NEW ORLEANS – , adding to mounting evidence of the significant toll the chronic condition can have on mental health.
“Many clinicians have observed the symptoms we describe in this study, however this report is among the first which identify the specific deficits using neuropsychological testing to better characterize the syndrome,” Sean T. Lynch, MD, first author of a study on the issue presented at the annual meeting of the American Psychiatric Association, said in an interview.
Dr. Sean T. Lynch
Dr. Lynch, of the department of psychiatry, Westchester Medical Center Health System, Valhalla, N.Y., and his colleagues enrolled 60 participants who had experienced acute COVID-19 disease 6-8 months earlier and had undergone neuropsychological, psychiatric, medical, functional, and quality-of-life assessments. Results from the study were published online in the Journal of the Academy of Consultation–Liaison Psychiatry (2022 Jan 25. doi: 10.1016/j.jaclp.2022.01.003).
Among the study participants, 32 were seeking treatment for brain fog in a clinical program for survivors of COVID-19, while the remaining 28 were part of an ongoing longitudinal investigation of neuropsychological, medical, and psychiatric sequelae of COVID-19, but were not seeking care for the persistent symptoms.
Assessments for neurocognitive impairment included a battery of tests used in infectious and other diseases, including the Test of Premorbid Function, the Patient Assessment of Own Function, the Trail Making Test parts A and B, the Stroop Color and Word Test, and others.
Overall, the battery of assessments showed that 37 (62%) of participants had neuropsychological test impairment, with results below the 16th percentile in two tests, while 16 (27%) showed scores indicative of severe impairment (below the second percentile in at least one test and below the 16th percentile in one test).
Those reporting brain fog had scores that were even lower than expected on tests of attention, processing speed, memory, and executive function. And among those reporting brain fog, significantly more had scores reflecting severe impairment compared with the controls (38% vs. 14%; P < .04).
“Based on what we’ve observed in our patients and what others have previously reported, we did expect to find some impairment in this study sample,” Dr. Lynch noted.
“However, we were surprised to find that 27% of the study sample had extremely low neuropsychological test scores, meaning that they scored at least two standard deviations below the expected score on at least one neuropsychological test based on their age and level of education.”
The brain fog group also reported significantly higher levels of depression, fatigue, PTSD, and functional difficulties, and lower quality of life.
Severe impairment on the neuropsychological tests correlated with the extent of acute COVID-19 symptoms, as well as depression scores, number of medical comorbidities, and subjective cognitive complaints.
An analysis of serum levels of the inflammatory markers among 50 of the 60 participants showed that 45% of the patients had an elevated IL-6, 20% had elevated TNF-alpha, and 41% had elevated CRP, compared with reference ranges.
IL-6 levels were found to correlate with acute COVID-19 symptoms, the number of medical comorbidities, fatigue, and measures of executive function, while C-reactive protein (CRP) correlated with current COVID-19 symptoms and depression scores.
In terms of clinical factors that might predict low neuropsychological test scores, Dr. Lynch noted that the “markers that we found to be significant included severity of acute COVID-19 illness, current post-COVID-19 symptoms, measures of depression and anxiety, level of fatigue, and number of medical comorbidities.”
Dr. Lynch noted that the ongoing study will include up to 18-month follow-ups that are currently underway. “The [follow-ups] will examine if symptoms improve over time and evaluate if any intervention that took place was successful,” he said.