Demographic characteristics and serum NFL levels of disease controls
| Diagnosis | n | M/F | Age | Serum NFL (pg/mL) |
| Axonal polyneuropathy | 7 | 7/0 | 71 (57–83) | 42.2 (1.1–114) |
| Hereditary spastic paraparesis (HSP) | 4 | 3/1 | 47 (21–56) | 30.3 (12.4–41.2) |
| Inclusion body myopathy (IBM) | 4 | 2/2 | 66 (46–77) | 48.9 (27.4–71.4) |
| Chronic inflammatory demyelinating polyneuropathy (CIDP) | 3 | 2/1 | 81 (75–82) | 135 (132–155) |
| Peroneal nerve lesion | 3 | 2/1 | 48 (48–69) | 11.4 (9.3–90.1) |
| Benign fasciculations | 2 | 2/0 | 44 (38–50) | 17.2 (16.4–18) |
| Unspecified myopathy | 2 | 2/0 | 65 (44–86) | 10.9 (0.7–21.2) |
| Somatoform disorder | 2 | 1/1 | 52 (46–58) | 16.3 (14.3–18.4) |
| Subjective weakness without evidence of neurological disease | 2 | 1/1 | 44 (39–49) | 9.5 (6.1–12.9) |
| Spinocerebellar ataxia (SCA) | 1 | 0/1 | 72 | 27.3 |
| Pseudobulbar and cerebellar syndrome without evidence of MND | 1 | 1/0 | 71 | 81.6 |
| Anterior spinal artery syndrome | 1 | 0/1 | 49 | 36 |
| Transverse myelitis | 1 | 0/1 | 47 | 90.4 |
| Polyradiculomyelitis | 1 | 1/0 | 61 | 36.5 |
| Neuralgic amyotrophy | 1 | 1/0 | 63 | 22 |
| Spondylosis with lumbar radiculopathies | 1 | 1/0 | 74 | 47.9 |
| Bilateral L5 radiculitis | 1 | 1/0 | 66 | 20.1 |
| Mononeuritis multiplex | 1 | 1/0 | 79 | 26.8 |
| Autoimmune polyneuropathy and myopathy | 1 | 1/0 | 72 | 46.9 |
| Limb-girdle muscular dystrophy (LGMD) | 1 | 1/0 | 24 | 210 |
| Myositis | 1 | 0/1 | 70 | 16.1 |
| Myalgia-cramp-fasciculation syndrome | 1 | 1/0 | 56 | 14 |
| Lower limb weakness without evidence of MND | 1 | 1/0 | 43 | 16.8 |
| Lingual atrophy without evidence of MND | 1 | 0/1 | 43 | 17 |
For age and NFL levels, when the group includes more than one patient, median values are given, with ranges in brackets; when there is only one patient, his/her serum NFL level is indicated. MND, motor neuron disease; NFL, neurofilament light chain.