Migraines have four phases: predrome, aura, headache and prodrome. Silent migraines are thought to be a misnomer by many since they lack the headache phase. Silent migraines are diagnosed when three of the four phases of a migraine are present. Migraines with all the phases except aura are the most prevalent.
Significance
Migraines are a top 20 disability-inducing disease, according to the World Health Organization. The prevalence of silent migraines is on the rise as the rate of migraine-induced emergency room visits has risen 60 percent from 1998 to 2008, according to the National Migraine Association.
Identification
The National Headache Foundation lists many potential triggers for a silent migraine. Typically the predrome begins after a visual or auditory stimulus. For instance, bright sunlight is a common trigger. Auras manifest as blurred vision or blindness, zigzag lines or color distortions. The headache phase is absent, and the prodrome is the recovery period. Recovery may also include the same sensitivities present in the predrome as well as nausea. Silent migraines are typically associated with visual migraines that have exacerbated aura symptoms. Any migraine should be investigated by a health care professional in order to rule out any more serious condition.
Causes
There are two primary causes of silent migraines. First, a small vasospasm or dilation of blood vessels occurs at or around the eye or visual cortex of the brain, according to Dr. Steven Ofner, an Oregon-based ophthalmologist. These vasospasms are often the cause of visual distortions perceived by the migraine sufferer. Secondly, a small constriction of blood vessels anywhere in the brain may not be above a person's pain threshold but still have the potential to induce a sense of nausea or fatigue often associated with silent migraines.
Prevention/Solution
The easiest method to prevent silent migraines from occurring is to avoid triggers. Since each trigger is unique to the migraine sufferer, avoidance can be difficult. In order to identify triggers, a detailed journal should be kept that outlines daily activities, time of day performed, and all foods eaten. Triggers can range from environmental factors to food allergens. Documentation can reveal patterns and help determine triggers.
Treatment
Over-the-counter pain medication may treat some predrome and prodrome symptoms; however, the majority of silent migraine symptoms are visual and must be treated with prescription medications. The National Headache Foundation indicates that medications for epilepsy, depression and beta-blockers are effective migraine preventative treatments. All of these medications require strict physician oversight and each has its own side effects to consider.
