Those with COVID-19 hospitalizations see lower cognitive function

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The year may be new, but the concerns about COVID-19 are old: A new study in JAMA shows that people who have been hospitalized with COVID-19 perform worse on cognitive and neurological tests, suggesting impaired brain function.

These cognitive struggles persist 18 months after the hospitalization, the data shows. Patients diagnosed with the coronavirus often had new psychiatric diagnoses, fatigue and impaired olfaction compared to the control group.

In the group with COVID-19, there was a substantial improvement in cognitive scores between discharge and the 18-month follow-up, but not between 6-month and 18-month follow-ups. Coronavirus patients also experienced an increase in psychiatric comorbidities, neurological findings and subjective symptoms involving memory and sleep between their 6-month and 18-month follow-up.

WHAT'S THE IMPACT?

The findings are in harmony with previous research showing persistent cognitive impairment among 12 to 50% of patients one year after infection. Thirty-eight percent of patients with COVID-19 had Montreal Cognitive Assessment (MoCA) scores below 26 (out of a possible 30) at 18-month follow-up and performed worse in all cognitive tests compared with the healthy population. MoCA scores are a rapid screening instrument for mild cognitive impairment.

Anxiety and depression were more frequent among patients with COVID-19 compared with healthy controls, but no more frequent than among other hospitalized patients. As for neurological outcomes, patients with COVID-19 more often had neurological "soft signs" – subtle neurological abnormalities – compared to healthy patients, but these were similar to patients hospitalized for other reasons.

There was a link between COVID-19 and long-term cognitive deterioration among older adults, and these cognitive scores sometimes decrease over time: The study noted an increase in psychiatric diagnoses (17.9% to 32.1%) and neurological abnormalities (25 t% to 51.8%) over time, though one explanation could be selection bias, whereby individuals who chose to participate in both follow-up visits might have had ongoing concerns and requested further evaluation.

However, previous studies have reported similar rates of psychiatric morbidity (45%) and neurological abnormalities (64%) one year after infection.

"Altogether, while it is essential to interpret these findings with caution due to the limited longitudinal data available, the possibility of worsening brain health over time cannot be ruled out," authors wrote.

THE LARGER TREND

The Centers for Disease Control and Prevention is closely monitoring JN.1, currently the fastest-growing COVID-19 variant in the U.S., representing about 21% of new cases, according to the agency's numbers.

The variant is closely related to the prior variant BA.2.86. It has just one additional change in its spike protein. This small change, the L455S mutation, may make it more apt to evade immune system responses, the CDC said.

JN.1 was first detected in the U.S. in September, and for the first month or so only accounted for 0.1% of coronavirus transmissions. The fact that it has continued to grow, and the rate at which it's growing, suggests that it's either more transmissible or is better at working around people's immune systems. Still, the CDC didn't find evidence that the variant presents an increased risk to public health compared to other current variants.

That's a positive finding not just for patients, but for hospitals, whose resources and workforces were strained almost to the breaking point during the height of the pandemic.
 

Twitter: @JELagasse
Email the writer: Jeff.Lagasse@himssmedia.com