Approach to Headache
Headache is one of the most common neurological symptoms and the source of frequent referrals to neurology. Proper diagnosis and management of headache has a positive impact on the lives of many children and their parents, and may significantly reduce the direct and indirect cost associated with this symptom. The World Health Organization ranks migraines as one of the top 20 disabilities in the world. Magnetic resonance imaging (MRI) and computed tomography (CT) scan are not always necessary or justified, and exposing the patient to radiation or anesthesia when not needed is not a good practice. A thorough history and neurological examination serves the child better than imaging studies in most cases. Migraine is the most common headache diagnosis in children. Some of these children develop more frequent and less disabling headaches due to additional contributing factors (analgesics, caffeine, stress, depression, etc.). The prevalence of migraines increases from 3 % in children age 3 to 7 years to 4–11 % in children age 7 to 11 years and 8–23 % in adolescents. The mean age of onset for boys is 7 years and for girls 11 years ( ). Children with migraine average twice as many days lost from school as those without migraine.
Sources of Pain
Box 3-1 summarizes pain-sensitive structures of the head and neck. The main pain-sensitive structures inside the skull are blood vessels. Mechanisms that stimulate pain from blood vessels are vasodilatation, inflammation, and traction-displacement. Increased intracranial pressure causes pain mainly by the traction and displacement of intracranial arteries (see Chapter 4 ). The brain parenchyma, its ependymal lining, and the meninges, other than the basal dura, are insensitive to pain.
Intracranial
Cerebral and dural arteries
Dura mater at base of brain
Large veins and venous sinuses
Extracranial
Cervical roots
Cranial nerves
Extracranial arteries
Muscles attached to skull
Periosteum/sinuses
Pain transmission from supratentorial intracranial vessels is by the trigeminal nerve, whereas pain transmission from infratentorial vessels is by the first three cervical nerves. The ophthalmic division of the trigeminal nerve innervates the arteries in the superficial portion of the dura and refers pain to the eye and forehead. The second and third divisions of the trigeminal nerve innervate the middle meningeal artery and refer pain to the temple. All three divisions of the trigeminal nerve innervate the cerebral arteries and refer pain to the eye, forehead, and temple. In contrast, referred pain from all structures in the posterior fossa is to the occiput and neck.
Several extracranial structures are pain sensitive. Major scalp arteries are present around the eye, forehead, and temple and produce pain when dilated or stretched. Cranial bones are insensitive, but periosteum, especially in the sinuses and near the teeth, is painful when inflamed. The inflamed periosteum is usually tender to palpation or other forms of physical stimulation. Muscles attached to the skull such as the neck extensors, the masseter muscles, the temporalis, and the frontalis are a possible source of pain. Understanding of the mechanism of muscle pain is incomplete, but probably involves prolonged contraction (literally uptight) . The extraocular muscles are a source of muscle contraction pain in patients with heterophoria. When an imbalance exists, especially in convergence, long periods of close work cause difficulty in maintaining conjugate gaze and pain localizes to the orbit and forehead. Decreased visual acuity causes blurred vision, not headaches. Impaired vision is a common delay in the diagnosis and management of migraines.
Pain from the cervical roots and cranial nerves is generally due to mechanical traction from injury or malformation. Pain follows this nerve distribution: the neck and back of the head up to the vertex for the cervical roots and the face for the cranial nerves.
Taking the History
History is the most important tool in diagnosing headaches. The first step is to identify the headache temporal pattern:
Acute generalized headaches: This pattern is common with systemic or central nervous system (CNS) infections, exertional, cerebrospinal fluid (CSF) leak, postseizure, CNS hemorrhage, hypertension or metabolic causes (hypoglycemia, hypercapnea, and hypoxia).
Acute localized headaches: Sinusitis, otitis, temporomandibular joint (TMJ), ocular disease, neuralgia (trigeminal, glossopharyngeal, occipital), trauma or dental disease.
Acute recurrent headaches: Migraine, cluster, paroxysmal hemicranias, episodic tension headache, ice-pick, exertional, cough and intercourse headaches.
Chronic progressive headaches: CNS neoplasm, pseudotumor cerebri, brain abscess, subdural hematoma, hydrocephalus.
Chronic nonprogressive headaches: Depression, chronic tension, post-concussion, analgesic and caffeine induced, psychogenic and malingering headaches.
The following four questions are useful in determining the headache pattern:
- 1.
