Objective:

To examine changes in cognition in adults with “Brain Fog” secondary to Post-Acute Sequelae of COVID-19 (PASC).

Background:

While “brain fog” is common in PASC, little is known about the trajectory of cognitive functioning in these patients.

Design/Methods:

119 patients completed baseline neuropsychological evaluation, including clinical interview, cognitive assessments, and a comprehensive battery of self-report questionnaires, 12 to 134 weeks after symptom onset. Patients had mean age 50 years (range:18 to 74, SD=10.1), were primarily female (74%) and White/Caucasian (75%). 43 patients underwent follow-up neuropsychological evaluation, 6 months after initial evaluation. Hierarchical agglomerative clustering was used to partition data into groups based on cognitive performance.  Paired t-tests were used to compare performance of clusters between baseline and follow-up. 

Results:

Clustering yielded two distinct clusters: Group 1(n=57) performed worse than Group 2(n=62) on most cognitive variables at baseline and follow-up.  There were no significant differences between groups in age, gender, income, or infection severity. Group 1 had a lower education level than Group 2 (M=14.7, SD=2.45 vs. M=16.2, SD=2.42; p=.001) and more minorities than Group 2 (40% vs. 8%; p<.001).  At follow-up, group 1(n=20) showed improvement on the MoCA (M=23.0, SD=3.60 vs. M=25.3, SD=3.50, p=0.016) and CVLT delayed recall (M=18.0, SD=17.5 vs. M=39.1, SD=29.7, p=0.006) but not on tests of attention/working memory, executive function, or processing speed.  Group 2(n=23) showed improvement on the MoCA (M=26.4, SD=2.19 vs M=27.5, SD=1.97, p=0.034), letter fluency (M=36.1, SD=26.8 vs M=49.5, SD=23.8, p=0.031), animal fluency (M=44.6, SD=30.3 vs M=66.8, SD=28.8, p=0.003), and story recall (M=59.5, SD=24.8 vs M=73.0, SD=25.7, p=0.040).

Conclusions:

Neuropsychological scores 6 months after initial evaluation in patients experiencing brain fog from PASC show improvement in global cognition and aspects of memory. Findings suggest that these patients may not experience spontaneous resolution of all cognitive symptoms within 6-12 months but may have gradual improvement in specific cognitive symptoms.