NEFL and amyotrophic lateral sclerosis: AD (30.8 pg/ml, 22.6-41.9), GBS (79.4 pg/ml, 24.3-259.6) and ALS (95.4 pg/ml, 57.9-157.0) had higher serum NfL levels compared with HC and CP (AD versus CP: p=0.002 all other comparisons versus HC and CP: p<0.0001).