Comparison between seropositive and seronegative neuromyelitis optica
| Seropositive neuromyelitis optica | Seronegative neuromyelitis optica | p Value | |
| No of patients | 382 | 19 | |
| Male:female (female%) | 32:344 (91.5%) | 5:14 (73.6%) | 0.0241* |
| Age at onset (median, year) | 45 (6–86) | 33 (15–70) | 0.0179† |
| Disease duration (median, year) | 5 (1–46) | 8 (1–36) | 0.3433 |
| Annual relapse rate (median) | 1.0 (0.1–9.0) | 1.4 (0.2–4.0) | 0.8860 |
| Extended Disability Status Scale score (median) | 6.5 (0–10) | 7.5 (4–9) | 0.1511 |
| Visual outcome | |||
| Blindness | 61/350 (17.4%) | 4/19 (21.0%) | NS |
| Severe impairment | 114/350 (32.5%) | 15/19 (78.9%) | 0.00010‡ |
| First attack | |||
| Optic nerve | 162/382 (42.4%) | 11/19 (57.8%) | NS |
| Spinal cord | 203/382 (53.1%) | 6/19 (31.5%) | NS |
| Brainstem | 29/382 (7.5%) | 0/19 (0.0%) | NS |
| Cerebrum | 30/382 (7.8%) | 3/19 (15.7%) | NS |
| MRI lesions | |||
| Spinal cord | 342/372 (91.9%) | 19/19 (100%) | NS |
| Longitudinally extensive transverse myelitis | 326/372 (87.6%) | 19/19 (100%) | NS |
| Cerebrum | 196/365 (53.6%) | 13/19 (68.4%) | NS |
| Optic nerve | 129/369 (34.9%) | 13/19 (68.4%) | 0.0031‡ |
| Brainstem | 103/364 (28.2%) | 8/19 (42.1%) | NS |
| Systemic disease | |||
| Sjögren syndrome | 34/168 (20.2%) | 1/8 (12.5%) | NS |
| Thyroid diseases | 20/169 (11.8%) | 2/8 (25.0%) | NS |
| Autoantibody | |||
| Sjögren syndrome A antibody or Sjögren syndrome B antibody | 64/188 (34.0%) | 1/9 (11.1%) | NS |
| Antinuclear autoantibody | 99/188 (52.6%) | 1/9 (11.1%) | 0.036‡ |
| Cerebrospinal fluid | |||
| Oligoclonal band | 22/221 (9.9%) | 2/15 (13.3%) | NS |
| Myelin basic protein | 121/207 (58.4%) | 6/12 (50.0%) | NS |