Assessing Brain Injury After Extra-Axial Brain Tumor Resection: Circulating Neurofilament Light Levels, Neurological Deficits, and Fatigue.

Background and objectives: Circulating brain-injury biomarkers have recently gained increased interest, as new ultrasensitive measurement techniques have enabled quantification of brain injury through blood sampling. This prospective study explores relationships between plasma levels of the axonal injury biomarker neurofilament light chain (NfL) and postoperative outcomes, including new neurological deficits and fatigue, in patients undergoing extra-axial brain tumor surgery. In addition, we aimed to establish the temporal profile of changes in NfL levels after surgery.

Methods: We included 41 adult patients scheduled for surgery for meningiomas or vestibular schwannomas. Plasma concentrations of NfL were measured the day before surgery and on postoperative days 1, 10, 30, and 60, with new neurological deficits assessed on day 1 postsurgery. Fatigue was measured using the Multidimensional Fatigue Inventory before and 6 months after surgery.

Results: NfL levels peaked on day 10 after surgery, and patients with new neurological deficits postsurgery had higher NfL levels on days 10, 30, and 60 relative to those without new deficits. NfL levels at day 10 had the highest sensitivity and specificity in relation with new neurological deficits. No association was found between postoperative NfL levels and development of fatigue.

Conclusion: The results suggest measuring NfL level as a promising method for quantifying structural brain damage associated with extra-axial tumor surgery. However, these findings did not reveal associations between elevated NfL levels and postoperative fatigue.