Headache is a common complaint in the ED. The emergency physician's key goal is to detect life- or organ-threatening causes of headache.
Headaches are divided into primary headaches and those due to secondary causes. Primary headache syndromes include the various types of migraine, tension-type, and cluster headaches, while secondary headaches have a legion of causes (Table 140-1). The particular clinical features of a given headache depend on the specific etiology.
Table 140-1 Etiology of Headache |Favorite Table|Download (.pdf)
Table 140-1 Etiology of Headache
|Critical Secondary Causes||Reversible Secondary Causes||Primary Headache Syndromes|
Cavernous/venous sinus thrombosis
Carotid or vertebral artery dissection
Central nervous system infection
Nitrates and nitrites
Monoamine oxidase inhibitors
Carbon monoxide poisoning
High-altitude cerebral edema
Noncentral nervous system infections
Long-term analgesic use (medication overuse)
A careful history should be taken to elicit the headache pattern (constant, waxing, waning, different from previous headaches), onset (especially sudden onset, which is often a harbinger of a dangerous etiology), location, associated symptoms (syncope, altered level of consciousness, neck pain/stiffness, persistent visual changes, fever, seizure), medications, toxic exposures (eg, carbon monoxide), relevant comorbidities (HIV, malignancy, coagulopathy, hypercoagulable state, hypertension), and family history (migraine, subarachnoid hemorrhage [SAH]).
Physical examination should be tailored to the differential. Relevant parts of the exam may include vital signs (fever), HEENT examination (sinuses, temporal arteries, slit lamp examination, funduscopy, tonometry, meningismus testing), and neurological examination (mental status, cranial nerves, motor and sensory function, reflexes, cerebellar exam, gait, and station).
The primary imaging modality for headache in the ED remains the noncontrast head CT, which usually excludes causes requiring emergent intervention, with the notable exception of subarachnoid hemorrhage. In 2008, the American College of Emergency Physicians (ACEP) made the following recommendations:
Patients presenting to the ED with headache and new abnormal findings in a neurologic examination (eg, focal deficit, altered mental status, altered cognitive function) should undergo emergent noncontrast head CT (Level B recommendation).
Patients presenting with new sudden-onset severe headache should undergo an emergent head CT (Level B recommendation).
HIV-positive patients with a new type of headache should be considered for an emergent neuroimaging study (Level B recommendation).
Patients who are older than 50 years and presenting with new type of headache but with a normal neurologic examination should be considered for an urgent (arranged prior to ED discharge) neuroimaging study (Level C recommendation).
Depending on the most likely diagnosis, other modalities, such as MRI (tumors, isodense subdural hemorrhages, cerebral venous thrombosis) and CT angiogram (strong ...