Steven Go
EPIDEMIOLOGY
Approximately 3.8% of patients presenting to the ED have a serious cause of their headache.
PATHOPHYSIOLOGY
The vast majority of subarachnoid hemorrhages (SAH) are caused by a ruptured cerebral aneurysm.
Temporal arteritis is a systemic panarteritis.
Migraine headaches are caused by a trigger, with resultant dysfunction of brainstem pathways that modulate sensory input, followed by disordered activity of blood vessels.
CLINICAL FEATURES
Headaches are divided into primary headaches and those due to secondary causes. Secondary causes require further evaluation for the etiology.
SUBARACHNOID HEMORRHAGE
SAH (see Chapter 143) classically presents as the severe, sudden onset at maximal intensity of “the worst headache of my life,” precipitated by exertional activities in 20% of cases.
The headache may be associated with nausea and vomiting, photophobia, and stroke symptoms.
The neurological examination is normal in 50% of cases.
MENINGITIS
Meningitis (see Chapter 150) can cause a headache of rapid onset, generally associated with fever, mening-ismus, and photophobia.
Immunocompromised patients can experience a more insidious onset with opportunistic infections, without fever or meningismus.
INTRAPARENCHYMAL HEMORRHAGE AND ISCHEMIC STROKE
These two entities can present with headaches, approximately 50% (intracranial hemorrhage) and <25% (ischemic stroke). Other neurological signs and symptoms are often present.
SUBDURAL HEMATOMA
Subdural hematoma should be suspected when headaches occur in the setting of remote trauma, usually in at-risk patients (alcoholics, elders, and those on anticoagulants).
BRAIN TUMOR
Brain tumor headaches may be bilateral, unilateral, constant, or intermittent. The headache may be worse in the morning, associated with nausea and vomiting, and positional in a minority of cases.
Only 8% have neurological examination abnormalities.
CEREBRAL VENOUS THROMBOSIS
Cerebral venous thrombosis (CVT) is a rare condition that presents with headache, vomiting, and seizures in patients with a hypercoagulable state (oral contraceptives, postpartum, perioperative, various clotting factor deficiencies, mutations, or polycythemia).
Papilledema can be present, and neurological findings can wax and wane.
TEMPORAL ARTERITIS
Temporal arteritis most commonly presents with headache (60-90%), which is most often unilateral frontotemporal (can be bilateral), severe, and throbbing. Associated symptoms may include jaw claudication, polymyalgia rheumatica, upper respiratory infection symptoms, and vision changes.
It usually occurs in patients >50 years old and more commonly in women (Table 142-1).
The involved temporal artery can be tender or non-pulsatile, or have a diminished pulse, but can also be normal.
TABLE 142-1 Criteria for Diagnosis of Temporal Arteritis*
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Age >50 y |
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New-onset localized headache |
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Temporal artery tenderness or decreased pulse |
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Erythrocyte sedimentation rate >50 mm/h |
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Abnormal arterial biopsy findings |
*Three of the five criteria must be met.
OPHTHALMIC DISORDERS
Ophthalmic disorders can present with severe headache and are commonly associated with nausea and vomiting (eg, acute glaucoma).
HYPERTENSIVE HEADACHES
Hypertensive headaches typically become more severe as the diastolic blood pressure rises, and improve with reduction of blood pressure.
Care must be taken to consider other causes of hypertension, such as stroke, pheochromocytoma, preeclamp-sia, or any other cause of life-threatening headache.
Distinction must be made from a true hypertensive emergency, in which there is other organ system involvement.
SINUSITIS
Sinusitis can result in pain in various sites depending on the particular sinuses that are infected. For maxillary sinusitis (the most common sinusitis) the pain is in the anterior face. The other sinuses include frontal (forehead), ethmoid (behind/between eyes), and sphenoid (diffuse). Headache typically varies with head position.
Patients with four or more of the following symptoms and signs: colored nasal discharge, maxillary toothache, poor response to decongestants, visible purulent nasal discharge, or abnormal transillumination, have a high likelihood of sinusitis, whereas sinusitis is unlikely if less than two of these findings are present.
BENIGN INTRACRANIAL HYPERTENSION
Benign intracranial hypertension (pseudotumor cere-bri) occurs most commonly in young women of childbearing age who are not necessarily obese. These chronic headaches are associated with thyroid disease and the use of oral contraceptives, vitamin A, and tetracycline. Associated symptoms include nausea, vomiting, and various visual disturbances, including visual field defects.
Papilledema with a normal level of consciousness is a hallmark of the disease.
CERVICAL ARTERY DISSECTION
Cervical artery dissection can be either traumatic or atraumatic and typically occurs in patients <40 years of age.
Internal carotid artery dissection causes unilateral anterior headache, usually around the eye or frontal area, commonly associated with neck pain. Most patients will have or develop neurologic signs such as transient ischemic attack (TIA), stroke, Horner syndrome, monocular blindness, or cranial nerve abnormalities.
Vertebral artery dissection causes occipital or posterior neck pain, commonly associated with signs of brain stem TIA or stroke.