“ Is the headache chronic but not disabling, or does it occur occasionally and prevent normal activity? ” The number of school days missed because of headache is a good indication of frequency, severity, and disability.
- 2.
“ What is the longest period of time that you have been headache free? ” This identifies a common headache pattern in which the child has a flurry of headaches over a period of a week or two and then, after a prolonged headache-free interval, experiences another flurry of daily headaches.
- 3.
“ How many different kinds of headache do you have? ” A common response is that child has two kinds of headache: one headache is severe and causes the child to look sick (migraine), and the other is a mild headache that is almost constant but not disabling (analgesic rebound headache).
- 4.
“ What analgesics have you used and how often? ” This helps establish what has worked and what has failed, and may establish the diagnosis of analgesic rebound headache as a contributing factor.
Helpful responses to traditional questions concerning the history of headache can be obtained from children 10 years of age or older. Several typical headache patterns, when present, allow recognition of either the source or the mechanism of pain:
- 1.
A continuous, low-intensity, chronic headache, in the absence of associated symptoms or signs, is unlikely to indicate a serious intracranial disease.
- 2.
Intermittent headaches, especially those that make the child look and feel sick, from which the child recovers completely and is normal between attacks, are likely to be migraine.
- 3.
A severe headache of recent onset, unlike anything previously experienced, from which the child never returns to a normal baseline, is probably due to significant intracranial disease.
- 4.
Brief, intense pain lasting for seconds, in an otherwise normal child, is unusual and suggests ice-pick headache.
- 5.
Periosteal pain, especially inflammation of the sinuses, localizes to the affected sinus and the area is tender to palpation. Sinusitis and allergies as a cause of headache are grossly overstated. Evidence of “sinusitis” is a common feature of CT studies on children evaluated for other reasons.
- 6.
Cervical root and cranial nerve pain has a radiating or shooting quality.
Evaluation
A routine brain imaging study on every child with chronic headache is not cost effective and is not a substitute for an adequate history and physical examination. A joint committee of the American Academy of Neurology and The Child Neurology Society published a practice parameter for the evaluation of children and adolescents with recurrent headaches. Those with normal neurological examinations require neither electroencephalography (EEG) nor neuroimaging ( ). A CT scan of the head is helpful in most cases of suspected intracranial pathology as cause of headache. Lumbar puncture, magnetic resonance angiography and/or CT angiogram are useful when suspecting aneurysm leaks. MRI with magnetic resonance venogram may be useful when suspecting venous thrombosis in cases of increased intracranial pressure (see Chapter 4 ).
Migraine
Ten percent of children aged 5 to 15 years old have migraine, and migraine accounts for 75 % of headaches in young children referred for neurological consultation. Children with migraine average twice as many days lost from school as those without migraine. Migraine is an hereditary disorder with a multifactorial inheritance pattern. When interviewing both parents, at least one parent gives a history of migraine in 90 % of cases. The figure drops to 80 % if only the mother is present. The prevalence of migraine is 2.5 % under the age of 7 (both genders equally affected), 5 % from age 7 to puberty (female-to-male ratio of 3:2), 5 % in postpubertal boys, and 10 % in postpubertal girls. The higher incidence of migraine in pubertal girls than in boys probably relates to the triggering effect of the menstrual cycle on migraine attacks. Approximately one-quarter of children will be migraine free by age 25 years, boys significantly more often than girls, and more than half will still have headaches at age 50 years. Of those who become parents, 50 % will have at least one child who suffers from migraine ( ). When evaluating for family history of migraine, it is useful to expand your questioning if the parent initially reports a negative family history. Often the family labels their headaches as “normal headaches,” “sinus headaches,” or “allergy headache,” and when asked about the qualities of these headaches they describe typical migraines.
Genetics of Migraine
Familial hemiplegic migraine is the only well-established monogenic migraine syndrome ( ). This condition is mapped to chromosome 19 and seems to affect calcium and sodium channels, resulting in enhanced neurotransmission and probable facilitation of the cortical spreading depression that occurs in migraines ( ). Other migraine types are more complex, appearing to result from the interaction of genetic susceptibility and environmental factors. Genetic factors are more evident in migraine with aura than in migraine without aura. Migraine and migraine-like headaches are part of several known genetic disorders.
