Summary about Disease
Devic's disease, now more commonly known as Neuromyelitis Optica Spectrum Disorder (NMOSD), is a rare autoimmune disorder that primarily affects the optic nerves and spinal cord. It's characterized by inflammation and demyelination (damage to the protective covering of nerve fibers) in these areas. NMOSD can cause vision loss, muscle weakness, paralysis, sensory problems, and bladder/bowel dysfunction. Unlike multiple sclerosis (MS), which it was initially confused with, NMOSD is typically associated with specific antibodies, most commonly against aquaporin-4 (AQP4).
Symptoms
Symptoms of NMOSD vary depending on the individual and the severity of the attack, but common signs include:
Optic Neuritis: Eye pain, blurred vision, vision loss (usually in one or both eyes), decreased color vision.
Transverse Myelitis: Weakness in the legs or arms, numbness, tingling, pain, bowel and bladder dysfunction (incontinence or retention), muscle spasms.
Area Postrema Syndrome: Nausea, vomiting, and hiccups that are difficult to control.
Other brainstem symptoms: Double vision, facial weakness, difficulty swallowing and slurred speech.
Narcolepsy or acute symptomatic diencephalic clinical syndrome
Symptomatic cerebral involvement with typical NMOSD lesions
Causes
NMOSD is an autoimmune disorder, meaning the body's immune system mistakenly attacks its own tissues. In most cases, this attack is directed at aquaporin-4 (AQP4), a water channel protein found predominantly in the central nervous system, particularly in astrocytes (a type of glial cell). The presence of AQP4 antibodies in the blood is a key diagnostic marker for NMOSD. The exact trigger for this autoimmune response is not fully understood, but genetic predisposition and environmental factors (such as viral infections) may play a role. A smaller percentage of people with NMOSD have antibodies against myelin oligodendrocyte glycoprotein (MOG). The cause of MOG-antibody-associated disease is also unknown.
Medicine Used
Treatment for NMOSD focuses on managing acute attacks and preventing future relapses.
Acute Attacks:
High-dose intravenous corticosteroids (e.g., methylprednisolone): To reduce inflammation.
Plasma exchange (PLEX) or Immunoadsorption: To remove antibodies from the blood if corticosteroids are ineffective.
Intravenous immunoglobulin (IVIg)
Preventive (Maintenance) Therapies:
Immunosuppressants: These medications suppress the immune system to prevent attacks. Examples include:
Rituximab: A monoclonal antibody that targets B cells.
Azathioprine: An older immunosuppressant.
Mycophenolate mofetil: Another immunosuppressant.
Methotrexate
Monoclonal Antibodies:
Eculizumab: A complement inhibitor that blocks part of the immune cascade.
Satralizumab: An IL-6 receptor antibody.
Inebilizumab: A B-cell depleting antibody.
Is Communicable
No, NMOSD is not communicable. It is an autoimmune disorder, not an infectious disease, and cannot be spread from person to person.
Precautions
Since NMOSD is an autoimmune condition, there are no specific precautions to prevent acquiring it. However, individuals diagnosed with NMOSD can take precautions to manage the condition and prevent complications:
Adherence to Treatment: Closely follow the prescribed treatment plan, including medications and follow-up appointments, to minimize the risk of relapses.
Infection Prevention: Infections can sometimes trigger NMOSD attacks, so practice good hygiene, get vaccinated as recommended by your doctor, and avoid close contact with sick individuals.
Healthy Lifestyle: Maintain a healthy lifestyle with a balanced diet, regular exercise (within your physical capabilities), and sufficient sleep to support overall health and immune function.
Avoid Smoking: Smoking may worsen autoimmune conditions.
Manage Stress: Chronic stress can impact the immune system. Practice stress-reducing techniques such as meditation, yoga, or deep breathing exercises.
Rehabilitation: Physical, occupational, and speech therapy can help manage symptoms and improve quality of life.
Inform Healthcare Providers: Always inform healthcare providers about your NMOSD diagnosis and medications before undergoing any medical procedures or treatments.
How long does an outbreak last?
The duration of an NMOSD attack (outbreak) can vary significantly. Some attacks may resolve within weeks or months with treatment, while others can take longer. The severity of the attack, the promptness of treatment, and individual factors all influence the duration. Relapses can cause cumulative disability.
How is it diagnosed?
Diagnosis of NMOSD typically involves the following:
Neurological Examination: To assess symptoms and identify neurological deficits.
Medical History: Review of the patient's symptoms and medical history.
MRI of the Brain and Spinal Cord: To look for characteristic lesions in the optic nerves and spinal cord. These lesions may be longer than typically seen in multiple sclerosis.
Blood Tests:
AQP4-IgG antibody test: A highly specific test to detect antibodies against aquaporin-4. A positive result is a key diagnostic criterion for NMOSD.
MOG-IgG antibody test: To detect antibodies against myelin oligodendrocyte glycoprotein.
Other blood tests: To rule out other conditions.
Visual Evoked Potentials (VEP): To assess the function of the optic nerves.
Lumbar Puncture (Spinal Tap): To analyze cerebrospinal fluid, which may show specific inflammatory markers. Diagnostic criteria have evolved over time. The 2015 International Panel for NMO Diagnosis (IPND) criteria are commonly used and incorporate AQP4-IgG status, clinical presentation, and MRI findings.
Timeline of Symptoms
The timeline of symptoms in NMOSD can vary greatly.
Initial Attack: The first attack can occur at any age. It might involve optic neuritis, transverse myelitis, or both.
Relapses: NMOSD is typically a relapsing-remitting disease, meaning that there are periods of attacks (relapses) followed by periods of relative stability (remission). The frequency and severity of relapses vary. Some individuals may experience frequent relapses, while others may have longer periods of remission.
Progression: With each relapse, there can be accumulation of neurological damage and disability. Early diagnosis and treatment are essential to minimize this.
Important Considerations
Early Diagnosis is Crucial: Prompt diagnosis and treatment are critical to minimize the risk of permanent neurological damage.
Differentiation from MS: It is important to distinguish NMOSD from multiple sclerosis (MS) because the treatments differ. Some MS treatments can be harmful in NMOSD.
Lifelong Management: NMOSD is a chronic condition that typically requires lifelong management with immunosuppressive medications to prevent relapses.
Individualized Treatment: Treatment plans should be tailored to the individual's specific symptoms, disease severity, and tolerance of medications.
Monitoring for Side Effects: Regular monitoring for side effects of medications is essential.
Rehabilitation: Physical, occupational, and speech therapy can help manage symptoms and improve quality of life.
Support Groups: Joining support groups can provide emotional support and connect individuals with others living with NMOSD.
Pregnancy: Careful planning and management are needed for women with NMOSD who wish to become pregnant, as some medications can be harmful during pregnancy.
Research: Ongoing research is aimed at developing new and more effective treatments for NMOSD.