POST-LUMBAR PUNCTURE HEADACHE
This occurs in 10% to 36% of patients within 24 to 48 hours of a lumbar puncture (LP). Headache worsens with upright position and improves with recumbency.
MIGRAINE HEADACHES
Headaches generally have a gradual onset, last 4 to 72 hours, and are typically unilateral, pulsating, and worsened by physical activity. Nausea and vomiting, photophobia, and phonophobia are frequently present.
Other neurological symptoms such as visual auras, hemiparesthesias, hemiparesis, and aphasia can be present, but other causes of headache must be excluded if these findings are present.
If four of the five “POUND” criteria (pulsatile quality, duration 4-72 hours, unilateral location, nausea or vomiting, disabling intensity) are present, the likelihood ratio (LR) is 24 for a migraine diagnosis.
CLUSTER HEADACHES
Cluster headaches present with severe, unilateral orbital, supraorbital, or temporal pain lasting 15 to 180 minutes, frequently associated with lacrimation, nasal congestion, rhinorrhea, and con-junctival injection.
Symptoms tend to occur daily for weeks before remitting for weeks to years.
DIAGNOSIS AND DIFFERENTIAL
Noncontrast CT scan of the brain is the initial imaging modality of choice to detect dangerous causes of headache. Latest generation CT scanners have a very high sensitivity for SAH (98%) within 12 hours of symptom onset, but this diminishes rapidly with time (80% after 12 hours).
LP is indicated in suspected meningitis and to detect SAH if the initial noncontrast CT scan of the brain is negative.
Imaging of the brain is not necessary prior to LP if there is no papilledema and if the level of consciousness and neurological examination (including lack of cerebellar findings) are completely normal.
Xanthochromia in cerebrospinal fluid (CSF) is useful to exclude SAH if the LP is done >12 hours after symptom onset and if the local laboratory uses a spectrophoto-metric test to detect it. However, most laboratories in the United States use visual inspection only.
CT angiography of the vasculature of the brain and neck is useful in selected cases to detect the presence of an aneurysm or cervical artery dissection.
MRI has only limited applications in the ED for acute evaluation of headache. It is no more sensitive than CT for acute SAH.
Most laboratory studies are unhelpful in determining the etiology of headache in the ED. However, various CSF studies such as cell count and differential, glucose, protein, Gram’s stain, latex antigen studies, and various cultures are useful in determining the etiology of meningitis (see Chapter 150 for details). In addition, while nonspecific, an elevated erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are useful in detecting temporal arteritis.
EMERGENCY DEPARTMENT CARE AND DISPOSITION
In SAH, the chances of rebleeding can be reduced by maintaining the patient’s pre-bleed blood pressure (or MAP <130 mm Hg if baseline blood pressure is unknown). This is best done by administering an IV titratable antihypertensive, such as labetalol (typical adult starting dose is 10-20 milligrams over 1-2 minutes IVP; continuous infusion dosage generally starts at 2 milligrams/min, titrated to effect). Nimodipine (60 milligrams orally every 4 hours) may produce modest improvements in outcome by decreasing vasospasm. Emergent neurosurgical consultation is indicated.
Patients suspected of having meningitis should receive prompt empiric antibiotic therapy. Antibiotic therapy should not be delayed for LP or imaging (see Chapter 150 for details).
Patients suspected of having temporal arteritis should be empirically treated with prednisone 40 to 60 milligrams PO daily, and urgent specialty consultation is indicated.
Medications effective in the treatment of the patient with migraine headache include dihydroergotamine (DHE), sumatriptan, dopamine-antagonist antiemetics (metoclopramide, chlorpromazine, prochlorperazine), and ketorolac. Current guidelines recommend opiates only if migraine-specific therapy fails.
Cluster headaches will resolve with the administration of high-flow oxygen in 70% of patients. Dihydroergotamine mesylate, NSAIDs, and sumatriptan also may be effective.
Improvement of a presumed primary headache with treatment does not necessarily exclude an important secondary cause for the headache.
Indications for admission for headache include presence of life-threatening cause of headache or failure to achieve adequate symptom control in the ED.
CRANIAL AND FACIAL PAIN DISORDERS
TEMPOROMANDIBULAR DISORDER
Temporomandibular disorder (TMD) causes pain at the temporomandibular joint, surrounding muscles, and ligaments. Patients often will complain of joint pain and noise with movement, locking of the jaw, limited jaw movements, and bruxism.
ED treatment of TMD consists of NSAIDs and narcotic analgesics. Radiographs are of little value in the ED.
Follow-up should be made with a dentist or oral surgeon.
TRIGEMINAL NEURALGIA
Trigeminal neuralgia (Tic Douloureux) presents as an intermittent, seconds-long, “electric shock”-like pain in a unilateral trigeminal nerve distribution.
Initial treatment may include carbamazepine (100 milligrams PO twice daily), which has been shown to be very effective.
Referral to a neurologist should be made for intractable cases.
For further reading in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 159, “Headache and Facial Pain,” by Christopher J. Denny and Michael J. Schull.