Headache

101 Headache

Joshua N. Goldstein, Jonathan A. Edlow

• Inquire about the onset, quality, severity, associated symptoms, and past history of the headache; a new headache that is due to a serious “cannot miss” cause will usually have unique features.

• The most frequently missed components of the neurologic examination are visual fields and gait; they are helpful in the diagnosis of subtle disorders.

• New abnormal neurologic findings must be evaluated and explained.

• Patients whose headaches are abrupt, with maximal intensity at or close to onset (“thunderclap” headaches), should be evaluated for subarachnoid hemorrhage even if the findings on neurologic examination are entirely normal.

• When evaluating for a nontraumatic subarachnoid hemorrhage, a negative computed tomography scan should be followed by a lumbar puncture.

Perspective

Headache is a high-risk symptom because it is very common and a small percentage of patients with headache will have serious treatable life-, brain-, or eye-threatening causes. Emergency physicians (EPs) must use the history and physical examination to decide which patients need diagnostic testing beyond the history and physical examination because a delayed or missed diagnosis of disorders such as meningitis or subarachnoid hemorrhage can lead to catastrophic outcomes.

Epidemiology

Approximately 2% to 4% of all emergency department (ED) visits are for headache. Only a small proportion (as low as 2%) of patients seen in the ED with a headache suffer a life-, limb-, or vision-threatening illnesses.

Pathophysiology

The sensation of headache is rarely due to injury to the brain parenchyma itself. Rather, head pain results from tension, traction, distention, dilation, or inflammation of pain-sensitive structures external to the skull, portions of the dura mater, and blood vessels. Each of these mechanisms is probably mediated by a final common biochemical pathway that results in pain; therefore, a favorable response to analgesics should not be used to judge the cause of an individual headache.¹

Presenting Signs and Symptoms

EPs should develop a logical, practical, and accurate approach to identification of patients with serious pathology. A comprehensive organizational scheme developed by the International Headache Society has recently been updated (Table 101.1); however, this scheme is cumbersome in emergency practice. For practical purposes, headaches can be divided into “benign” and “cannot miss” categories (Table 101.2).

Table 101.1 International Headache Society Classification of Headaches

HEADACHE ASSOCIATED WITH	COMMENTS
Migraine	Requires 5 or more attacks of a specific nature lasting 4-72 hr. Can be unilateral, pulsating, moderate, or severe in intensity; aggravated by physical activity; or associated with nausea, vomiting, or photophobia
Tension type	Requires 10 or more attacks of a specific nature lasting 30 min to 7 days; absence of nausea, vomiting, and photophobia
Cluster type	Requires 5 or more attacks of a specific nature lasting 15-180 min; always unilateral; associated with eye, nose, or face symptoms
Other primary headaches	Includes a variety of brief (idiopathic stabbing headache) and situational (cough, exertional, coital) headache syndromes
Head trauma	Includes minor postinjury headaches
Vascular disorders	Includes cerebral ischemia and infarction, all forms of intracranial hemorrhage, venous sinus thrombosis, giant cell arteritis, arterial dissections
Nonvascular intracranial disorders	Includes idiopathic intracranial hypertension, post–lumbar puncture headache, tumor
Substance abuse or withdrawal	Includes drugs and food additives (e.g., monosodium glutamate headache, or Chinese restaurant syndrome); also includes headache from carbon monoxide poisoning
Infections	Includes headaches secondary to intracranial (meningitis, abscess) or extracranial infection
Disorders of homeostasis	Includes headaches secondary to hypercapnia, high-altitude illness, hypertensive encephalopathy, preeclampsia
HEENT (head, eyes, ears, nose, and throat) disorders (includes dental)	Includes narrow angle-closure glaucoma, sinusitis, temporomandibular joint disorder
Cranial neuralgias, nerve trunk and deafferentation pain	Most of these are cranial neuropathies or associated with herpes zoster

From Olesen J. International Classification of Headache Disorders, Second Edition (ICHD-2): current status and future revisions. Cephalalgia 2006;26:1409–10.

