MOGAD (MOG Antibody Disease)

MOG antibody disease (MOGAD) is an autoimmune inflammatory condition affecting the central nervous system. It primarily causes optic neuritis and myelitis (spinal cord inflammation). While it can appear similar to multiple sclerosis or neuromyelitis optica, MOGAD has distinct features and generally better outcomes.

Understanding MOGAD

MOG (myelin oligodendrocyte glycoprotein) is a protein found on the surface of myelin, the protective coating of nerve fibers. In MOGAD, the immune system produces antibodies against MOG, leading to inflammation in the optic nerves, spinal cord, or brain. This is different from MS and NMO, which involve different targets.

Symptoms

Optic Neuritis (Most Common)

• Eye pain with eye movement
• Vision loss—can be severe
• Often affects both eyes (simultaneously or sequentially)
• More bilateral than typical MS optic neuritis

Myelitis (Spinal Cord Inflammation)

• Weakness in legs or arms
• Numbness or tingling
• Bowel or bladder problems
• May be severe

ADEM (Acute Disseminated Encephalomyelitis)

• Brain inflammation
• More common in children
• May cause confusion, seizures
• Often follows viral illness

Other Features

• Headache
• Nausea
• Fever (sometimes)
• Symptoms from other affected areas

Who Gets MOGAD?

• Can affect any age
• Children and young adults most common
• No strong gender preference
• May follow infection

Diagnosis

MOG Antibody Testing

• Blood test for MOG-IgG antibodies
• Should be done by reliable laboratory
• Test may be negative if done too early or late

MRI Imaging

MRI brain and orbits

• Shows optic nerve enhancement/swelling
• May show brain lesions (different pattern than MS)
• Spinal cord imaging if myelitis symptoms

Distinguish from Other Conditions

Feature	MOGAD	MS	NMO
Antibody	MOG-IgG	None	AQP4-IgG
Optic neuritis	Often bilateral	Usually unilateral	Often severe
Visual recovery	Good	Good	Often poor
Relapse pattern	May be monophasic	Typically relapsing	Relapsing

Other Testing

• Lumbar puncture—CSF analysis
• Visual evoked potentials
• OCT—retinal nerve fiber layer

Treatment

Acute Attacks

High-dose IV corticosteroids

• Methylprednisolone 1g daily for 3-5 days
• Usually very effective
• Slow oral taper often needed (rebound common)

Plasma exchange (PLEX)

• For severe attacks or steroid failures
• Removes antibodies from blood

IV immunoglobulin (IVIg)

• Alternative for acute treatment
• May also prevent relapses

Preventing Relapses

For relapsing disease:

• Maintenance immunotherapy
• Options include: mycophenolate, azathioprine, rituximab
• IVIg may help maintain remission
• Treatment duration uncertain

Important Considerations

Prognosis

Generally Favorable

• Visual recovery usually good
• Better outcomes than NMO
• Many patients have single episode
• Some have relapses

Relapse Risk

• About 50% have relapses
• Persistent MOG antibodies may indicate higher relapse risk
• Relapses more likely if steroids stopped quickly

Long-Term

• Most patients maintain good vision
• Disability generally mild
• Some accumulate deficits with multiple attacks

Frequently Asked Questions

Is MOGAD the same as multiple sclerosis?

No. While both cause inflammation in the nervous system, they are distinct diseases. MOGAD involves antibodies against MOG, has different MRI patterns, and generally has better outcomes than MS. Treatment approaches also differ.

Will my vision recover?

In MOGAD, visual recovery is generally good, especially with prompt treatment. Most patients recover useful vision, though some may have persistent deficits. This is better than the outcomes typically seen in NMO.

Will I have more attacks?

About half of MOGAD patients have only a single attack. The other half may have relapses. Your doctor may recommend preventive treatment based on your risk factors, including whether MOG antibodies persist.

Is this hereditary?

MOGAD is not considered hereditary, though autoimmune conditions may have some genetic component. It's not passed directly to children.

Do I need to take medication forever?

This is still being studied. Some patients can stop treatment after a period of remission, especially if MOG antibodies become negative. Your doctor will advise based on your individual situation.

References