Long COVID’s Impact On The Brain

According to the Centers for Disease Control and Prevention (CDC), around 17% of U.S. adults say they've experienced the symptoms of long COVID, which can linger for weeks, months, or years after being infected with the COVID-19 virus. For many, that can include neurologic symptoms like headaches, brain fog, and more.

"I see people in our practice who suffer particularly with headache issues associated with long COVID. And that plays a role with concentration, attention, and memory," says Noah Rosen, MD, a neurologist at Northwell Health.

Experts are still figuring out the best way to treat these issues, but we do have more knowledge on how COVID infections may impact the brain, when long-term symptoms tend to ease up, and what you can do to protect yourself. Here's what you should know.

What are the symptoms of long COVID?

People with long COVID have reported a wide range of symptoms—more than 200 to date. Many are similar to the symptoms of an active COVID infection, including fatigue, coughing, chest pain, trouble breathing, or digestive issues.

Neurological symptoms are also common, including:

• New or worsening headaches (like pre-existing migraines that become more frequent or severe)
• Trouble thinking or concentrating
• Sleep problems
• Dizziness upon standing
• Pins and needles or tingling sensations
• Changes in smell or taste
• Depression or anxiety

For many people, COVID-related headaches "tend to be fairly short and self-resolving, with around four days of moderate headaches," says Rosen. "But that isn't the case for everyone.” In fact, it’s not uncommon for long-COVID symptoms to last for three to six months. And for some, the neurological effects may last for two to three years, recent research suggests.

Why does long COVID affect the brain?

There's still a lot to piece together, but researchers are rapidly learning more about why COVID causes long-term symptoms. One theory is that COVID infections trigger an autoimmune reaction where the immune system mistakenly attacks the body's own healthy cells.

Post-infection inflammation could also play a role. "There’s no evidence that COVID stays around in the body the way that some other viruses do, like chickenpox, which can reemerge as shingles in adulthood," Rosen explains. "But the inflammation caused by the virus can linger."

Some of this inflammation may occur in the brain. Animal studies have shown that hamsters infected with COVID-19 experienced inflammation that caused tissue in the brain to change.

And changes in the gut microbiome may factor in. Studies suggest that COVID-19 may live in a person's gut even after the infection. That in turn may influence the brain's production of the feel-good neurotransmitter serotonin, which plays a key role in memory storage and other mood-related functions.

Are there serious long-term impacts?

Since long COVID is still relatively new, experts can't say for certain how the condition could affect the brain many years down the road.

While long-COVID symptoms do resolve within three to six months for most people, research suggests that some could suffer longer-term effects. One small British study found that some patients who were hospitalized for severe COVID had worse cognitive function a year after their infection compared to those who weren't hospitalized. These deficits were similar to 20 years of normal brain aging, the researchers estimate. Patients with severe infections or a history of encephalopathy (reduced blood flow to the brain) were most at risk.

These findings may be unsettling, but you shouldn't panic. While COVID can make you feel lousy, sometimes for a while, "most people who have had COVID have no significant impact on their cognition," says Rosen.

And even among people who do develop neurological symptoms, there's hope that the effects will ease up over time. Ongoing follow-up to the British study suggests that many of the patients who experienced worse cognitive function are recovering.

Managing neurological symptoms of long COVID

It's important to work with your health care provider to address problems like headache or brain fog, or if you have other symptoms that seem like long COVID. "If these symptoms are interfering with your daily interactions or activities, it warrants further investigation, regardless of the cause," says Rosen.

Headaches can often be managed with medications, although the types of meds your doctor might recommend will depend on your specific symptoms and headache history. Over-the-counter pain relievers like ibuprofen or acetaminophen can also be helpful, especially for milder headaches. But you should discuss your usage with your doctor. "People who use these medications more than 15 days a month might be putting themselves at risk for rebound headaches, so these treatments should be reviewed," says Rosen.

When it comes to brain fog, unfortunately, there isn't one specific treatment. Intentional lifestyle changes like getting more sleep, exercising regularly, eating wholesome food, and giving yourself breaks throughout the day can make a difference. Antidepressants can also be beneficial in some cases.

That could change in the future. Early research has shown that a combination of the medication guanfacine and the antioxidant N-acetylcysteine (NAC) may reduce long COVID-related brain fog symptoms.

How to protect yourself from long COVID

Getting vaccinated against COVID-19 is the best way to reduce your chance for a serious infection, and in turn, developing long-COVID symptoms. "There's good evidence that regular vaccination improves long-term outcomes," Rosen says.

And if you do come down with COVID-like symptoms, get tested to confirm your infection—and let your doctor know. Antiviral treatments can reduce your likelihood for severe symptoms and help you get better faster, although they need to be taken within five to seven days of your symptoms starting. Together, you and your doctor can decide if the treatment is right for you.

• A COVID long-hauler’s first-person perspective.
• Can you get COVID from the COVID vaccine?
• Learn about Northwell’s telehealth options.