Triggering Factors
Among persons with a predisposition to migraine, the provocation of individual attacks is usually an idiosyncratic triggering factor. Common triggering factors are stress, exercise, head trauma, the premenstrual decline in circulating estrogen, and barometric pressure changes. An allergic basis for migraine is not established. I accept without comment parental statements implicating specific foods and food additives, but discourage extensive evaluation of food as a trigger.
Stress and Exercise
Migraine symptoms may first occur during stress or exercise or, more often, during a time of relaxation following a period of stress. When stress is the triggering factor, attacks are most likely to occur in school or just after returning home. Attacks rarely occur upon awakening. Children with migraine do not have a specific personality type. Migraine is just as likely in a “slug” as in an overachiever. However, the overachiever is more likely to reach the threshold for a migraine, and sometimes the management of anxiety or obsessive-compulsiveness results in decreased migraine frequency in these patients.
Head Trauma
The mechanism by which blows to the head and whiplash head movements provoke migraine attacks is unknown. Trivial blows to the head during competitive sports are significant triggering factors because they occur against a background of vigorous exercise and stress. A severe migraine attack – headache, vomiting, and transitory neurological deficits, following a head injury – suggests the possibility of intracranial hemorrhage. Appreciating the cause-and-effect relationship between head trauma and migraine reduces the number of diagnostic tests requested.
Transitory cerebral blindness, as well as other transitory neurological deficits, sometimes occurs after head trauma in children with migraine (see Chapter 16 ).
Menstrual Cycle
The higher rate of migraine among postpubertal girls as compared with prepubertal children of both genders or with postpubertal boys supports the observation that hormonal changes in the normal female cycle trigger attacks of migraine. The widespread use of oral contraceptives has provided some insight into the relationship between the female hormonal cycle and migraine. Some oral contraceptives increase the frequency and intensity of migraine attacks in many women with a history of migraine and may precipitate the initial attack in genetically predisposed women who have previously been migraine free. Among women taking oral contraceptives, the greatest increase in frequency of migraine occurs at midcycle. The decline in the concentration of circulating estrogens is probably the critical factor in precipitating an attack.
Clinical Syndromes
Migraine in children is divisible into three groups: (1) migraine with aura (classic migraine); (2) migraine without aura (common migraine); and (3) migraine equivalent syndromes. Migraine without aura is more than twice as common as migraine with aura in school-age children. Migraine with and without aura are variable expressions of the same genetic defect, and both kinds of attacks may occur in the same individual at different times. The main feature of migraine equivalent syndromes is a transitory disturbance in neurological function. Headache is a minor feature or is not present. One percent of migraineurs do not experience headache. Discussion of these syndromes occurs in several other chapters ( Box 3-2 ).
Acute confusional migraine ∗
∗ Denotes the most common conditions and the ones with disease modifying treatments
(see Chapter 2 )
Basilar migraine (see Chapter 10 )
Benign paroxysmal vertigo ∗ (see Chapter 10 )
Cyclic vomiting
Hemiplegic migraine ∗ (see Chapter 11 )
Ophthalmoplegic migraine (see Chapter 15 )
Paroxysmal torticollis (see Chapter 14 )
Transient global amnesia (see Chapter 2 )
Ice-pick headache, called primary stabbing headache by the , is a peculiar migraine equivalent that occurs mainly during adolescence or later. A severe pain on top of the head drives the patient to the floor. It ends as quickly as it comes. Bouts may repeat over days or months and then remit spontaneously. Ice-pick headaches end so quickly that treatment is not required, only reassurance.
Migraine with Aura
Migraine with aura is a biphasic event. In the initial phase, a wave of excitation followed by depression of cortical function spreads (cortical spreading depression) over both hemispheres from back to front associated with decreased regional cerebral blood flow and transient neurological dysfunction. The cause of dysfunction is primarily neuronal depression rather than ischemia. The second phase is usually, but not necessarily, associated with increased blood flow in both the internal and external carotid circulations. Headache, nausea, and sometimes vomiting occur in the second phase.
During an attack, the main clinical features (aura) may reflect only the first phase, only the second phase, or both phases. The usual features of the aura are visual aberrations: the perception of sparkling lights or colored lines, blind spots, blurred vision, hemianopia, transient blindness, micropsia, or visual hallucinations. Only a third of children describe visual symptoms. The visual aura tends to be stereotyped and unique to the child. The perception of the imagery may be limited to one eye, one visual field, or without localization.
