Late-onset neuromyelitis optica spectrum disorder mimicking stroke in an elderly Chinese man: Case report

Neuromyelitis optica spectrum disorder mimicking stroke: A case report and literature review

Hemiparesis is a frequently observed manifestation of stroke but exceptionally rare in the context of neuromyelitis optica spectrum disorder (NMOSD). In this case, a 68-year-old woman initially presented with acute right-sided weakness, leading to suspicion of ischemic stroke. However, her symptoms worsened despite treatment with aspirin and statins. Subsequent spinal MRI and aquaporin 4 antibody testing confirmed the diagnosis of NMOSD. The administration of methylprednisolone and immunoglobulin resulted in improved clinical outcomes. This case serves as an illustrative example of the diverse manifestations encountered in NMOSD and underscores the significance of considering this potential etiology in elderly patients to facilitate prompt diagnosis and therapeutic intervention.

Neuromyelitis Optica Spectrum Disorder Mimicking Pontine Stroke: A Case Report and Systematic Literature Review

Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disorder that was first described in the late 1800s as a variant of multiple sclerosis (MS). However, it has recently been categorized, as a disease, especially with the discovery of aquaporin-4 (AQP4-Ab) and myelin oligodendrocyte glycoprotein antibodies (MOG-Ab). Unfortunately, patient presentation is not always clear, and NMOSD may initially be diagnosed as an alternative neurological disease. We present a 58-year-old woman who was hospitalized several times for what was initially perceived as a pontine stroke. However, given worsening symptoms, serologic testing confirmed AQP4-Ab positivity and, subsequently, the NMOSD diagnosis. In addition to the case report, a systematic literature review was performed to identify NMOSD cases initially misdiagnosed as stroke. Publications were selected and curated in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Six NMOSD patients were initially thought to have had acute strokes. However, steady progression and/or the recurrence of symptoms suggested that further investigations with neuroimaging studies and serological immune assays were necessary to exclude alternative etiologies. Notably, the age at onset in all cases was significantly more advanced than patients with typical NMOSD presentations (median age 32-41). In conclusion, the NMOSD diagnosis should be considered in cases with atypical stroke-like presentations, particularly those of later onset (defined as equal to or greater than 50 years of age). This is important as early recognition and treatment with immune therapies can improve functional outcomes.

Age of onset correlates with clinical characteristics and prognostic outcomes in neuromyelitis optica spectrum disorder

Objective

Neuromyelitis optica spectrum disorder (NMOSD) is an inflammatory disease preferentially affects the optic nerve and the spinal cord. The first attack usually occurs in the third or fourth decade, though patients with disease onset in the fifties or later are not uncommon. This study aimed to investigate the clinical characteristics and prognosis in patients with different age of onset and to explore the correlations between age of onset and clinical characteristics and prognostic outcomes.

Method

We retrospectively reviewed the medical records of 298 NMOSD patients diagnosed according to the 2015 updated version of diagnostic criteria. Patients were divided into early-onset NMOSD (EO-NMOSD) (<50 years at disease onset) and late-onset NMOSD (LO-NMOSD) (≥50 years at disease onset) based on the age of disease onset. LO-NMOSD patients were divided into two subgroups: relative-late-onset NMOSD (RLO-NMOSD) (50~70 years at disease onset) and very-late-onset NMOSD (≥70 years at disease onset). Clinical characteristics, laboratory findings, neuroimaging features, and prognostic outcomes were investigated.

Results

Compared to EO-NMOSD patients, patients with LO-NMOSD showed more frequent transverse myelitis (TM) (58.20% vs. 36.00%, p = 0.007) while less frequent optic neuritis (ON) (23.10% vs. 34.80%, p = 0.031) and brainstem/cerebral attacks (7.50% vs. 18.30%, p = 0.006) as the first attack. Patients with LO-NMOSD showed less frequent relapses, higher Expanded Disability Status Scale (EDSS) score at the last follow-up, fewer NMOSD-typical brain lesions, and longer segments of spinal cord lesions. Patients with older onset age showed a higher proportion of increased protein levels in cerebrospinal fluid during the acute phase of attacks. Age at disease onset positively correlated with length of spinal cord lesions at first attack and at last follow-up, negatively correlated with ARR-1 (ARR excluding the first attack, calculated from disease onset to final follow-up), irrespective of AQP4-IgG serostatus. Patients with older age at disease onset progressed to severe motor disability sooner, and age of onset positively correlated with EDSS score at the last follow-up, irrespective of AQP4-IgG serostatus.

Conclusion

Age of disease onset affects clinical characteristics and prognosis outcomes of patients with NMOSD.

Case Report: Neuromyelitis Optica Spectrum Disorder With Progressive Elevation of Cerebrospinal Fluid Cell Count and Protein Level Mimicking Infectious Meningomyelitis: A Diagnostic Challenge

Neuromyelitis optica spectrum disorder (NMOSD) is an autoimmune-mediated idiopathic inflammatory demyelinating disease with a typical clinical presentation of optic neuritis, acute myelitis, and area postrema syndrome. Most NMOSD patients are seropositive for disease-specific and pathogenic aquaporin-4 (AQP4) antibodies, which are key markers for the NMOSD diagnosis. Herein, we report an atypical case of a 41-year-old man who complained of intractable hiccups and vomiting at disease onset, followed by fever, headache, back pain, progressive paresthesia, and weakness of extremities later on. Magnetic resonance imaging revealed longitudinally extensive transverse myelitis. Cerebrospinal fluid analysis showed progressive increases in the white blood cell count and the protein level, which were accompanied by the deterioration of clinical manifestations. The patient was initially suspected of infectious meningomyelitis but was finally diagnosed with NMOSD. This case with distinct cerebrospinal fluid findings broadens the phenotypic spectrum of NMOSD. Furthermore, it also highlights the clinical value of AQP4 antibody test for early definitive diagnosis and proper treatment.