Background and Purpose Biomarkers for neuronal damage have been shown to be elevated during the acute phase of COVID‐19 in plasma and cerebrospinal fluid (CSF) of patients with neurological symptoms. Little is known about the temporal dynamics of these biomarkers and their pathophysiological relationship to neurocognitive post‐COVID condition (neuro‐PCC). Our aim was to conduct a follow‐up of clinical symptoms and biomarkers of patients with neurological symptoms in the acute phase of COVID‐19. Methods Follow‐up was conducted > 4 months after onset of COVID‐19 symptoms. Twenty‐eight patients were included and underwent neurological examination, neuropsychiatric and cognitive assessments, and serological testing. Eight patients underwent lumbar puncture. Neurofilament light (NfL), total tau (T‐tau), glial fibrillary acidic protein (GFAP), and neuronal antibodies were analyzed in serum or plasma and CSF. Results New‐onset symptoms post‐COVID were reported in 82%. Neurological examination revealed abnormalities in 32% of patients. GFAP and T‐tau had normalized in CSF in all patients. However, one patient still showed elevated NfL chain levels in CSF, while two patients had elevated NfL in plasma. New‐onset neuronal antibodies in serum were found in 5/27 (19%) and in one patient in CSF. No correlation was found between biomarker levels during acute COVID‐19 disease and subsequent neurological symptoms or examination findings at follow‐up. Conclusion Several patients reported new‐onset neurological and cognitive symptoms, despite the absence of evidence of ongoing neuronal damage. Additionally, the presence of newly developed autoantibodies was detected in several patients, potentially signaling the emergence of post‐COVID autoimmunity.
Karakoyun et al. (Thu,) studied this question.