Neuromyelitis optica is an inflammatory autoimmune disease that affects the central nervous system and leads to degradation of certain insulating nerve sheaths (medical term demyelination). As a result, inflammation of the optic nerve develops over a period of between a few months and two years. This occurs either unilaterally or bilaterally. In addition, the spinal cord becomes inflamed (myelitis).
What is neuromyelitis optica?
In neuromyelitis optica, specific antibodies against a particular water channel, called the aquaporin-4 channel, are present in numerous cases. The pathophysiologic significance of these substances is not yet fully understood and is the subject of current medical research. The disease is synonymously referred to in some cases as Devic syndrome or by the abbreviation NMO. It is a relatively rare disease of the central nervous system. Neuromyelitis optica accounts for approximately one percent of all demyelinating diseases. It is also debated whether neuromyelitis optica is a special form of multiple sclerosis or whether it is a disease in its own right. The disease was first described scientifically at the beginning of the 19th century. Subsequently, Eugène Devic and Fernand Gault conducted research on the disease, so that neuromyelitis optica is sometimes also referred to as Devic’s syndrome. Currently, there is a study group dedicated to the research of neuromyelitis optica. The topic is to link scientific and clinical knowledge to study the clinical course of the disease as well as its incidence.
Causes
Based on current knowledge of medical research, there is not yet complete clarity about the causes that lead to the development of neuromyelitis optica. However, it is suspected that specific defense substances against the so-called aquaporin-4 channels play a central role in the development of the disease. This is because these defenses show up in numerous patients affected by neuromyelitis optica.
Symptoms, complaints, and signs
Neuromyelitis optica is associated with numerous typical symptoms and complaints. First of all, it is characteristic of the disease that the myelin layer of central nerves is degraded. In connection with this, there is also a degradation of the neuritis nervi optici and the spinal cord. In the further course of the disease, visual disturbances appear, which in some cases lead to blindness (medical term amaurosis). The blindness appears in either one or both eyes and develops within a few hours or days. In addition, a paraplegic syndrome is possible in the context of neuromyelitis optica, which is associated, for example, with sensory disturbances, paralyzed extremities or disturbances in bladder function. Basically, the disease shows either a monophasic or a multiphasic course. In addition, it may progress chronically. Histological examinations sometimes reveal demyelinating lesions that resemble multiple sclerosis. Irreversible necrosis is also possible.
Diagnosis and disease progression
If symptoms typical of neuromyelitis optica appear, an appropriate specialist should be consulted immediately. Together with the affected patient, he or she will discuss the patient’s medical history (anamnesis) and the individual symptoms. This enables a clinical diagnosis to be made. In connection with this, various neurological examinations are necessary, in which, for example, inflammations in the optic nerves and in the spinal cord are searched for. Damage to the brain, which in some cases shows similar symptoms, must also be ruled out. Aquaporin-4 antibodies are determined to establish the diagnosis with certainty. In addition, a magnetic resonance imaging of the skull bone as well as the spine is required. This is because multiple sclerosis and retrobulbar neuritis, for example, must be ruled out as part of the differential diagnosis. It should be noted that, especially at the beginning of the disease, an exact differentiation from multiple sclerosis is not possible in every case. Retrobulbar neuritis often presents with visual disturbances similar to neuromyelitis optica, but progresses without spinal cord involvement.
Complications
Usually, neuromyelitis optica results in inflammation of the optic nerve.Therefore, if this disease is not treated, it can also lead to a complete loss of vision in the patient. Particularly in children or in young people, loss of vision can lead to severe psychological damage or even depression. In children, neuromyelitis optica therefore also significantly impairs development. However, whether the loss of vision is bilateral or unilateral cannot be universally predicted. Furthermore, due to neuromyelitis optica, other disorders of sensibility or paralysis may occur in different parts of the body. The function of the bladder may eventually be disturbed as a result, causing patients to develop incontinence. Neuromyelitis optica can be treated with the help of medication. If the affected person has lost vision, it cannot be restored and the loss of vision is usually irreversible. If psychological symptoms occur, the affected person is dependent on psychological treatment. Complications usually do not occur. The patient’s life expectancy is also not negatively affected by neuromyelitis optica.
When should you see a doctor?
Visual complaints or pain in the area of one or both eyes indicate eye disease. A physician must determine whether this is neuromyelitis optica and take further action if necessary. At the latest, if the well-being is impaired or further physical complaints occur in the area of muscles, intestines and bladder, the help of a doctor is needed. People who already suffer from a chronic disease of the nerves should quickly contact the responsible physician if the mentioned complaints occur. People with gastrointestinal disorders or neurological disorders are also best to speak to a specialist promptly so that neurmyelitis optica can be recognized and treated before further complications occur. Away from the primary care physician, an ophthalmologist may also be consulted. Concomitant bladder and bowel incontinence should be treated by a gastroenterologist or other internist. If a muscle disorder is also present, an orthopedist or a sports medicine specialist should also be consulted. In the long term, sufferers often need therapeutic support as well.
