Demographic and clinical features of the participants
| Controls | ALS | |
| Male (%) (n/N) | 80 (20/25) | 80 (36/45) |
| Age (years) (mean (SD)) | 55.1 (10.5) | 54.6 (13.3) |
| Duration of disease (months) (mean (SD)) | 17.2 (13.3) | |
| Type of onset (%) (n/N) | ||
| Bulbar | 15.6 (7/45) | |
| Cervical | 53.3 (24/45) | |
| Lumbosacral | 31.1 (14/45) | |
| El Escorial diagnostic category (%) (n/N) | ||
| Possible | 17.8 (8/45) | |
| Probable laboratory supported | 26.7 (12/45) | |
| Probable | 37.8 (17/45) | |
| Definite | 17.8 (8/45) | |
| Time since diagnosis (%) (n/N) | ||
| 0–6 months | 71.1 (32/45) | |
| 6–12 months | 17.8 (8/45) | |
| >12 months | 11.1 (5/45) | |
| ALSFRS-R (mean (SD)) | 40.6 (4.2) | |
| Progression rate (mean (SD)) | 0.62 (0.49) | |
Progression rate=48−ALSFRS-R/disease duration (months).
ALS, amyotrophic lateral sclerosis; ALSFRS-R, ALS Functional Rating Scale-Revised.