Migraine Diagnosis and Management

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Wyeth

TRENDS IN PHARMACY AND PHARMACEUTICAL CARE

Headache is a common ailment suffered by humans for centuries. References to headache can be found in ancient Greek, Egyptian, and Persian medical writings. Even the great Zeus suffered from a headache that was alleviated only by the blade of Vulcan's ax. Ancient treatments for headache varied from application of herbal poultices to head-binding instruments and ingestion of mercury. One of the most frightening therapies was cranial trephination, a process by which the cranium was pierced with a hot iron. The resulting foramen allowed evil spirits or vapors to escape, theoretically eliminating the source of the headache.

The term migraine originated from the Latin word hemicrania, which Galen used to describe pain on one side of the head. He theorized that accumulation of bile in the body irritated the intracranial structures and thus caused headache. He hypothesized that the throbbing pain of migraine occurred due to alteration of blood vessels.

Second only to tension headaches, migraines are a very common primary headache disorder. The point prevalence of migraines is about 12% (an estimated 12% of the population suffers from a migraine headache at any given point in time). The typical migraineur is a young, reproductive age female with a family history of migraines. Individuals with a migraineur relative are thought to have a three times higher risk for migraines than individuals without an afflicted relative.

Pathophysiology and classification

Headaches are divided into primary or secondary disorders. The International Headache Society classifies headaches based upon diagnostic criteria. The patient history and the headache history are the crux of diagnosis and correct classification. Primary headache disorders are divided into the following main categories: tension type, migraine, cluster, and chronic daily headache. Secondary causes of headache are listed in Table 1. Several secondary causes of headache can result in significant morbidity or death. Secondary causes of headache and other headache disorders must be excluded prior to the accurate diagnosis of migraine.

The diagnosis of migraine is often difficult. An estimated 60% of migraineurs have not been diagnosed as such. Non-neurologist, primary care physicians may not accurately diagnose migraines. Migraines may often be incorrectly classified as tension type or cluster headaches. Finally, headache classification by symptomatology can be challenging. For example, to assume all migraineurs suffer from photophobia is poor practice. Similarly, a patient with classic tension type headache may present with photophobia. Patients may also present with more than one type of headache, which further complicates correct diagnosis and optimal treatment.

Migraine symptoms are diverse and can vary appreciably among patients. The two main types of migraine are classic (migraine with aura) and common (migraine without aura). The chronology of migraine can be divided into four phases: prodrome, aura, headache, and postdrome. The prodrome can occur up to 24 hours prior to the onset of pain. Patients may experience irritability, yawning, food cravings, depression, and other nonspecific symptoms during this phase. The aura usually occurs within an hour before pain onset; however, aura may occur without headache onset or may occur while the patient is asleep. The most common auras are visual. The patient may describe the visual aura as similar to "heat" rising off pavement in the summertime. Other auras may resemble water cascading down a window pane or sparkling stars. Another regularly described visual aura is a fortification spectrum where the patient sees highlighted, zigzag lines around objects or in portions of the visual field.

The second-most common aura is paresthesia or a tingling sensation. …