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37-year-old male with history of recurrent LETM and seizure disorder was admitted for worsening lower extremity weakness and unresponsiveness. History was significant for transverse myelitis diagnosed 8 months ago after presenting with lower extremity weakness and urinary incontinence. MRI of the spine at that time revealed focus of abnormal T2 signal in upper thoracic spinal cord extending from the mid T3 level inferiorly through the T5-6 level, with associated cord expansion.

Repeat MRI of the spine and brain showed progression of disease in the spine with nodular leptomeningeal enhancement most prominent within the posterior fossa. Extensive workup including neuromyeltitis optica, paraneoplastic panel, anti-aquaporin Ab and Anti-MOG Ab testing was negative. Patient was treated with steroids and plasmapheresis treatment (PLEX). PLEX treatments were held due to concern for infection. He was switched to steroid taper and biweekly Rituximab infusion. Rituximab infusions were stopped due to side effects and patient was trialed on mycophenolate mofetil. However, patient was transitioned back to steroid taper and rituximab infusion after worsening of symptoms. Patient eventually underwent meningeal biopsy which showed granulomatous leptomeningitis and parenchymal microglial activation. With strong suspicion for Neurosarcoidosis now based on accumulated evidence the patient was restarted on IV methylprednisolone and subsequent steroid taper. Improvement of his symptoms with partial recovery of strength was noted. Patient was subsequently transitioned to Leflunomide, infliximab infusions and steroid taper. Follow up MRI of the brain and spinal cord showing improvement in areas of enhancement.

Our patient presented with neurosarcoidosis manifesting as LETM with no prior diagnosis of sarcoidosis or evidence of system involvement on further thorough workup. The diagnosis was challenging confirmed after a neural biopsy given absence of non-neurological manifestations.