Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD)

Overview

Myelin oligodendrocyte glycoprotein antibody-associated disease, also known as MOGAD, is a rare inflammatory disease that affects the central nervous system. In MOGAD, the immune system attacks the fatty substance that protects nerve fibers in the optic nerves, brain and spinal cord.

Symptoms of MOGAD may include vision loss, muscle weakness, stiffness or paralysis, confusion, seizures, and headaches. These symptoms can be sometimes confused with other diseases such as multiple sclerosis.

There's no cure for MOGAD. However, there are treatments to help speed the recovery from attacks, manage symptoms and reduce the likelihood of symptoms returning.

Symptoms

MOGAD causes painful swelling, known as inflammation. Symptoms are caused by attacks from:

• Inflammation of the optic nerve. Called optic neuritis, this condition may lead to vision loss in one or both eyes and eye pain that gets worse with eye movement. Optic neuritis in children may be mistaken for a headache.
• Inflammation of the spinal cord. Called transverse myelitis, this condition may lead to arm or leg weakness, muscle stiffness, or paralysis. It also may cause sensory loss and changes in bowel, bladder or sexual function.
• Inflammation of the brain and spinal cord. Called acute disseminated encephalomyelitis, also known as ADEM, this condition may lead to vision loss, weakness, unsteady walk and confusion. ADEM is more common in children with MOGAD.

Other symptoms of MOGAD may include:

• Seizures.
• Headaches.
• Fever.

Disease course

Some people who have MOGAD only experience one attack of symptoms. This is called monophasic MOGAD and is slightly more common. However, some people experience multiple attacks, called relapsing MOGAD. Attacks usually develop over days and can be severe and debilitating. Disability usually gets worse with each attack. Attack recovery can take weeks to months.

When to see a doctor

See a doctor or other healthcare professional if you experience any of the above symptoms for unknown reasons.

Causes

The cause of MOGAD is not known. It's an autoimmune disorder in which the body's immune system attacks its own tissues. In people with MOGAD, the immune system destroys the fatty substance called myelin. Myelin coats and protects nerve fibers in the optic nerve, brain and spinal cord.

The brain sends messages down nerve fibers that help tell parts of the body what to do. When the myelin is damaged and nerve fibers are exposed, those messages may be slowed or blocked. This means those parts of the body won't work properly.

MOGAD is often misdiagnosed as another disease that attacks myelin and causes similar symptoms. It may be mistaken for multiple sclerosis, known as MS. Or it may be confused with a condition called neuromyelitis optica spectrum disorder, also known as NMOSD.

MOGAD is different from MS and NMOSD because the first attack of MOGAD is usually the most severe, but people with the disease can have a complete recovery. MOGAD also is diagnosed differently, using results from MRI and blood tests. People with MS and NMOSD typically have multiple attacks, while about half of people with MOGAD have only one attack.

Risk factors

These factors may increase your risk of developing MOGAD:

• Age. Children and young adults are slightly more likely to develop MOGAD.
• Recent infection or vaccination. MOGAD may develop after an infectious illness or vaccination, such as SARS-CoV-2.

Complications

MOGAD complications are caused by the attacks on the fatty substance that protects nerve fibers in the optic nerves, brain and spinal cord. The first attack is usually the worst, but each attack can cause more damage. Some possible complications may include:

• Permanent paralysis in the arms and legs.
• Long-term bowel and bladder difficulties.
• Blindness in one or both eyes.
• Trouble with language, memory and thinking.

Some MOGAD treatments also may cause complications. Long-term use of certain medicines may result in:

• Infection.
• Lymphoma or skin cancers.
• Slowed growth in children.
• Headaches.
• Kidney failure.

Your healthcare team will work with you to decide which treatment options are the best and how long to continue them.