Neuromyelitis Optica Spectrum Disorder (NMOSD)

Synonyms of Neuromyelitis Optica Spectrum Disorder

? (Asian, Japanese) opticospinal MS

? Devic disease

? Devic syndrome

? optic neuromyelitis

? opticomyelitis

? NMOSD

What is NMOSD??

Neuromyelitis Optica Spectrum Disorder (NMOSD) is a rare autoimmune syndrome of the central nervous system (CNS) separate from Multiple Sclerosis (MS) where antibodies can damage the spinal cord and/or optic nerves during attacks. It’s a demyelinating condition, which means that it damages the protective myelin sheath around nerve fibers. The main clinical features of NMO are optic neuritis (inflammation of the optic nerve) that affects eye function, transverse myelitis (inflammation of the spinal cord that affects limb function, and area postrema syndrome (APS) which are episodes of otherwise unexplained hiccups or nausea and vomiting.?

Subdivisions of NMOSD

? NMOSD with aquaporin-4 antibodies (AQP4)

? NMOSD without aquaporin-4 antibodies (or not tested)

Who gets NMOSD??

NMOSD is most seen in women between the ages of 20 and 40. However, NMOSD has been diagnosed in children as young as 2 years old and adults in their 60’s.?

In Canada, there are approximately 1000 to 3000 people living with NMOSD. Research estimates the NMODS affects up to 10 in 10,0000 persons, which means hundreds of thousands of people live with NMODS worldwide. The prevalence of NMOSD appears to vary in different regions and among distinct populations around the world. NMOSD also appears to be more common among individuals having genetic ancestry including African, Asian, Pacific Island, Polynesian, or Caribbean descent. However, anyone can be affected by NMOSD.?

How common is pediatric NMOSD??

Pediatric onset NMOSD, categorized as symptoms that appear before age of 10 and represent about 3-5 percent of all NMOSD cases. In more than half of pediatric onset NMOSD, the first symptom is optic neuritis or longitudinally extensive transverse myelitis. A distinguishing feature of pediatric onset NMOSD is low frequency of AQP4 seropositivity compared with adult onset NMOSD. However, children have high prevalence of MOG-IgG antibodies. In more than half of all cases, children with MOG-IgG* antibodies have an acute disseminated encephalomyelitis (ADEM) presentation, which is characterized by a short-lived but widespread attack of inflammation in the CNS (brain, optic nerve and spinal cord)?

*MOG (Myelin Oligodendrocyte Glycoprotein)

What are the symptoms of NMODS??

Symptoms of NMOSD vary from one person to another in terms of duration and severity, including level of disability. Generally, NMOSD symptoms begin rapidly. after the initial attack, NMOSD follows an unpredictable course, and time to remission can vary. Recurring episodes of optic neuritis and/or transverse myelitis can be weeks to months in duration and in rare cases can last for years. Usually, these symptoms are temporary and resolve fully or partially with treatments. While the syndrome of NMOSD is characterized by the following clinical features, a growing understanding of NMOSD suggests that the symptoms experienced depend on which antibody (AQP4-IgG or MOG-IgG) is found in the individual:?

Symptoms and signs of optic neuritis (ON):?

- Rapid onset of eye pain or eye headache that is worsened by eye movement?

- Impaired or complete loss of vision, usually in one eye. But in some cases, in both eyes?

- Reduced light perception, colour vison, visual clarity and/or depth perception.?

Symptoms and signs of transverse myelitis (TM):?

- Pain in the neck or back?

- Tightness or corset like sensation in the abdomen, as well as arms or legs?

- Sensitivity to touch, cold, and heat?

- Feeling of numbness, tingling, coldness, itchiness or burning, often spreading to large spots of the body over period of minutes, hours or occasionally days.?

- Weakness in arms or legs ranging from mild to complete paralysis in one or multiple limbs?

- Urgent need to urinate or difficulty urinating, urine incontinence.?

- Constipation leading to vomiting, abdominal bloating, pain and inability to pass stool or gas or bowel incontinence?

- Muscle spasm that lasts for several minutes accompanied by arm and leg pain?