Table 101.2 “Cannot Miss” Diagnoses

DIAGNOSIS	SUGGESTIVE HISTORY AND PHYSICAL FINDINGS	DIAGNOSTIC TESTING
Meningitis and encephalitis	Fever, stiff neck, accentuation by jolts, altered mental status, seizure	LP; if preceded by CT, administer antibiotics before CT
Subarachnoid hemorrhage*	Abrupt onset of severe headache, stiff neck, third nerve palsy	CT scan; LP if CT is not diagnostic
Stroke (ischemic or hemorrhagic)	Abrupt onset and focal neurologic deficit conforming to an arterial territory	CT scan; if available, MRI will give more information (should not delay thrombolytic therapy)
Dissection of craniocervical arteries	Neck pain, abrupt onset, variable presence of neurologic deficit	CT angiography, MRA, or conventional angiography
Hypertensive encephalopathy	Severe (usually chronic) hypertension; often papilledema and other signs of end-organ damage	Careful, titratable lowering of blood pressure by ≈25% of the peak level will decrease the headache
Idiopathic intracranial hypertension	Obese, female patient; papilledema; often sixth nerve palsy	LP (following an imaging study, which by definition will be normal)
Giant cell arteritis	Nearly always age > 50 yr, symptoms of polymyalgia rheumatica, abnormal scalp vessels	ESR, temporal artery biopsy
Acute angle–closure glaucoma	Painful red eye with midposition pupil and corneal edema	Tonometry
Intracranial mass (tumor, abscess, hematoma)^†	Any focal or generalized neurologic finding	CT scan; if available, MRI will provide more information
Cerebral venous sinus thrombosis	Hypercoagulable state of any type	MRI and MRA with venous phase, CT with venous phase
Carbon monoxide poisoning	Cluster of cases, winter season	COHb level
Pituitary apoplexy	Visual acuity or field abnormalities	MRI
Pituitary apoplexy	Known pituitary tumor	MRI

COHb, Carboxyhemoglobin; CT, computed tomography; LP, lumbar puncture; MRA, magnetic resonance angiography; MRI, magnetic resonance imaging.

^* See Figure 101.1.

^† See Figure 101.2.

Treatment of pain should occur in parallel with the history and physical examination. Appropriate analgesia is all that most patients require, and comfortable patients are more willing to undergo tests and procedures (e.g., lumbar puncture [LP]). Immediate pain control results in greater patient satisfaction and more rapid disposition. That said, a given patient’s response to analgesics should not alter the diagnostic strategy, so there is no reason to withhold treatment.

Evaluation should focus on signs and symptoms that can differentiate a benign headache from one requiring emergency work-up and treatment. For example, although location of the headache is often considered significant, unilateral headache is a hallmark of both primary (migraine, cluster) and secondary (intracerebral hemorrhage, glaucoma) headaches, thus limiting its usefulness in diagnosis. In contrast, fever and neck stiffness are uncommon with primary headache and are therefore very useful.

Timing and Duration

Identifying the timing and duration of the headache is useful. Questions such as “What brings you here today rather than any other day?” can help focus patients on the timing of their symptoms. Worrisome features include a new acute headache or a subacute headache that is increasing in severity. An abrupt or “thunderclap” onset suggests intracranial hemorrhage or cerebral venous sinus thrombosis. If the maximum intensity of the pain occurred at the onset, aneurysmal bleeding should be considered. Very fleeting headaches, termed “jabs and jolts,” that last seconds are typically benign. In abrupt-onset headaches, the activity at the onset sometimes suggests the cause, such as with coital headache or benign exertional headache. However, even though a history of these activities can be a sensitive indicator of the corresponding diagnoses, specificity is poor. Therefore, subarachnoid hemorrhage cannot be excluded on the basis of activity before the headache.

Location

Location of the pain is not very helpful in diagnosing headaches because of the significant overlap between benign and serious causes. Some recommend work-up of patients whose headaches always occur on the same side.

Severity

Severity of the pain also has limitations in differentiating benign from serious headaches. Although the “worst-of-my-life” headache suggests a more serious problem, most severe headaches seen in the ED have benign causes. Patients without a previous history of similar, severe headaches should be evaluated for a secondary cause of the headache. In patients with a history of previous headaches, ask about details and consider evaluating those whose headaches are clearly increased in severity or different in quality.

