Over recent years, the identification of specific autoantibody-associated conditions distinct from MS, including neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein-antibody disease (MOGAD), has changed the concept of inflammatory demyelinating disorders of the central nervous system (CNS) (Lennon et al., 2014; Sechi et al., 2022).
Awareness of the specific features that define each demyelinating disorder is crucial for a nurse in shaping a correct diagnosis and timely initiation of an appropriate treatment together with a neurologist. Hence, the blog will expand on NMOSD and MOGAD, with a focus on how to differentiate them from MS.
NMOSD (also known as Devic’s disease) is an autoimmune condition of the CNS, causing inflammation to the optic nerve and spinal cord. It is a rare disease with a worldwide prevalence between 0.5 and 10 per 100,000 persons (Hor et al., 2020). It can occur at any age but appears most often in females between the ages of 30–50 years, with a median age of disease onset at 40 years (Etemadifar et al., 2015).
NMOSD is a relapsing disease where relapses are followed by periods of some recovery. The most common relapses in NMOSD are optic neuritis, transverse myelitis, and area postrema syndrome, resulting in symptoms including eye pain, loss of vision, muscle weakness, paralysis, loss of bowel and bladder control, and severe nausea, vomiting, and hiccups (taken from The Sumaira Foundation).
Relapses in NMOSD are often very severe and can result in incomplete recovery, leading to an accumulation of damage and permanent disability (Kessler et al., 2016). Preventing attacks through early and ongoing treatment is therefore important to prevent long-term permanent disability.
MOGAD is an immune-mediated disorder that mainly targets the CNS. It is associated with the presence of antibodies directed against myelin oligodendrocyte glycoprotein (MOG) (Sharma et al., 2022).
MOGAD appears to be equally common among males and females. It presents in both adults and in children in different ways:
The neurological manifestations of NMOSD and MOGAD may mimic those of MS, often leading to misdiagnosis. DMTs used to treat MS can be ineffective against NMOSD, with evidence showing that some can even aggravate it further (Min et al., 2012; Gelfand et al., 2014). It is therefore important to distinguish between these disorders owing to the differences in both therapeutic and diagnostic implications (Fadda et al., 2022).
The following table highlights some of the differences to look out for between the disorders (Sechi et al., 2022; Fadda et al., 2022):
| MS | NMOSD (AQP4 +ve_ | MOGAD |
Commonly affected age | 20–40 | 30–50 | 0–40 |
Sex (female:male) | 2–3:1 | 9:1 | 1:1 |
Ethnicity | Any, mostly Caucasian | Any, African-American and Asian at higher risk | Any, unclear ethnic differences |
Disease course | Relapsing (85%) or progressive from onset (15%); secondary progression can develop in relapsing form | Relapsing (>95%); progressive course extremely rare | Relapsing (50%) or monophasic (50%); progressive course is rare |
Recovery from attacks | Generally good | Often incomplete, leading to permanent CNS damage | Generally good despite severe attacks |
Key symptoms | Often fatigue or cognitive impairment | Severe vision impairment | Vision impairment, often with better recovery than in NMOSD |
Area postrema syndrome | Rare | Sometimes seen | Rare |
Encephalopathy | Rare | Rare | Sometimes seen |
AQP4 | AQP4 antibody seronegative | AQP4 antibody seropositive |
The presence of aquaporin 4 (AQP4) antibodies is very specific to a diagnosis of NMOSD, with the antibody being detected in up to 80% of patients with NMOSD. More stringent clinical criteria, with additional neuroimaging findings, are required for diagnosis of NMOSD without AQP4-IgG or when serologic testing is unavailable (Wingerchuk et al., 2015).
For more information about NMOSD and MOGAD, visit The Sumaira Foundation. The Sumaira Foundation is dedicated to raising global awareness of NMOSD and MOGAD, building communities of support for patients and their caregivers, funding research and patient advocacy.
