Biomarkers in Neurologic Disease

Neurology is undergoing a transformative shift towards using biomarkers, mainly through the introduction of blood-based biomarkers. These emerging tools stand out for their minimally invasive nature and their potential to provide new prognostic insights affordably and broadly. Our editorial team is thrilled to present a series of review articles that delve into the forefront of biomarker research in neurology alongside discussing the current challenges that must be addressed to integrate these tests into clinical practice.

Neurofilament light chain (NfL) is a promising biomarker in multiple sclerosis (MS), showing potential for the detection of recent clinical and subclinical disease activity, treatment monitoring, and prognosis. The measurement of NfL levels may facilitate the identification of preclinical MS stages with studies showing its elevation years before the manifestation of clinical symptoms. In their review, Itorralba and Schneider stress the urgent need for additional research to enhance the clinical utility of blood NfL testing in MS, particularly its predictive value for anticipating disease progression to more severe stages, which would inform more personalized management approaches.

Similarly, Akarsu et al explore serum biomarkers in stroke care, highlighting the current challenges associated with such testing and emphasizing the ongoing quest for specificity and utility in stroke management. They discuss biomarkers for the early identification of transient ischemic attacks or minor ischemic strokes to facilitate timely intervention and prevention of further clinical events. The review also covers the role of cardiac biomarkers in identifying strokes related to heart conditions. Furthermore, it examines inflammatory biomarkers and biomarkers that can identify pro-thrombotic states.

Pleen et al explore the role and limitations of blood-based biomarkers in Alzheimer disease (AD), detailing their potential to transform early detection by reducing dependency on invasive tests and costly imaging. They identify several obstacles to the integration of these biomarkers into routine clinical practice, ranging from technical issues, such as the low abundance of tau and amyloid proteins in the bloodstream, to clinical challenges, such as the gradual emergence of symptoms, shifting biomarker profiles over time, inconsistent disease progression, and the presence of multiple pathologies in some individuals.

Next, Ducharme’s review points out that people experiencing cognitive decline in mid or late life require thorough evaluation to discern if symptoms stem from a primary psychiatric disorder or an underlying neurodegenerative process such as AD, frontotemporal dementia, or Lewy body dementia. The frequent occurrence of mild abnormalities in both imaging and blood biomarker profiles among people with psychiatric conditions indicates that neuroaxonal damage and neuroinflammation might play a role in these conditions, underscoring the importance of developing a nuanced approach to diagnosing cognitive deficits in this population.

Roberto and Lim-Fat review how blood biomarkers or “liquid biopsies” present a promising approach for glioma diagnosis, therapy selection, and monitoring, offering a less invasive alternative to traditional biopsies, especially for inoperable tumors or when tissue samples are insufficient. They explore novel circulating biomarkers, including circulating tumor cells, cell-free DNA, and the content of extracellular vesicles. The review further addresses the challenges and future directions for integrating these biomarkers into clinical practice, stressing the need for further research to validate their utility in clinical practice.

Finally, AlKharbooshi et al highlight the critical role of neural antibodies in diagnosing autoimmune encephalitis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein antibody-associated disease. The review underscores the importance of adopting best testing practices for the detection of these antibodies and discusses the potential for these biomarkers to refine diagnostic criteria, thereby enhancing patient care in autoimmune neurological disorders.

This burgeoning field of biomarkers in neurology is set to transform the way we diagnose, predict outcomes, and tailor treatments for neurological disorders, promising significant improvements in patient care. As we edge into this promising era, the successful incorporation of biomarkers into everyday clinical practice will require dedicated efforts in research and education to maximize their benefits in enhancing patient outcomes.