Visual hallucinations and other visual distortions may disturb time sense and body image. This symptom complex in migraine is called the Alice-in-Wonderland syndrome . More extreme disturbances in mental state – amnesia, confusion, and psychosis – are discussed in the sections on confusional migraine and transient global amnesia (see Chapter 2 ).
Dysesthesias of the limbs and perioral region are the next most common sensory features. Other possible features of the aura are focal motor deficits, usually hemiplegia (see Hemiplegic Migraine) or ophthalmoplegia (see Ophthalmoplegic Migraine), and aphasia. Such deficits, although alarming, are transient; normal function usually returns within 24 hours and always within 72 hours.
A migraine attack may terminate at the end of the initial phase without headache. Alternatively, the initial phase may be brief or asymptomatic and headache is the major symptom (see Migraine without Aura). The pain is usually dull at first and then becomes throbbing, pulsating, or pounding. A severe headache that is maximal at onset is not suggestive of migraine. Pain is unilateral in approximately two-thirds of patients and bilateral in the rest. It is most intense in the region of the eye, forehead, and temple. Eventually the pain becomes constant and diffuse. Most headaches last for 2 to 6 hours, and are associated with nausea and sometimes vomiting. Anorexia and photophobia are concomitant symptoms. The child looks sick and wants to lie down; always ask the parent, “Does the child look sick?” With migraine, the answer is always “Yes.” Vomiting frequently heralds the end of the attack, and the fatigued child falls into a deep sleep. Normal function resumes when the child awakens. Most children average one attack per month but may have long intervals without attacks and other intervals when attacks occur weekly. The intervals with frequent headaches are probably times of stress.
Migraine without Aura
The attacks of migraine without aura are monophasic. The typical initial symptoms are personality change, malaise, and nausea. Recurrent vomiting may be the only feature of the attack in preschool children.
The headache may be unilateral and pounding, but more often the child has difficulty localizing the pain and describing its quality. When the headache is prolonged, the pain is not of uniform intensity; instead, intermittent severe headaches superimpose on a background of chronic discomfort in the neck and other pericranial muscles. Physical activity aggravates the pain. Migraine without aura may be difficult to separate from other headache syndromes or from intercurrent illness. The important clues are that the child appears sick, wants to lie down, and is sensitive to light and sound. Nausea and vomiting may occur repeatedly, need not herald the termination of the attack, and can be more prominent than the headache.
Diagnosis
The clinical features are the basis for migraine diagnosis; migraine is one of the few remaining neurological disorders in which the physician cannot stumble on the diagnosis by imaging the brain. Salient features are a family history of migraine and some combination of recurrent headache, nausea, or neurological disturbances, especially if aggravated by activity and relieved by rest and sleep. Many children will also have an increased perception of all sensory modalities including photophobia (lights), sonophobia (sounds), and osmophobia (smells). The physician should be reluctant to make the diagnosis if questioning of both biological parents does not elicit a family history of migraine. When obtaining the history, be certain that you are speaking with the biological parents and you ask for a family history of headaches and not only migraines as they usually classify their headaches as “normal headaches,” “sinus headaches” or “allergy headaches.” Almost half of children with migraine also have a history of motion sickness.
Diagnostic tests are unnecessary when the family history and clinical features clearly establishe a migraine diagnosis. Brain imaging is indicated only when uncertainty exists. The main reason is new abnormalities on examination. Lesser reasons are a negative family history or atypical features of the attack. The only reason to request an EEG in children with migraine-like headaches is to exclude the possibility of benign occipital epilepsy (see Chapter 1 ).
Management
Some improvement is common after the initial diagnosis of migraine. This is probably due to a reassurance given to the child and the family of not having a tumor or other more serious problem. Once the child’s parents are convinced that the headache is due to migraine and not brain tumor, they are less anxious, the child is more relaxed, and headaches either decrease in frequency or become less a topic of discussion and concern.
The two approaches to migraine therapy are treatment of the acute attack and prophylaxis. Many children need both. Most boys do not have migraine attacks during adult life, but girls often continue having attacks until menopause.
Good advice for all migraineurs includes: (1) healthy eating and sleep habits: (2) avoid use of caffeine; (3) avoid overuse of analgesics; (4) avoid triggers when identified and possible; and (5) avoid narcotics as this may compound the problem.
