Long Covid: neurological symptoms can last more than a year after initial infection, study finds

People who have caught Covid can still experience debilitating neurological effects more than a year after their initial infection, new research shows.

A new study, published in the journal Annals of Clinical Translational Neurology, is the longest follow-up study of the neurological symptoms among long Covid patients.

It follows on from a shorter-term study published last spring that focused on 100 patients with long Covid and found that 85% of patients reported at least four lasting neurological problems at least six weeks after their acute infections.

This new research, published on Tuesday (24 May), is the first to look at neurological symptoms over a long time period in patients who did not need to be hospitalised for Covid.

Researchers continued to survey 52 of the original participants who were seen at a Northwestern Neuro Covid clinic between May 2020 and November 2020 for 18 months.

The patients all initially had mild coronavirus symptoms and did not require hospital treatment.

Three-quarters (75%) of the patients were female, the average age of the cohort was 43, and almost 80% of the participants were vaccinated.

What Covid symptoms can last for more than a year?

The study found that patients were still experiencing neurological symptoms for more than a year after first contracting Covid.

The most frequently reported symptoms found found to last for an average of 15 months after the initial infection include:

• Brain fog
• Fatigue
• Headaches
• Dizziness
• Numbness/tingling
• Blurred vision
• Tinnitus

Other symptoms, including heart rate and blood pressure variation, and gastrointestinal problems, were also found to increase over time. By comparison, loss or change to sense of taste or smell tended to improve.

Researchers said that vaccination against Covid did not alleviate symptoms, but it also did not make long Covid any worse.

Most patients did report improvements in their cognitive function and fatigue over time, but the symptoms had not completely gone away and still affected their quality of life.

Dr Igor Koralnik, study co-leader and chief of neuro-infectious diseases and global neurology at Northwestern Medicine, said: “A lot of those patients still have difficulties with their cognition that prevent them from working like they used to.”

What causes long Covid?

Dr. Avindra Nath, the clinical director of the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, who was not involved with the new research said that long Covid symptoms may be the result of damage from the body’s inflammatory response to the virs.

A viral infection activates inflammatory cells in the body, including in the brain, and this inflammation is meant to attack the invading virus. However, it can also cause damage to brain cells and neurons in the process, and Covid triggers a particularly strong inflammatory response, according to Dr Nath.

He said: “Covid is probably the most severe respiratory illness we have ever had, so it’s no surprise that we are seeing long-term effects from it.”

What support is available for long Covid sufferers?

Anyone who is suffering from persistent symptoms four or more weeks after having Covid is encouraged to seek advice from a GP.

A doctor may recommend some tests to find out more about the symptoms and to rule out other factors that could be causing them. This may include a blood test, checking your blood pressure and heart rate, or a chest X-ray.

You may be given advice to help manage and monitor symptoms at home, but if the effects are having a disruptive impact on your life, it is possible you may be referred to a specialist rehabilitation service, or a service that specialises in the specific symptoms you have.

More information to support your recovery can be found on the Your COVID Recovery website.