P010 - Neuromyelitis optica: Case reports from Oman

Abstract

Neuromyelitis optica (NMO), a multiple sclerosis mimic, is a rare disorder with a combination of optic neuritis and transverse myelitis. Only few cases were reported in Oman and were considered a diagnostic challenge. Most of them had an unusual presentation and were confused with multiple sclerosis. The neuromyelitis optica IgG test helped confirming the diagnosis. We present 4 cases of neuromyelitis optica from a tertiary referral hospital, Royal Hospital, Oman. The criterion of Wingerchuk et al. was used for the diagnosis. All patients had MRI brain and spine and neuromyelitis optica IgG test. First patient , a 29 years old female, was referred to outpatient clinic with a history of an attack of left optic neuritis. Subsequently had 3 recurrent attacks in Rt eye. After each attack she received IV methylprednisolone followed by a tapering dose of oral prednisolone. She had a partial recovery after each attack. Initial CSF oligoclonal bands and NMO IgG were −ve. MRI brain showed non-specific white matter changes. After the 4th attack of optic neuritis she was started on a monthly dose of cyclophosphamide. After the 7th dose she was changed to oral mycophenolate. After 9 months she had a new attack of optic neuritis and same treatment was continued. After 2 years free of relapses mycophenolate was stopped. After 4 months she developed acute paraplegia. MRI spine showed focal T2 hyperintensities from T3 to T5. Repeat NMO IgG was +ve. At this point a diagnosis of neuromyelitis optica was made and patient was planned for Rituximab therapy. Second patient is a 35 years old female, presented to neurology clinic with history of recurrent optic neuritis for which she was followed up by ophthalmologist. After 16 months she was admitted with acute transverse myelitis and optic neuritis. Initial NMO IgG was −ve. MRI brain showed nonspecific T2 hyperintensities. MRI spine showed diffuse T2 hyperintensties from C5 through T10. She was treated with IV methyl prednisolone, and because the response was not favorable, IV immunoglubulins was given, and maintained on prednisolone (tapering dose) and mycophenolate. On out patient follow up she continued to have mild residual weakness. After a year she developed another attack of paraplegia and optic neuritis; and was started on interferon. A repeat NMO IgG was +ve. After 2 months she developed another attack of paraplegia. And after 4 months it also recurred. She was offered treatment with Mitoxantrone but refused. Third patient is a 24 years old female, transferred to our hospital with 2 months H/O acute transverse myelitis and optic neuritis for which she was admitted to a local hospital and received IV methyl prednisolon. MRI brain showed multiple white matter T2 hyperintensities. MRI spine showed diffuse T2 hyperintensities C2 to T1 and T7–T12. Patient refused lumbar puncture. She was seen in neurology clinic after 2 months with 3 weeks H/O Lt optic neuritis and received IV methyl prednisolone. NMO IgG was +ve and was started on interferon. Seen again after 4 months. Doing well, ambulant without support. Patient lost to follow up. She subsequently deteriorated and was started on Rituximab. Fourth patient is a 46 years old female, admitted with urinary retention, generalized weakness, and altered sensorium. MRI brain : non-specific T2 white matter changes. MRI spine : extensive T2 hyperintensities from C2 to T1 and from T8 to T10 with contrast enhancement. Treated with methyl prednisolone. Had gradual progressive recovery. After 4 months had another attack of transverse myelitis. MRI spine : T2 hyperintensities from lower medulla to T10. Received IV methyl prednisolone. CSF oligoclonal bands was +ve. NMO IgG was +ve. ANCA-PR3 A6 was +ve. Cyclophosphamaide treatment was attempted but was not tolerated by patient and was stopped. Neuromyelitis optica should be suspected in any patient presenting with optic neuritis, transverse myelitis or both with an MRI brain not suggestive of multiple sclerosis. Neither a positive oligo clonal band in CSF, nor an initial negative NMO IgG test can exclude the diagnosis of NMO, as the former may be present in 35% of patients with NOM and the last can turn positive later on in the disease coarse. The diagnosis of NMO warrants early initiation of a disease specific therapy to prevent relapses.