Migraine is one of the most common neurologic diseases, affecting about 14% of the population. Migraines may also be associated with auras or visual or sensory symptoms that precede the headache. However, approximately 4% of people with migraine experience their usual migraines and sometimes also experience episodes of an aura that is not followed by a headache. Silent migraines, also known as acephalgic migraines or "migraine auras without headache," typically cause symptoms that accompany the phases of a migraine, but without the classic headache pain. It is most common among young adults in their 20s and 30s and older adults between 40 and 60 years of age, especially in those who had auras accompanied by migraine headaches when younger.
According to the International Headache Society, a migraine aura develops gradually over 5 to 10 minutes and lasts for less than 1 hour. Although the symptoms of a silent migraine may vary from person to person, visual symptoms occur in more than 90% of migraine auras. Visual symptoms may also be accompanied by other neurologic symptoms such as dizziness, numbness or tingling, and aphasia. The most common visual symptoms are positive symptoms, such as flash scotoma, visual distortion, colored spots, and flash hallucinations. Visual symptoms may easily be confused with symptoms of a transient ischemic attack (TIA). However, migraine auras generally last 15 to 30 minutes. They are often described as dynamic, bright, multicolored forms in geometric patterns. In contrast, the visual symptoms of a TIA last on average 3 to 10 minutes and are described as a static, dark dimming of vision.
The diagnosis of migraine aura without headache should be made after all other possible causes have been excluded, particularly TIAs and focal seizures because of the diagnostic, therapeutic, and prognostic implications. Testing may include a neurologic and eye examination, MRI, CT angiography, and laboratory testing for clotting disorders.
Migraine aura without headache is a benign condition and generally does not require treatment. When symptoms of silent migraines are severe enough, low-dose aspirin and calcium-channel blockers may be considered as treatment options. However, triptans, which are often used in patients with migraine headaches, should not be used to treat silent migraines because they do not act fast enough to affect an aura. In addition, triptans should be used with caution in older patients, who may have vascular disease, hypertension, and other cardiovascular risk factors.
Jasmin Harpe, MD, MPH, Headache Fellow, Department of Neurology, Harvard University, John R. Graham Headache Center, Mass General Brigham, Boston, MA
Jasmin Harpe, MD, MPH, has disclosed no relevant financial relationships.
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