Neurobiological Underpinnings of Neuropsychological Consequences in Long COVID

COVID-19 patients with persistent complaints of cognitive disabilities (more than 4 weeks post-infection) in daily life are examined with an extensive neuropsychological test battery (see below) at the outpatient clinic of the University Psychiatric Centre in Duffel and at the University Hospital Antwerp. This battery covers a broad range of reliable and valid tests divided into six cognitive domains: attention, memory, visuospatial functions, language, executive functions and psychomotor speed/coordination. The neuropsychological examination lasts an average of 2 hours per participant. The tests are carried out by the same experienced neuropsychologist and also follow a standardized sequence. In addition to the neuropsychological assessment, two self-report scales are filled out by each patient. These scales are used to detect possible complaints of fatigue and possible cognitive problems which are experienced by the patient during daily life activities.

Both self-rated surveys and clinician administered questionnaires

"Blood samples will be collected in a standardized manner by venipuncture. Two blood vials will be collected and processed to perform the following analyses:~* serum collection tube(s) allowing for HERV-W ENV and serological assays~* plasma collection tubes for the assessment of other immune-related biomarkers (including but not limited to CRP, IL-6, IL-1b, TNF-a, IFN-g, tryptophan, kynurenine, 3-OH-kynurenine, quinolinic acid, kynurenic acid, enzymes of the kynurenine pathway)."

Salivary cortisol measures will be used as functional measure of the HPA axis activity, as the unbound cortisol fraction in saliva is highly correlated to plasma cortisol. Baseline diurnal cortisol and CAR levels will be measured using saliva, collected at home with Salivette® (Sarstedt) synthetic swabs. The rationale behind the choice of home sampling, is to maximize normal circumstances and to minimize stress related to the measuring procedure.