In this Cyberounds^®, we present two patients with a chief complaint of headache and discuss their diagnosis and management. As usual, the cases will be interactive. Some of the questions may not pertain directly to headache but, instead, ask you to consider some of the difficulties inherent in investigating headache.

Headache is one of the most common of human afflictions. It is thought that there is a one-year period prevalence of >90% and a lifetime prevalence of >99%. The cause of headache may range from the completely benign to the immediately life threatening.

Q What would you think are some of the problems involved in investigating the incidence and causes of headache?

A. The potential problems are many. I have listed some. I am sure there are more.

1. The site of investigation. Clearly, the types of headaches seen by a neurologist may vary from the range of headache conditions seen by an internist or by a family practitioner or by an emergency room physician. This is because patients will be 'selected' to attend one or other of these practitioners, either because of self-perceived need or by a referral process from another physician or health care provider. It is estimated that only 15% of persons with migraine actually seek formal medical assistance. In order to try and obtain accurate figures for the true incidence of headache, population based studies are required. Examples are the telephone study by Celentano et al., where investigators telephoned 10,169 subjects and asked about severity of headache and associated symptoms(1) and the prospective study of an HMO member cohort by Breslau et al.(2) This latter study demonstrated an incidence of migraine per 1000 person years of 5.0 in men, and 22.0 in women.
2. Diagnosis. Previously there has been a range of conditions described as 'migraine'. In an attempt to standardize the definitions of these conditions, the International Headache Society (IHS) has produced diagnostic criteria for a range of headache disorders. Even with these criteria, one study demonstrated that there is still only moderate agreement in diagnosis among physicians when shown a structured interview.(3)

In the emergency department, headache is a very common complaint, accounting for between one per cent and 16% of all visits (Note, once more, the wide variation -- presumably resulting from variations in patient populations, differences in diagnostic criteria and in study designs). I will describe a range of scenarios and then discuss the investigation and the management of each.

Newman and Lipton have developed a useful method of thinking about headache in the emergency department.(4) They discuss 'headache alarms' as being aspects of the history or examination that should alert the emergency physician to the possible presence of a secondary cause for the headache.

In general, the cause of a headache can be divided into primary and secondary groups. Primary causes of headache are conditions such as migraine or tension type headache, while secondary causes of headache include tumor, infection and inflammatory conditions such as temporal arteritis.

Q. What diagnoses would you consider most likely and how would you investigate headache occurring in each of the following scenarios?

A patient over the age of 50 years, presenting for the first time, with a generalized headache.

A. The diagnoses that need to be considered include temporal arteritis and a mass lesion. Appropriate investigations in the emergency department would include an erythrocyte sedimentation rate and neuroimaging.

Q. A patient in their 30s with the sudden onset of a severe headache described as "the worst headache of my life."

A. Consider subarachnoid hemorrhage, pituitary apoplexy, hemorrhage into a mass lesion or vascular malformation and a mass lesion (especially in the posterior fossa). Appropriate investigations in the emergency department would include neuroimaging. A lumbar puncture should be performed if the CT is negative.

Q. A patient with a long history of occasional headaches, usually eased with over-the-counter mild analgesia, where the headaches seem to be increasing, both in severity and in frequency.

A. Mass lesions, subdural hematoma and medication overuse must be considered. Appropriate investigations in the emergency department would include neuroimaging and a drug screen.

Q. An immunocompromised patient (perhaps from HIV or malignancy) who presents with a severe headache.

A. Differential diagnoses include meningitis (which may be chronic or carcinomatous), brain abscess, metastases and toxoplasmosis. Neuroimaging followed by a lumbar puncture if the CT was reported as negative should be conducted.

Q. A patient who has a fever, a stiff neck and headache.

A. When there is fever and headache, consider meningitis, encephalitis, Lyme disease, systemic infections and connective tissue diseases, such as collagen vascular disease, as possibilities. Appropriate investigations in the emergency department would include neuroimaging, lumbar puncture and serum serology (even though the results of this investigation may not be available for some weeks).

