A 34-year-old male with no significant past medical history developed lower extremity numbness and paresthesia. Spinal cord MRI suggested the presence of an enhancing lesion spanning from the medulla to the C2 and the extensive expansion and enhancing spinal cord signal spanning from the C3 level through the thoracic cord. The enhancement in the central cord, dorsal columns and dorsolateral cord at these levels presented as the striking  “trident sign” on axial views.  MRI revealed multiple non-enhancing white matter foci of the abnormal increased T2/FLAIR signal in the corpus callosum and periventricular white matter. Routine CSF studies demonstrated CSF lymphocytic pleocytosis (310 nucleated cells/mm3), elevated CSF protein (114mg/dL) and intrathecal synthesis of oligoclonal IgG. A mediastinal lymph node biopsy pathology was suggestive of sarcoidosis. Screening tests for infectious and other autoimmune and metabolic causes of myelopathy were negative.

Despite the treatment with intravenous high-dose steroids and a maintenance course of oral prednisone, new attack of myelitis occurred after 9 months, and the patient started treatment with Rituximab (10 months after the initial presentation). Three months after the start with Rituximab, the patient had a mild and purely sensory myelitis attack, and he is relapse-free since then. After 2.5 years of Rituximab treatment, the spinal cord “trident sign” pattern of enhancement resolved almost completely. 

The spinal cord “Trident sign” pattern of enhancement is strongly suggestive of spinal cord sarcoidosis. Rituximab may be a treatment option in patients with neurosarcoidosis with suboptimal response to steroid treatment.