NEFL and amyotrophic lateral sclerosis: We observed increased Nf, particularly pNfH, concentrations in classical ALS compared to PMA, in accordance with recent findings for serum NfL.48 As of our best knowledge, this is the first study systematically comparing BMD with regard to clinical ALS phenotypes and revealing higher Mb and TnT concentrations in PMA compared to PLS, independent of disease progression, presumably caused by the predominant muscle atrophy.