Title : Longitudinally extensive transverse myelitis revealing seronegative neuromyelitis optica spectrum disorder in a patient with systemic lupus erythematosus–Sjogren overlap syndrome: A case report
Abstract:
Neuro Myelitis Optica Spectrum Disorder (NMOSD) is a rare autoimmune inflammatory disorder of the central nervous system characterized by recurrent optic neuritis, longitudinally extensive transverse myelitis (LETM), and other core neurologic syndromes. Although most patients are positive for aquaporin-4 immunoglobulin G (AQP4-IgG), approximately 10–30% remain seronegative, making diagnosis particularly challenging because of its clinical overlap with multiple sclerosis, infectious myelitis, paraneoplastic syndromes, and connective tissue disease-associated myelitis. The coexistence of seronegative NMOSD with Systemic Lupus Erythematosus (SLE) and Sjögren syndrome is uncommon and may delay recognition, particularly when neurologic manifestations precede systemic autoimmune features.
We report the case of a 42-year-old Filipino woman who presented with a three-month history of progressive right upper extremity paresthesia and weakness that gradually involved the contralateral upper extremity and was accompanied by intermittent electric shock-like sensations in both lower extremities. She was initially managed as peripheral neuropathy, cervical muscle spasm, cervical radiculopathy, and cervical spondylosis without sustained clinical improvement. Electromyography and nerve conduction studies were unremarkable. Magnetic resonance imaging demonstrated a longitudinally extensive intramedullary cervical spinal cord lesion extending from C2 to C7, consistent with transverse myelitis. Visual evoked potentials revealed delayed right P100 latency suggestive of subclinical optic nerve demyelination, while cerebrospinal fluid analysis demonstrated type III oligoclonal bands. Comprehensive autoimmune evaluation revealed positive antinuclear antibody (1:320, speckled), anti-double-stranded DNA, anti-Smith, anti-SSA/Ro, anti-SSB/La, and anti-RNP antibodies with normal complement levels. Serum AQP4-IgG was negative. Following exclusion of infectious, vascular, neoplastic, and alternative demyelinating etiologies through multidisciplinary evaluation, the patient was diagnosed with seronegative NMOSD associated with SLE–Sjögren overlap syndrome. High-dose intravenous methylprednisolone was initiated after treatment of concurrent pneumonia, resulting in significant neurological improvement. Although rituximab was initially deferred because of financial constraints, the patient subsequently received rituximab during a later hospital admission as maintenance immunotherapy, with continued clinical improvement and no further neurologic deterioration during follow-up.
This case highlights the diagnostic complexity of seronegative NMOSD presenting as LETM in patients with previously unrecognized connective tissue disease. It emphasizes the importance of recognizing characteristic spinal magnetic resonance imaging findings, pursuing comprehensive autoimmune evaluation despite negative AQP4 antibodies, and adopting a multidisciplinary approach to facilitate early diagnosis and timely initiation of immunosuppressive therapy. Early recognition and appropriate long-term immunotherapy are essential to minimize relapse risk and prevent irreversible neurologic disability.
