Headaches

A recent editorial in the Annals of Emergency Medicine summarizes this issue, concluding that though it appears many CTs are being ordered unnecessarily, a low yield is necessary to avoid misdiagnoses.⁸ This is particularly true in the case of older adults and patients with new or severe headache. Increasingly, the EP is placed in a bind with the implication being that clinical choices will never be “just right.” He or she will continue to be retrospectively studied for performing workups without yield but criticized for failure to do extensive workups when a serious cause of headache is later found.

Approach to Patient

The tools used to evaluate a patient with headache in the ED are the same as those employed for other patient encounters. Each patient evaluation begins with an appropriate history and physical examination. Arguably, history is the most important to determine whether the patient’s headache is recurrent, a first-time headache, or the worst headache in his or her life.

Obtaining an accurate patient history can be a challenge. One provocative article noted that the order in which a patient was asked about his or her headache seemed to change responses to key questions.⁹ Even the time-honored “worst headache of my life” should be viewed in context of other factors. One Internet search turned up a migraine blog where the comment was made by a patient who experienced severe migraines, “I have the worst headache of my life every month.”¹⁰

Does the headache exist in isolation? The concept of the lone acute severe headache (LASH) was developed as part of a clinical decision-making study, but the acronym helps to remind the EP that headache may or may not exist in isolation.¹¹ Altered mental status not only makes a fine neurological examination impossible but suggests possible serious etiologies of headache. For example, a headache following a new seizure would divert diagnostic attention to the cause of seizure, and the presence of fever would of course suggest a possible infectious cause.

The initial diagnostic sorting of headaches must be either a likely primary headache (migraine, tension-type, etc) or so-called secondary headache. The concept of “red flags” has been developed to alert the practitioner to historical or physical examination findings that drive decisions for additional testing.^12-17 Although widely advocated in the literature, the sensitivity of a red flag or flags have never been studied in a prospective manner. While different red flags are listed in various publications, no weighting or comparison has been published to date. A guideline that used red-flag features to drive additional investigations listed the evidentiary support for the concept of red flags at the lowest level of evidence.¹⁷

Notably, some of the teachings repeated in medical training have no evidential basis and simply do not stand up when studied. An example is the so-called “neurosurgical headache,” in which the headache is worse in the morning but improves throughout the day following upright position that is thought to reduce ICP. This makes sense—until someone actually studies patients with intracranial tumors and finds that their headache characteristics most typically resemble tension-type headaches.¹⁸ Even though this study was published more than 20 years ago, the traditional teaching that the “neurosurgical headaches are worse in the morning” continues.

The Table lists some of the red-flag features that may suggest the presence of a secondary headache and could identify patients who could benefit from additional investigations or neuroimaging. This listing is provided as a summary of current recommendations and though many of these seem to be consistent with anecdotal experiences, these red flags have not been studied in an organized manner. The use of any simple list is only an aid to clinical judgment. For example, every migraine has a first onset. The diagnosis of a first hemiplegic migraine can confidently be made only with additional historical information, additional testing, or evolution of a recurrent pattern, and probably with imaging studies to rule-out other possible causes. Another example is that of benign coital headache, a diagnosis of exclusion since subarachnoid hemorrhage certainly may occur with exertion.

A careful physical examination always should be performed. Some key signs are noted in the Table. The presence or absence of papilledema has been traditionally considered a red flag. Certainly the presence of papilledema warrants evaluation, but it may be quite difficult to detect by simple inspection—even by neurologists or ophthalmologists. Other funduscopic findings may mimic papilledema, and it may not be present with acute increased ICP since it may take some time to develop. The role of bedside ultrasound in detecting papilledema in the patient with acute headache is unclear, though a few small case series suggests its utility.¹⁹