Atypical Fulminant Seronegative Neuromyelitis Optica in a Post-Renal Transplant Patient

Background: Few case reports have highlighted NMO involving the entire spinal cord. Moreover, NMO has been described as a CNS disease, without evidence to date of peripheral nervous system (PNS) involvement. The effect of immunosupression on NMO severity has not been well studied.

Objectives: Neuromyelitis Optica (NMO) has generated significant interest in recent years as a severely disabling antibody-mediated autoimmune disease of the central nervous system (CNS). Factors affecting disease severity in immunocompromised patients are still largely unknown.

Methods: We report a renal transplant patient who developed severe, rapidly progressive aquaporin 4 antibody (AQP4 Ab) negative, clinically definite NMO, resulting in quadriparesis and blindness. Subsequent peripheral involvement was suggested by nerve conduction studies (NCS).

Results: A 51 year old Hispanic female, status post renal transplant one year ago, on tapering dose of tacrolimus, with post transplant course complicated by cytomegalovirus infection, presented with sudden onset lower extremity numbness. Symptoms progressed to complete paraplegia and sensory loss over 24 hours. The following day, she developed weakness and numbness in bilateral upper extremities, T3-T4 sensory level, and complete vision loss. Cerebrospinal fluid analysis documented elevated protein with neutrophilic pleocytosis. MRI showed T2 hyperintensity involving the entire spine and pre-chiasmatic optic nerves. Serum AQP4 Ab was negative. High dose methyprednisone and plasmapheresis were initiated. Subsequently, four weekly cycles of rituximab therapy were administered. At discharge, the patient had significant improvement in muscle strength and sensation in upper extremities. However, she had persistent paraplegia despite repeat MRI showing near complete resolution of lesions. NCS revealed severe reduction in compound motor action potential amplitudes with denervation bilaterally on needle exam, most obvious in lower extremities. Discharge AQP4 Ab was again negative.

Conclusions: Clinical spectrum of NMO may be wider than previously thought. Further studies are needed to assess PNS involvement in fulminant presentations of NMO and the effect of immunocompromised state on disease severity.