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MIGRAINE HEADACHES: UNDERDIAGNOSED, UNDERTREATED, AND MISUNDERSTOOD

MIGRAINE DIAGNOSIS: A BRIEF SUMMARY

Common migraine and classic migraine

Migraine headache is a primary headache disorder that presents as a progressively severe, unilateral, throbbing headache that involves the ocular or frontotemporal regions. The condition can affect up to 15% of the population and is more common in women than in men. The headaches may be accompanied by nausea, vomiting, photophobia, phonophobia, focal neurological deficits, or a combination of these symptoms. Migraine headaches are further classified by the International Headache Society into distinct categories of headaches with aura or without aura. Migraine without aura (also known as common migraine) is the most common and affects about 80% of patients with the condition. Migraine with aura (also known as classic migraine) occurs in the remaining 20% of patients.¹

Approximately 60% of migraine headaches have an associated prodrome that consists of warning symptoms, which may precede the actual headache by hours to days. These premonitory symptoms are varied and diffuse. They may include difficulty sleeping, depression, or fatigue.

Prior thinking classified migraine events as vascular headaches that involved periods of vasoconstriction-induced cerebral ischemia (during the aura phase) followed by vasodilation. Migraine is now more thought of as a neurologic process mitigated by the trigeminovascular system with several distinct phases that include (1) prodrome, (2) aura (absent, mild, moderate, or severe), and (3) postdrome. During any particular attack, each phase may or may not be present.²

In classic migraine headaches, the aura is typically a visual disturbance and is defined as a specific subjective report from the patient that precedes the headache. The visual report usually consists of a pattern of brightly colored lights that begins in the middle of the visual field and progresses outward to the periphery. This specific pattern is referred to as fortification spectra. A patient may also describe a hole within the visual field, which is referred to as a scotoma.

Less common types of aura may involve other sensory systems; such symptoms may include intermittent numbness of a hand or one side of the body. Auditory hallucinations may occur, as well as abnormalities in taste and smell. In all cases of migraine with aura, the physician must be concerned that another neurological process may be present, such as transient ischemic attack (TIA), stroke, mass lesion, or seizure disorder. Because of this concern, migraine with aura becomes a diagnosis of exclusion and may often be misdiagnosed.

Complicated migraine

Another type of migraine, which is termed complicated migraine, can lead to a misdiagnosis or improper treatment. Complicated migraine headaches occur with focal neurological dysfunction such as hemiplegia, vertigo, or hemisensory loss. Given the acuity of the presentation, cerebrovascular disease (bland infarcts vs bleeds) must be excluded. Other forms of cerebrovascular disease, such as TIA, must also be considered.

Complicated migraine is accompanied by clear neurological deficits. Complicated migraines may present as problems that involve the brainstem and posterior circulation. Initially, the patient may report vertigo, diplopia, and visual disturbances in the absence of headache. Migraines in which these symptoms are predominant are referred to as vertebrobasilar migraine. Clinical presentations of such headaches should be evaluated emergently, and progressive basilar thrombosis needs to be excluded.

Complicated migraine may also take the form of hemiplegic migraine. These events are associated with a paralysis of one side of the body and, upon initial presentation, may be misdiagnosed as a stroke. The paralysis is reversible as the episode subsides, although the patient may not fully regain function until days later.

Many patients describe fatigue for approximately 24 hours after a migraine episode ends. They may feel weakened and continue to experience sensitivity to light, sounds, and smells. The headache may resurface during this time, as well. Migraines may be poorly controlled for various reasons, including lack of patient compliance, multiple comorbidities, misdiagnosis, undertreatment, and chronic self-medication with caffeinated products or butalbital. A poorly controlled migraine may lead to an attack that can last days.³ This prolongation of a migraine headache is termed status migrainosus. In such instances, a patient may need to be hospitalized to break the headache cycle and begin a prophylactic medication protocol tailored to his or her needs.

MIGRAINE-RELATED EVENTS: WHERE MISDIAGNOSIS BEGINS

In some cases, migraine may exhibit itself in a form other than head pain. Such cases are called migraine variant or migraine equivalent. These events are characterized by episodes that have the following features:

1. The events are paroxysmal.
2. The events involve auras, which may manifest as prolonged visual events or atypical sensory, motor, or visual auras.
3. Focal neurologic deficits such as hemiplegia, hemisensory loss, visual field deficits, or difficulty speaking may be present.
4. Gastrointestinal presentations (eg, abdominal pain, cyclic vomiting) may occur.
5. More varied and generalized symptoms, such as chronic fatigue or confusion, can occur.

MIGRAINE TREATMENT: MONITOR CLOSELY AND TREAT AGGRESSIVELY

Migraine treatment involves abortive and prophylactic care. Abortive care simply involves taking a medication at the onset of the headache or aura. Prophylactic therapy is more involved and is reserved for those patients who experience more than 8 headaches per month that do not respond to abortive care or whose headaches last more than one day during each episode. In many cases, both types of therapy are used simultaneously.

The clinician needs to rapidly and accurately assess a patient’s presentation of headaches in order to prescribe appropriate care. Headaches of sudden onset and severity suggest a potentially serious organic etiology, such as subarachnoid hemorrhage or intracerebral bleed, and are beyond the scope of the current discussion.

In the evaluation of patients with a headache, clinicians may use not only the past medical history of the patient and the typical symptoms and features of migraine headaches (including those discussed above) but also simple and efficient headache screens from the literature, some designed specifically for migraine headaches. These headache screens allow clinicians to delve deeper to further classify the events in terms of their characteristics (ie, premonitory signs, auras), duration, frequency, and severity.⁴ In the current era of cost-effective and evidence-based medicine, careful diagnosis leads the patient to a rapid treatment protocol and allows the patient to resume full function of daily activities.

REFERENCES

1. Rasmussen BK. Epidemiology of headache. Cephalalgia. 1995;15(1):48-68.

2. Goadsby PJ, Edvissson L, Ekman R. Relasase of vasoactive peptides in the extracerebral circulation of man and the cat during activation of the trigeminovascular system. Ann Neurol. 1988;23193-6.

3. Osterhaus JT, Townsend RJ, Gandek B, Ware JE Jr. Measuring the functional status and well-being of patients with migraine headache. Headache. 1994;34:337-43.

4. Cady RK, Borchert LD, Spalding W, et al. Simple and efficient recognition of migraine with 3-question headache screen. Headache. 2004;44(4):323-27.