What Should Non-specialists Look for When They Suspect a Patient May be Suffering from Migraines?

Gary Jay, MD, DAAPM, FAAPM, a neurologist and independent consultant in Raleigh-Durham, NC, discusses the challenges associated with properly diagnosing migraine, reviews the overlapping symptoms that can lead clinicians to confuse migraine with other headache types and misdiagnose a patient, and explains the potential consequences for patients who have been misdiagnosed. This interview is based on information Dr. Jay presented during a presentation titled “Differential Diagnosis of Migraine Headache” at PAINWeek 2011.

What are the challenges associated with assessing and diagnosing a migraine?

The diagnosis of episodic migraine with or without aura is fairly straightforward. The assessment challenges occur when dealing with a headache that doesn’t present in a straightforward manner, such as a migraine with a neurologically complicated aura. For example, patients who experience an acephalgic migraine (a visual aura but no headache) are frequently scared that they are experiencing a stroke, and physicians who don’t know the difference between that and amaurosis fugax (transient loss of vision in one eye) will need to do everything they can to ensure they rule out a transient ischemic attack (TIA) and/or cerebral vascular accident (CVA, aka stroke). The physician needs to know to ask about the time course of the incident—amaurosis fugax occurs essentially “instantly,” or “like a curtain dropping,” whereas the visual aura takes time to develop and it moves across the visual field (at about 4mm/min).

What characterizes a migraine and how does it differ from a tension-type headache?

Per the International Headache Society, (IHS; http://hcp.lv/prvs96) the 2004 definition of episodic migraine includes:

Migraine without aura (about 75-80% of migraine) is formally diagnosed, with at least five lifetime attacks that fulfill the following: The headache must have two of the following four characteristics:

• Moderate to severe intensity
• Throbbing quality
• Unilateral
• Aggravated by Activity
• Nausea and/or vomiting
• Photophobia and phonophobia

Migraine with aura has a typically visual aura associated with the above criteria. Tension-type headache (the IHS notes tension-type headache with or without pericranial muscle spasm/pain) can be generally a diffuse, mild to moderate pain that a patient may describe as akin to a “tight band around my head.” This is the most common form of headache.

Knowing the differential diagnosis of migraine, knowing what questions to ask, knowing how the different headache types present—these are the keys.

What are some of the most frequent missteps non-pain specialists make in diagnosing a migraine?

The most frequent misstep non-specialists make when diagnosing a migraine is not understanding what it is. For example, about 95% of “sinus headache” is actually migraine and responds well to a triptan. The bottom line is that physicians who treat migraine, aside from needing to know how to do a GOOD neurological examination, also need to know how to diagnose a migraine. That requires knowing what questions to ask the patient to help make the diagnosis. Not all headache is migraine, and some forms of head pain can presage significant medical problems. (Can you say “thunderclap” headache?)

Does migraine have a genetic component, and what role does gender play in prevalence?

Migraine does indeed have a genetic predisposition, with over 70%-80% of migraineurs having a positive family history of migraine. Migraine can begin early; some evidence shows that prior to puberty, the male to female ratio is about equal. However, some studies show that boys may constitute a higher percentage of migraine sufferers until puberty, after which point girls begin to make up the majority of cases (this may in part be associated with the flow of estrogen at puberty). The ratio is something like three or four girls for every boy after puberty. Nearly two-thirds of women with migraine experience less severe symptoms (or even cessation of symptoms) during and after menopause. It is rare to develop migraine after age 60.

The most frequent misstep non-specialists make when diagnosing a migraine is not understanding what it is.

With many headache types and symptoms that overlap migraine, what are the most important factors for clinicians to be aware of when diagnosing a potential migraine?

It has been established that a tensiontype headache (for example) may closely follow a migraine, so proper diagnosis and treatment depends on what symptoms the patient presents with, what symptoms they may have had previously, and what symptoms may develop upon with further observation. There are also times when a patient may have the signs and symptoms of an episodic migraine or tension-type headache and also have symptoms of the other form of headache.

Some experts feel that this would be explained by developing a headache continuum with episodic tension-type headache on one side and migraine on the other. I disagree with this approach. Although we know more about the pathophysiology of migraine than we do of tension-type headache, I believe that we know enough to differentiate them. Both involve central sensitization (chronic tension-type headache, not episodic—the same with chronic migraine). This all comes back to the clinician’s understanding of headache diagnosis and awareness that nothing is really as cut and dried as might be thought looking at the IHS classifications.

Sometimes diagnosis is determined by the success or failure of a treatment; however, that must also be taken with a grain of salt (eg, 7% or so of migraineurs don’t respond to a triptan, so failure of a triptan doesn’t make it a tension-type headache).

Once a patient receives a diagnosis of migraine, it is easier for any new physician who sees that patient to adopt that diagnosis and proceed as if it were an established fact, rather than perform an exam and attempt to formulate an alternative diagnosis.

What are the implications of misdiagnosing a patient with migraine?

One major implication of an incorrect assessment of a patient—stating that they have migraine when they may not—is that this establishes a pre-existing diagnosis; some insurance companies may abreact. Another problem is that once a patient receives such a diagnosis, it is easier for any new physician who sees that patient to adopt that diagnosis and proceed as if it were an established fact, rather than perform an exam and attempt to formulate an alternative diagnosis. Also, a patient who has been misdiagnosed with a migraine may be treated incorrectly with a migraineabortive medication. This can cause real problems, as the patient can develop vasoconstrictor rebound headache (a form of medication overuse headache) if he or she takes a triptan or ergot frequently, even though they may not have migraine.

The other side of the coin is that opiates work, especially on tension-type headache. Although I have not placed any patient on a daily opiate, too many physicians have, and thus helped create “chronic migraine” patients with analgesic rebound headache. In 2009, Bigal and Lipton noted that taking opioids eight times a month or more would induce migraine progression, with the effect more pronounced in men than women. They also reported that taking a barbiturate five days or more a month could create the problem, with the effect more pronounced in women (http://hcp. lv/q9Pi5P; http://hcp.lv/nlS3eq). Patients of either sex taking frequent triptans or ergots can develop a vasoconstrictor rebound headache form of medication overuse headache.

What factors should clinicians be aware of when trying to differentiate between episodic tension-type headaches and migraine?

First, many patients who experience a migraine may develop a secondary tensiontype headache afterward. Also, many patients who have a tension-type headache may develop a vascular component that may be secondary to tight musculature compressing the blood vessels. I’ve also seen several patients who developed a myogenic thoracic outlet syndrome secondary to significant muscle spasm concurrent with moderate to severe tension-type headache.

Also, patients with migraine typically report that their headache becomes worse with activity, while activity does not prevent patients with tension-type headache from continuing to work. Nausea and even vomiting may accompany any severe pain, even severe tension-type headache, but this is not common.

How can clinicians improve their assessment and diagnosis of migraine?

Practice! Knowing the differential diagnosis of migraine, knowing what questions to ask, knowing how the different headache types present—these are the keys. Also, there are typically no neurological findings for either form of headache, unless there is a neurologically complicated aura (ie, ophthalmoplegia, hemiplegia), but the musculoskeletal examination may be positive, especially in chronic tension-type headache patients.

Are tension-type headaches overdiagnosed?

Tension-type headaches are the most frequently seen type of headache. If the patient states that his or her headaches are severe, and that they occur frequently, many physicians tend to label them as migrainous in nature. Of the major headache types, tension-type headache has gotten a relatively small amount of research, especially compared to migraine.