Q. A patient who has a headache, associated with a focal neurological deficit, for example a cranial nerve deficit.

A. A mass lesion, vascular malformations, stroke, and collagen vascular disease could all present with these symptoms. Appropriate investigations in the emergency department would include neuroimaging. In some cases, immunological studies may be appropriate also.

Q. A patient with headache, who is found to have papilledema on examination.

A. Search for an intracranial mass lesion, pseudotumor or meningitis. Appropriate investigations in the emergency department would include neuroimaging and a lumbar puncture.

Q. A patient who had motor vehicle crash four days earlier, associated with loss of consciousness, who now presents, for the first time, with a severe headache.

A. The diagnoses that need to be considered include intracranial hemorrhage, subdural hematoma, epidural hematoma and a posttraumatic headache. Appropriate investigations in the emergency department would include neuroimaging of the brain and skull. If there is any suggestive history, then imaging of the cervical spine should also be considered.

Now, we're ready to discuss our two patients.

Patient Number One

She is a 22-year-old and presents with a severe unilateral headache. The patient has experienced similar headaches on a number of occasions in the past and was investigated at another institution where she was told she has migraine. The young woman states that she is nauseated, had a visual aura prior to the commencement of the headache (as is usual for her) and has a strong family history of migraine-type headaches. She is usually able to control the headache by taking an over-the-counter analgesic and going to bed for a few hours in a darkened room. She has no other relevant past history and is on no medication. Physical examination is unremarkable, except that she complained that the light hurt her eyes when you examined her fundi. Today, she was visiting her sick mother in the hospital and so decided to come to the emergency department for assistance. She had taken 1000 mg of acetaminophen about three hours earlier but has had no relief.

Q. How would you manage this young lady, given that she wishes to try and remain awake and alert to support her mother?

A. It is very likely that this patient is suffering a recurrence of her migraine headache. The features are exactly similar to those she usually experiences and she displays no signs or symptoms of any other probable process. For this patient, even though it may be the first time she has been seen at this emergency department, I would not pursue further investigation but rather treat her migraine headache. The question, then, is how to best relieve the headache without excessive side effects, such as drowsiness. What options are available in the emergency department and what are the risks and benefits of each?

Simple analgesia, such as acetaminophen or salicylates, can be used as first line measures. Today, however, acetaminophen has been ineffective. Nonsteroidal anti-inflammatory drugs, such as ibuprofen, ketorolac, indomethacin and naproxen sodium, have been shown to be effective in the management of migraine pain. Oral medications are probably not going to be helpful in this patient, as she is so nauseated. An intramuscular preparation of ketorolac is available and this is an option in this case. A rectal form of indomethacin could be used if the patient declined an injection.

Side effects from nonsteroidal anti-inflammatory agents include nausea, abdominal pain, diarrhea, somnolence, fluid retention and, especially with long term use, hepatic toxicity and nephrotoxicity. Contraindications include sensitivity to the agents and active peptic ulcer disease.

Underutilized therapies in the management of migraine are the ergot preparations. Ergotamine tartrate may be given orally or rectally. Blood levels are about 20 times higher after rectal administration. Ergotamine tartrate can be highly nauseating, so it is best to start with a low dose and gradually increase, or to administer an anti-emetic first.

Ergotamine/caffeine suppositories are available with 2 mg of ergotamine and 100 mg of caffeine. Ergotamine tartrate is contraindicated in women who are pregnant or considering pregnancy, patients with sepsis, uncontrolled hypertension, evidence of vascular disease and in hepatic or renal insufficiency. Side effects include abdominal cramps, nausea and parasethesia. No more than two of the ergotamine suppositories should be used in a 24-hour period and, at the most, for two days in a seven-day period. If the preparations are overused the patient runs the risk of chronic daily headaches and ergotism.

Dihydroergotamine (DHE) is a potent venoconstrictor but only minimally constricts peripheral arteries. It may be used intramuscularly or intravenously. The dose is 0.5 to 1.0 mg. It produces significant nausea and so an anti-emetic is recommended prior to intravenous administration. The contraindications are the same as those for ergotamine. Although not an issue in the case under discussion, DHE is highly effective when given intravenously for intractable migraine. Intractable migraine is defined as migraine lasting longer than 72 hours.

