Background/Purpose:

NMOSD are autoimmune disorders characterized by optic neuritis (ON), longitudinal extensive transverse myelitis (LETM), and other clinical features. Aquaporin 4 antibodies (AQP4 Ab) have enhanced diagnostic accuracy of NMOSD. We aimed to characterize the clinical features, diagnostic laboratory and imaging studies of NMOSD in our Afro-Caribbean patient population to identify associated autoimmune disorders.

Methods:

Retrospective chart review of patients ≥ 18 years of age, with a diagnosis of multiple sclerosis, optic neuritis, acute transverse myelitis and NMOSD at 2 urban hospitals from 1/2005 to 4/2017.  Demographics, clinical presentation, laboratory, imaging and treatment data were collected to confirm NMOSD as per International Panel for NMOSD Diagnosis.  Imaging studies were reviewed for NMOSD details by a Neuro-radiologist.

Results: 

Of the 1,227 charts reviewed, 39 patients (3.17%) met criteria for NMOSD. Of those 82.1% had positive AQP4 Abs., 87.2% were women, 84.6% were Blacks, and 38.7% had another autoimmune disease, with SLE being the most common (66.7%). ANA and anti-dsDNA were positive in 41.7% and 21.4% of the patients respectively. Motor weakness (55.3%) and visual changes (35.9%) were the most common presenting symptoms. In brain-MRI 62.8% of patients had non-specific white matter lesions, followed by T2 hyperintense lesions in optic nerve (37.1%), spindle like hemispheric lesions (34.3%), and dorsal medulla lesions (34.3%). Spine MRI revealed LETM in 48.6%, and gadolinium enhancement in 68.6% of the cases.  Initial therapy included pulse CS in 53.5% followed by pulse CS-plasma exchange (PLEX) (23.1%) and pulse CS-PLEX-IVIG (7.7%). Maintenance therapy included CS in 38.5%, followed by CS-AZA (17.9%) and CS-MMF (10.3%). Four cases received Rituximab after initial therapy. 89.4% of the patients had follow-up imaging. Among the 7 cases of AQP4 negative NMOSD patients, M:F ratio was 2:5, and only 14.3% had other autoimmune diseases, tended to have a lower disability score when compared to AQP4 positive patients, and 50% had optic nerve involvement.

Conclusion:

NMOSD prevalence in our population was higher (3.2% vs.1.5%) than previously reported among patients with suspected inflammatory demyelinating disease. Black middle age women were most frequently affected. SLE was the most prevalent rheumatic disease present prior to NMOSD diagnosis in the majority of the cases. AQP4 seronegative cases had higher male ratio, less association with autoimmune diseases, lower disability scale score and less abnormalities on MRI except for optic nerve involvement.