Rinsho Shinkeigaku (Clinical Neurology)

Treatment of NMO

Takahiko Saida, M.D., Ph.D.

Kyoto-Miniren Central Hospital

The commonly used clinical diagnostic criteria for NMO still requires the presence of clinical episodes of both optic neuritis and myelitis. We believe this criteria has disadvantages for making early diagnosis in patients who fail to meet the criteria yet have the same disease process. Therefore we propose a simple new criteria which requires one of the following two: (1) centrally located, fully contiguous long spinal cord lesion (LCL) extending three or more spinal segments length or long segmental spinal cord atrophy and (2) presence of specific antibody to aquaporin-4 (AQP4). We also propose a new naming "autoimmune astrocytopathy" for such patients, since the autoimmune destructive process against astrocytes is the characteristic common underlying mechanism, the majority of patients show the clinical brain symptoms, and anti-AQP4 antibodies are frequently, but not exclusively, associated. The reanalysis of Japanese interferon β-1b clinical trial data failed to show efficacy in patients meeting the diagnostic criteria for multiple sclerosis and showed MRI evidence of LCL. Although there is no evidence-based guideline for NMO, expert opinions generally agree with the treatment strategy. My treatment algorithm is shown in the table. At acute exacerbation, high-dose steroid infusion is the choice. If two cycles of infusion treatment fails to show recovery, plasma-exchange treatment should be initiated quickly. Medium dose oral steroids are started immediately after the end of high dose steroid infusion therapy. In moderate to severe activity cases additional usage of one of the immunosuppressants, Mizoribine, Tacrolimus, or Azathiopurine is quite useful, and the immunosuppressive effects on NMO are higher in this order, but the safety is higher at the opposite order. Therefore, selection of one of immunosuppressants should be made on individual basis and slow achievement of the immunosuppressive effects should be kept in mind especially in case of Azathiopurine. If any of these immunosuppressants are not successful in inducing stable state, then Mitoxantrone or Tituximab is the choice. The monthly infusion of former drug usually stablizes the disease activity quite quickly, but treatment duration is limited due to it's cardiotoxicity. Rituximab is also quite powerful in stabilizing the activity, but there still exist some non-or poor responder to this medicine, and insurance coverage is not expected for MS or NMO in Japan. Cyclophosphamide infusion is also an alternative choice for very difficult cases. Physicians working on NMO treatment in Japan are very much hoping the initiation of well controlled clinical trials in order to treat our patients with more scientific strategy based on evidences.
Full Text of this Article in Japanese PDF (322K)

(CLINICA NEUROL, 49: 902|905, 2009)
key words: Neuromyelitis optica, treatment, algorithm, aquaporin-4, diagnostic criteria

(Received: 22-May-09)