Neuromyelitis optica spectrum disorder (NMOSD) is a rare neurological disease where the body’s own immune system attacks the optic nerves and spinal cord. Due to its initial course and relapses, it is often confused with multiple sclerosis (MS). But NMOSD outbreaks are usually more severe and often cause permanent damage and disability. It is estimated that this rare disease affects more than 7,300 people in Europe, about 300 in Spain.
The majority are women since they are nine times more likely to suffer from it and it normally appears around the age of 40. NMOSD is caused by inflammation of the central nervous system and is characterized by recurrent outbreaks that, if not treated properly, can lead to blindness or paralysis. In addition to its severity, NMOSD is often confused with multiple sclerosis, which complicates its diagnosis and delays its treatment. In fact, until recently, this disease was considered an optic-spinal form of multiple sclerosis.
However, although the clinical manifestations may be similar, between 50% and 70% of people with NMOSD are seropositive for the AQP-4 antibody, while those with MS are always seronegative. This confirms that they are two different pathologies. Even the symptoms and flare-ups of NMOSD are often more severe than those of sclerosis. However, despite being different, even today, 41% of cases receive an erroneous diagnosis of sclerosis.
An important difference between multiple sclerosis and NMOSD is the age of onset: NMOSD usually appears around the age of 40, about 11 years later than multiple sclerosis does. On the other hand, in neuromyelitis optica spectrum disorder, other cells of the central nervous system are involved and long-lasting inflammations of the optic nerve and spinal cord are common, uncommon in MS. Another difference is that patients with multiple sclerosis usually recover from episodes of the disease, which rarely happens after NMOSD attacks.
The decisive factor in distinguishing both diseases is, in most cases, a laboratory test. In the blood serum of the vast majority of patients with NMOSD, specific autoantibodies against the so-called water channel protein aquaporin-4 are detected, which do not appear in multiple sclerosis.
Currently, there is no cure for NMOSD, so the main therapeutic objective is to reduce and prevent outbreaks associated with the disease. It is estimated that 90% of affected people continue to experience crises within five years of the initial outbreak. Even so, with the current management of the disease and early diagnosis and treatment, the consequences are minor and can be considerably prevented in the long term.
Regarding these consequences, almost two thirds of people affected by this rare disease have significant vision loss within three years, which can end up leading to total blindness. Another three quarters of NMOSD patients suffer from chronic pain, and for 40% depression is part of their daily lives. NMOSD patients also present intestinal and bladder involvement, as well as sexual dysfunction. They are ailments that considerably reduce your quality of life.
Severe motor disorders with signs of paralysis are also common and in some cases are so severe that patients have to use a wheelchair. If the disease is not recognized or treated in time, one in three patients will die within ten years.
During the recent Congress of the Spanish Society of Neurology, Horizon, a company recently acquired by the biotechnology company Amgen, organized a symposium to discuss new perspectives in the management of NMOSD. During the meeting, specialists presented the results of the latest approved treatments for this disease. “For us it is incredibly important to have experts of this level who can expand knowledge about a rare disease like this,” explains Marta de Andrés, medical director at Horizon Therapeutics. “We know that science and empathy combined can change lives, which is why we are proud to be able to contribute to the availability of new therapeutic options for people with NMOSD,” adds Marta de Andrés.