- Fever in some cases?

Symptoms and signs of brainstem or brain involvement:?

- Area postrema syndrome (APS) which are episodes of otherwise unexplained hiccups or nausea and vomiting.?

- Dizziness and confusion?

How is NMOSD diagnosed?

A diagnosis of NMOSD usually begins with medical history, questions about signs and symptoms, a neurological examination of other diagnostic tests.?

Neurological examination:?

It’s a key step in the diagnosis process, through examining patients for two types of signs and symptoms:?

- Cognitive function (thinking, logic, memory, and speech)?

- Sensory function (vison, sensation, taste, or smell) muscle strength, balance, reflexes and coordination?

Blood testing for antibodies:?

Blood tests that can detect anti-MOG-IgG and anti- AQP4- IgG antibodies (or NMO-IgG) are available. Some people may test negative for NMO-IgG, but still have NMOSD. Around one third of adults with the clinical symptoms of NMOSD who test negative for anti- AQP4- IgG antibodies may be tested positive for autoantibodies directed against myelin oligodendrocytes glycoprotein (MOG-IgG). Children with demyelinating syndromes are more likely to be positive for MOG-IgG antibodies than AQP-4 IgG antibodies?

Magnetic Resonance Imaging (MRI):

MRI is one of the main tools in the diagnosis of NMOSD. Results often show lesions indicative of inflammation in the Spinal cord, optic nerve, brainstem, Hypothalamus, and the brain.?

Lumbar puncture (spinal tap):?

A lumbar puncture is used to collect a small amount of cerebrospinal fluid (CSF), the clear liquid which surrounds your brain and spinal cord. If this is done during an acute attack of transverse myelitis, there may be increased white blood cells and raised proteins during initial neurological episode or during relapse?

Ophthalmological test (vison test):?

People may be referred to an ophthalmologist or neurological eye specialist known as neuro-ophthalmologist to assess if there is vison impairment or loss due to damage or inflammation (optic neuritis). Visual testing will include both special testing to evaluate the structure of the back of the eye as well as testing to look for abnormalities in colour vison, contrast sensitivity or one’s field of vison.?

What can I expect during disease course??

NMOSD is a chronic relapsing condition, where acute attacks occur intermittently if inflammation is not controlled. Unlike MS, current thinking does not suggest ongoing, active injury with slow progression between attacks in most people with NMOSD. However, each attack in APQ-4 related NMOSD may cause permanent neurological disability. MOG-IgG related NMOSD is mor likely than APQ-4 related NMOSD to be associated with good recovery after an attack. NMOSD symptoms may develop quickly – even within few hours – increase over the course if a few days then plateau. Symptoms may improve with treatments over weeks and months.

Lasting signs and symptoms of NMODS may differ in each person and vary according to many factors:?

- The severity and degree of recovery from the first attack?

- The number and frequency of subsequent attacks?

- The effectiveness of therapies?

- Other comorbidities or autoimmune disorders?

- Gender?

- Age?

- Pregnancy?

- Which antibody is causing NMODS?

Early diagnosis and treatment may reduce the relapse and /or lessen the severity of relapses should they occur.?

How to recognize a relapse or an attack??

People living with NMODS can experience a recurrence of similar symptoms due to inflammation of optic nerves and spinal cord, mimicking the initial episode. such symptoms may also be after effect of a prior episode, referred as “ghost” or residual pain following an attack. It’s very important to determine if the symptoms are related to a new relapse or the lingering effect of a previous one. It’s recommended to see neurologist immediately if there are unresolved symptoms and maintaining regular communication with the healthcare team.?

How is NMOSD treated??

There are many effective strategies for individuals who have both AQP4-IgG positive and negative. In addition to medications there are non-pharmacological therapies like physiotherapy and rehabilitation.?

AQP4 seropositive treatment options:?

Current disease modifying therapies (DMTs) are effective in suppressing the inflammation that occurs in NMODS and can prevent relapses of people with NMODS who AQP4-IgG are positive.?

Prevention of NMODS attacks:?