Treating the Acute Attack
Acute treatment of migraines is always more effective when given early during the attack. Medication should be available at home, when traveling and at school if possible. The first line of medications includes ibuprofen or naproxen 10 mg/kg or acetaminophen 15 mg/kg. Nonprescription analgesics and nonsteroidal anti-inflammatory drugs, especially ibuprofen, are more effective than placebo in controlling pain ( ). Nasal sumatriptan 5 or 20 mg and oral triptans such as sumitriptan (50–100 mg), rizatriptan (5–10 mg), eletriptan (20–40 mg) or zolmitriptan (2.5–5 mg) may be useful. Sumatriptan nasal spray is well tolerated, more effective that placebo, and recommended ( ). Adverse effects include fatigue, tingling of the head and arms, and a sensation of pressure or stiffness in the neck, throat, and chest.
The orally dissolved formulations of zolmitriptan and rizatriptan may be useful for children unable to swallow pills. The time of absorption is the same as other tablets as the absorption is not sublingual. For patients requiring faster onset, or when vomiting precludes oral medications, the nasal (5–20 mg) or injectable (3–6 mg) sumatriptan and the nasal or injectable (0.5–1 mg) dihydroergotamine (DHE) is a better option. The triptans and DHE are not FDA approved for children, but off-label use is common among headache specialists.
Rectal promethazine (12.5–25 mg) or prochloperazine injectable (5–10 mg) are also used when vomit interferes with oral administrations. Both promethazine and prochlorperazine can be given orally but sedation from this medication occurs in about 90 % of patients and may be as disabling as the illness. These options are helpful and less expensive when the treatment is needed at bedtime.
The following is one possible protocol for the management of severe migraine in the emergency room and hospital ( ). Prochlorperazine maleate 0.15 mg/kg with a maximum of 10 mg injected intravenously. If headache is not completely relieved, then use intravenous DHE. Pregnancy testing is required for girls over 12 years of age. Use 0.5 mg for children younger than 9 years and 1 mg for children 9 years or older. Doses may be repeated every 6 to 8 hours. If DHE fails, load with intravenous valproate sodium, 15 mg/kg followed by 5 mg/kg every 8 hours.
Migraine Prophylaxis
An extraordinarily large number of agents with diverse pharmacological properties are available for daily use to prevent migraine attacks. The use of prophylaxis agents should be considered in the following situations:
- 1.
Migraines once a week (frequent abortive therapy may lead to medication induced headaches).
- 2.
Failure to respond to abortive therapy.
- 3.
Only responsive to abortive medications that also cause sedation (sedation may be as disabling in terms of loss of productivity).
- 4.
Disability (loss of school or social activities).
The drugs with proven efficacy in older populations include amitriptyline, propranolol, valproate, topiramate. Cyproheptadine, commonly used by pediatricians, is only slightly better than placebo in controlled clinical trials.
Amitriptyline
Amitriptyline is inexpensive and has an acceptable side effect profile at low dosages, 0.5–1 mg/kg up to 50 mg at bedtime. Amitriptyline is our first choice. The mechanism of action is unknown. Nortriptyline has less sedation and may be used in patients sensitive to this side effect the morning after their dose.
Propranolol
Propranolol is a β-adrenergic blocking agent. It decreases headache frequency by at least half in 80 % of patients. The mechanism of action is probably central and not by β-adrenergic blockade. Propranolol must have central action because depression is a common side effect. This and exercise intolerance are the main reason it is often not used in children and adolescents.
The dosage in children is 2 mg/kg in three divided doses. Because depression is a dose-related adverse reaction and because lower doses may be effective, start treatment at 1 mg/kg/day. Asthma and diabetes are contraindications to usage. The maintenance dose of the sustained-release tablet is one-third greater than that of the short-acting preparation. Plasma levels of propranolol are not useful in determining the effective dose for migraine.
People who respond to propranolol do not develop tolerance. However, if abruptly stopping the drug after 6 to 12 months of therapy, some individuals will have rebound headaches of increased frequency. Others will continue to show the benefits achieved during therapy.
Topiramate and Valproate
Topiramate and valproate are widely used for epilepsy prophylaxis. In children, a dose of topiramate 50–100 mg daily or divided twice a day, or valproate 250–500 mg twice a day is effective for migraine prophylaxis. Side effects at low dosages are minimal. Be cautious with the use of valproate in adolescent females because of the significant potential for birth defects. I suggest topiramate for children who are overweight and valproate in those who are underweight or have bipolar traits. These are also good options for children with epilepsy and migraine as comorbidity.
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