Quality

The quality of the patient’s pain is critical. Most secondary headaches are qualitatively unique, unusual, or distinctly different from prior headaches. Diagnostic work-up of patients with chronic headaches that have new or unusual features should be strongly considered.

Associated Symptoms

Specific associated symptoms can provide important clues to a dangerous cause of the headache. Fever and neck stiffness suggest meningitis. Syncope, seizure, or any focal neurologic symptoms or new signs associated with a headache should prompt an evaluation. Diplopia suggests a mass, cerebral aneurysm, or elevated intracranial pressure (ICP).

Unfortunately, migraine headaches can produce an array of associated symptoms traditionally associated with secondary headaches. Although nausea, vomiting, and photophobia can occur with increased ICP or infection, they are also associated with migraines. A helpful differentiating factor in migraineurs is whether these symptoms accompanied previous migraines or whether the finding is new. Visual abnormalities are associated with migraine headaches but also with idiopathic intracranial hypertension, temporal arteritis, and pituitary apoplexy.

Exacerbating and Alleviating Factors

Determining exacerbating and alleviating factors is occasionally helpful. Post-LP headache tends to worsen on standing upright, and headache from sinusitis often worsens on bending forward with the head dependent. In contrast, the classic history of a headache caused by a brain tumor—worse on awakening—is neither specific nor sensitive because it is also seen in patients with hypercapnic chronic lung disease (in which the headache worsens during sleep). In terms of alleviating factors, diagnostic significance should not be ascribed to pain relief, even with over-the-counter medications.

Other Factors

Age is useful as a consideration because new-onset headache at older ages suggests a secondary cause such as giant cell arteritis, tumors, subdural hematoma, and side effects of medications. Environmental considerations include winter season and common-source clusters, which can indicate carbon monoxide poisoning.

Past and Family History

Predisposing factors for a secondary cause of headache should be determined. For example, poorly treated hypertension may lead to hypertensive encephalopathy, vascular risk factors can result in stroke, and a past or family history of cerebral aneurysm increases the likelihood of subarachnoid hemorrhage (Box 101.1).

Box 101.1 Critical Features of the History in the Emergency Department

Timing

Abrupt onset, “thunderclap” (pain rapidly reaches maximal intensity)

Location

Nonspecific with regard to the differential diagnosis

Severity

Worst of my life, most severe; have never been to an emergency department before for headache

Quality

New type, qualitatively different from previous headaches

Associated Symptoms

Fever, neck stiffness

Seizure, syncope

Focal neurologic complaints

Visual abnormalities (diplopia, decreased or altered vision)

Exacerbating or Alleviating Factors

Worse with cough or lying down suggests increased intracranial pressure (but is not specific)

Past Medical History

Stroke, vascular disease, cancer

Immunocompromised status

Hypercoaguable states or bleeding diathesis

Family History

Hypercoaguable states, bleeding diathesis, cerebral aneurysm

A history of thromboembolic events should raise the possibility of cerebral venous sinus thrombosis. In contrast, patients with hemophilia are at higher risk for bleeding. Obesity suggests idiopathic intracranial hypertension (pseudotumor cerebri), especially in women. A history of cancer can raise suspicion for brain metastasis, and patients infected with human immunodeficiency virus or taking immunosuppressive medicines are at higher risk for infection.

Physical Examination

The physical examination (Box 101.2) is critical in guiding the differential diagnosis and appropriate work-up.

Box 101.2 Critical Features (Potential Diagnoses) of the Physical Examination

Vital Signs

Fever (meningitis, encephalitis, abscess)

Elevated blood pressure (stroke or problems associated with elevated intracranial pressure)

Head

Vesicles on the scalp (herpes zoster of the upper two cervical roots or the root of the fifth trigeminal nerve)

Tender temporal artery (giant cell arteritis)

Tender sinuses (sinusitis)

Eyes

Red, edematous (acute angle–closure glaucoma)

Proptosis (cavernous sinus thrombosis)

Papilledema (increased intracranial pressure)

Ears

Vesicles in the external ear canal (Ramsay Hunt syndrome)

Tags: Emergency Medicine Clinical Essentials

Jun 14, 2016 | Posted by admin in EMERGENCY MEDICINE | Comments Off

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