Abstract

Biomarkers are necessary for the evaluation of disease activity and treatment effects in neurological diseases. However, current tests such as cerebrospinal fluid analysis or imaging cannot be used widely because of several limitations, such as high invasiveness, high costs, and a limited number of tests per day. The blood neurofilament light chain (NFL) assay is a promising test for neuronal injury with low invasiveness and high scalability and has attracted a great deal of attention. It became more precise and accurate because of the newly developed ultrasensitive immunoassay called the Simoa assay. Blood NFL assay could reportedly track disease activity, monitor treatment response, and predict clinical outcomes in various neurological diseases such as multiple sclerosis, amyotrophic lateral sclerosis, dementia, stroke, and traumatic brain injury. In this review, we describe the scope and limitations of blood NFL assay in neurological diseases and future research directions needed for clinical application.