Sumatriptan is a selective 5-HT₁ receptor agonist. Changes in the serotonergic system are important precursors to migraine. Blocking the 5-HT₁ receptor appears to inhibit the release of vasoactive neuropeptides. Sumatriptan is administered subcutaneously at a dose of 6 mg. An oral preparation is now available but takes longer to be effective. Subcutaneous administration results in a measurable improvement in headache within ten minutes. Headache may recur in up to 40% of patients probably due to the short half-life (two hours) of the drug. Sumatriptan should not be used in pregnant women, patients with uncontrolled hypertension, ischemic heart disease or complicated migraine. Side effects include pain at the injection site, diffuse burning, tingling, and chest and neck pain. It should not be used if the patient has received ergots within 24 hours.

Other medications that could be considered include intravenous chlorpromazine and prochlorperazine. Both agents have been shown to be effective in controlled clinical trials. These agents may produce drowsiness and can also induce dystonic type reactions in susceptible people.

The patient under discussion received a 60 mg intramuscular injection of ketorolac with an excellent response. If this had failed, DHE or sumatriptan would have been appropriate alternatives. She returned to her mother's bedside within an hour.

Patient Number Two

A 34-year-old patient presents to the emergency department three days after she had been investigated for a sudden severe headache. A CAT scan and a lumbar puncture performed at the time of the first visit were both normal. The headache had responded to the intravenous administration of 10 mg of chlorpromazine and the patient was discharged. Over the past two days, the patient had experienced severe headache, worse on standing and relieved by lying down. The pain was a bilateral frontal headache. The patient felt nauseated. She had no other relevant past history. She had no fever and complete physical examination, including neurological examination, was unremarkable.

Q. What is the diagnosis here and how may she be managed in the emergency department?

A. This patient is describing a classical 'post dural puncture headache'. Most of these headaches are mild or moderate and subside within three to four days. In 15% of patients, however, the headache is severe and incapacitating. In these patients, therapy specific to the underlying pathology (as opposed to symptomatic treatment such as non-steroidal analgesics) is appropriate. The emergency room physician has a couple of options. The first is the use of intravenous caffeine. The dose is 500 mg caffeine sodium benzoate administered in 1L of Saline 0.9% over one hour. It is reported to be effective in more than 75% of patients. A second infusion, eight hours after the first, can be used if the first dose does not afford relief.

If intravenous caffeine were ineffective, then the next step would be the use of an epidural autologous blood patch. In this technique, 10-20 ml of blood are withdrawn from the patient and injected into the epidural space at the site of the initial lumbar puncture. The blood is injected at a rate of 1-2 ml every 10 seconds or so. After the injection, the patient remains supine for about an hour and is rehydrated. Relief is usually evident within 30 minutes of the completion of the procedure. This technique is not without complications and, hence, the reason that caffeine infusions are a first line therapy. Complications of the epidural blood patch procedure include back pain and stiffness, paresthesias, radicular pain, subdural hematoma, adhesive arachnoiditis and bacterial meningitis.

Q. What can emergency room physicians do to decrease the rate of post lumbar puncture headache in their patients?

A. Post dural puncture headache appears to occur more commonly in females and in adults between the ages of 20 and 40. It is also more common in obese patients and in patients with a prior headache history.

There is no evidence that keeping patients lying down for prolonged periods after the procedure has any impact on the development of post dural puncture headache. Equally, psychological factors, rapidity of CSF removal and patient position during lumbar puncture do not seem to be related to the onset of post dural puncture headache.

Factors that have been found to be important include the size of the needle and the angulation of the bevel of the needle in relationship to the fibers of the dura. The incidence of post dural puncture headache is reduced when the bevel is angled to be parallel with the dural fibers that run lengthwise down the spine. The theory is that this orientation tends to part the fibers, while having the bevel at right angles tends to cut the fibers and, thus, be more likely to produce a hole through which CSF may leak.

This patient responded promptly to the administration of 500 mg of caffeine and was discharged home.