improvement of headache with vomiting, double vision, episodes of transient visual loss, or worsening of headache when lying flat), imaging should be considered. If mastoiditis is present or an epidural abscess is suspected, a noncontrast CT using a temporal bone window is recommended. If cerebral sinovenous thrombosis is suspected, magnetic resonance imaging (MRI) including magnetic resonance venography (MRV) may be warranted. Vertebral artery dissection should be strongly considered in patients with neurologic deficits associated with neck pain or posterior head pain following trauma. Imaging the vasculature of the head and neck using either magnetic resonance angiography (MRA) or CT angiography should be performed in these cases. In children with indwelling ventricular shunts, a shunt series to evaluate the integrity of the shunt as well as a noncontrast head CT should be obtained.

Many excellent algorithms exist for evaluating the acute pediatric headache.11Figure 10–2 lists a simplified algorithm for how to approach headache in a previously healthy child using history and physical examination to guide the laboratory and imaging evaluations. Children with chronic medical conditions presenting with headache should be evaluated with close collaboration of their subspecialty physician and/or a neurologist.

Headache with accompanying neurologic deficit requires immediate referral to an emergency department and neurology consultation. Any child with papilledema or other signs of increased ICP needs an urgent neuroimaging study. Neurology consultation is typically warranted in most children with chronic medical conditions presenting with headache. The management of acute recurrent headache suspected to be migraine can initially be managed conservatively with referral to a neurologist on a nonurgent basis. Treatment of complicated migraine (i.e., those with accompanying neurologic symptoms) should be deferred until speaking with a pediatric neurologist.