A small study, conducted by researchers at the University of California, San Francisco, may help explain the cause behind brain fog, the persisting mental confusion observed in some people whove had COVID-19 infection.

The researchers evaluated 32 adults who had recovered from COVID-19 but did not require hospitalization. Twenty two of them had cognitive symptoms. All study subjects underwent in-person cognitive tests and were scored with the help of criteria for HIV-associated neurocognitive disorder (HAND). Seventeen participants had their cerebrospinal fluid analyzed, which included 13 individuals with symptoms of brain fog. The fluid was taken an average of 10 months after COVID symptoms.

Investigators noted abnormalities in the cerebrospinal fluid of 10 out of 13 people who were infected with COVID-19 and reported having thinking problems. Four fluid samples from people who had COVID but no thinking problems were found to have no abnormalities.

The study is published in the Annals of Clinical and Translational Neurology… (Medscape)