Review Question - QID 214376

This young patient with optic neuritis (afferent pupillary defect, painful eye movements, and decreased visual acuity) and a prior history of transverse myelitis (bilateral lower extremity weakness and urinary retention) is most likely presenting multiple sclerosis attack (or flare) and should be appropriately treated with intravenous methylprednisolone.

Multiple sclerosis is an immune-mediated demyelinating disorder affecting the central nervous system. Patients can present with optic neuritis, which is due to demyelination affecting the optic nerve. Optic neuritis presents with decreased visual acuity, red desaturation (the color red appears pink, orange, or "washed out"), and pain with eye movements. On physical examination, there is an afferent pupillary defect - when light is shined in the unaffected eye, there is consensual pupillary constriction; however, when swung to the affected eye, there is a relative pupillary dilation. Both oral prednisone and intravenous methylprednisolone are efficacious in hastening recovery; nevertheless, intravenous methylprednisolone is preferred since oral prednisone is associated with an increased risk of developing recurrent optic neuritis.

Incorrect Answers:
Answer 1: Cyclophosphamide is an alkylating medication that cross-links DNA strands and impairs DNA synthesis. This is not used in acute multiple sclerosis flares. However, it is useful in drug regimens to manage certain malignancies (e.g., acute lymphoblastic leukemia).

Answer 3: Ocrelizumab is a monoclonal antibody against CD20 positive B-cells. It is a disease-modifying agent used to decrease the rate of a future multiple sclerosis flares and to decrease the rate of accumulation of demyelinating lesions. This medication is not used to treat an acute multiple sclerosis flare.

Answer 4: Prednisone is an oral medication that suppresses the immune system by a multitude of mechanisms (e.g., decreased leukocyte migration). It is associated with an increased risk of developing recurrent optic neuritis in patients with optic neuritis. Patients have better outcomes with IV methylprednisolone.

Answer 5: Rituximab is a monoclonal antibody against CD20 positive B-cells. It is not used in the management of acute multiple sclerosis flares. It is useful in the treatment of certain malignancies (e.g., chronic lymphocytic leukemia) and vasculitides (e.g., granulomatosis with polyangiitis).

Bullet Summary:
The first-line treatment of an acute multiple sclerosis attack with optic neuritis is with intravenous methylprednisolone.