the clinical variants due to anti-AQP4, plus other non-related but clinically similar syndromes such as anti-MOG associated encephalomyelitis. Some cases with MOG+ and AQP4+ antibodies have been found. These variants are expected to respond to the same treatments as standard NMO. Some authors propose to use the name "autoimmune aquaporin-4 channelopathy" for these diseases, while others prefer a more generic term "AQP4-astrocytopathy", which also includes deficiencies of AQP4 with a non-autoimmune origin. Treatment There is no cure for NMO, but it is treatable. Some patients recover, but many are left with impairment of vision and limbs, which can be severe in some cases. Attacks Long term neurologic deficits are the cumulative effects of acute attacks, emphasizing the importance of acute treatment. Traditionally, attacks have been treated with short courses (3–5 days) of high dosage intravenous corticosteroids, such as methylprednisolone IV (Solu-Medrol). Early initiation of treatment with steroids have shown to improve vision-related outcomes after acute attacks. However, there is no high-level evidence for steroids affecting long-term outcomes; this treatment strategy was borrowed from that for similar diseases (idiopathic optic neuritis and multiple sclerosis). Plasmapheresis can be an effective treatment when attacks progress after the administration of corticosteroids. This treatment involves the patient's own blood being pumped out, blood cells being removed from the plasma and mixed with a solution, then the new blood mixture being pumped back in. Secondary prevention Prophylactic treatment, to prevent relapses of NMO, is generally employed; but the exact duration of such treatment is debatable. FDA-approved pharmaceuticals FDA-approved pharmaceuticals against AQP4-IgG-positive NMOSD, shown to be effective in phase III clinical trials, first became available in 2019. As of 2020, they are among the most expensive drugs worldwide. They are not available in pill form, which, along with their high price, limits their accessibility. These new drugs' effectiveness against AQP4-IgG-negative NMOSD is unknown. Off-label treatments Many treatments are used despite the lack of phase III clinical trials testing their efficacy. Neither inferiority nor superiority to the newer, FDA approved drugs has been clearly demonstrated; and, considering their being relatively inexpensive and being availability in pill format, these drugs are the current standard treatment. Most of these medications affect the immune system in various ways. It is important to note that certain immunosuppressants used to treat MS—such as interferon-β, fingolimod, natalizumab, and alemtuzumab—worsen NMO disease progression and should not be used to treat NMO. Prognosis Normally, some improvement