Persistent Cognitive Dysfunction Following Long Covid

New data has found high rates of lasting “brain fog” or cognitive dysfunction to average close to 8 months after patients have been diagnosed and treated for Covid-19.

A study of 740 people, with a mean age of 49 years, was published as a research letter in the Jama Network Open. The study was conducted in the United States and included individuals treated in outpatient settings, as well as those admitted to the hospital or treated in emergency departments. All participants in the study did not have any previous issues with memory or cognitive problems.

In this cross-sectional study, researchers analysed data from April 2020 to May 2021, adjusting for race, ethnicity, smoking status (smoker or non-smoker), body mass index, comorbidities, and any previous or existing depression.

One of the co-authors of the study, Jacqueline H. Becker, PhD, from the Division of General Internal Medicine at the Icahn School of Medicine at Mount Sinai in New York City, noted that this study has implications for both younger people and older populations, who are known to be more susceptible to cognitive impairment.

The paper suggests that there are long-term cognitive repercussions from COVID-19, regardless of disease severity, that may impact people across various age groups.

Most common impairments

The study found some of the most common impairments to be:

• Memory encoding (the act of getting information into our memory system through automatic or effortful processing) -> 24%
• Memory recall -> 23%
• Category, or letter, fluency (ability to produce as many unique words as possible within a semantic category tested by listing as many animals as possible in a minute, for example) -> 20%
• Reported deficits in processing speed -> 18%
• Executive functioning (working memory, flexible thinking, and self-control) -> 16%
• Phonemic fluency (sum of correct, non-repeated words that an individual produced in the N and A letter trials) -> 15%

Serious impairments

More broadly, for many people across the world, long COVID is associated with serious neurological and neurocognitive impairments, a phenomenon sometimes also referred to as neuro-COVID.

“Pointy orange things, and of course, they’re carrots. I was struggling to search for the names of things,” said Dr Kerry Smith, a UK family doctor, referring to her post-COVID symptoms after she contracted the virus from a patient who had returned from Wuhan, China, who presented with a fever and persistent cough.

As the COVID-19 pandemic continues to progress, there is increased awareness that close to 1 in 3 who tested positive for COVID-19 and were usually not admitted to the hospital for treatment, commonly referred to as long COVID, do not recover fully by 3 months.

An international study of people with long COVID documented 203 different symptoms across 10 body systems, with more than 88% of the 3,762 people who completed the online survey reporting memory problems and cognitive dysfunction, making these the “most persistent and pervasive symptoms in this cohort, equally common across all age groups.”

Two-thirds (65%) reported experiencing symptoms for 6 months, with cognitive dysfunction one of the top three most debilitating symptoms, alongside fatigue and breathlessness. Brain fog is the most common symptom described by people with cognitive dysfunction following COVID-19.

If you would like more guidance on managing long COVID and alleviating your symptoms, we are here to help.