At first glance, NMOSD (Neuromyelitis optica spectrum disorder) and multiple sclerosis (MS) seem like they are the same disorder. Yet, they are considered two entirely separate diagnoses with different treatment options.
The difficulty in distinguishing the two is that both are autoimmune disorders that affect the central nervous system, including the brain, optic nerves, and spinal cord. Both damage the coating of the nerve cells (myelin). So, the symptoms may look quite similar both to patients and doctors, and as a result, patients carry the wrong diagnosis for years.
What is the overlap between NMOSD and MS?
- Both affect women more than men
- Both are autoimmune disorders
- Both often present with eye symptoms (eye pain, loss of color vision, blurred or decreased visual acuity)
- Both can affect the optic nerve (vision) and the spinal cord (numbness/tingling, weakness of the extremities, loss of control of bowel and bladder)
- Both can have relapses (sudden neurologic symptoms followed by partial or complete improvement)
How is NMOSD different from MS?
- NMOSD is more rare: 250,000 people worldwide have NMOSD as compared to the 1,000,000 Americans who have MS.
- MS often presents with mild symptoms while NMOSD often begins suddenly with severe symptoms
- While both can affect the optic nerves, it is almost always unilateral during a MS flare while can be bilateral in a NMOSD flare.
- If left untreated, NMOSD attacks can lead to paralysis and blindness but do not affect other parts of the brain like MS, which can cause unsteadiness from cerebellar dysfunction and cognitive impairment.
- While patients with both disorders can have plaques (inflammation in the spinal cord), these lesions are larger in NMOSD
- 50% of people with NMOSD have a family history of autoimmune disease
- 75% of patients with NMOSD have a specific antibody biomarker called aquaporin 4 immunoglobulin G (AQP4-IgG)
- While many of the symptoms overlap between MS and NMOSD, patients with NMOSD are much more likely to have long-lasting hiccups, confusion/encephalopathy, and more sudden and severe relapses that tend not to improve as much
- MS has a more diffuse effect on the brain leading to more cognitive impairment, depression, information processing
How to distinguish between NMOSD and MS?
- MRI appearance is distinct: MRI scans in MS patients typically show small, scattered white appearing lesions while brain lesions are much less common; MRI scans in NMOSD patients show long continuous spinal cord lesions
- Blood tests for the biomarker for NMOSD (AQP4-IgG)
- Spinal fluid examination for different biomarkers in the two disorders
BeCare MS App can help both in making the diagnosis and in monitoring progression with cognitive, visual, motor and ambulatory assessments. Share you results with your doctor to make sure you have the correct diagnosis and treatment-become empowered to have the best possible clinical journey.