Clinical characteristics and outcome of neurosarcoidosis‐associated myelitis: A retrospective cohort study and review of the literature

BACKGROUND AND PURPOSE: Neurosarcoidosis can affect all parts of the nervous system of which myelitis is relatively frequent. The aim of this study was to describe clinical characteristics, treatment and prognosis of patients with myelitis attributable to neurosarcoidosis. METHODS: We performed a retrospective cohort study and a systematic review and meta‐analysis of neurosarcoidosis‐associated myelitis. RESULTS: Myelitis was identified in 41 of 153 (27%) neurosarcoidosis patients seen at our clinic from 2015 to 2020. Classification of neurosarcoidosis was definite in three (7%), probable in 29 (71%) and possible in nine patients (22%). The median (interquartile range) age at onset was 49 (41–53) years and 20 of the patients were female (49%). The presenting symptoms included muscle weakness in 31 of 41 patients (78%), sensory loss in 35 (88%) and micturition abnormalities in 30 (75%). Spinal magnetic resonance imaging showed longitudinally extensive myelitis in 27 of 36 patients (75%) and cerebrospinal fluid examination showed an elevated leukocyte count in 21 patients (81%). Initial treatment consisted of glucocorticoids in 38 of 41 patients (93%), with additional methotrexate or azathioprine in 21 of 41 patients (51%) and infliximab in 10 of 41 patients (24%). Treatment led to remission, improvement or stabilization of disease in 37 of 39 patients (95%). Despite treatment, 18 of 30 patients (60%) could not walk independently at the end of follow‐up (median 36 months). A review of the literature published between 2000 and 2020 identified 215 patients with comparable clinical characteristics and results of ancillary investigations. CONCLUSION: Sarcoidosis‐associated myelitis is observed in 27% of neurosarcoidosis patients. Although treatment often led to a decrease in disease activity, residual neurological deficits leading to loss of ambulation occurred frequently.