NEFL and amyotrophic lateral sclerosis: Elevations in CSF NFL are a sensitive surrogate marker of neuronal damage, as evidenced by pathological white matter changes, in several neurodegenerative diseases, including Alzheimer’s disease, subcortical vascular dementia (Norgren et al. 2003), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS) (Malmestrom et al. 2003; Rosengren et al. 1996).