An Overview of Silent Migraines

Acephalgic migraine, or "silent migraine," is a form of migraine that occurs without an actual headache. This type of migraine is more common in people over the age of 50 and can happen to people who have had migraines before as well as people who have never had migraines.

This article will go over the phases of silent migraine symptoms, the causes, and the risk factors for this type of migraine, as well as how silent migraines are diagnosed and treated. 

Symptoms of a Silent Migraine

Symptoms of silent migraines typically involve three of four migraine phases. A silent migraine goes through the prodrome, aura, and post-dome phases but skips the headache phase.

The four phases of a typical migraine are:

• Prodrome phase: Symptoms appear that are warning signs a migraine is coming on
• Aura phase: Visual disturbances some people have before a migraine attack
• Headache phase: Pain from the headache starts (the hallmark symptom of most kinds of migraine). Silent migraines skip this phase.
• Post-drome phase: After the headache, the "hangover" feeling people may have when an attack is done

People with silent migraine usually do not have one-sided head pain and they are also less likely to have other classic migraine symptoms like sensitivity to light, sound, and odors at the height of their episodes.

Even without a headache, silent migraines can disrupt a person’s daily activities. The classic "half-moon" visual disturbance (where there is vision loss in half of both eyes), changes in color perception, and other vision problems are common. 

Types of Migraine

A silent migraine is just one type of migraine. The different types of migraines are usually described based on the symptoms they cause and where they’re felt:

• Migraine with and without aura. Some people get "warning signs" or symptoms before the pain of a migraine headache starts. Some people get migraines without an aura.
• Hemiplegic migraine. This migraine causes symptoms that some people mistake for a stroke, like temporary weakness or even paralysis on one side of the body.
• Ophthalmoplegic migraine. This migraine is not common but can cause vision problems like trouble moving the eyes. 
• Vestibular migraine. This type of migraine causes people to feel very dizzy (vertigo) for a few minutes or even a few hours.
• Abdominal migraine. This type of migraine causes GI symptoms like stomach pain and nausea instead of a headache.
• Menstrual migraine. This type of migraine is linked to a person’s menstrual cycle. 
• Basilar migraine. This uncommon migraine can be very scary, as it causes intense symptoms like passing out (fainting), vision changes, and trouble talking. 

Causes and Risk Factors for Silent Migraines

As with migraine disease in general, the exact causes of a silent migraine are not fully understood. However, there are a few possible risk factors:

• History of migraines. Silent migraines can happen in people who have had migraine symptoms before, but they can also develop “out of the blue” in people who have never had a migraine.
• Age. People of any age can get migraines and they tend to start in adolescence or young adulthood. Some studies suggest that people over age 50 are more likely to have symptoms of acephalgic migraine. When older people who have had migraines before get silent migraines, symptoms such as nausea, vomiting, and sensitivity to light and sound tend to diminish along with the headaches.
• Sex. Some research suggests that acephalgic migraines account for 3% of migraines in females and 1% in males.
• Genetics. Migraines often run in families. People who have family members who get migraines are often more likely to have some kind of migraine themselves.
  

The triggers for silent migraines are the same as those for other types of migraines and headaches and include:

• Certain foods (e.g., chocolate, artificial sweeteners) and drinks (e.g., caffeine, alcohol)
• Getting dehydrated and skipping meals
• Environmental factors (e.g., lights, smells, sounds, weather changes)
• Stress
• Not getting enough sleep 
• Hormones
• Certain medications (including overusing medications that treat headaches)

Diagnosing Silent Migraines

Diagnosing migraines without headaches can be tricky. A provider may need to use different tests to rule out other conditions. For example, they may do some blood work or use imaging tests (like an MRI or CT scan) to see inside the head or neck.

Sometimes, a provider will want to do a more involved test (like a spinal tap) to rule out a serious condition like an infection. One of the exams a provider will do can test a person's brain and nerve function (neurological exam).

It’s possible for a person to be mistakenly diagnosed with epilepsy because the symptoms they get during a migraine attack and the results of their neurological exam can be similar. Acephalgic migraines are also misdiagnosed as transient ischemic attacks (TIAs) or strokes.

Some specialists say that an acephalgic migraine should be considered a cause of an acute episodic neurologic disorder, whether it includes headache symptoms or not.

Treating Silent Migraines

Treatment of silent migraines depends on your symptoms.

Prevention is usually the first place to start. It often includes many of the same things that are used for typical migraines with headaches, such as medications for certain health conditions (e.g., high blood pressure or seizures) or antidepressants. Learning your triggers and trying to avoid them is also key.

There are some new treatments to prevent migraines with and without auras, including anti-CGRP (calcitonin gene-related peptide) medications like Zavzpret (zavegepant) and devices like Cefaly (a transcutaneous electrical nerve stimulation device). However, these have not been studied in people with acephalgic migraine. 

While you’re having an attack, your provider may recommend over-the-counter (OTC) and/or prescription treatments to help with your symptoms.

Summary

A silent migraine is similar to other types of migraines but does not cause a headache. While they are different from other kinds of migraines, the diagnosis and treatment are similar. Your provider will want to rule out other causes for your symptoms before diagnosing you with silent migraines and starting treatment and migraine prevention.