Standard treatment involves high dose intravenous steroids, and sometimes, additional treatments to remove antibodies (intravenous immunoglobulin or plasmapheresis/plasma exchange). These treatments should be started as soon as possible at onset of a severe attack.?

- Steroids?

A course of methylprednisolone, a type of corticosteroid, is usually given to manage acute attacks of NMOSD – either intravenously or orally. Steroids work to reduce inflammation and can decrease the severity and duration of NMOSD relapses.?

- Plasma exchange?

If a course of steroids hasn’t helped your attack, or if your attacks have progressed, you may be offered plasma exchange (PE). The goal of PE is to lower the level of NMO-IgG in the blood. This procedure involves taking some of your blood and mechanically separating the blood cells from the fluid (plasma). The blood cells are then mixed with a replacement solution, typically albumin or a synthetic fluid with properties like plasma. The solution with the blood is then returned to your body. PE temporarily clears the blood of antibodies that attack the myelin. The procedure lasts several hours and may be repeated multiple times over a number of days.?

- Immunosuppressive medications?

If a course of PE doesn’t help the attack, some doctors may use a therapy to “reboot” the immune system. It is important to speak with your doctor or pharmacist about the range of possible side effects from these medications.?

- Intravenous immunoglobulin (IVIg)?

IVIG is a blood product containing plasma of thousands of doners and is administrated by intravenous infusion (IV infusion). IVIg works to reduce inflammatory attacks. In some cases, it’s given in combination with or after high dose of steroids.?

Treatment of symptoms:?

Symptoms such as neuropathy, pain, stiffness, muscle spasms, bladder and bowel control problems can be managed with various medications and therapies.?

Physical activity:

Exercise is recognized as an important step towards the wellbeing when living with a chronic condition. The benefits of exercise are numerous and include improvement in balance and coordination, prevent stiffness, increase energy, and overall endurance. Be sure to consult your healthcare provider before starting any form of exercise. You may also be referred to a physiotherapist or occupational therapist.?

Physiotherapist (PTs)?:

Evaluate your movement and functioning pain management, including strength, mobility, balance, posture, fatigue, and pain management. PTs can help to meet physical challenges and demands of life. They can also suggest an appropriate exercise regime and should be counseling on the proper use of mobility aids such as orthotics , canes crutches , walkers , wheelchairs , and scooters.?

Occupational therapist (OTs):?

They help with the everyday skills that you need to function as independently as possible at home and work. They target upper body strength, mobility and coordination and can help to use assistive technology to increase ease of access and independence.?

Healthy eating :

There is no special diet for NMOSD . Nevertheless , people living with NMOSD find they can improve their quality of life and sense of well being by focusing on aspects of heath that can be controlled and changed. Such as eating a nutritionally balance diet as recommended by the Canadian food guide . This , combined with appropriate exercise can help control body weight ,decrease fatigue , maintain regular bowel movement and bladder function . Minimize the risk of skin problems , keep bones heathy and strong , maintain heathy teeth and gums and strengthen the heart.?

Reference :?

https://rarediseases.org/rarediseases/neuromyelitisoptica/#:~:text=Neuromyelitis%20optica%20spectrum%20disorder%20(NMOSD,the%20spinal%20cord%20(myelitis).?

MS society of Canada : Neuromyelitis Optica Spectrum Disorder (NMOSD) ( newly diagnosed guide)?

https://www.nationalmssociety.org/Symptoms-Diagnosis/Other-Conditions-to-Rule-Out?

https://mssociety.ca/about-ms/diagnosing-ms/ms-allied-diseases-and-conditions-to-rule-out?

https://mssociety.ca/about-ms/diagnosing-ms/neuromyelitis-optica-spectrum-disorder?

https://www.nationalmssociety.org/Symptoms-Diagnosis/Other-Conditions-to-Rule-Out/Lupus?

https://www.nationalmssociety.org/Symptoms-Diagnosis/Other-Conditions-to-Rule-Out/Neuromyelitis-Optica?

https://www.nationalmssociety.org/Symptoms-Diagnosis/Other-Conditions-to-Rule-Out/ADEM