Dr. Subramaniam Sriram, from Vanderbilt University, spoke at Grand Rounds this week. His topic was the role of the innate immune system in the development and pathogenesis of MS and he spoke a good deal about his research on nitric oxide. Following his presentation, we discussed how Methotrexate modulates nitric oxide pathways and may be an additional mechanism of its benefit in progressive forms of MS. We will be supplying Dr. Sriram with frozen CSF samples of patients before and after treatment with intrathecal methotrexate so that he can further investigate nitric oxide levels.