Treatment and therapy
Various options are available for the treatment of neuromyelitis optica. These are used depending on the individual case and are based on the individual symptoms and the severity of the symptoms. In many cases, neuromyelitis optica progresses in one episode, i.e. it is monophasic. On the other hand, a multiphasic or chronic course of the disease is also possible. The demyelinating lesions often regress. However, permanent damage due to tissue death is also possible. In the case of a relapsing course, therapy begins with the administration of cortisone. In some cases, however, the affected patient does not respond to the cortisone. In this way, the treatment differs from that for multiple sclerosis, where special immunomodulators are mainly used. Long-term therapy of the disease is based on the administration of immunosuppressants, for example the active substance azathioprine. Studies indicate that the antibody rituximab may also show good efficacy in neuromyelitis optica. In addition to cortisone, relapses in neuromyelitis optica can also be treated with plasmapheresis.
Prospects and prognosis
The prognosis of neuromyelitis optica is favorable with early diagnosis and successful drug therapy. The prerequisite for this is that the active ingredients of the prescribed drugs are well absorbed by the organism and lead to a regression of the inflammation. Within a few weeks, a considerable improvement or recovery is documented in these patients. If medical assistance is not sought, the otherwise favorable prognosis worsens. The ability to see continuously decreases and can lead to permanent blindness of the affected person. Due to the emotional burden of the symptoms, the risk of psychological sequelae is thereby significantly increased. The prognosis also worsens if a chronic course of the disease develops. Irreversible damage to the optic nerve may occur. As a result, the vision of the affected person is impaired for life.People who already suffer from previous illnesses and thus have a weakened immune system also experience delays in the healing process or persistent health complaints. In these cases, psychotherapeutic support should be provided, as there is often an interplay between emotional and physical factors. Both areas influence each other and can therefore bring about an improvement in the overall situation if appropriate support is provided. Patients who have an episodic or recurrent course of the disease require regular drug treatment throughout life.
Prevention
Effective measures to prevent neuromyelitis optica are not yet known based on current medical research. On the one hand, there is uncertainty about the exact causes of the disease, and on the other hand, it is an autoimmune disease. In general, such diseases can hardly be prevented. It is therefore particularly important to consult a specialist quickly at the first suspicion of the disease or the appearance of typical symptoms in order to initiate adequate therapy.
Follow-up care
Follow-up examinations should take place for neuromyelitis optica, even when symptoms are no longer apparent. Follow-up examinations include checking the visual field (field of vision), visual evoked potential (VEP, also called VECP = visually evoked cortical potentials), and magnetic resonance imaging (MRI) of the brain. The visual field is examined by ophthalmologists. Both eyes are examined individually. It is tested which area the respective eye perceives when looking straight ahead. A VEP is performed by a neurologist and an MRI is performed in a radiology office. Decreased reaction time on the VEP may indicate lingering or renewed inflammation in the visual pathway, a circulatory problem, or degenerative processes. An MRI of the brain then provides a picture of this. Which of the procedures should be performed is decided by the treating neurologist. Unless symptoms are present, a single checkup is usually sufficient. In some cases, an annual follow-up examination is recommended. Based on the results of the examination, a decision is then made as to whether and in what form renewed treatment is necessary. For this purpose, it must be checked whether the optic neuritis is part of another disease. Depending on the results, further treatment is then given. A specific drug for the follow-up treatment of neuromyelitis optica does not exist.
What you can do yourself
The disease is accompanied by a gradually increasing deterioration of the optic nerve. Since self-help measures are not sufficient to achieve an improvement in vision, a doctor should be consulted as early as possible. In addition, the eyes should not be exposed to strong strains. Looking directly into the sun or other bright light sources should be avoided. This can lead to an immediate deterioration of vision. In addition, when reading or working at a computer screen, there should be sufficient light sources in the environment so that the optic nerve is not exposed to further overstrain. There is always a risk of irreparable damage, which should be avoided. If complaints occur in the area of the back, the permanent adoption of relieving or incorrect postures is not conducive. These can lead to irreversible impairments of the skeletal system and trigger secondary diseases. Restrictions in mobility would be the consequence. In the case of inflammatory symptoms in the back, pain or tension, cooperation with a doctor is essential. In order for the organism to have sufficient defenses available for the healing process, care must be taken to maintain a stable immune system. The body’s self-healing system can be supported with a diet rich in vitamins, the avoidance of excess weight, and sufficient exercise in fresh air.
