Headache is one of the most common symptoms of COVID-19. Some studies have reported headaches in up to 70 percent of people with COVID-19.
Typically, people describe COVID-19 headaches as either a migraine episode or a tension on the sides of their head.
The term “ocular migraine” has been used to describe two conditions. It may refer to a retinal migraine that causes brief loss of vision in one eye with a headache, or a migraine with aura that causes visual disturbances.
In this article, we’re going to examine the difference between these two types of migraines, and examine the link between ocular migraines and COVID-19.
The term “eye migraine” is often used to refer to any type of headache that causes visual changes. Sometimes it is used to refer specifically to a type of migraine called a retinal migraine.
Retinal migraine is a condition that causes partial or total loss of vision in one eye and headache within 60 minutes of loss of vision.
The reason why these migraine episodes develop is debatable. Some researchers suggest a possibility that narrowing of the retinal or ciliary arteries is causing them. Other researchers suggest that electrical changes in the neurons of the retina cause them.
Partial or complete vision loss usually lasts 10 to 20 minutes before it returns to normal. Your vision can also become blurry or cloudy. You can see lightning or mosaic-like patterns of light.
There is currently no research linking this particular type of migraine to COVID-19.
Migraine aura with visual disturbances
Migraine is a neurological condition that often causes severe headaches. Migraines tend to run in families.
A migraine aura is experienced by approximately 25 percent of people with a migraine, either before or at the same time as a migraine episode.
Typically, people with migraines with aura do not experience all of their migraine episodes, only some of them.
An aura is a temporary visual, auditory, motor, or other sensory change. Visual disturbances can be:
Of the people who experience an aura, about 99 percent have at least one visual symptom with some of their auras.
Some people with a history of migraines report worsening migraine episodes during COVID-19. Some people without a history of migraines report having migraine-like headaches.
A 2020 study found that of 47 people with COVID-19 who reported having a headache, 24 people (51 percent) reported having migraine-like headaches, while 40 percent had symptoms of a tension headache.
Before the development of COVID-19, only 12 of the study participants had previously experienced migraine episodes.
According to a June 2020 research report, the most commonly reported neurological symptoms of COVID-19 are headache and loss of smell.
Serious neurological complications such as stroke or seizures have also been reported, although these are not common with COVID-19.
People who develop COVID-19 sometimes develop symptoms that affect their eyes. A research report from January 2021 found that more than 11 percent of study participants with COVID-19 had eye symptoms.
The most common eye symptoms were:
- dry eyes or a foreign body sensation
- Eye pain
Researchers are still trying to figure out how the virus that causes COVID-19 interacts with our nervous systems. Some people with a history of migraines report an increased frequency or intensity of migraine episodes during COVID-19.
A study from May 2021 highlights three case studies of people with a history of migraines who had migraine episodes during COVID-19.
In two of the people, migraines with aura were the first symptom of COVID-19. The third person developed visual auras at the same time as other COVID-19 symptoms.
Here is a summary of the migraine symptoms the three people had before and during COVID-19:
Why can COVID-19 increase the frequency or intensity of migraines?
In an observational study from August 2020, researchers looked at the symptoms of 13 people with COVID-19 whose main symptom was a headache. Five of the 13 people were previously diagnosed with migraines and three of the people developed a headache as the first symptom.
According to the study’s authors, headaches may develop due to the coronavirus entering the trigeminal nerve, which could activate mechanisms known to cause migraine episodes and other types of pain. The trigeminal nerve is the largest of your 12 cranial nerves.
Research has shown that parts of the trigeminal nerve lack the protective blood-brain barrier that prevents microorganisms from entering the central nervous system.
Autopsy studies have found evidence of degeneration of the trigeminal nerve in people with COVID-19, suggesting either direct damage from the coronavirus or damage from the body’s immune response.
COVID-19 is thought to get into your body’s cells through receptors for an enzyme called angiotensin converting enzyme 2 (ACE2). ACE2 receptors have been found in neuronal cells of the trigeminal nerve as well as in many other parts of the body.
Effects of the pandemic on people with migraines
Various factors related to the COVID-19 pandemic that are not related to direct viral infection may have increased the frequency or severity of migraines in some people.
A September 2020 study found that in a group of 1,018 people with migraines in Kuwait, more than half reported an increase in migraine frequency or severity from before the pandemic.
Factors such as lack of communication with a neurologist and increased stress could have played a role.
Only 4 percent of study participants developed COVID-19, but 63.4 percent of those people said their migraines got worse.
It is possible that ocular migraines may persist in some people even after recovering from COVID-19.
Some people develop headaches that last for months after COVID-19. For example, in one case study, a woman experienced persistent loss of smell and headache 80 days after the onset of symptoms.
During her COVID-19 illness, she suffered from migraine-like headaches, but reported that her subsequent headaches felt different.
Researchers are still trying to understand why some people develop long-lasting COVID-19 symptoms after recovering from their initial infection. Increased inflammation and neurological damage may play a role.
Eye migraines often refer to headaches that cause visual disturbances. It can also refer to a specific type of migraine that causes vision loss called a retinal migraine.
Case studies report that some people with a history of migraines are more likely to develop migraine episodes during COVID-19. Some people without a history of migraines also have migraine-like headaches.