Clinical features and prognostic factors of spinal cord sarcoidosis: a multicenter observational study of 20 BIOPSY-PROVEN patients

Sarcoidosis of the spinal cord is a rare disease. The aims of this study are to describe the features of spinal cord sarcoidosis (SCS) and identify prognostic markers. We analyzed 20 patients over a 20-year period in 8 French hospitals. There were 12 men (60 %), mostly Caucasian (75 %). The median ages at diagnosis of sarcoidosis and myelitis were 34.5 and 37 years, respectively. SCS revealed sarcoidosis in 12 patients (60 %). Eleven patients presented with motor deficit (55 %) and 9 had sphincter dysfunction (45 %). The median initial Edmus Grading Scale (EGS) score was 2.5. The cerebrospinal fluid (CSF) showed elevated protein level (median: 1.00 g/L, interquartile range (IQR) 0.72–1.97), low glucose level (median 2.84 mmol/L, IQR 1.42–3.45), and elevated white cell count (median 22/mm³, IQR 6–45). The cervical and thoracic cords were most often affected (90 %). All patients received steroids and an immunosuppressive drug was added in 10 cases (50 %). After a mean follow-up of 52.1 months (range 8–43), 18 patients had partial response (90 %), 7 displayed functional impairment (35 %), and the median final EGS score was 1. Six patients experienced relapse (30 %). There was an association between the initial and the final EGS scores (p = 0.006). High CSF protein level showed a trend toward an association with relapse (p = 0.076). The spinal cord lesion was often the presenting feature of sarcoidosis. Most patients experienced clinical improvement with corticosteroids and/or immunosuppressive treatment. The long-term functional prognosis was correlated with the initial severity.