PRPH and amyotrophic lateral sclerosis: No differences (Mann–Whitney p > 0.1) are observed at baseline in terms of gender (M:F ratio 0.58 vs. 0.54), age (64.5 ± 11.9 vs. 64.1 ± 9.5), ALSFRSr (38.8 ± 4.8 vs. 38.3 ± 5.7), PR (0.90 ± 0.93 vs. 0.96 ± 0.98), MRC (126 ± 11 vs. 127 ± 11), and FVC (89 ± 20 vs. 90 ± 20) between the general group of 100 ALS patients and the subgroup of 41 subjects with ALS, for whom we measured PRPH levels approximately 6 months (mean: 6.68 ± 1.67; median 6.37 [IQR 5.30–7.73]) after the initial collection.