A Multi-Center Retrospective Cohort Study of Neurosarcoidosis Myelitis: Current Observations and Future Directions.

Objective: The optimal treatment for neurosarcoidosis myelitis is uncertain. We characterize incident neurosarcoidosis myelitis and assess treatment response by MRI and clinical scales.

Methods: Incident probable or definite neurosarcoidosis myelitis in adults was retrospectively identified from 13 academic medical centers. Cases were analyzed by initial treatment. The primary outcome was T1 post-contrast gadolinium enhancement resolution at 6 months post-treatment. Secondary outcomes were changes in modified Rankin scale (mRS) and Expanded Disability Status Scale (EDSS) from nadir to final follow-up.

Results: Two hundred two patients were identified (median diagnosis age: 47 years (IQR 39-55); male: female 1.3:1). Median nadir mRS and EDSS were 2 (IQR 2-3) and 4 (IQR 2.5-6). At initial treatment, 129 (63.9%) received prolonged corticosteroids ≥ 4 weeks (group A₁), 36 (17.8%) received corticosteroids < 4 weeks (B₁), 21 (10.4%) received corticosteroids plus sarcoidosis-directed immunosuppressant (E), and 16 (7.9%) received corticosteroids plus non-sarcoidosis-directed agents (F). In 167 cases with sufficient imaging, there were no significant differences in contrast enhancement resolution at 6 months (A₁ 27/106 (25.5%), B₁ 9/28 (32.1%), E 5/19 (26.3%), F 5/14 (35.7%); Fisher's exact p = 0.76). There were no significant differences in changes in mRS or EDSS among treatment groups (Kruskal-Wallis p = 0.69 and 0.63, respectively) after median follow-up of 46.5 months (IQR 18-91.3).

Interpretation: Different initial immunosuppression strategies did not correlate with MRI contrast enhancement resolution at 6 months or clinical scales (mRS, EDSS). However, conclusions are limited by retrospective design, imbalanced cohorts, and insensitivity of binary MRI outcomes and available clinical scales for treatment response in neurosarcoidosis.